Broadband Space Conservative On-Wafer Network Analyzer Calibrations With More Complex Load and Thru Models

An improved vector network analyzer (VNA) calibration approach is demonstrated that utilizes planar lumped short-open-load-thru standards and achieves accuracy comparable to thru-reflect-line (TRL) at high frequency, without the commonly occurring errors in TRL at low frequency. The approach relies on complex load and thru models for coplanar waveguide and microstrip standards that are not currently available in typical VNA firmware. It is shown that the RF performance changes due to variations in fabrication of load can be addressed by "calibrating" or adjusting the load model with the measured dc resistance for a particular load. Good results are shown for a wide range of substrates (GaAs, alumina, and FR-4) and frequencies to 110 GHz