Electronic Calibration for Submillimeter-Wave On-Wafer Scattering Parameter Measurements Using Schottky Diodes

Abstract

A proof-of-concept demonstration of on-wafer electronic calibration in the submillimeter-wave band (325–500 GHz) is presented. A GaAs Schottky diode shunting a coplanar transmission line is employed as an electronic standard that is tuned by bias applied through wafer probes. Error-corrected scattering parameter measurements, based on a Thru-Reflect-Line (TRL) calibration, are used to characterize the on-wafer diode and establish it as a standard for electronic calibration. Subsequently, ensembles of measurements from a multiline TRL calibration and the diode calibration standard are performed and compared to assess the uncertainty associated with the two approaches. It is found that the error coefficients estimated using the electronic standard are in good agreement with those found from the multiline TRL calibration. Moreover, the electronic standard exhibits a significant improvement in precision compared with the TRL standards, consistent with previous work showing that error in probe placement between measurements was a principle source of uncertainty for TRL-based calibration.