Nice to see more network analysis stuff. This is a nice peace of kit and seeing you get usable results without ( i think) working through the manual and many, many hours practice, the software must be user friendly.
VNA's are great for impedance around 50 ohm. For very high or very low impedance you use IV measurements (impedance meters/analysers use that) and for some VNA's (like the SDR-kits VNWA) there are adapters to do that. The software needs to support that (like the VNWA does) if you do not want to do the math. I did that once just for fun with a 1968 build HP VNA (the ESR of a 1nF cap) See the attached photo. But there are also tricks like measuring a 100 K resistor parallel to a 50 ohm or a 0,001 ohm in series with a 50 ohm. The 50 ohm can be your cal load or just measure it, a 50 ohm resistor can be measured extremely well with a
good calibrated VNA. In both cases I use the custom trace function so I do not need top do the math.
I would expect the Monicron supports IV measurements in the bodeplot function and "normal" wave parameters for the VNA part ?
Dave, the results of a vna are at the best as good as the calibration.
This is often a rather time consuming thing and needs a very good calkit (a male and a female based kit and then the things you used fort that fixtures) and very advanced software implementation to do n-term error corrections. That is why VNA's have very extensive calibration functions and things like de-embeding and port extension functions. Even a hobby VNA as the SDR-kits VNWA can do that. I missed that in your review.
Are the fixtures and their cal-kit parts already characterized in the software ? I would expect a cal certificate with the numbers
The resistor value does not have to be a precision one, as long as you know the resistance and are able to tell that to the VNA. Things like open and short are more important (OK, for 0-50 MHz probably everything will do
) I use my SDR-Kits VNWA often in the span 1 KHz tot 10 MHz and calibration there is not really a big thing. Above 500 MHz it becomes the most important part of the measurement.
I like the fact it can make bode plots and do s-parameters, that combination is very nice.
The DUT fixtures look cheap if you compare them with the keysight ones. But I do not know the prices from those, probably much higher.
http://literature.cdn.keysight.com/litweb/pdf/5968-5329E.pdf this pdf tell a lot about the things to know when using fixtures.
When I started playing around with VNA's there was almost no information for non RF graduated EE's That is why I made a series of tutorials. They are not flawless but I tried to make it easy to understand and for most practical. I used the SDR-kits VNWA for it, back then more or less the only choice.
For those who are new in this field, check them out, they are free pdf's.
http://www.pa4tim.nl/?p=1594 All in English and some are translated in French and German by other VNWA users.
Keysight has a free PDF, the impedance measurement handbook.
https://literature.cdn.keysight.com/litweb/pdf/5950-3000.pdf very interesting and "easy" to understand