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Match standard in SOLT and LRM calibration method

Question asked by linan0827 on Aug 12, 2013
Hi Agilent friends,

We met another problem, again...

About the *Match* standard in LRM and *Term* standard in SOLT.

We have a cal kit have a match/term standard, which has a series L0 term for its non-ideal characteristic. In SOLT, we normally use L0/Z0 to transform this inductance term to the offset delay of a transmission line, with Z0 = 500Ohm.

Now we would like to do a TRL/LRM calibration, but now how could we deal with the non-ideal characteristic of the Match standard? If we set the Match standard to have an offset Z0 = 500Ohm and an offset delay to L0/Z0, the calibrated results seem to use Z0 as the system impedance, causing some error results. So in the application of the Agilent's VNA, in SOLT calibration the offset Z0 is treated correctly as the characteristic impedance of the transmission line, but in LRM this Z0 is treated as the characteristic impedance of the Match standard itself?

In the Agilent's documents, Match in LRM calibration method seems to be described as a perfect match. So I am guessing we should set offset Z0 to be 50Ohm. Then it will be irrelevant what's the value we set for the offset delay term. Then the L0 term of the Match standard will be ignored. My question is it will be useless if we know the Match standard more clear in LRM calibration?

Thanks for the replies!  

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