On Fri, Nov 12, 2021 at 05:16 PM, Dr. David Kirkby, Kirkby Microwave Ltd wrote:
There is a circuit, which I think was published in QEX, that drops the frequency of a VNA by mixing the input with the 10 MHz reference output. So 0-300 kHz would be seen at 10 to 10.3 MHz.
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The software supports using external mixers for both up and down conversion.? There no free ride of course.?? My interest in the lower frequency (20kHz and up) is for PDN measurements.? I would like to have a continuous sweep with a fairly wide dynamic range (PDNs can have a fairly low impedance).?? What I have been doing to get around it is using a second vintage analyzer and stitching the Touchstone files together.?? For example:
"Some time ago I had come across an paper written by Jeroen Belleman where he was studying the parasitic shunt capacitance of some 1206 resistors. "
https://www.eevblog.com/forum/rf-microwave/shunt-capacitance-of-1206-smd-resistors-jeroen-belleman-december-2010/msg3606722/#msg3606722
It's not ideal but I knew that before I bought the PNA.? Copper Mountain Tech offers a product that would have been perfect for my hobby use, except for the price tag. ?
I made a video where I attempt to demonstrate making a few PDN measurements with a $50 VNA.? The software is is very similar to what I use with the PNA (basically running it headless).
