I have a 2 stage downconverter which I am attempting to measure group delay on. I am using an N5245A PNA-X and have gone through the SMC+Phase calibration with the U9391F Comb Generator many times. What I cannot figure out is how to correct for the discontinuities that appear in the group delay measurement.
I got a copy of your book through our library and have read through section 7.5 (Mixer calibration). You identified the same problems I have in Figure 7.39 and 7.40, but did not mention how you arrived at the "corrected data" of figure 7.43.
Would you please share some insight into how I may correct for this?
I attached a plot of the forward conversion gain and group delay response.