Calibration and Measurement of Ceramic Microstrip Circuits Using a Wafer Probe Station

Two methods for calibration and measurement of microstrip circuits fabricated on 10 mil thick alumina will be presented. The first method may be used from 7 to 30 GHz. The second method is best suited for measurements below 10 GHz. The basic measurement configuration consisted of: 1) an automatic network analyzer with thru-reflect-line (TRL) [l] calibration capability; 2) wafer probe station and coplanar probe heads normally used for measurement of GaAs circuits; and 3) microstrip TRL calibration standards with coplanar to microstrip transitions. Data will be presented on two types of coplanar to microstrip transitions including: 1) circuit dimensions; 2) transition data calibrated to the coplanar probe tips; 3) calibration data using microstrip TRL calibrations; 4) repeatability data of the transitions including circuit to circuit variations and substrate to substrate variations; and 5) error estimates.