Patent ID: 6249128
Filing Date: 2001-06-19
Classification: G01R

Abstract:
In automatic test equipment having a source, a method of calibrating the automatic test equipment for source match comprising the steps of:a) measuring the s-parameter e.sub.s of measurement circuitry provided with the automatic test equipment;b) connecting a first calibration reference to the measurement circuitry;c) measuring a reflection coefficient .GAMMA..sub.l1 of the first calibration reference, and measuring a first signal (I.sub.1) incident on the measurement circuitry from a first direction;d) connecting a second calibration reference to the measurement circuitry;e) measuring a reflection coefficient .GAMMA..sub.l2 of the second calibration reference, and measuring a second signal (I.sub.2) incident on the measurement circuitry from the first direction in a way that preserves the phase relationship between the first signal and the second signal; andf) computing, responsive to the measuring steps a, c, and e, an indication of error attributable to source match (.GAMMA..sub.s), said indication accounting for reflections of the first and second signals from the source.