Patent ID: 7865319
Filing Date: 2011-01-04
Classification: G01R

Abstract:
1. A method to accurately measure the loading impedance of measurement systems using a test fixture, said method comprising the steps of: (a) providing a test fixture having at least one transmission line, each said at least one transmission line having a port at two ends, said test fixture having a plurality of transmission line legs, each transmission line leg extending between a mid-point reference plane of said at least one transmission line and a port; (b) measuring characteristics of an unloaded test fixture to obtain scattering parameters of said test fixture, said scattering parameters arranged in at least one test fixture scattering matrix; and (c) calculating scattering parameters of each transmission line leg of said test fixture, said step of calculating scattering parameters of each transmission line leg of said test fixture comprising the steps of: (d) measuring said test fixture loaded with a measurement system to produce a combined measurement of said test fixture and said measurement system; and (e) removing test fixture effects defined by said scattering parameters of each transmission line leg of said test fixture from said combined measurement by a de-embedding calculation to obtain measurement system effects of said measurement system alone.