This webpages contains descriptions and links for documents which I have created in connection with use of the wonderfull Vector Network Analyzer VNWA2, VNWA3 and VNWA3E designed by DG8SAQ Tom Baier and to purchase from Jan Verduyn at SDR-KIT www.sdr-kits.neton the webshop Find a Yahoo Forum solely for VNWA "lover's" at: http://groups.yahoo.com/group/VNWA/
At HAMRADIO 2012 in Friedrichhafen DG8SAQ Tom Baier was presenting the VNWA on Saturday June 23 at 14:00 and I had the pleasure to record the presentation.
I produced a German and a English version and published on YouTube. You can also download from my VNWA support page http://www.hamcom.dk/VNWA where you are presently. The German Powerpoint presentation created by DG8SAQ is translated to English and Danish also available as pdf files: Furthermore a written Transcript in English of the original presentation is also available as pdf file, for a detailed study of the presentation. This Transcript used for creating the English soundtrack, and may be translated to other languages. Fell free to do so and let me host it here.
1. Rosenberger Cal standards rev2.pdf This document explains how to set up the various parameters in the VNWA Software, for a quality calibration, using the Rosenberger Female Short, Open Load (SOL) calibration standards in addition to a Female-Female adaptor used for the Through (T) calibration. The entire calibrationis then called SOLT. As there exist very accurate data for this Rosenberger calibration kits, it has become "the Master kit" for the "VNWA environment" when price is a concern. The Rosenberger SOLT kit can be purchased by a German resident directly from Customer Service at Rosenberger Hochfrequenztechnik GmbH & Co. KG, but "outsiders" can only purchase via national distributors, and they require volume orders (e.g. 10 pc. of each item) and at quite "elevated" prices. So find a German friend !!!
2. Amphenol Connex Cal standards rev3.pdf However the Amphenol Connex (SOLT) Calibration kit exist, in both Male and Female versions, and can be purchased by SDR-Kits at fair prices. In the document you will find all the relevant data for setting up the VNWA software, for a quality calibration, and this SOLT kit is quite identical to the Rosenberger kit up to 500MHz, and by all means very little different up to 1.3GHz, the limit of the VNWA, provided the data described is used.
3. What new for the Rosenberger Cal standards rev2 and Amphenol Connex Cal standards rev3 ? In the process of calibration, using the detailed data in above two documents, the calibration setting for VNWA software ensures a quality calibration for meaurements of S11 and S22 data, on the testobjects called DUT (Device Under Test), (in popular terms measurements of impedance) you do a SOL calibration using the Short Open and Load standard. However for measurement of e.g low pass filter you also have to do a T (Through) calibration, where the VNWA TX port (used during SOL calibration) is connected with the VNWA RX port. Normally two short test cables is fitted to the TX and RX port, both having e.g. a male connected at the DUT ends. During the S21/S12 (Through) calibration, a Female Female adaptor is used, to provide the sigal path from TX port to RX port. After calibration this Female Female adaptor is no longer in use, during actual measurements, and the delay introduced by the Female Female adaptor during S21 calibration, has to be compensated for, to ensure S11/S22 and S21/S12 mesurement are in correct phase relationship. From VNWA software version 36.2.xm this compensation is done by entering the Thru adaptor delay in the Calibration settings.
4. Instruction for use of SMA Load Testbox.pdf One important observation to make, is that any calibration Load has to have it resistance measured, as it varies from item to item from 50 ohm up to 1.5 ohm. I have designed a simple instrument to measure the Load Resistance of a Rosenberger or Amphenol Connex Load with 0.1% accuracy. For those interested contact me for schematic and PCB layout.
5. How to measure on SOL calibration kits_REV1.pdf Further to above 4 documents the How to measure on SOL calibrations kits_REV1.pdf is worth to study, at least to pick up the stock numbers for the Rosenberger Female SOLT Calibration kit, and study the source data. where I have explained in details. how the data in Rosenberger Cal standards rev1.pdf has been derived. Further the document includes a large amount of measurements performed on N connector homemade Short, Open and Load calibration kits. But do not use this information for nothing but "technical entertainment", as I shortly will describe a "superb" homemade N calibration Kit much more simple to make and more reproduceable by anyone.
6. T-Check testing Rohde & Schwarz has developed a mathematical method, to check the quality of a VNWA SOLT (Short Open Load Through) calibration. For the VNWA software it is a simple matteer of inserting a published text string in a Custom trace (a VNWA facility) and run a set of forward and reverse measurement, where the Thru Female-Female adaptor is exchanged with a Female-Male-Female adaptor, where on the Male part is fitted the Female Load used for Load calibration. To get the background explained and obtain the Rohde & Schwarz T-Check software, which I have got permission to publish freely. Thus a pdf file and a zip file is available.
Visit this page from time to time as it will be updated with many more of the document I have written in the past and will write in the future. You may also contact me for further question at email@example.com The VNWA software can be installed and used without being the owner of the VNWA. Thus you can get a good understanding of the product and as integral part of the VNWA software you will find perfect Helpfile. The link for the software is: http://sdr-kits.net/DG8SAQ/VNWA-installer.exe