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Custom calibration board on HP8753ES

Question asked by wiwyam on Nov 9, 2018
Latest reply on Nov 12, 2018 by Dr_joel

Hi,

We built a custom calibration kit to calibrate out our RF switch and cable. Below is a picture of it and the VNA response to "open" post calibration.

My problem is that there seems to be a large error in my measurements. For example I am measuring the impedance of a dev-kit which is supposed to be 50ohms, but my VNA shows 20 + 10j; really far off.

I think the issue is my "calkit" settings, for this custom calibration board I must define the calkit. I don't need this to be extremely accurate, in fact all I want is for the VNA to NOT correct for any calkit parasitics. I'm sure the calkit parasitics are way less than the parasitics I'm trying to match out - my matching network will be an order of magnitude larger than any calkit parasitics.

I'm struggling to get my "open" impedance to have no imaginary component when connected to the VNA, can you offer any advice?

Looking at my calibration board, can you offer rough offset delay,loss and impedance values?

Thanks a lot, Will

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