On Mon, Apr 28, 2025 at 08:22 AM, RANDY JOST wrote:
Really looking forward to your updated program to show students in my EM
courses how it should be done.
Randy, if the program proves helpful for your students, that would be just great.
I didn't set out to write an s-parameter plotter. I wrote a little utility to renormalize the s-parameter reference impedance. This lets you use a VNA to measure a filter whose termination impedances differ from 50 ohms without building a matching network. When it came time to test the program, I looked around for an s-parameter plotter. The only ones I could find either did not handle all s-parameters, had bugs, or were very awkward to use. So I wrote my own. While I was at it, I built renormalization into it.
If you need an s-parameter plotter oriented toward amplifiers for your students, try AppCAD:
It hasn't been updated since 2012, but it has many features for amplifiers I found nowhere else. I think this is the program that took me 45 minute to see a plot! This also may be the one with points slightly off in a group delay plot. Nevertheless, I think students might find it helpful.
Brian
