We ran into an issue where the only available cal kit for the particular adapter we have to use does not cover the full frequency range we need to measure over. One suggestion I got the other day was to cal the VNA/cables with our Ecal, connect a M/F adapter pair together, measure the combo and halve the S2P data. I feel like this would have quite a bit of error due to making a lot of assumptions on the performance of the two in combination.
Question: Is this even a viable option and am I going about it the right way? Would a better alternative be automatic fixture removal? Is there an error model for either of these methods?