16-term error model and calibration procedure for on-wafer network analysis measurements

Vector network measurements are enhanced by calibrating the measurement system over the entire band of interest. This is done using a 12-term error correction model. Many measurement systems, including open air devices such as MMIC wafer probes, contain leakage and coupling error terms not modeled in current calibration systems. All error terms in such a system are included in a new 16-term error model and calibration procedure. Corrected measurements using the 16-term calibration procedure are compared with thru-reflect-line (TRL) and 12-term calibration measurements, and excellent agreement is observed for a nonleaky system. For a leaky system, the 12-term model is shown to break down, while the 16-term model retains its accuracy. The results validate the accuracy and viability of the calibration procedure for MMIC wafer probe measurements and other measurement systems containing leakage.