Electronic Network Analyzer Calibration for Submillimeter Wafer Measurements

Network analyzers determine the S-parameters of RF and microwave devices to describe their circuit behavior. Network analyzers require a calibration procedure to account for the systematic errors within the test environment to provide accurate measurements of devices under test. Coplanar wafer probes are prevalent in submillimeter network analyzer measurements and, due to their unshielded environment, are subjected to leakage at high frequencies. Additionally, coplanar wafer probes are prone to skidding, generating uncertainty about precise probe placement location which contributes to non-systematic errors that cannot be corrected through calibration. Electronic calibration has the potential to address these error sources to provide accurate network analyzer measurements.
This research aims to reduce the effects of calibration errors for on-wafer measurements. This work employs the nonlinear characteristics of a Schottky diode to realize an electronic calibration procedure for the frequency band WR2.2 (325-500 GHz). The electronic calibration reduces the number of variables associated with physically measuring individual calibration standards. This methodology has the potential to improve the accuracy of network analyzer measurements for high leakage systems, specifically coplanar wafer measurements.