AnsweredAssumed Answered

SOLT cal short or open fringe parameters

Question asked by Lucux on Jun 1, 2011
Latest reply on Aug 3, 2011 by Lucux

We’re trying to develop a set of SOLT cal kit. When defining fringe capacitance for the open standard. We used Ansoft HFSS to simulate the open to get capacitance vs frequency reading from the imaginary part of Z(1,1).

We noticed that as the open gets longer, the imaginary part of Z gets to inductive. This also can be showed by Smith Chart where the curve starts at the right most point and turns close wise and reaches inductive area, the upper half of the circle.

In Agilent PNA, the open’s fringe capacitance has to be represented by a polynomial equation vs frequency with coefficients of c0 to c3.

If it gets to the inductive area, I am not sure how to do that properly. Is there any solution there?

Thank you!