Scattering parameters of test fixtures from TRL calibration

[thefly0]

Hi all,
my first time on this forum.
I'm trying to find the scattering parameters of two test fixtures using TRL, but I cannot get the complete scattering matrix. My test fixtures are essentially coaxial to waveguide transitions.
Following exactly TRL procedure I don't get the correct value of S12 and S21 of each test fixture, but only the correct value for S12*S21. I need the correct scattering matrix of one test fixture to de-embed it from another measurement made with it. Is there another method to obtain the complete scattering of both test fixtures?
Can you suggest some reference or hint to do this.
thanks for any help

 

[jayce3390]

Re: Scattering parameters of test fixtures from TRL calibrat

Hi,

If your Test Fixture is symmetrical you can perform a thru measurement ent get the file. Then consider that is a symmetrical TF end cut the file.

Another way consists in performing thru measurement and in open conditions. You have one information more.
ΓM1 = SA21*SA12*ΓOpen
ΓM2 = SB12*SB21*ΓOpen