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1 path 2 port cal vs. Enhanced Response cal

Question asked by rmc256 on Jul 13, 2007
Latest reply on Jul 24, 2007 by Dr_joel
I read a response by David Blackham describing some of the benefits of Enhanced Response cal over a 1 path 2 port cal here:

(search for Enhanced Response, all terms, its titled Calibration mode One-path 2-Port Cal. This is my first post so I can't post URL's yet )

I was wondering if someone could go into a little more detail on the corrections and compensations Enhanced Response cal does (specifically I'm using an E5061A VNA) over what a 1 path 2 port cal does?

I ask because I have a VNA from a different company that performs an OSLIT 1 path 2 port cal, and the S21 of my DUT is completely different from what it should be when using a long test port extension cable on the response or load port. In addition, varying the length of that cable gives different S21 signals of my DUT. My Agilent VNA with Enhanced Response cal gives the expected S21 signal using the same cables. I'm trying to figure out the reasons why, and maybe a workaround for the other VNA if one exists. I was told having a 10dB in-line attenuator on the response port (during cal and measurements) would reduce the load port mismatch error, which isn't compensated for in the 1 path 2 port cal. But according to the E5061A, the load port mismatch error isn't compensated for either when using Enhanced Response cal. Does the Agilent VNA compensate for it anyways?