Hi, as I am quite new to SOLT calibration, I would like to know more in detail as to how to obtain C0 through C3 and L0 through L3 coefficients when specifying in-fixture's Open and Short standards respectively. I have with me an Agilent's Application Note 8510-5B which describes the methods. Kindly pardon my understanding in Page 10 of the document, it seems that we can directly measure the effective open capacitance. What we need is to arbitrary define the C0 through C3 coefficients and solve the formula so that the resultant is equal to the measured effective capacitance. Am I correct? In addition, how do we determine which frequency for measurement? Do we use the Fmax in my sweep range? Are there alternative methods to obtain the coefficients? Is there experts who can advice me? Thanks very much in advance.

When one is specifying the fringing capacitance when a fixture is connected to a NA, it becomes very difficult to distinguish between the fringing capacitance value as a result of the open and the electrical delay due to the fixture.

On a smith or admittance chart, the trace will wrap around these charts numerous times.

Adding to the difficulty, more often than not, the short standard will be physically longer than the open.

Please assert a method whereby we can fix a reference point to eliminate the electrical delay of the fixture because this is the source of the greatest error possible.

Can you show us a method using TDR where we can calculate the fringing capacitance?