Version 0.4 Results

Here are some test plots from the v0.4 VNA of 2018. The first is a plot of S_11 for a Z0 load from 1 to 30MHz. As expected from the calibration, it is exactly correct. The open and short standards produced the same kind of expected perfect results. The next is of a 20 Ohm resistor over the same frequency range This was just a quarter watt resistor held in the end of the BNC connector and of course shows a little inductance. The next one is a 100 Ohm resistor with a bit shorter leads. All of the S_{11} plots were after SOL calibration, using the also homemade reflection bridge.

The next plots are testing the isolation. There is no connection between the TX and RX ports in these plots, and they don't use any kind of calibration, so as to show the isolation. Magnitude and phase plots of S_12 showing the rather poor of between 50 and 60 dB up to 100 MHz. Even below, it would be nice to see more isolation. The phase response is rather linear, which might indicate that there is some constant delay getting from the TX port to the RX port, which might mean there is one principle place the signal is getting through.