If you have, or know of, an Amateur Radio related site worth visiting, email me with the details to email@example.com and I will take a look with a view to including a link - this will only be on the understanding that a link is provided from that site to here of course. Each site URL is given along with a link to that site. 73s Andy
Links published in VHF Communications magazine 3/2000 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 3/2000 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 1/2001 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 2/2001 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 3/2001 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 4/2001 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 1/2002 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 2/2002 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 3/2002 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 4/2002 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 1/2003 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 2/2003 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 3/2003 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 4/2003 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 1/2004 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 2/2004 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 3/2004 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 4/2004 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 1/2005 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 2/2005 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 3/2005 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 4/2005 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 1/2006 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 2/2006 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 3/2006 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 4/2006 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 1/2007 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 2/2007 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 3/2007 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 4/2007 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 1/2008 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 2/2008 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 3/2008 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 4/2008 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 1/2009 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 2/2009 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 3/2009 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 4/2009 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 1/2010 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 2/2010 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 3/2010 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 4/2010 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 1/2011 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 2/2011 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 3/2011 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 4/2011 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 1/2012 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 2/2012 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 3/2012 in the Internet Treasure Trove article by Gunthard Kraus.
Links published in VHF Communications magazine 4/2012 in the Internet Treasure Trove article by Gunthard Kraus.
Ham Radio Community Chapter
HAM RADIO MODS
HAM RADIO RESOURCES
HAM RADIO REVIEWS
URL: http://www.qsl.net/kd4sai A place for amateur radio operators to learn more about the ham raido hobby, share photos, news, audio and video interactive, ham radio webcam, radio mods, solar updates, special events and ham chat. Great for all ages beginners, and experts.
The CQ-Magazine site
The ATVQ Magazine site
The Communications Quarterly Magazine site
UK Six Metre Group
Prinz ModultechnikA range of linear amplifiers for the Radio Amateur from 1 - 10 Ghz and 1 to 160 watts
Association Departmentale Des Radioamateurs De L'isere- F5KGA a French Radio Amateur site
The Popular Communications Magazine site
Roy Clarke's Site
The WESTERN AUSTRALIAN AMATEUR DIGITAL COMMUNICATION ASSOCIATION page - the group's site giving loads of info on the Australian data scene.
The JOHN LANGNER SSTV HANDBOOK page - giving all the information on standards, equipment, operating, etc., in fact all you need to know about SSTV from one of the acknowledged experts.
The BRITISH AMATEUR TELEVISION CLUB site, where you can get all the information you need about the Club, how to join, the journal CQ-TV and amateur television in general.
The RSGB VHF COMMITTEE site, where you can get all the information you need about the Committee with links to the RSGB Web pages. Lots of info about VHF and up, with links to other related sites..
The WAVELINE COMMUNICATION site in Sweden. The internet site for the Satellite Communication Enthusiast. Lots of information on satellite communication with descriptions of specialist units available from Waveline. Lots of links to satellite oriented sites.
The BLACKSHEEP CONTEST GROUP site. This is a great site if you are an active contester. Included here are the results of the RSGB VHF contests.
The WEB BASED CALL BOOK - QRZ information on-line. You have to enter your own details to gain access to the site, but once entered access is always available.
The WEATHER & SOLAR INFO site is just that and much more. Loads of information on all sorts of amateur radio modes and topics. Lots of links to other useful sites. A visit is a must!
The SUPER-DUPER VHF LOG site is where the much acclaimed Super-Duper Contest Log software is available. This logging package is the only one that allows tracking of any combination of county, country and locator square multpliers in UK VHF contests. It is freely available, by anonymous ftp, as fully working unresticted shareware, from ftp.iol.ie in the /users/okanep diectrory as sdv.zip.
The NORTH EAST WEAK SIGNAL VHF GROUP site has a wealth of information regarding the group and VHF activities in the north east of the USA.
The HAM RADIO TODAY magazine site. Full of all sorts of information, HRT special offers and links to other amateur radio sites. Well worth a visit.
The HAM RADIO ON-LINE DISCOUNT CATALOGUE site is a USA based discount Ham Radio store offering a large range of equipment. A regularly updated on-line opinion poll is also conducted at this site.
The G4NJH SITE which has lots of amateur radio related information.
The D.R.COMPUTER PRODUCTS site, where information on their range of computer-based amateur radio kits can be obtained.
The web site of Carl G Lotstrom, there is quite a lot of useful information, including details of a log probe for use up to 600 MHz and a page of small projects that Carl has documented.
Elsie, a pasive filter design program from Jim Tonne, WB6BLD
The name of a well-known manufacturer of mixers, VCOs, directional couplers, power dividers etc.. The range is continuously being expanded and it is worth glancing at this homepage from time to time to check on the most recent developments or to order the newest free Designers Handbook. Although it has the format and the weight of a catalogue from a big department store!
Another friendly gesture is the provision of interesting and well put together Online-Tutorials offering basic introductions to many of the products on offer.
This is not the Internet site for a zoo or something to do with womens liberation. Its much more interesting, for it means that anyone who has been searching in confusion for reference sources or for someone who could supply British or American technical books can now lean back and relax. You enter the search area on the screen (try, say, oscillator or microwave or antenna....) and then check the price (in US-$ or DM or Euros) to have the appropriate book delivered to your home address. The money will then be deducted from your (German) Giro account, so theres no longer any need for any mental gymnastics with American accounts or credit cards.
There is also a US store - http://www.amazon.com and an English store http://www.amazon.co.uk
This company produces modern measurement equipment for microwave circuit development (key words: Noise Measurements, Harmonic Tuners, Load Pull Measuring Sets, etc.). This is an opportunity to become familiar with these areas of technology with the help of various Application Notes. For refined topics (example: Windows-led Design-Software for RF-Power-Amplifier) you do need to enter a personal password. It will be mailed to you after registration.
Address: http://www.focus-microwaves.comDigital Signal Processing
You can no longer tiptoe around this subject, for this technology has long ago penetrated every nook and cranny of communications technology. So its worth getting to grips with it, and the only question is: whats the best way to get into this and where can I find more documentation, applications, programs, books, contacts, clubs......?
Here are a number of Internet addresses which will help you on your way:
HAMVIEW and SPECTRAN
These names conceal two DSP programs for radio amateurs. With their help (and with the help of the sound card in your PC), you can, for example, filter noisy receiver signals, or even track the signals down in the noise. Both programs were written by the same authors, but they are stored on different homepages.
Another of the big names in the microwave sector with a correspondingly wide range of components and assemblies on offer. Their homepage is always worth a visit. Among the many attractive things on offer is a professional Freeware-Program (Name: WIN N.R.T. TM) for calculating field strengths in the environment of antennae.
Anyone who wants to be well informed about the most recent developments in microwave diodes should take a glance at the homepage of these specialists. Here you can download the usual data sheets, but also Application Notes for Step Recovery Diodes, Tuning Varacter Diodes, PIN-Diodes etc..
This site covers coaxial and dielectric resonators and ceramic filters. In addition to the usual selection ranges of the firms products, you can also download a whole series of good and useful Application Notes concerning this technical area at one go.
There is a very simple reason for this, it is currently fashionable to split relatively large companies up into smaller parts and make them into independent entities, naturally with new names!. So we also have to make the corresponding move in this case.New address: http://www.agilent.com ANRITSU
A well-known name in the world of gauging equipment manufacturers, especially in the field of microwave, noise and distortion measurement technology. If you search the homepage site carefully, you can find a page with application notes on this subject to be downloaded. Naturally, the companys own equipment is used here, but the basics concerning each individual subject are very well done and can be used both for familiarisation and for personal information on the current state of art.
List of German electronic shops on the INTERNET
Have you ever had that problem when you certainly know who might have something, but you just cant remember the address any more? Well, now some friendly person has rectified this by listing the most important shops and their links theyre now just a click away. Moreover, you are cordially invited to help by adding to the list, if you think an important or interesting name is missing.
Now, do you have any idea what thats about? This is actually a site for Slovenian radio amateurs, and anyone who already knows the name Matjaz Vidmar, S53MV from earlier publications will already have some idea of whats going on. He has now become a professor at the Slovenian Technical University, but his passion for development and DIY projects and his enthusiasm for amateur radio remain undiminished. Thus, if we visit the homepage and go to Hardware Information Desk", we find a whole lot of projects old and new on every possible subject. For example, he found the "No - Tune Transceiver" between 1296 MHz and 10 GHz particularly appealing, there are some very comprehensive circuit descriptions, with lots of diagrams and details to be downloaded..
Such good operational amplifiers are available today that you can already use them to build active filters for frequencies going up to between 50 and 100 MHz. All a reasonable person needs for a design is the programs already prepared on the INTERNET, and you can even work on line. So heres a small selection.
If you want to do some on-line design work, go to the "Onscreen - Design - Program for active filters" homepage (Address: http://www.circuitsim.com).
On the Homepage of the Burr-Brown company, you should not only search for the "Bbfpro.zip" filter program, but also download the application notes: AB-017.pdf, AB-034.pdf, AB-035.pdf. They contain the theoretical principles of active filters and all the instructions needed to work successfully with the software.
The manufacturer of the PIC micro-controller (= microchip) has something completely new and free of charge, the Windows design program "Filterlab" for active low-pass equipment. Very well-made and practical specially the option for variations in the component values to lay out the circuit with practical values. You just need to load the file "flb1039.zip" into your own computer -- but there are obviously still problems on the first version with regard to conversations involving very fast PCs and CD-ROM drives which are just as fast. This will no doubt be put right at some time, but I had to write the file onto my external ZIP drive and install it from there. And then it worked. I found a few more little bugs. But once you start to get used to filter design, you soon recognise things that cant be right...
You can use the "Alta Vista" search engine, or look under "http://www.rfglobalnet.com" to find the following programms and put them onto your own computer: afilter.zip, A-filter.zip, filter.zip, filtry10.zip, filter11.zip
Electronic Repair Service
Anyone looking for a semi-conductor data bank, or for generous helpings of computer repair tips, or for a program which simulates a pattern generator for monitors, or for documentation on TV technology....just take a closer look at this link and download what you need.
Anyone who wants to design complete communications or receiving systems and analyse or predict their precise characteristics also needs suitable software nowadays. It is well worth while installing the demo version of such a design program and seeing how it operates, and getting some ideas for your own work. So just take a look at the "Tesla System Calculator" program!
The number of EM simulation program manufacturers seems to go up by the hour, and you have to investigate in great detail to see what advantages each new player is offering. So you just take a closer look and install the thing on a trial basis. Not only can you download the demo version of XFDTD 5.0 from the Remcom homepage for this purpose, but you can also obtain the Quickstart tutorial, the complete manual and two very fine simulation examples (= a short vertical antenna and a patch antenna) for familiarisation.
address: http://www.ansoft.comIrfanView32 What PC user hasnt come across the problem of a graphics file which the systems on his / her computer cant open? This loophole has now been closed by IrfanView32. With this new freeware you can now open and convert any and I really mean any graphics in even the craziest formats. One further detail is that you can also use it to set up a slide show. So we should all have this useful software handy on our PCs.
Address: http://www.jfwindustries.comTest & Measurement World The homepage of this technical review has an interesting Article Archive, which you can access through the search function in the usual way. There are also some publications on HF and microwave technology in html or pdf format ready for downloading. This service is free and its always worth going back from time to time to see whats new.
Address: http://www.tmworld.com/index.htmdB Everyone knows this measurement unit and so its no surprise that a company should have chosen it as its name. Here you can find microwave amplifiers and oscillators for sale and, as is so often the case, there is also some good technical information available on the homepage.
In the amateur sector, the EZNEC program from Roy Lewallen, W7EL, has recently been earning a very good name for itself. For US $ 80 it certainly offers the best compromise currently available between price and accuracy (which again is dependent on the number of individual elements with which the aerial structure can be modelled). An easily comprehensible operator surface, an update service on the Internet and something completely new! a manual in Word format which can be printed out have put this program out in front for the moment.
Anyone who met Roy and talked to him at HAM-Radio 2000 (he had a little stand of his own there) will know how enthusiastic he is and how committed to this sector. Naturally, you can also download a demo version free for testing from the homepage before you spend any money.
Trompeter This firms homepage offers comprehensive information on radio-frequency plugs and sockets. In addition to catalogues and application notes, there is also an interesting publication. For radio-frequency circuit developers in particular, this publication is indispensable, as it includes all the tricks and tips required with regard to the subject of radio-frequency printed circuit board drafting and the correct ways to connect plugs or sockets with a printed circuit board:
Printed circuit board design guide.
Philips Anyone who has not visited the Philips homepage for some time will be pleasantly surprised, not only is the presentation now very good and user-friendly, but the number of prepared application notes has risen to well above 400. There is now 35 megabytes of information of interest to radio-frequency engineers.
We go from "Professional Products" through "Semiconductors" to "Product Catalog". And there we finally find "Application Notes".
Dayton Hamvention The best-known American amateur radio exhibition has its own homepage. In live sound: The greatest Amateur Radio Convention in the world!
Aplac Up in the far North, the Finns have been continually developing and improving their simulation program, and now we have version 7.6. We have already pointed out that the student version can be downloaded, together with all the documentation and manuals, from the APLAC homepage. However, if you send an E-mail and ask for the test CD, you will also receive some publicity material and a very useful application note. "Using APLAC to simulate RFIC Mixers". Taking a closer look at a decidedly interesting product, we find that, not only can it simulate the standard IP point measurement with several sounds, but it even has a chapter headed "Measuring Non-Linear Noise".
Naturally, due to the limitations of the student version, it can not simply be applied to investigating circuits of any size, but its certainly worth experimenting with. Operation and input procedures for this software need some getting used to, since it is a little different from the normal "Windows pattern",
Address: http://www.aplac.comStellex Anyone who has anything to do with mixers, needs an SMD version quickly, or just wants information on the most recent state of the art, should just take a glance at the Stellex homepage.
The company is famous for offering the widest choice of SMD mixers and frequency doublers in the range between 10 kHz and 26 GHz.
Address: http://www.stellexms.comSawtek For anyone who does not yet know Sawtek: according to its own publicity, it is the right contact for anyone interested in SAW filters (surface acoustic wave filters) for all possible applications. Mostly SAW filters for the radio and mobile phone markets, and naturally in SMD formats as well. Theres always some interesting information here, which you can download as the most recent "Product Brochure".
Address: http://www.sawtek.comAnsoft Ensemble After "Harmonica", the well-known microwave circuit simulation program, Ansoft has now also put a student version of its EM simulator, "Ensemble" on the Internet for testing. This can be used to analyse well-known structures such as couplers, microstrips, patch antennas, etc..
Address: http://www.ansoft.comNote: Such well-known products as Sonnet, APLAC, etc. are now competing with one another for the "student version market".
Yet, of course, we do not know whether all products are equally good, fast, reliable or precise. You can only test this yourself by using the different programs on a fully completed project (e.g. a patch antenna).Microwave Journal The well-known trade journal has taken the trouble to post the technical articles from back numbers going back to the middle of 1997 on its homepage as the "Editorial Archive" a fantastic treasure trove.
There are certainly some small snags. Firstly, you have to register, giving your full user profile. Secondly, whoever is in charge has made a mistake, and so you suddenly find illustrations and diagrams are missing from many articles. Thirdly, you are offered a mixture of HTML pages, PDF files and *asp files for download, which changes from one issue to another. To make sense of this, youll need to know some tricks for downloading non-PDF format files. Any simple-minded soul who just saves an opened HTML page will wonder where all the illustrations have gone...
Heres a brief explanation of the path to follow for Netscape users:
Address: http://www.mwjournal.comRLC If you want to use coaxial switches in SMD format (e.g. SPDT type = single pole / double through) in your development work, you could well just take a look at this companys site. The frequency range on offer goes from DC up to 26 GHz, but there are also couplers, dividers, terminations, attenuators, DC blocks, BIAS tees, detectors, etc..
Internet Treasure Trove article links from VHF Communications 4/2001
SONNET Lite 7.0 The manufacturer of the well-known EM simulator, which has already been introduced here in Part 1 of the article on modern designs for patch antennas, has improved the free "Lite Version". SonnetLite 7.0 now offers expanded simulation options. Thus, for example, there are now more ports available, the online help has been rewritten, pared-down algorithms allow more extensive simulations to be carried out with the same main memory restrictions as previously, etc..
In addition, a version is now on sale with max. 32 MB main memory, but for $ 500.Address: http://www.sonnetusa.com Applied Microwave and Wireless The well-known American technical revue has now archived almost all technical articles up to 1989 like the "Microwave Journal" and they can be accessed through the homepage. Some highly interesting subjects are covered, although even here the conspicuous copyright stamp must be respected, including the ban on reproduction. Copies of material can be obtained without charge following registration. Address: http://www.amwireless.com MINI-CIRCUITS A well-known name for a very wide range of HF and microwave components (couplers, mixers, amplifier components, dividers, attenuators, etc.....). Its worth visiting their homepage, as there you will find not only numerous documents for downloading but also an endless succession of new ideas. The most recent products are passive mixers with fabulous IP3 values going up to +38 dBm, or the interesting and reasonably priced "Bluecell Mixer".
Address: http://www.minicircuits.comAPLAC The Finns in the far North are also hard at work: now APLAC 7.61 rolls up as a free student version with the usual advance publicity and improvements.
Address: http://www.aplac.comPCAAD40 If this heading sounds somehow familiar, theres a good reason why: version 2.1 was recently introduced in VHF Communications in the section entitled "An interesting program".
The data sheets for each product are in pdf format. They are very attractive, thorough and informative, as are also the large number of application notes available for downloading on almost every subject in this area.
Under the heading "myTactron" an HF electronics "flea market" has been set up, where anyone can offer surplus components, new or used equipment, stickers, etc. at no charge.
Internet Treasure Trove article links from VHF Communications 1/2002Stanford Microdevices / Sirenza Microdevices Here you have to make a quick re-adjustment, the well known firm of Stanford has suddenly changed its name. Nevertheless, its activities remain unchanged. They still make new low noise amplifiers, mixers, gain blocks, etc for the frequency range between 0 and 10GHz.
And there are naturally lots of application notes and other interesting data to download.
Address:http://www.stanfordmicro.com Flex-PDE The Internet has some new EM simulation software, known as "Flex-PDE" for 2D and 3D analyses in the microwave range. This is especially suitable for the extremely high frequency range between 10 and 100GHz. Those interested can download the free test version.
The program is so universal that it can also be used to investigate many other phenomena, e.g. currents in fluids, heat conduction and distribution, chemical processes, etc. The homepage also lists some other interesting documents. The textbooks, in particular, are first class, and worth the price (e.g. $12 for "Fields of Physics").
Address:http://www.pdesolutions.com Linmic Again, something similar, but centring on what is (according to the publicity) a combination of EM simulators and layout orientated CAD software packages which is unique in the world. Here too there is a demo version for testing.
MetelicsHere you can, find out all about microwave diodes, i.e. Schottky diodes, PIN diodes, tunnel diodes, varactor diodes, etc. Naturally, there are also comprehensive catalogues, data sheets and application notes.
http://www.metelics.comMarki Microwave Never heard of them? Well, anyone whos looking for fast doublers, mixers, multipliers or converters at reasonable prices for the frequency range between 0 and 40GHz in SMD format should take a glance at this page.
http://www.MarkiMicrowave.comRf Nitro This site has nothing to do with artificial fertilisers or explosives. It deals with the cutting edge of MMIC development in GaAs or GaN technology. A wide range of products for the microwave range and some excellent application notes practically compel you to visit this site.
http://www.nitro.comNational Instruments A company manufacturing and marketing measurement technology hardware and software on such a large scale (think of "LabView", for example) is naturally a real Treasure Trove for those with relevant interests. Here we find not only data sheets and test software CDs but also separate document packages for users and developers. Also on offer are tutorials on various subjects and product groups.
You could spend hours finding more and more items of interest. The documentation on FFT, in particular, is outstanding!
Internet Treasure Trove article links from VHF Communications 2/2002KACHINA Here, among other things, we can find a set of wiring diagrams for the Transceiver 505DSP, which is no longer manufactured. (Obviously you can still obtain residual stocks of this transceiver at favourable prices.) You can also look at some application reports. Address:
http://www.kachina-az.comSynergy The well known microwave component manufacturer has made a really big effort once again and has completely revised its homepage. So now under a specific heading we find not only data sheets but also appropriate application notes, technical documentation and technical articles (from periodicals). Treasure Trove indeed!
http://www.synergymwave.comNEC Archive The website of Ray Anderson, WB6TPU, contains an NEC archive; here, among other things, you can download the Yagi design program YGO3.ZIP, this is also available from the VHF Communications web site.
http://www.qsl.net/wb6tpu/swindex.htmlAnalog Devices A big name in the field of IC production, mainly active in analogue circuits, D/A converters, RF-ICs, etc. and also in digital signal processors. The technical documentation has been greatly expanded, and especially the basic tutorials (e. g. on digital signal processors). You can look around for hours now and find more and more new stuff to downlowad.
http://www.analog.comSoftware Radios Under the precise address given below:
you can download some interesting application reports, especially on the subject of "Software Radios" .
Software and Links
Under the address
you can download a free program for designing mains rectifier circuits. In addition, there are links relating, to hi-fi amplifiers and SPICE.The Longwave Homepage
Amateur activities in the longwave area are a really new challenge for do-it-yourselfers and for anyone who enjoys fiddling about. And it was only a matter of time until like minded people met up and got organised on the Internet as well. This homepage is the first address anyone interested in longwave reception should visit, as here you can find the technical equipment for getting started, both theoretically and practically. And naturally there are lots of links to similar sites or interesting documents.
Internet Treasure Trove article links from VHF Communications 3/2002Agilent Following the change of name and the re-organisation of the company (formerly Hewlett Packard), calm is slowly returning to the homepage as well, together with the quality that we were used to. So its worthwhile taking another trip through the various areas on display, and in particular having a look at "Semiconductors/RF and Microwave", where all the previous application notes are back with a new look together with some genuinely new items.
Some splendid new tutorials have been added in the "Gauging Equipment" section as well (e.g. how to use network analysers or the basic principles of noise factor measurement). An intensive search (using the Agilent search engine) is not only rewarding but should not be missed.
Texas Instruments / Burr Brown The sectors giant and the inventor of TTL technology has made a discovery. High quality analogue technology is also important, and has a big future in connection with modern digital signal processing. So its not a question of re-inventing the wheel, its more that a well-known and worthy representative of the analogue branch has simply bought it up. So we also find the former Burr-Brown application notes here in the TI homepage in downloadable form.
Naturally, the themes are essentially concerned with every conceivable OPV application, but rf communications engineering and the analogue components required in DSP systems are also appreciated.
AppcadThe earlier DOS program package from the good old HP days can now be obtained free of charge once again in the most recent Windows version from the successor company (Agilent) and can be downloaded from the Internet.
Various aids are on offer for the committed rf and microwave developer (e.g. a stripline calculator or a coil calculation program or operating point calculations, etc.). They support, not only circuit simulation, but also the simulation of complete systems. So no developers PC should be without this.
http://www.hp.woodshot.comAlpha Industries This is an important address for all types of microwave semiconductors. The "millimeter wave squad", in particular, will not only rejoice over the circuits on offer for applications from 20GHz upwards, but will also treasure the data sheets and application notes prepared. What is also really great and very informative is that a whole collection of splendidly crafted complete circuit diagrams of modern transmitters, receivers, etc. can be fetched onto your own computer. Even diagrams and formularies are available as aids to development.
DSP Guide For Scientists And Engineers A specialist volume more than 600 pages long, excellently produced from both the technical and educational points of view, and dealing with digital signal processing, that wouldnt be cheap, would it? And yet it can be, if you take the trouble to download all 33 chapters from the PDF files individually, free of charge from the authors homepage. It does take some time to transfer 20 megabytes, but that isnt the problem. Every time you download a chapter, the humorous author makes comments such as: "Do you really expect your laser printer to do this?" or "I think now its easier for you to buy the hardback edition", etc..
Linear Technology Another specialist in analogue circuits: from operational amplifiers through AD converters, right through to switch regulators for power supplies.
So in the homepage we find, not only a PSPI-CE simulator provided free of charge for the simulation of switched power supplies (which is also suitable for general simulations), together with appropriate regulator models, but also an active filter design program (FilterCAD). There are also numerous application notes and articles on analogue engineering.
If you dont believe me, try it. Once youve successfully downloaded all thats on offer, youll have a new file on your computer containing 130 megabytes of program and data material.
RFMD (RF Micro Devices) Another well-known manufacturer of standard microwave components, producing everything needed for circuit development from amplifiers or mixers through the front end right to the attenuator or the switch MMIC. Support is exemplary once again, in the form of many data sheets and technical notes that are available free of charge from the homepage.
http://www.rfmd.comGraphTrack The GraphTrack program, formerly marketed by Silicon Solutions, is available in an updated version for the MTI interface for satellite rotors.
Internet Treasure Trove article links from VHF Communications 4/2002PUFF and LINUX Its taken a long time and more and more people have been asking for it. The homepage referred to below finally provides an adaptation program for operating the much-loved microwave CAD program Puff using Linux.
Of course, you have to read the instructions thoroughly. Of course, you need a free Turbopascal compiler (theres a link on the same page!). And of course theres still some delicate work to do before everythings up and running. But Linux users are used to that.
http://wwwhome.cs.utwente.nl/~ ptdeboer/ham/puff.htmlApplied Radio Labs This is a company in Australia that specialises in the problem area associated with VCO, PLL and noise. Thus we find here the "SimPLL" program for the design, optimising and simulation of PLL synthesisers. The program can be downloaded free. Of still greater interest are the basic articles on these subjects in the on-line tutorial, which you really should look at very well put together and easy to understand, in particular the sections on the basic facts about noise or sideband noise.
http://www.radiolab.com.auAmateur Radio Download Page There must certainly be a lot of these on the Internet, but this page offers a good mixture for various applications. Thus we find the following areas represented here:
http://www.qsl.net/df0che/dwn.htmFAISYN The proven DOS filter calculation program, available for years, now has a Windows successor. Its easy to operate, a good, precise program, and it has the usual modern printing options. It comes over as a worthy representative of its name. However, the program must be either deleted or registered after a 30-day test period. Unfortunately, you then have to pay $99...
http://members.aol.com/faisyn/faisyn.htmTechnical University Of Munich The Electro-Technical Institute has collected some interesting things that can be downloaded from its RF section. We dont merely find collections of formulae and nomograms for all possible areas of high-frequency engineering here. This homepage is also very important as a source of diagrams with, in particular, the current limiting values for the electrical and magnetic field strengths of signals.
http://www.hfs.ei.tum.deMSTRIP40 The title story in issue 2/2002 of VHF Communications dealt with this free EM simulator, and there are some good new features here. Professor Splitt has now posted the unrestricted full version on his homepage to be downloaded. The program makes it possible to simulate structures with a maximum of 5 layers.
The above article is available as a pdf file from the VHF Communications web site. In addition, the same article, in German, from issue 4/2001 of UKW Berichte can be obtained as a pdf file from the site below as "German Operating Instructions". One particularly nice touch the many diagrams that unfortunately appeared only in black and white in the article are now suddenly aglow with their dazzling original colours!
I did find a printing error when I looked through the material, though. In Section 3, I used the Meteosat patch antenna as a typical example, and determined the radiation resistance in the fifth step. Almost everywhere (and in Fig. 17 too), we refer to a "circuit with radius r = 0.7" for the reflection factor at the resonance point and for the rotation process which must be undertaken with the cursor. It would have to be in the text where we are instructed to rotate to the display "rho - 0.07". Sorry, I really am, because the value of rho 0.7 is naturally the logical and correct choice!
http://www.intek.e-technik.th-kiel.de/splitt.htmMicrowave Engineering This is one of those typically American technical reviews (similar to "Microwave Journal") with a motley assortment of advertising, situations vacant and technical articles, which can be obtained free of charge following registration. There are also sections such as "News" or "Features", which represent outstanding sources of information for the specialist. And you can also search the archives of previous issues.
It is also worth mentioning a new subsidiary site, which is concerned only with the area of modern semi-conductor engineering. The name chosen for it, "GaAsNET" is highly appropriate.
Internet Treasure Trove article links from VHF Communications 1/2003Antenna Design Calculator Anyone who visits the homepage of "Q-Par Angus" in England is entering a forest of microwave antennas. Innumerable microwave antenna types, going up to 100GHz, are designed, manufactured and marketed there, and naturally there are detailed descriptions as well. Theres certainly a lot of useful information available here.
One very nice gesture is a free "Antenna Design Calculator" in the form of two slide rules that can be downloaded. One deals with the connections between gain, efficiency, antenna diameter, frequency and beam width. The other can be used to investigate the relationships between antenna diameter, frequency and far field range. These are a real boon, very informative and very easy to handle using the cursor. Highly recommended, you simply must have this on your own computer right away!
But thats just a comment. Heres the really important thing:
In the most recent version 3.0, not only have many details been improved, but also a new tool has been incorporated known as "Everything S-Parameters". It lives up to its name, for you can use it to analyse the S-parameter file of a component or a circuit, right down to the last detail. You can calculate some interesting facts from the analysis and then display them (e.g. to demonstrate stability circuits or noise factor curves, carry out matching procedures, etc.).
This little free package has now grown to a size of 14 megabytes and merits a more detailed description at some time in our section on "An interesting program".
Internet Treasure Trove article links from VHF Communications 2/2003Ansoft The free download site of the well known supplier of simulation tools has expanded yet again. In addition to the student versions of Serenade SV (High frequency circuit design) and Ensemble (Wireless circuits and planar antennas), we now also have "Simplorer" (Multi-Technolgy Simulation for automotive, aerospace and power design). And the very latest thing is "Maxwell SV", an electromagnetic field simulator. These are stripped down versions of the professional tools written for Windows NT and cannot be guaranteed to operate satisfactorily with Windows ME or XP. Address:
The advantage for us is the numerous application notes, updated to take in the most recent developments. Anyone who has not visited this homepage for some time will be amazed, and will start downloading right away.
More of the same, with the Java scripts for rapid calculation of
every possible aspect of telecommunications, but this time provided by a big company and
on offer to customers or to anyone interested. Considerably more extensive than the
previous link, but just as interesting.
The simplest thing is just to quote, word for word, the heading and
description for the freeware which can be obtained here:
"This software is a tool used to predict the performance of a radio system".
Very neatly done, and free of charge into the bargain. You can see precisely how the landscape influences wave propagation because it is superimposed for this purpose once you have entered the co-ordinates. This is accompanied by some very good instructions and a "first example" demonstrates the freewares use.
Any number of interesting downloads await the radio amateur who
calls up this page. The site covers both databases and online tools for calculating many
things (not only relating to antenna technology or to circuit engineering). Just take a
And just as interesting is this page, in which you can finally discover, in a fascinating format, something about the history of this new technology (...or perhaps you already knew that the Hollywood actress Hedy Lamarr had something to do with it?)
Such a large amount of literature, application notes, information and online calculators does make for a lot of work. Especially since the site is not confined to antenna engineering. The various fields are alphabetically listed.
Theory of AntennasThat's the heading above the lists of links and downloads on this homepage. But we're dealing with tutorials on the basic principles here, the list is never ending, and it's impossible to itemise everything there is here on this subject. So just have fun rummaging around!
Address: http://home.t-online.de/home/hhcuno/afu/ longlink.htm
Internet Treasure Trove article links from VHF Communications 1/2004
There’s some very important news for those using the free “Light” version of this familiar EM simulation program: the newest update gives you free access to something people have been waiting for a long time. Now you can finally connect an exciter port into the centre of the structure as well, and not just (as until now) to the wall of the metal box which is required for the simulation. So now, for example, patch antennas can also be powered directly on the patch and not just via a tiresome long supply line. That’s really a concession worth having!
University of Ulm
And now for something completely different: here you can find the processes taking place in waveguides, couplers, circuits and filters, etc, presented in vivid animated form. And to round things off, both a demo version of the analysis program in use (TLM = Transmission Line Matrix Method) and a link relating to the animation program are available. Very informative and amusing, even as revision for people who already know everything!
The heading for this homepage, run by a Turkish university, makes an interesting promise. Just looking at the sections on offer is a pleasure, as you contemplate the data available concerning microwave technology.
This website has some interesting application notes, which you can study and download, they are mainly concerned with couplers and circulators. But they also include information on the practical fitting of SMD components on microwave printed circuit boards.
This is an acronym for "£The Millenium Education Group" and consequently there are some very nice tutorials. The two sections on "Transmission Lines" and "Antennas" are particularly interesting, but there is also "Babylonian Mathematics" or "an electronic needle gun". So, for anyone who’s interested .....
Another of those homepages where you almost find yourself feeling giddy: innumerable RF tools and documents of all kinds are on show for interested users to sniff out and download. You just can’t count everything there is here. I recommend you set aside sufficient time, then just open up the site.
Chenjian's Electronic Packaging
Anyone looking for up-to-date information on the state of manufacturing technology, including housings for integrated RF components (amplifiers with integrated coils, capacitors and resistors, couplers, etc.) should have a look at this site. The content ranges from information on trends, technologies, production processes and opinions on reliability right through to material trials, and finally an "Online Dictionary".
The classical touch extends beyond the
company's name to its product, MEFiSTo.
This is (another...!) EM simulator, but here, for a change, the company has found a different way to awaken customers' interest. They're currently introducing the most recent version onto the market as a 3D simulator, and so they're giving away an older, fully operational "Classic 2D Version", to be downloaded free of charge. Quite an interesting move!
Or, to reveal its full title: "The Multidisciplinary University Research Initiative (MURI) for High Power, Broadband, Linear, Solid State Amplifiers at the Cornell University".
Fortunately, these friendly people do not lock their findings and their documents away in the safe but make them freely available. But clearly not without reservations, or maybe an enthusiast for memory games is in charge of the homepage! There is no index, and everything is actually hidden away behind anonymous report numbers in a huge file, and it really is like playing some game. You have to uncover and examine everything first to find out whether you can get anything out of it. Luckily, the hit rate is really excellent......
Jim Hardy's Homepage
For once, something from a private individual, very nice and amusingly put together. Not just links to many of our areas (it turns out the man is also a radio ham!), but also a lot of funny material. The following section is particularly worth reading: "How Things would be different if Microsoft built cars" It’s true you have to root around a bit, but it’s worth it for what you can find.
Software for the Radio Amateur
Here’s another link for people who like to spend hours surfing and rooting around. Luckily, everything is listed alphabetically, and so you can carry out a targeted search.
Internet Treasure Trove article links from VHF Communications 2/2004
Once there was a feature film called “The Empire Strikes Back”. That’s what I was reminded of when I downloaded the all new free of charge student version of the RF CAD “Designer” software from Ansoft (N.B.: almost 80 megabytes!). Never have so many tools been made available for simulation and for development in general. Naturally, it takes a while to familiarise yourself with the package, but it’s worth it. Virtually all areas are covered, virtually all the calculators for RF and microwave engineering are provided. However, there is unfortunately one way in which Ansoft has stayed true to its old habits. There is scarcely any documentation – in some cases, none at all – to explain what has been left out of the student version. And of course, you find this out as soon as you ask the software to solve any really complicated practical problems. But apart from this, it’s first class!
The N4UJW Antenna Design Lab
That’s exactly what this site has to offer: any amount of software and information relating to antennas and antenna calculation. And a search through the list of links unearths some interesting things. There’s something hidden behind every item on the screen.
RF Avenue Resources Directory
Anyone opening up this page has a few problems, as you’re initially confronted with an endless list of documents concerning RF and microwave engineering. Of course, it’s all nicely and neatly sorted out. You could spend hours here...
This doesn’t refer to a resonant circuit but to the firm of LaCray – who are well known for their extremely fast mainframe computer. It’s no surprise that people use such expensive equipment mainly for complicated EM simulations of expensive antennas. But it’s not exactly obvious why the company is now allowing people to download the “LC” EM simulator used for this purpose at no charge. Certainly the computer you use should be a Cray computer, but a Linux version is kindly provided for those possessing Intelx86. Do feel free to nose around on your own. It’s really very interesting.
Marska WLAN Pages
Even up in Finland there are some active people, which is why it’s worth rummaging around on this homepage. One very interesting subject is what you can find here under the heading “2.4 GHz WLAN antenna – Do it yourself”. You can choose between English or Finnish texts. But anyone who doesn’t speak any Finnish will have given up already during the search, and will not be looking for it any longer.
This manufacturer describes itself as a “manufacturer of MIC thin film technology” That means it’s a source of unending interest for those who want to be comprehensively informed concerning the state of the art in relation to all types of these active and passive microwave components. In addition to the data, layout design rules and/or application notes, etc. are also available in all sections.
Semiconductor Datasheets on the WEB
This is a page full of pleasant surprises for original developers and anyone who likes messing around, as everything here is nicely and neatly alphabetically sorted and frequently provided with links.
Just for a change, not pure technology, but tips and technology concerning the subject of “Long-distance reception on the medium wave and short wave”. Plus a collection of facts relating to the relevant antennas.
Microwave Active Antenna Group
This site (which is run by the University of Colorado) is also guaranteed not to be boring, for the students are very active and post their well documented research results on the homepage.
Free Radio and Computer Programs
What makes this such a fascinating site is that you can just call up one program after another to see whether you might need them. The choice is wide, and there’s certainly enough here to be going on with...
All about crystals - that’s the motto here. Follow the links listed to find the application notes which cover every conceivable aspect of this subject.
Estland Amateur Group
How about a trip to see the real Northern Lights in Estonia? Here you will discover that progress and hi-tech have penetrated almost as far as the Arctic Circle. Some very interesting links and articles!
Fertile ground for all radio enthusiasts. Here too, you can rummage around endlessly among programs and technical documents...
Another site to rummage around and browse in – everything you could need in relation to physics, technology and equipment know-how for DX reception.
This is an animation program (Waves on Transmission Lines) from the Flensburg Technical College. It can help to clarify the propagation of signals on lines in the time domain. Various transmission signals can be selected from a catalogue, such as sinusoidal signals and pseudo-statistical digital signals of various lengths, among others. The WAOTRALI program is available for downloading from the website of the Institute for Communications Technology of the Flensburg Technical College.
Internet Treasure Trove article links from VHF Communications 3/2004
Microwave and millimetre wave IC products...that’s what it says in the publicity. A very nice homepage, recently revised, done by someone I know well. In addition to comprehensive data sheets and basic information, you can also find some interesting new application notes here.
Technical development marches on – and that includes receiver technology too. Digital receivers, loosely referred to as “software radio”, are in the vanguard. Anyone wishing to read up on this new technology and get some idea of the concepts involved might like to download the “Digital Receiver Handbook” from Pentek. The principles, characteristics and advantages of this new technology are very nicely explained here – and, best of all, direct comparisons are made with standard analogue receiver technology.
If you explore the homepage in a little more detail and download the company’s main catalogue onto your home computer, you’ll get another surprise. Chapter 2 includes a very interesting collection of miscellaneous tutorials dealing with this area!
Software Radio Resource Page
Something else on this subject in the form of every possible link which is relevant to it. Once you really get into it, you’ll soon lose track of the time...
An old acquaintance that supplies every possible type of microwave module. The homepage has been re-designed and, most importantly, there is now a much wider range of articles and application notes. Of particular interest is the documentation on offer in relation to synthesisers and microwave oscillators.
Amateur Radio Soundblaster Software Collection
This homepage, which is run by Dr. Oliver Welp (DL9QJ), deals with the use of the PC sound card for all possible purposes and operating modes in amateur radio. A very comprehensive collection, especially the enormous number of links to other pages and topics.
Electronics for physicists
The University of Kiel is behind this site, and it’s really great how teaching materials are designed and prepared nowadays. In particular, you should just take a look at the topics that cover our own area (AM, FM etc.). But there’s some interesting new stuff here even for specialists — just call up subjects like “Types of Modulation” or “Noise and Noise Suppression”. I guarantee that you won’t be bored.
It’s both amusing and comforting when you come across sites run by other “mad D.I.Y. people”. Steve Blackmore has a day job as an electronics specialist, but it clearly doesn’t take up all his energy. So he goes in for decoding digital transmissions in a big way. He has generously made available his experience in relation to weather satellite reception, and you should work your way through all the cross-references of his homepage, where you’ll find all sorts of interesting things. Here’s a tip: there’s also a page (it’s a bit hard to find) that deals with quadrifilar helix antennas.
It’s good to know that the well-known microcontroller manufacturer is also going into the HF market for WLAN, Smartcard, Bluetooth and the rest in a big way. Consequently, as well as containing data sheets relating to the IC’s the company manufactures, the homepage also has application notes and some good articles on the principles. Highly recommended: “A Tutorial on WLAN”, which also contains easy-to-understand information on spread spectrum technology.
This company is from the far North – it’s head offices are in Oslo. But the product range (RF transceiver IC’s) is really first class. So it also comes as no surprise to find a very wide-ranging collection of application notes and other documentation. You can even take part in a “Wireless Quiz”, and win prizes.
It must be because of the time of year, new products are sprouting in HF companies. The homepages have new products and the document collections are being extended. If you haven’t seen the new version of this site yet, you might find it all a bit overwhelming when you make your net visit.
A specialist in VCO’s and PLL’s, with a very attractive range of products for the HF and gigahertz sectors. Also very attractive is the documentation on offer, including a lot of interesting application notes.
Internet Treasure Trove article links from VHF Communications 4/2004
We know that antenna developers come up with numerous “infinitely variable concepts”, which they never stop playing around with and changing – there’s no end to it. This often leads to solutions that we would never have dreamed of. The “Vivaldi antenna” falls into this category. Just take a look at how something like this makes out in a radio telescope. And if this is your kind of thing, a search engine can provide plenty of additional links on the subject.
It’s a safe bet that no one will guess what this abbreviation means, since for once, and for a change, we’re dealing with an interesting and meaningful application of high-frequency technology in medicine. So we won’t keep you in suspense any longer. The University of Victoria in Canada is introducing the concept of a “microwave detector for breast cancer”. Since this page summarises data ranging from principles through simulation to balun and microstrip design, the high-frequency specialist will also find it worth reading.
This is a concept that is on everyone’s lips nowadays, and is even causing many people to have panic attacks. So this homepage is extremely useful, as you can look forward to investigating the physical and technical principles, the measuring process and the range of measuring devices on offer - and there’s even a downloadable test report from the Technical Inspections Association.
This page offers a total of 115 links for you to click on, and each one leads to a program or a set of programs for antenna calculation. The same homepage also offers any amount of practical examples, and they’re even broken down by type or frequency range.
Would you like a bit more information about the principles of antennas? If so, please just take a look at this page, as information is presented here in an attractive form, and it’s a joy to read. There are also additional links to half the antenna world.
Anyone who wants to become better informed by using an easy to understand introduction to this area should pay a visit to this address. Well put together, easy to understand, not too wide-ranging and yet precise – this is the right mix for a pleasant introduction.
Since even more interesting things are on offer, we’re also giving you the link to the main page for tutorials (“College Page”).
However, if you find the Spread Spectrum introduction a bit too brief, just try this link.
This is probably the biggest collection of German language direct links that you can find on the Internet. Everything’s already alphabetically sorted, and even every exotic little shop is accessible (provided it has an Internet address). But anyone taking a closer look at this homepage will find still more interesting information.
Would you like a few application notes on the subject of microstrips / antennas / couplers? There’s some stuff you can download here, but it’s also worth taking the time just to look.
Berkeley Ultra-Wide Band Group
There’s a lot happening at most universities, and when the right team is on hand some very interesting things come out of their projects.
For example, just take a look at the project entitled “A Subsampling Radio Architecture for 3-10GHz UWB”. Look at the way these microwave freaks present and explain their results: you can do that too (...which is why I think it’s great!).
This sounds as if it should have something to do with Hawaii and the South Seas, but in reality it’s a giant online encyclopedia and user forum in several languages. You can even contribute to it if you wish. It’s somewhat hard to describe, but all our Earthly wisdom is categorised and made available, broken down by subject. Just take a look, choosing a subject that interests you.
The various aspects of radio navigation and the associated processes are the section headings for a PDF dissertation at:
You can find a (Powerpoint) presentation on FM and combined modulation signals at the address:
High Frequency Electronics
This page should act as an appetiser. Firstly, it lists the good, informative periodicals that are available for our sector. Secondly, the article headed: “The Design, Fabrication and Measurement of Microstrip Filter and Coupler Circuits” can and should inspire people to a bit of DIY work. Please have a good look round!
Internet Treasure Trove article links from VHF Communications 1/2005
All about the Smith chart
You often need to print out a Smith diagram quickly in order to indicate or monitor something. On this homepage you can find everything (but everything!) on this subject. It doesn’t matter whether you’re looking for a tutorial or printed blanks or tools or books or other websites: it’s all here somewhere, all you have to do is look.
The MINT Project
Here you can find information on the technology behind a modern radio telescope or radio interferometer for measuring the CMB (Cosmic Microwave Background). The receiver and evaluation technology is very interesting, but then the links to appropriate CMB tutorials etc. are good fun as well.
Collection of antenna design software
Just another little collection of CAD programs for antennas. Things keep turning up here that you didn’t know before.
The Designer’s Guide
This link’s title doesn’t tell you all there is to be found there: the best plan is to search in every nook and cranny and open every file. Some very nice application notes!
You won’t be here long before you are amazed, as this company’s area of activity is inter-modulation measurement. And the publications available for downloading are on a suitable generous scale. And of course, we can’t do without an IM calculator for doing calculations at home.
Here’s something for people who work with the higher frequencies in the millimetre wave range. The link in question leads to some interesting technical articles and application notes.
LC Filter Design
Anyone who has to develop an LC filter in a big hurry usually turns to our tried and tested “fds.zip” or “Faisysn”. For those who are in a real hurry but don’t have these programs installed on their computers, there’s this online calculator. You just key in the data and press <Enter> - and you’ve already got the component values, the circuit and the simulated attenuation path on the screen. Slightly simplified, it’s true, but the readings are absolutely correct. Do please try it out.
Besser (“better”) – it sounds like an incentive for someone’s own work ethic, and in fact it does have something to do with that. What’s actually behind the name is a company that is mainly active in the field of further education in the RF and communications technology area. Not only are these people kind enough to let you download quite a lot of good calculators for HF engineering, but there are also first-class articles on offer as “BesserBits” (“Better Bits”) covering various subjects (DSP / noise measurement in mixers, etc.).
Cubical Quad Antenna Calculator
If you’re planning a project like this, you need only click on this page and then you can design the whole antenna, right down to the mast.
And here’s another lovely little microwave RF calculator. Very nice, very practical. Just give it a try.
Internet Treasure Trove article links from VHF Communications 2/2005
If you need to refresh your basic knowledge of antennas, or you want to gen up on the problems and concepts associated with modern WLAN antennas, or to look for frequency occupancy tables, or to examine this, that or the other, you can look at problems more closely by visiting the “Technical Reference” section of this homepage
has specialised in microwave communications systems, and can therefore make
comprehensive aids to systems planning available through the Internet without
The “Andrew Microwave System Planner” is very attractive and is also very convenient for use at home (...but you can find even more under the heading “Andrew Power Tools”).
Microwaves & RF
It’s worth subscribing to this free periodical, or at least taking a regular glance at the homepage and saving what interests you. You can even access old articles and complete old issues. For example, there’s a link to an article on “Designing a low-noise VCO”.
An old name, but a company that has remained young. In addition to oscilloscopes and anything else modern you can imagine, the firm now also provides modern RF wireless test sets. So there’s naturally extensive technical help available, together with some very interesting application notes.
seems to be a shop on the Internet where you can buy a huge amount of earlier
versions of programs – they’re even sorted into alphabetical order! There are
bound to be some “gaps”, but a painstakingly thorough search still came up with
some surprisingly well-known and interesting names (APLAC 7.61 / Ansoft Designer
/ HFSS / Microwave Studio, etc.). And all at suspiciously low prices.
Should purchasers be worried about any legal problems here?
A famous and very well-known authority in the USA. So it’s all the nicer to have online tools for free use under this link.
Version 5 of the popular “RF Manuals” from Philips-Semiconductors has appeared.
How about a lexicon in which you can find a brief and precise clarification of almost any term from modern communications technology (e. g. from “Frequency Hopping” through to all the IEEE 802 standards)? A useful address – make a note of it!
Martindale’s Calculators On-Line Centre
No detailed explanation needed here: someone has collected together everything he could find on calculators on the Net from all over the world, sorted the information and made it available to other people. There seem to be over a thousand titles listed, so have fun rummaging around!
Internet Treasure Trove article links from VHF Communications 3/2005
145GHz amateur band
Variety is the spice of life – of course everyone knows this saying. Why shouldn't it sometimes be some completely different frequency ranges? So anyone who wants to take a trip to such high frequencies should begin by taking a look at this page.
Anyone who, in contrast, is attracted by really low frequencies, will find an attractive little range of items here - circuits, antennas, ideas, etc...
They are a company that produces all kinds of things for RF technology, such as mixers, directional, other couplers and dividers. Not only is it interesting to glance at the specifications of the components (for example, there's a tiny little directional coupler which covers a range from 1MHz to 1GHz), but the application notes are of interest too.
Those who like to simulate their circuits before testing the first prototypes will enjoy this site. Not only will they find links there to various SPICE model lists, but also data on something really splendid: a converter that generates an S-parameter file for simulation.
Some more people who are very active in the modern communications technology sector and supply interesting modules or components. There is a very informative list of the “Technical Papers“ available, which should make developers' eyes light up straight away. For example, “A 2 -18GHz Receiver Frontend“ or “A Monolithic, 2 to 18GHz Up-converter“ or “RF Mixer Design“ or “Synthesizer Design“ or....
Broadband multi-function antenna suitable for incorporation into vehicles
Something in German for once - though the bad news is that it takes a lot of downloading This modest and unassuming title conceals a Karlsruhe University doctoral thesis 200 pages long, with a good introductory section on the basic principles of antennas.
Anyone looking for interesting programs for “fiddly little jobs” should make a note of this address and pay the site a visit from time to time. New items appear here at regular intervals.
Here we have an online calculator, which can be used to determine all the important characteristics of a receiver if the various stage characteristics are entered. These characteristics are: overall amplification, total noise factor, spurious free dynamic range and noise floor in dBm.
An easy-to-understand and accurately written introduction to the characteristics of directional couplers, including illustrations and formulae. Compiled as an online lexicon of RF technology by Bilkent University in Turkey.
GlobalSpec - The Engineering Search Engine
There's not much explanation needed here: anyone needing links in connection with a problem or a term should try their luck here. Normally you end up with more information than you can use.
Internet Treasure Trove article links from VHF Communications 4/2005
A very well-known name among IC manufacturers. This company has markedly increased its activities under the heading of “Modern wireless communications technology” and massively increased the quantity of application notes are available. All of this has been revised and now appears with a new look that makes it a pleasure just to go into various subjects a bit more deeply (which naturally include the “Wireless, RF and Cable” section).
University of San Diego / RF & Microwave Engineering
A real treasure trove for people who are interested in various RF subjects, since the pdf files available are not limited to lectures from courses. The site in fact has links to interesting articles by other people that are perfectly matched to the theme.
Here's something from a part of the world in which people (looked at from our point of view) are standing on their heads. An Australian site, crammed full of interesting links and tutorials - so somewhere you can root and rummage around in for hours. And here's one thing you can search for straightway: just look for the Marine Corps “Field Antenna Handbook” (192 pages, downloadable as a pdf file). A handsome and interesting book!
Amateur radio links
There are some very industrious people in our amateur radio community, because here we have alphabetically listed links to every possible aspect of our hobby. So this is something that you're bound to need again and again, so that you can make a search more selective and make more progress. There's a lot of hard work behind this site.
University of Essex / Nanofab
You've guessed it already: this site deals with the cutting edge stuff in semi-conductor manufacture and nanotechnology. This site has been conceived as an information centre for people from the appropriate technological fields, but it's also very interesting for the ordinary person who's interested in electronics to have a look behind the scenes and marvel at what can be done nowadays and how it's accomplished.
When did you last visit the homepage of the successor to HP? If it was more than 2 months ago, you should just take another look at it. The RF and microwave application notes have been greatly expanded and revised.
By using the link below, you'll reach the “developer zone” of National Instruments, and many other paths branch out from there. Lots of literature available, but you can also access a well-constructed online lexicon of communications technology and signal processing. Just take a look around!
This company is mainly involved with capacitors of every kind, but it also handles inductances and couplers. Consequently, microwave technology is well represented. The site contains a huge number of documents, but there are also Spice model collections and the like.
Datasheetarchive and Alldatasheet
Anyone looking for the data sheet for any semi-conductor component or IC should start the search with these two sites. You'd certainly have trouble finding a site where things are made so easy.
Spice Model Resources
The name says it all: this is where to start your search if you need Spice models for a specific component.
Internet Treasure Trove article links from VHF Communications 1/2006
For anyone who might want to download the most important current SPICE programs on the market and compare them, this is the right place.
That sounds so simple, but it conceals a comprehensive homepage providing information on an unbelievable number of topics. The whole weather satellite scene seems to be concentrated here. From antennas to technology, everything is discussed and made available here.
The „PSPICE“ article in the last issue clearly aroused great interest and led to quite a lot of E-mails and new leads. One of these was especially interesting: Linear Technology are offering a complete Spice machine on their homepage under the name of „SWITCHER CAD“ for research into DC-DC converter circuits. Fortunately, any other circuit can also be simulated there, and the company boasts that it is „making the most accurate and stable PSPICE version available free of charge“. When we checked up, it became clear that there was a whole lot of interesting stuff waiting to be downloaded here:
“Noise” ( Program for research into noise in OPV's);
„BodeCAD“ ( Program for drawing up Bode's diagrams)
„FilterCAD“ (Program for research into active filters)
„Spice Models“ (Collection of miscellaneous Spice models)
„The Configurator” (Amplifier design tool)
“LT1568 Filter Design Guide (Designing active filters using the LT1568)
emWONDER / S-Parameter Resources
This unpretentious-looking homepage not only deals with S-parameters and their Internet links, but also handles the integration of SPICE and S-Parameters (...which was touched on recently in the PSPICE article in VHF Reports...). You can go into the subject in even greater detail here, so you shouldn't miss the chance to read about the „S-parameter to SPICE model converter“.
The company used to be called „Teledyne“ and is no doubt still familiar under this name to many microwave specialists. But the new name has clearly been good for the firm, and there is much to discover on the new website. In addition to application notes, there are naturally some data sheets, but there are also some interesting conversion tables.
There are some very active companies whose sites should be visited regularly to see what's new. Watkins Johnson is among them, and the application notes and technical notes are first class. Plus the technical archive has been expanded, and you can now call up almost all the elderly but very well written documents, as they have been made available in scanned-in form (it's unbelievable: right back to 1974!).
Mentor Graphics / IC Nanometer Design
For some reason, people tend to associate this company more with computer technology, but, thanks to the WLAN and Bluetooth standards, RF technology is now also appearing everywhere. So what we have here (under the heading „Physical Verification") is a whole collection of successfully completed circuit simulations. Well hidden, it's true, but worth hunting for...
Useful links from electronics
Here's a Hungarian homepage which, with great attention to detail, brings together countless links relating to miscellaneous aspects of electronics. Just call something up and see whether there's anything interesting here for you!Address:
Internet Treasure Trove article links from VHF Communications 2/2006
This is a new name to learn and get accustomed to looking at their home page from time to time. Following the change from Hewlett Packard to Agilent there have been more changes making a completely separate company for all semiconductor activities. It will take time to get accustomed to the new homepage until you find familiar things (Application Notes, data sheets etc.).
Right at the top of Finland there are some people who are unbelievably active on the microwave bands and are not frighten of anything (EME attempts soon). Looking around the homepage of Michael Fletcher you have to ask yourself, when did he learn all this and when does he build it all. Respect!
Address: http://www.kolumbus.fi/michael.fletcher/ index.html
Tonne of software
The personal site of James A. Tonne. It offers some interesting filter and antenna programs, these are partly for downloading and partly interactive versions.
This is a joy for anyone who works with PSPICE and will probably be repeatedly visited. It offers thousands of SPICE models for all components and not just “standard Spice” versions. Also modern things are to be found such as “ILIB, IsSPICE, OrCAD template “and other exotic things. These can be found very simply using the desired keyword in the search machine.
Address: http://www.onsemi.com/PowerSolutions/ supportDoc.do? type=models&category =503
MMT stands for Millimetre Wave Technology Group. A surprising insight into where modern technology is going. There are; ideas, still crazier production technology for unbelievable things. Simply interesting to spend some time browsing
For readers of VHF Communications Magazine, Matjaz Vidmar, S53MV, is well known. Many of his interesting articles have been published over the last few years. He is a professor in Slovenia and has an enthusiasm for technology. His projects are very interesting and worth looking at again.
The free simulation software TINA-TI from Texas Instruments: TINA is an easy-to-use, but powerful, circuit simulation program based on a SPICE engine. TINA-TI™ is a fully functional version of TINA, loaded with a library of TI macromodels plus passive and active models. TINA-TI is limited to circuits with two ICs and up to 20 additional nodes.
The program “filter pro” is an active filter design program from Texas Instruments and is described by them:
FilterPro™ Multiple Feedback (MFB) and Sallen-Key Design Program is a Windows application. This application designs MFB and Sallen-Key low-pass and high-pass filters using Voltage Feedback Op Amps, resistors and capacitors. It also supports a fully-differential version of the MFB circuit. This program includes Bessell, Butterworth, Chebychev, and linear phase filter types and can be used to design filters from 1 to 10 poles. The capacitor values in each stage can be either selected by the computer or entered by the designer. An "always on" prompt window provides context-sensitive help information to the user. The response of the filter is displayed on a graph, showing gain, phase and group delay over frequency.
The program “TPS40K - designers software” is power supply design program from Texas Instruments and is described by them:
The TPS40K Designer software provides a simple design tool for both novice and experienced power supply designers using the Texas Instruments TPS40xxx family of controllers. The software includes advanced analysis tools for the experienced designer to do worst-case loop response analysis and component characterisation. A customisable component database is included. It allows the user to add or remove parts to any of the TI Designer series of power supply software (including SWIFT Designer, V3.3 or Higher).Address: http://focus.ti.com/docs/toolsw/folders/print/tps40k-sw.html
Internet Treasure Trove article links from VHF Communications 3/2006
ASI (Advanced Semiconductor)
The speciality of this company is the manufacture of microwave transistors and diodes. The web site has data sheets available under the Downloads and Resources headings, a fantastic find!
SM5BSZ Home Page - Equipment for VHF DX
This is a simple homepage of the Swedish radio amateur, Leif Asbrink, SM5BSZ, who is a reader of the German version of the magazine, UKW Berichte. His web site has many interesting topics that are easy to access..
List of Semiconductor Manufacturers
A very useful list from Digchip. For anyone looking for the web site of a semiconductor manufacturer, this is an alphabetic list of semiconductor manufacturers worldwide.
Once you have found the web site you can browse at your leisure.
There are a great many EM-simulators for microwave circuits and microwave antennas. One cannot buy or test every program, therefore it is interesting to search for simulation examples and successfully projects to learn from their experiences. This web site has some interesting examples from established technical publications.
It is often difficult to find interesting articles and publications from large companies or universities. Because Caltech University is well know from the publication of the microwave CAD software PUUF, it promises a good source of articles. This page contains a complete collection of microwave publications from students and lecturers.
INTEL Technical journal
Who would expect PC development to have anything to do with RF technology, so you would probably not search here. But because of the rapid expansion of WLAN technology, INTEL does cover this topic. You can find fundamental or trailblazing articles about applications in the GHz range in the regular Technical Journal.
University of Calgary
Homepages of universities are often a treasure chest for interesting publications. That applies to this Canadian web site.
It is simply joyful to browse in this extensive library. On this web site you can find basic articles, interesting Application Notes, many technical documents and many other interesting things.
This web site is a secret store of articles and tutorials on RF technology., particularly to the area of RFIC. They are very well presented even if you sometimes have to search for things. First class!
Internet Treasure Trove article links from VHF Communications 4/2006
Microwave Antenna Book
For anyone who wants to understand the field of microwave antennas, this has all of the basic information. It is a complete textbook with individual chapters downloadable as pdf files. Very well produced, very informative and kept up to date with many revisions. Recommended!
This site covers the topic “digital signal processing and digital signal processors “. This includes interesting and free of charge tutorials and Application Notes for applications in the audio range.
L.B. Cebik, W4RNL
An interesting site for antenna enthusiasts. There is a lot of information on the site plus downloadable information, including a comprehensive history of antennas but the emphasis is on modern technology, in all variations.
University of Idaho
Universities usually specialised in certain areas, in Idaho there is “a centre for Advanced Electronics and Biomedical Research”. The “NASA symposium on VLSI Design” takes place at the university, afterwards interesting contributions or article are made available free of charge as pdf files. There are things like “A 1.2V 2.4GHz Integrated Direct Downconversion Receiver front-ends” or “Design of a CMOS Low Noise Amplifier (LNA) for 5.8 GHz” to read, and many other topics…
This homepage gives many useful links to antenna design and calculation software.
Applied Computational Sciences
Computer simulation of microwave circuits is indispensable for modern design work. This site has some beautiful and detailed examples on LNA design for minimum noise or improved adjustment. They are worth reading, even if you do not use the LINC2 design program used in these examples.
Down East Microwave
Down East Microwave are a rare company, they not only publish a picture of the finished component and the technical data but also a photo of the PCB as well as a circuit diagram. Interesting for own work! The example is a low noise amplifier but the full catalogue has much of interest.
Example LNA article Address: http://www.downeastmicrowave.com/PDF/915lna.PDF
Full catalogue Address: http://www.downeastmicrowave.com/Catalog.htm
Institute for the Telecommunications Sciences, offers a large selection of information on a wide range of different topics. Worth reading!
Internet Treasure Trove article links from VHF Communications 1/2007
A very well known Far East company famous for coils, capacitors, filter etc. There are not only the product specifications, but also the collection at S-parameter files to the Download. The documentations with the measuring conditions are worth reading with the S-parameter files for separate frequency ranges.
a. homepage: http://www.murata-europe.com/
b. S-parameter collection: http://www.murata.co.jp/sparameter/index.html
c. Measurement of the S-parameters: http://www.murata.co.jp/sparameter/measure.html
University of Guelph (Canada)
One finds interesting things again and again at universities - one must search very thoroughly with them. On this homepage there is a tremendous collection at electronic hobby circuits. Just as interesting however there are links to a data sheet collections, SMD code, etc.
Address: http://www.uoguelph.ca/~antoon/circ/ circuits.htm
Eesoft - Agilent
This simulator is the “Rolls Royce” of RF circuit simulation - both from the price, as well as the extent and the possibilities. Nevertheless the search is worthwhile because the non Rolls Royce content. Here there are introductions or Application Notes for the simulation of different RF and microwave circuits. Also most can be used with little trouble for other cars (Pardon: Simulation programs). A really interesting site.
Helix Antenna Design and Construction detail
Who is interested in this type of antenna or would like to experiment. Here is a beautiful empirical report on this topic.
At experimental 10Mbit/sec Microwave Data Link
This project takes some time to appreciate, besides the empirical reports and/or results of measurement of the completed project, there are the planning documents, the initial considerations and the PCB layouts etc.
Unbelievably accurately and the last detail inside documents; even the views for RF security and the protection of systems are there.
Some on-line computations among other things converting SSB phase noise to jitter are to be found with RALTRON. Also the application for quartz crystal jitter and noise are worth reading.
Internet Treasure Trove article links from VHF Communications 2/2007
This is not individual strip line simulator but a matured 3D simulation software package for draft layout and simulation of microwave modules and antennas
An interesting and humorous collection information about “Microwaves”. The operators of the site stress that not everything is fully developed, but it can be used! The site is well designed with many alphabetically sorted articles, topics, Application Notes and software. It is a wealth of information.
This is a young American company offering software test suites for the wireless communications.
Internet Treasure Trove article links from VHF Communications 3/2007
A name that everyone should recognise because they produced the PUFF microwave CAD software. Naturally there is a lot of knowledge behind this and they have a collection of interesting RF and microwave documents in a data base stored here…
For anyone who develops microwave circuits, a vector network analyser is an essential but expensive part of the workshop. Despite it’s age the HP8410 does the job very well if used with care. It is easy to repair and documents are readily available. Here is a small selection of Internet addresses with interesting information:
This is a magazine that publishes articles about “RF and Microwave Technology for Design Engineers”. Articles range from software for VLF to the millimetre wavelengths and from the RFIC Design to complete radios. The articles are excellent and available to be downloaded from:
This site is mentioned in the section on the HP8410 but it is an excellent site for any manuals
Agilent Interactive Impedance Matching Model
There is something beautiful about playing on a computer with RF circuit design. An introduction to the problems and methods of interactive software with detailed exercises can be downloaded in the famous HP Application note 95-1.
Semiconductor manufacturers are an important source of information to learn about the latest technologies. This manufacturer is no exception with details of wireless LAN, Bluetooth, GPS and microwave semiconductors. There are datasheets and application notes.
Here is something for the microwave antenna enthusiast. Many designs are shown with simulated radiation patterns. These include the “Pringle” antenna made from an empty Pringle box.
Plextek is one of the largest independent electronics design consultancies in Europe. Their web site contains a large collection of technical papers on tecchnology for the GHz range.
Internet Treasure Trove article links from VHF Communications 4/2007
Microwaves & RF
This is an RF magazine with interesting articles and the occasional review. The “White Paper” and other documents are worth registration.
The Linear Technology web site is always worth a look . Under the Design Support section there are Application Notes and support. There is also a section for Design Simulation that contains a range of software.
Circuit simulator “Qucs”
This is an open source circuit simulator with the nice name “Qucs”; it stands for Quite Universal Circuit Simulator. The simulation tool is still being developed but should be no competition for PUFF but is an alternative with som potential.
The four metres web site
This site has all you want to know about the four metre band. This is becoming more available as the band II TV stations are switched off in favour of the digital channels.
This site has a introduction to Echolink the new digital mode for radio amateurs. There are some rigs being produced now with Echolink facilities so it is as well to know what it is all about.
The ADT-200 is an all-digital transceiver designed using the principles of a software defined radio (SDR). The only exceptions to digital components are the preselector and the transmitter output stage that uses high voltage MOSFETs. It was developed by the Swiss amateur Hans Zahnd, HB9CBU and is probably the world wide first all digital amateur transceiver to work independently (no PC!).
The ADT-200 has four independent receivers and eight internal VFOs for many split frequency options. Only three rotary controls and 18 keys switches are used to operate the transceiver. All relevant information appears on two high visibility displays. There are options for 2m or 70cm modules.The ADT-200 is going to be available from the end of the 3rd quarter of 2007. Further information is available from www.adat.ch
Internet Treasure Trove article links from VHF Communications 1/2008
The name says everything: tutorials are collected here and the topics are so varied that a thorough search is worthwhile. You will find some very useful topics covered that will be extremely useful. The scope of the topics will not be revealed here by suffice to say that the web site is well worth visiting.
Noise and Noise Figure Measurement
A very good detailed homepage. This is nearly a complete textbook online. Great fun to read either for the first time or to refresh knowledge from the past.
A very well presented and easy to read tutorial with plenty of information on antennas, wave equations, propagations, reflections, Noise….?
You will find many application notes here suitable for the experienced developer or the experimenter. Pleas sepne some quiet time to go through the appropriate pdf documents or download them to read later.
No introduction is needed to this company formerly known to us as Hewlett Packard. The company is still growing and to emphasise that there are (on 1 September 2007) exactly 2946 application notes available to download on this homepage. For those who are interested of do not believe this, visit:
Designing Antenna systems with maximum sensitivity
This is a very well presented and informative homepage. There are many interesting subjects mentioned on the homepage.
COMM Design - Design of center
This is a collection of useful articles and training material from different companies. You will find lots of useful information here.
Cisco - Carrier to Noise ratio in Cable network
Companies like Cisco who have their roots in computer and network technology make good tutorials on RF and communications available. A good example is this analysis signal to noise ratio. There is more information on this web site, so explore the home page.
Fast pdf reader
An alternative to the well-known pdf reader is the very small (only 2.1Mb download) and quick software FOXIT reader from the company FOXIT software.
Apart from the free Windows version there is a versions for mobile devices, desktop Linux and U3.
This is worth a look:
Satori Technology high dynamic range USB 26.5GHz power meters
Field pioneers Satori Technology have extended their product range of USB power meters with the release of the ST265. This pushes the frequency limit for high dynamic range USB power meters up to 26.5GHz going beyond what is currently available in the marketplace. The ST265 now covers a frequency range of 10 MHz to 26.5 GHz.
The ST series are complete miniature RF & microwave power meters. All measurement data and settings are sent via a USB interface to and from a PC or laptop. This gives the concept of using a computer as the user interface in classic microwave power measurement. Each power meters contains a CPU which controls the sensor, processes the measurement results and operates the USB interface.
The ST265 is a significant enhancement to the existing series (ST124 and ST185 USB Power Meters) and brings with it greatly improved performance. Extended individual calibration procedures have resulted in improved temperature compensation and better linearity performance with RF frequency. The use of a K-typeTM RF connector gives repeatedly low reflection coefficients up to 26.5GHz.
Satori Technology supplies its own easy to use software toolkit which is powerful, flexible and enables multiple power meters to be operated simultaneously. Drivers are available for Agilent VEETM and National Instruments LabVIEWTM. With a size of only 34 x 43 x 125 mm and weighing in at only 83g the ST range of power meters are the ultimate in portability as well as saving space and reducing costs in rack-mounted systems.Address: www.satori-technology.com/products.htm
Internet Treasure Trove article links from VHF Communications 2/2008
There are several interesting Application Notes for microwave and antenna enthusiasts: e.g. Basics of antenna arrays, Basics of patch antennas, An introduction to GPS patch antennas, An introduction to GPS low noise amplifiers etc.
100GHz Subharmonic mixer
Those who are interested in the current state of high frequency mixer development should look at this publication. It is very informatively, easy to understand but nevertheless very accurately. A good article like this looks good and extends your knowledge.
Address: http://www.eecs.umich.edu/rebeiz/Completed Research Papers/W_Band_Subharmonic_Mixer97.pdf
Professor Randy Katz
If you type the topics noise, modulation, propagation etc into a search engine you will inevitably encounter the name professor Randy Katz. Such lecturers are a genuine advantage to a university.
As an example, on this web page follow the link “Courses” on the left. In “Course 294.S96” you will find interesting pdf files with extremely good discussion on fundamentals. Also try other searches!
LNA Design for CDMA front ends
This is a ery beautiful and detailed application note about LNA Design from Philips. It accurately describes operating point stabilisation and signal to noise ratio adjustment. A joy to read.
Design of a CMOS LNA for 5.8GHz and its sensitivity analysis
Not everything that has been learned in the past is wasted. The good old cascode circuit has appeared in the newest and most modern integrated circuits on a chip… Fundamentals in new form for the GHz range.
Antenna Design software and Electrical engineering software - mostly free
This is a good place to find ideas. Everything downloaded and examined was found to be worthwhile and worth spending time to understand
Electric Waves and Antennas
This is a fine thing: someone has written a beautiful book with 21 chapters at present on this topic. It has be put on the Internet for eveluation
Microwave Antenna Design Calculator Download
This Calculator makes the design of a microwave antenna a joy and is easy to understand. You must register first, but the software is really worth it.Address: http://www.q-par.com/antenna-calculator
Internet Treasure Trove article links from VHF Communications 3/2008
This web site has many items to browse or download. There are detailed documents and application notes on components and modules for microwave engineering. To access these quickly choose the sub menu “Technical library “.
The introduction to this site says: IMEC is Europe's leading independent research center in the field of micro and nanoelectronics, nanotechnology, enabling design methods and technologies for ICT systems. This site has much of interest including information on Software Defined Radio (SDR) and a Direct Conversion Receiver for 5 GHz.
Radio telescope Effelsberg
For anyone who wants to know about the concepts used for extremely low-noise receivers between 400MHz and 100GHz, take a look at this homepage. The information is sorted by frequency range with ne document per receiver and the associated antennas. Radio telescopes work at the physical limit of receiver technology and it is interesting to study how they move closer and closer to these limits.
National Semiconductors school of analogue design
That is a great site for almost all areas of analogue techniques including: operation amplifiers, mixer, DC to DC converters… Please look at the on-line courses, in particular the wireless topics.
CMOS Self Mixing Free front end for Direct Conversion Applications
This publication from University of Hong Kong has good presentation and accurate information.
A simple printed broadband antenna
This is an informative and clearly written article on microstrip antennas with good suggestions on this topic.
Sounds like Science Fiction, it is however a company who specialise in millimetre wave systems and components. Beside documents on their products there are interesting applications. For example: Frequency Multiplier Application Notes and Gunn Oscillator Application Notes.
Universitiy of Berkeley California
It is always interesting to search the pages of universities. This homepage has many interesting topics.
Embedded Antennas get the signal
This is a strange title but it is a very interesting article. It describes the theoretical background and the production technology of this new technique.
This site is a joy to visit, it has an unbelievable array of topics for developers. The heading “RF and Microwave Resources” says it all.
Philips RF manual
It is a good idea to put a manual on the design basics for RF circuits on the Internet. This is an excellent document containing lots of useful information.
Address: http://www.nxp.com/acrobat_ download/other/discretes/philips_rf_manual_3rd_edition.pdf
QTH Viewer for Google Earth
Daerek Milka, SP6NVK has produced a QTH Locator Square overlay for Google Earth. Using the link below select “QTH Locators viewer” to download the .kmz file. When this is used for the first time with Google Earth it produces an overlay of the main QTH locator square over the globe. Under “My Places” there are three check boxes to control the overlay. A tick in the subdivisions check box will generate subdivision squares.
Ecoflex coax cable
For those in the UK the low loss coax cables from SSB electronics can be purchased from Diode Electronics. There is a range of cables in the Aircell, Ecoflex and Aircom ranges. Ecoflex 15 offers 9.8dB/100m loss at 1GHz with a maximum frequency of 6GHz, Aircom plus offers 13.4dB/100m at 1GHz with a maximum frequency of 12GHz.
G8PUT Logbook Project
With perfect timing the G8PUT logbook project was started just after the use of a logbook by UK radio amateurs had been made optional. The G8PUT Logbook, Contest and Award System is a computerised Logbook designed to look and feel like a real logbook. Having been available as a trial version for some time now, the first full release is available from the beginning of 2009.
Designed for quick and easy use with easy entry of QSO details into a screen that looks just like a page in a log book.
To enter a single QSO can take just 2 more key presses than there are letters in the callsign!
It allows for multiple contacts to remain open when operating in a Net. Single stations can be logged out individually, or the whole Net closed at the press of a button.
Including a rapid entry screen for contest working, and an ever growing number of contests and awards.
Whist the full version of the G8PUT Log Book is now available, the list of features and functions will continue to grow for the foreseeable future. A list of ideas and extra function requested by users has formed the basis of the programs development and will continue to do so.
The program is available at www.g8put.com, for information email firstname.lastname@example.org
Internet Treasure Trove article links from VHF Communications 4/2008
Links to SPICE simulation resources
Anyone who has changed to simulate a circuit before it is constructed should look at this site. It gives links to sites with free SPICE models, training courses, software, magazine articles and application notes etc.
VOACAP Quick Guide
“HF Ionospheric Communications Propagation Analysis and Prediction “ this is a wave forecasting and propagation prediction program. It gives information on the current conditions and a free software download.
Watkins Johnson Historical information
For those who are interested in the products manufactured by the well known companies Watkins Johnson or Communications Engineering, this site gives a good overview of their history and products. There are manuals and information on items that you may still find in your shack.
Various Scans of HP manual, etc.
If you are like the author always looking for manuals on measuring instruments, this site will be invaluable to find that special manual.
Keiths Vintage RACAL Enthusiasts Site
This is a site that will bring back memories for the older generation and inform the younger readers. In particular the RA17 was a milestone in short wave receivers design with its special mixing technique. Now that the analogue receiver is fast disappearing in favour of the SDR receiver the achievements of the pioneers should not be forgotten.
NEC LNAs for 2,4 GHz
There are lots of integrated LNA ICs available but this application note is interesting. There is an optimised circuit for a special application (wireless video camera) with information on using the IC and information on prototype. The results of measurement, the circuit and a photographs of the PCBs are published without restriction and therefore are most interesting for the circuit developer.
An 18 to 40GHz double balanced mixer MMIC
How do you build a passive mixer for 20 to 40GHz? This question is not only answered in this article with measurement results, but it also gives the reasons for certain technologies used and circuit details. Very informatively.
Address: http://www.plextek.co.uk/papers/BB Pass Mixer Full Paper2.pdf
But this article is not the only interesting item, at the address: http://www.plextek.com/technicalpapers.htm there is a complete collection of technical papers from this company e.g. Oscillator Design, RF mixer Design, Synthesiser Design.
Mini Circuits Application Notes
The information from this company is always very high quality and the application notes are exceptional. Thye have all the information required including a special mixture from basics, characteristics and applications. A very good site with a nice clean look.
The products from this company cannot be ignored. They are an RF and microwave specialist and supply an almost infinite number of interesting products. They have a lot of information on the Internet This site has many interesting items in the literature section such as a PLL calculator and a mixer track calculator, available under the heading “engineering tools”.
Internet Treasure Trove article links from VHF Communications 1/2009
Vivaldi Antenna for Snow radar
A really interesting project and a good article with lots of basic information for this type of antenna its characteristics and applications. Not only for antenna specialists.
Digitally signal processing Tutorial
This tutorial is for anyone who wants to read detailed information about modern technology. This is a pleasant read for an introduction to this subject. There is also a Java applet with information on topics such as FFT principles and designing digital filters or DTMF generators.
This is for lovers of modern software used in our hobby. Everything is here from antenna design to filter design, PLL calculation and some Application Notes.
EE Times Europe
You should visit this homepage regularly. Again and again there are interesting articles, particularly on the forefront of technical developments. An example is the article: “Using high-spees A/D converters beyond baseband frequencies”.
An interesting technical site with clearly divided topic areas and many useful things. There should be no fear of the registration with your own personal data; this gives access to a large amount of interesting documents.
For those for who become bored with conventional RF technology or become over courageous or who simply look for new electronic challenges, why not try the 24GHz microwave band. This homepage is the best way because there is concentrated information on the topic.
For the big players in the electronics industry communications is important. The frequency ranges are getting higher with ever more interesting and low priced components to stimulate your fantasies.
This applies to the “RF/IF and ZigBee Solutions” from this company. The page addressed below will stimulate your interest. What could you use it for? A further search of the homepage shows possible uses in the amateur radio range.
Matjaz Vidmar, S53MV
Readers of VHF Communications Magazine should know this name very well because of the developments and projects that have been published.
There seems to be no end to the new projects that come from Matjaz, probably something to do with his job as a university professor. Take the time to look at his latest activities.
Aerocomm Antenna Tutorial
Another antenna topic, but this time a general tutorial. This is not only for the specialists but for revision and to test your own knowledge or for filling the gaps in your knowledge.
Allocation of the radio spectrum
It is interesting: to see who uses certain frequencies or what frequencies are approved for which services. There are some unscrupulous people who make a lot of trouble.
144MHz Beacon list
Not of interest to everyone but if you needs it:
This is only a small part of the interests that this amateur shows the homepage. Please take a further look:.
NASA Tech briefs
A mine of information, white papers etc.. Partially accessible after free registration. The titles whet the appitite.
Logbook, contest and award system
The Chris Townsend, G8PUT Logbook Project started in late summer 2007, the original idea was to create a simple and easy to use logbook system. Since then he has received many requests to include additional features. The most significant are perhaps Contests and Awards. Work is progressing well on including these and many other features.
The way the project is developing is that new functions and features which have been requested are being added in no particular order. A feature which takes little time to include might be added on the day it is requested. Other features which take a significant amount of work will be made available when they are completed.
eBay shop: HamPlace
I came across this eBay shop while trawling for some parts for a new project. The shop has some interesting items at very good prices. Some eBay fans may not want to purchase from Hong Kong but I have had good experiences and in fact the items that I purchase from this shop arrived in 4 working days, much quicker that some major suppliers can manage. – Andy
Address: www.ebay.co.uk - then select shops and enter the shop name
Internet Treasure Trove article links from VHF Communications 2/2009
At first sight the title says nothing. Once you open the site you are greeted with by a complete collection of microwave documents including calculations and information etc. A lot of time is required to investigate everything.
Old things can be interesting and delightful. This information is over 30 years old but has been revised again and again plus presented as an Application Note by Agilent (formerly Hewlett Packard). It concerns the correct use of the detectors 423B and 8470B.
What makes this brochure so useful is the detailed cross section and exploded views of older plug e.g. BNC, N, ApC7 etc as well as the notes on correct handling them and the repair or exchange of such detectors. Some people will also find more memories in this Application Note.
Basic Antenna Theory
For those who want to study the basics of antennas at a very scientific level should take a look at this university site.
This site is for those who think they have missed something. It is a high quality engineering search engine that can seek out the maddest things. As an example try the result of this enquiry: Application Notes/Schottky Diodes.
Address: http://application-notes.globalspec.com/Search?query=Schottky Diodes&show=appnotes&frmtrk=ofInterest
For those who find normal RF technology boring, they should take a look at the technology and problems for the frequency range above 50GHz. This homepage has lots of information on measuring instruments and good Application Notes. This is a completely different world.
More and more often manufactures are trying to present information on their new products to their customers and prospective customers. As an example Plextek are introducing a new mixer.
For those who take a look will find some different and useful things. Click on “Technical Information” on the home page to get a choice between “Technical Paper” and “Downloads”. Selecting Downloads there is a “Smart Antenna Demonstration” that can be downloaded.
Amateur radio Astronomy/Western Australia
Radio astronomy always works on the edge of technical possibilities and is therefore worthwhile taking a look for any RF freak. These people begin with low frequencies (see the article on Schumann resonances) and do not stop at 10GHz. All the methods and devices are explained with no secrets. There is also plenty of interest to non astronomers.
Ultra Low Power ELF/VLF Receiver Project
Having mentioned Schumann resonances, this continues in the same frequency range. In such receivers the same thought processes and the same technical work is required as in 10GHz project.
This is worth a look and it will inspire your imagination.
Internet Treasure Trove article links from VHF Communications 3/2009
The abbreviation means Earth Moon Earth it is a specialist part of our hobby; QSOs with the moon as reflector. Everything concerned has to be at the forefront of technology and technical know-how because the transmitter powers are limited not much signal arrives at the receiving antenna or the following LNA. This homepage presents the current state of the art information to give an idea of the requirement including the financial ones needed to succeed.
Another exotic abbreviation that stands for: Searching for Extraterrestrial Intelligence. This web site has all the information about the many interesting spin aspects; this is sometimes at the edge of physical technology.
Noise Figure Measurements
For those who art interested in or develop low noise amplifiers the Central States VHF Society has a legue table of the best results achieved each year. It shows what other amateurs have achieved so that you can see how your efforts compare. Studying the lists will cause the genuine developer to think about their own projects.
For anyone who does not understand a term then this encyclopaedia is the place to look for the answer. There are many things to discover.
EZNEC Model files
EZNEC is a simulation program for wire antenna simulation in the frequency range up to 1GHz. It can save many unnecessary prototypes and tests. The program does not give complete building and assembly instruction, but the simulation results are so good that usually only fine adjustments are necessary. EZNEC is a good low cost entry into simulation. To save re-inventing the wheel it is a good idea to look at finished projects. This helps to learn how the software works and secondly and existing project can be adapted. Here is a source of such small project.
Also this site has an interesting offer at the end to download an antenna collection:
This is a free program from Analog Devices that sounds very mysterious. It enables various components (filters, mixers, amplifiers…) to be connected in cascade to form a complete system. The program can then simulate the overall gain, the noise figure, IP3, P1db etc. To use the program you must be registered.
Direct Conversion of Receivers
This is an interesting technology that demands high demands on design and construction. It is always interesting to study and see the solutions that other people have achieved. Here are several interesting examples:
http://www.njqrp.org/sop/schematic rev b.html
Internet Treasure Trove article links from VHF Communications 4/2009
Pentek’s software radio and A/D I/O products are the most comprehensive in the industry. Products available in PMC, PMC/XMC, PCI, PCIe, cPCI and VIM formats
SAC - EDUCULT: Education, hobby and culture related programs and texts
This site has an amazing list of software, it is displayed a page at a time but unfortunately there is no index. If you are patient you will find such things as the CAD program pcaad.zip to design antennas like log-periodic, patch antennas and the horn radiators.
Amateur radio links
This is a German site with many useful amateur radio links. Even if you do not speak German there is enough description to find some useful information.
This site is a catalogue of free online engineering calculators for engineers and Students worldwide. It features a few hundred calculators for solving complex equations and formulas in the fields of electrical, mechanical, chemical, electronics, civil, metallurgy, oil & gas, optical, plastics, ceramics, physics, maths and many more. The address below points to the electronics section.
Guided Wave Technology
This site is dedicated to design and analysis of micro and millimetre wave filters from 0.5GHz to above 100GHz
There are some very useful links for microwave filter design on their links page
Practical RF Circuit Design for decaying Wireless of system
It is unbelievable, but true: this is a 588 page technical book on the Internet - free of charge. It can read on-line or as a pdf file. If you go to the web site, be patient because it takes some time to start displaying the pages.
SynFox is a revolutionary very high accuracy, ultra-low noise wide-band RF synthesiser with 1Hz minimum steps, better than -100dBc/Hz @ 1kHz, associated with a few tens of µs lock time. SynFox is suitable for a tremendously large variety of applications programmable from 0 to 3GHz.
Tin Plate Boxes
Many of the projects published ion this magazine are designed to fit into tin plate boxes. These are nor easy to find in the UK but Alan Melia stock quite a range of these boxes.
Internet Treasure Trove article links from VHF Communications 1/2010
If you do no know; Philips has a new name for its semiconductor activities. Go to this site if you are looking for data sheets, SPICE models, S parameter files or Application Notes for components from this manufacturer.
Sometime homepages are boring but this homepage is full of tutorials ready to download. There is plenty worthwhile browsing here.
A tip: Begins with the “RF Technology and Design” section.
Tutorial on the double balanced mixer
A pdf file hides behind this inconspicuous title that describes this important component in detail and describes all possible applications. It is well worthwhile reading this article.
Practical RF circuit design for modern wireless of system
It is unbelievable, but true: this is a 588 side technical book on the Internet - free of charge. It can be read either online or download as a pdf file. That is a mad service.
Who would have thought that a PC magazine would offers a whole collection of useful free programs that can be downloaded entitled “Electrical engineering programs”.
Even the DOS antenna design program “pcaad.zip” is available from this site.
Orban - The Basics of Patch Antennas (Updated)
The original article was first class. It has been updated as a result of much feedback and many letters. So it can confidently be called obligatory reading for all who want to use patch antennas.
Hoverman HDTV UHF antenna
What age does this belong to? In any case curious electronics engineers will want to read this article. Above all there is plenty of history provided. For the ruthless the NEC2 simulation files are also included.
An alternative address: http://www.digitalhome.ca/ota/superantenna/index.htm
The WB0DGF Antenna Site
Since we are already looking at antennas, here are some more. Spend some time to browse through all of the information on offer.
The keyword “NEC” is well known for simulation of wire antennas. More precisely: NEC2, because the much improved current version NEC4, cost too much at the moment.
For some years 4nec2 has been at the forefront of design software. Not only because of its beautiful coloured 3D result diagrams and structures, but because it offers almost unbelievable possibilities during design and the optimisation - and it is free! (a friendly amateur made the comparison of the bicycle to the Porsche for the software changes).
UERJ - Professor Gil Pinheiro
Something from South America (UERJ – Univerity of Rio de Janeiro). A list of some older programs that are still useful today. Even without Portuguese knowledge they have a simply clean-look!
This site has lots of good information and it costs nothing. Plenty to interest everyone.
K1TTT Technical Reference
Again something to investigate and if necessary download.
Internet Treasure Trove article links from VHF Communications 2/2010
Ken’s web site
Ken is an accomplished professor from Alamba (a great acknowledgement from Gunthard who is a accomplished professor from Tettnang). This homepage has a wide variety of subjects it is well worth a read
A very high dynamic range LNA for 144MHz
Something for constructors and developers of low-noise preamplifiers. A very well written, detailed and informative magazine article in the pdf format; worth a close look.
It is difficult to imagine how the author has gathered so many articles for this web site. There is a surprise when opening this site: innumerable Java animations (applets) on the most diverse topics from electronics and physics and more to be examined and tried out e.g. the antenna simulation with facilities for varying the parameters. In addition the link list is first class.
From time to time you may need some entertainment (not only by the cinema) or have a view of another world. Therefore you should take a look at this site.
It is about Tesla currents and makes everything look very wild with metre electric arks hissing and sizzling in the air. It is not really relevant to electronic engineers but it is quite interesting.
Spread Spectrum Scene / S Parameter tutorial
This is a favourite site to be visited from time to time. It is regularly extended and reorganised. The author found the following special article while searching for some S Parameter files for a new development. The tutorials are very useful.
Again and again it is interesting to read are such introductions, particularly if they are easy to read and understand. In addition this is a visible pdf file - an interesting read.
Small Spacecraft Antenna Selection Tutorial
Particularly interesting for lovers of horns; not those used for music make, but those that can radiate and receive microwave signals. This is a good overview with an accurate technical background. This is a fascinating subject.
Address: http://www.antdevco.com/ADC-0807201305 - R0 Small Spacecraft Antenna Selection Tutorial.pdf
How radio Telescopes work
This title does is not completely fair because the contents clearly go beyond that. There is extra information under “Learn more” that is really interesting.
Scanned old books
Many interesting old books have been scanned; among other things the books of Sturley (about receiver engineering) are recommended for the fans of valve technology. According to the site there are about 1043Mb available.
Internet Treasure Trove article links from VHF Communications 3/2010
SWR Bridge and Power Meter
This is a very nice example of a home construction project. It is a good development project that is well documented. Looking closer you will find some interesting things.
Designing Antenna systems for Maximum Sensitivity
Everyone wants to try a new antenna system design. It is difficult to define the scope of a design in terms of the main lobe and side lobes. This article is well structured and very useful fopr such a project.
Communications Design for communications design engineers
This is something for the dedicated reader. This side looks harmless at first site but the deeper you look the more interesting it becomes.
This site has something for every radio amateur but you have to spend the time to look around and find the things that interest you.
Ian Purdie’s Amateur Eadio Tutorial Pages
The title says everything, there is a wealth of information on this site. As an example there are tutorials on Double Balanced Mixers and Baluns.
Tutorial on Basic Link Budget Analysis
This tutorial is for anyone who has something to do with digital communications (today nearly everything in communications is digital) or base stations. This is a good look at such applications; it is meticulous and accurate but also understandable. The chapter on Communications Basics has some good calculated examples.
Noise and Noise Figure Measurement
This is a very descriptive Website with extensive material. It is honestly more detailed and more accurately described than most people need.
Intersil have been a well-known company in the semiconductor industry for a long time (the author has memories of the first products more than 30 years ago. They were the first with an integrated sine/rectangle/triangle generator IC). They have moved on an this site shows their best products with application notes. The Design Assistance gives much more.
Spread Spectrum Scene
This homepage and Internet group should be visited regularly because there is always something new in the documents or tutorials. The page selected is “RF Topics” because everything is fascinating and dealt with from basics. There is plenty more to find if you look further.
There is everything you need to know about noise here. Not only the basics but some good practical application notes and tips.
Address: http://noisecom.com/en/Literature Library.aspx?brand=Noisecom&go=application_notes
Internet Treasure Trove article links from VHF Communications 4/2010
The Basics of Patch Antennas - updated
This Application note from the Orban Company was originally published 2005. Due to many letters and notes it has been fundamentally revised and extended with great success. Thus it is obligatory reading for everyone who would like to train into this topic.
The homepage the Orban Company has further interesting downloads to offer. For example there is “The Basics of Antenna arrays” or “Introduction to GPS Low Noise Amplifiers”.
Mathematical models for the simulation of wave propagation
This team work on the free University of Berlin forum and have produce a beautiful summary of the basics that are necessary for simulation and understanding of wave propagation. It is very clear and should be read.
Address: http://cst.mi.fu-berlin.de/teaching/SS06/19554-S-TI/Florian Deinert - Mathematische Modelle zur Wellenausbreitung fuer die Simulation drahtloser Netze.pdf
Alan `s Laboratory
Behind this inconspicuous title lays a tremendous number of documents and calculators for wireless technology and amateur radio. From antennas to receivers and up to transmitters: clearly sorted into categories and in each category there is an average of 30 articles. Where do some people find the time? For the techno freak this is a treasure chest.
This is a small collection of on-line calculators. Particularly aimed at antennas.
This tool box contains a very extensive and continuously updated collection at Application Notes, patent information, standards, data bases etc. Very interesting for RF engineers.
This is a collection of tutorials and tools for RF and microwave engineering. Highly interesting needing quite a while to examine everything.
NXP’s RF manual
The text on the homepage reads:
“NXP`s RF manual - one of the most important reference tools on the market for today’s RF of designers”.
The data book has so many block diagrams and explanations that make reading informative and always worthwhile.
OML Millimeter Wave test equipment
This homepage offers a wide spectrum of products plus many other documents. As an example there is “Harmonic mixer Application Notes”. Please try the search.
Internet Treasure Trove article links from VHF Communications 1/2011
NEC2 is well known as simulation software for wire antennas. However it was written in FORTRAN and that is no longer in generally use. Therefore it has been “ported” too the “C” programming language (happily used by many programmers). This has also made further complex program enhancements available such as coloured graphics for results.
W1GHZ online Microwave Antenna Book
This is really a fine book: a comprehensive representation of this topic that is well written and easily understandably with the latest developments. It is a very good book for its time, the complete work of 12 chapters can be downloaded and it works
Inside a typical SPICE file
For those who use SPICE for simulations and are interested in developing model files. For the curious it shows the suitable changes needed to adapt an existing Spice model to suit an older component.
W1GHZ 10GHz site
There are many things to discover. Among other things it is possible to download interesting practical projects and articles from QEX magazine as well as all DUBUS magazine for the period 1982 to 1992.
The WB0DGF Antenna Site
Again something about antennas. On this site all articles on this topic are listed. They are all worthwhile to read just look at the list for something of interest.
Return loss bridge
Those who have thought of building such a measuring bridge should visit this site. There are many fundamentals explained and also practical information.
This is very good: You will find a company that not only supplies the latest products but also worries about the emergency requirement of developers and radio amateurs.
There is a full online catalogue of all products. This includes a genuine electronics flea market in plain language and clear pictures, with “Surplus Offers” of microwave components or complete microwave modules. There is also PCB material and all at reasonable prices plus delivery anywhere. You must visit this site.
For those who carry out antenna measurements and are not only interested in radiation patterns. There is also impedance performance of the antenna and some beautiful Application Notes.
SHF Communication Technologies
That is a company that fights at the forefront of communications: very high frequencies and very high data rates. The Application Notes are also interesting that describe the state of the art. These useful for further training.
A well-known name as a supplier of high-quality RF and microwave components. The expansion of this site is particularly interesting; the “Technical Resources” have more pages for the reader. The Technical Literature and Application Notes have block diagrams and up to the minute technical articles. A fine site and very interesting.
Internet Treasure Trove article links from VHF Communications 2/2011
Ansoft designer SV
This software does not need much introduction. It the Student Version (SV) and therefore free of charge. It is the first choice for specialists and radio amateurs for RF simulation and microwave circuits. Above all it is because it is a complete linear simulator with hundreds of components and examples available.
It is difficult to understand but because of a change of Ansoft management policy this software suddenly disappeared from their homepage and from the entire Internet. Fortunately the author has received permission to use it in the context of his German and English Tutorial and offer the download to the order.
Introduction to IQ-demodulation of RF data
Modern communications use different types of modulation, among other things QAM (Quadrature Amplitude Modulation). A good manual is useful for those who would like to train themselves or gain some experience.
Here is one that is not only accurate but also written to be easily understood. It is actually part of a manual for a piece of equipment.
This is a company who develop and manufactures a most diverse range of ICs. Most people are looking for something new to investigate. Look no further for here they have complete receivers with all accessories on a chip, everything for AM, FM, short wave, long wave or weather band – it works with them all.
Hoverman HDTV UHF antenna
You never stop learning in the field of communications and this is no exception. If you have never heard of this antenna before it is worth investigating its properties.
Orban Microwave/The basics of patch antennas (updated)
There was a basic article about patch antennas that can also be found in many publications from other authors on this topic and it has bee in their bibliography for a long time. This lead to many letters making suggestions for extensions and corrections. Orban have now revised this application note and published it again. The result is first class.
Their homepage also contains other interesting literature on offer from the company on….
Circularly Polarised Microstrip Antenna for Cordless Phones
This is a very beautiful patch antenna, but this time in the form of a presentation. It is worthwhile to take a look
This is actually an old DOS program for computation, design and analysis of all possible forms of antenna up to horn radiators. It still works easily and efficiently and therefore it is still interesting but difficult to find. I was very surprised to find it hidden in the crowded download list of products in a computer magazine.
The greatest surprise was the individual topics in this download list that stretch as far as astronomy…
This homepage always has some new topics. It is a genuine “Pandora’s Box” that can consume lots of time. The small sample here shows to the topic of “Receivers“:
A regular view of this homepage seems to be an obligation because this company obviously takes its company name seriously. The Application Notes and the Technical Articles about communications are very interesting:
An Application Note on different kinds of power dividers (up to the two-stage Wilkinson divider) from this company is very interesting.
In addition there are many good things if you look thoroughly enough. An example is a Power Conversion Table and Reflection Loss Chart that is already makes its way round the RF enthusiasts.
There is a free circuit diagram and printed circuit board layout program called DESIGN PARK available after registration. The operation is very similar to the well-known EASY PC, however iot is not compatible.
Internet Treasure Trove article links from VHF Communications 3/2011
Without the circuit simulation of SPICE today's level of development in electronics would be not conceivable. It is therefore worthwhile to be familiar with it. When developing your own work there are moments when you need assistance to progress. Or you have devised something that you would like to make available to other people. There is a nice community, naturally free of charge where that is possible:
The homepage is already interesting and offers many things. However for the author the site was a pot of gold. I suddenly found an undreamt of quantity of the measuring instrument manuals that I had looked for for a long time. However the lists contain everything and the sublists must be searched like a forest. For example I had never seen the manual for a Nelson Ross spectrum analyser module used in old Tektronix oscilloscopes. I have had one in the cellar for decades. Really worth having a look.
Microwave power meter of information
Who always wanted to know how the HP power meter works or has searched for documents or information on the measuring heads. That can be found here.
Hewlett Packard archives
All companies should have access to their documents of older devices, it is good advertising and useful for customer relations. Here is a beautiful example.
136kHz Technical Pages
Something completely different to read but no less interesting. The possibilities, technology and problems of reception at such low frequencies. A nice and informative collection with short explanations.
RF Toolbox 3.8.0
A useful collection of programs for antenna design that has been extended again.
This is an historic homepage with information on Tektronix and HP measuring instruments with their data listed including a photo in a gallery.
The first impression is of a very simply and under developed homepage. Only if you scroll through the page do you realise that there are a number of more interesting topics.
AC6V´s amateur radio & DX Reference Guide
This one can keep you occupied for hours.
Internet Treasure Trove article links from VHF Communications 4/2011
Two readers of VHF Communications (José Geraldo Chiquito and Ted Bottomley) have contacted me and asked me to add this synthesiser to this list. The Windfreak Synthesizer is a low cost 137MHz to 4.4GHz software tuneable, PLL synthesized RF signal generator, controlled and powered by a PC running Windows XP or Windows 7 via its USB port. It costs €249.
Continental Compliance Ltd
This one is for the weak signal enthusiasts with noise sources and noise measurement products. Plus there is an impressive list of links for all those standards that you are wondering about.
A familiar name that we know from the free Spice software LTspice. But the product range is unbelievably extensively e.g. active mixers in the GHz range with high IP3. It is worthwhile looking at the documents that are available under “Technical Documentation”.
It is good that this magazine is available and it is on-line. For many years it has been the place that presents new components and good articles. In addition the on-line archives mean that you no longer need a mountain of paper.
A company that makes equipment at the forefront of technology and supplies test equipments for electrical and optical data communication up to 100GBit/s. It is worth looking at the application notes offered.
If there were a question mark behind the homepage name then the contents of this homepage would be clear. It is an enormous collection of practical circuit examples for almost all areas of electronics. Very interesting and sometimes somewhat amusing.
Internet Treasure Trove article links from VHF Communications 1/2012
MicroWaves & RF
The author found this site while carrying out some research on Patch and Vivaldi antennas. There is a lot of information on this site.
This is tha place for antenna theory. There is more than enough information on this site.
They are antennas specialists. The page indicated contains a useful nomogram showing the relationship between antenna height at the transmitter and receiver with the optical and radio horizons.
Lots of amateur radio downloads on this site. The page indicated has a voice shaper to process your audio signal before feeding your transmitter.
A familiar name for digital signal processing. This page shows an introduction to a most useful book; the Software Defined Radio Handbook, available free of charge once you have registered.
Address: http://www.pentek.com/applications/Applications.cfm#Software Radio
Key Telemetering Products
There is a very interesting article on Spread Spectrum Technology in the Tutorial section of this web site.
Morse code Trainer
CW still has a place even in this age of the Internet. This site could be the stimulus you need to lear Morse code. It has some good animated trainers.
The title of this web site is not an exaggeration because it is almost unbelievable what has been collected here.
Ultra Low Noise MMIC Amplifier
If you are looking for an MMIC with a noise figure of 0.8dB, a gain of 20dB, an IP3 of +36dBm, a maximum power output of +20dBm and usable from 50MHz to 6GHz should check this out.
High intercept low noise more amplifier with GaAs pHEMT MMIC
It is always interesting to see how other people solve a problem. This complete document shows all the details and is worth a detailed look.
Internet Treasure Trove article links from VHF Communications 2/2012
Many people have already heard of or use this archives, if you are looking for manuals on older measuring instruments and equipment. The address is shown again because the author has forgotten it several times already and then had to laboriously search with others enquiries. There are new manuals all the time so it is worthwhile looking occasionally. By the way: if you can contribute a manual from your archives you will be most welcome.
For those interested in the modern technology of “Software Defined Radio” this homepage should be exactly whet you need. Italian amateurs developed and make an interesting, low-priced kit with extensive documents as well as some accessories. The pdf manual is worth studying - did always want to know how a “QSD mixer” works? Its exact function is described e.g. including the remaining hardware in the manual.
Here is another modern piece of technology for playing and experimenting, e.g. a kit for a DDS-VCO including extensive documents. The heading of the homepage reads: „A 1-60MHz coverage VFO with built in amplifier and variable outputs level from 0 to 4V p-p. Would that be something for you?
This name is very familiar because this concerns one of the best EM-simulators for planar structures (e.g. Patch antennas, Microstrip couplers, filter etc.). They always had a heart for people with little money (pupils, students and private developers) and produce a free “Lite” version for a time that is available “free” on the Internet. Here is the most pleasing message: in the Lite version so far (after registration) there has been a 16 megabyte limit on the main memories now that has been increased to 32 megabyte making it possible to perform substantially more exact simulations. In addition there are again some improvements and advancements, which are also available in the Lite version.
A large name and a large manufacturer - and the following Application Notes shows that they are always very active with innovations in all areas. The title reads: “Smart Selection of ADC/DAC Enables Better Design of Software Defined Radio”. It also gives a very informative introduction to the topic “SDR”.
Baudline is a time-frequency browser designed for scientific visualisation of the spectral domain. Signal analysis is performed by Fourier, correlation, and raster transforms that create colourful spectrograms with vibrant detail. If that is what you are looking for then here it is.
Guided Wave Technology
For people who deal with high frequencies at high powers and therefore are dependent on waveguides, here is a set of useful on-line calculators.
Tonne of software
The heading of this homepage is very
descriptive: “A site for the technically inclined,
offering to the fraternity a collection of
original engineering software. Browse, choose, and download. These possibilities for downloading interesting programs should not be missed.
Sites for radio amateur
Something from France: a listing of interesting topics for radio amateurs. Studying the list is worthwhile in itself!
Internet Treasure Trove article links from VHF Communications 3/2012
A CMOS sub-harmonic mixer for WCDMA
Anyone who wants to learn more about the tub harmonic mixer should take a look at this pdf article from Berkeley University. It describes a circuit that converts a 2GHz RF signal directly to baseband using a 1GHz local oscillator.
The home page provides a detailed look at the transmission and communications via satellite by this company. The extensive "Satellite Communication Tutorials" are particularly interesting
Q-par Angus Ltd
A company that deals specifically with antennas and providing an incredible wealth of information for their customers. On the listed website has an historical perspective of wideband antennas.
SETI means "search for extraterrestrial intelligence” and the organization has opened a new chapter. They are looking worldwide for interested people to help with their PCs to search the vast amounts of data available. Data comes from the radio telescopes distributed over all the World.
Harmonic converters for Spectrum Analysers
An interesting article from this familiar author, Matjaz Vidmar. It is always a pleasure to read his articles and to see his ideas.
Image rejection receiver and techniques
There are several interesting publications for training on the Internet. These are recommended:
Address 1: http://EE.Sharif.edu/~comcir/readings/mixers/image reject.pdf
Address 2: http://www.eecg.utoronto.ca/~kphang/papers/2002/jchow_imagereject.pdf
Q factor measurement
Something for the RF Circuit developer because it is important to have good quality coils in resonant circiuits. These links are interesting.
The following sources are also good:
Address 1: http://www.sensorsportal.com/HTML/DIGEST/june_09/P_438.pdf
Address 2: http://www.ee.olemiss.edu/Darko/rfqmeas2b.pdf
LC filter calculator
As Windows 7 is becoming more and more common suddenly the beloved DOS programs no longer work. It is useful to switch to a modern "online filter Calculator". This is a short list of tested links:
Address 1: http://www-users.cs.York.AC.UK/~fisher/lcfilter/
Address 2: http://www.calculatoredge.com/electronics/ch pi low pass.htm
Address 3: http://www.calculatoredge.com/electronics/ch pi high pass.htm
Address 4: http://www.wa4dsy.NET/filter/hp_lp_filter.html
Address 5: http://www.odav-online.com/calculator-electrical-Butterworth-Pi-LC-Low-Pass-Filter-online-engineering-solutions.htmlAddress 6: http://www.circuitsage.com/filter_design
Internet Treasure Trove article links from VHF Communications 4/2012
Mixer Basics Primer - A Tutorial for RF and Microwave Mixers
A very nice introduction to this topic, the rest of the home page and the other documents from this company are very interesting e.g. mixer up to 65 GHz. Another application note that is equally important is: T3 mixer primer - A tutorial on high linearity, high IP3 RF & microwave mixers
Wireless solutions - design resources
A great service from the distributor Farnell. There is a huge collection of application notes on electronics and communication technology indexed by company.
Antenna circuit design for RFID applications
This application note is from Microchip, a company that is well known for their micro-controllers. They are expanding their product range and therefore such application notes can be found from them. There are more interesting things as well.
Links to the best amateur radio pages
The title speaks for itself. The list is in German but it is fairly self expalanatory and includes many useful links.
Directional BiQuad antenna
This web page is interesting not only because of the many pictures showing how to make these antennas, also because of the many links on this topic and the interesting details about the properties of a "Dual BiQuad".
Who wants to learn about the latest in aerial technology or refresh old knowledge. Here you will encounter a typical modern Internet tutorial with a huge range to inform.
An integrated 50GHz SiGe sub harmonic mixer/downconverter
It is always interesting to look at the "forefront of technology" and to see what is feasible now.
This brief article provides the necessary background information with the circuit details and measurements.
Service Manual download
If you have older instruments in the shack it is always worth looking for the appropriate manuals. In addition to the famous standard place (BAMA) you should sometimesconsult page like this one.
You often have to search for a long time to find the SPICE models for specific components required for simulation circuits.
So here are a small set of addresses that you can browse one by one.
Harmonic converter for Spectrum Analyser
Something by Matjaz Vidmar. His publications are legendary, this article is impressive with the skilful composition of theory, schematics and photographs of individual assemblies.
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