MEASUREMENTS OF PLANAR MICROWAVE CIRCUITS USING AN IMPROVED TRL CALIBRATION METHOD

In this paper, an improved TRL (Thru-Reflect-Line) calibration method is presented. This method is based on ten-term error model of a two-port vector network analyzer(VNA) measurement system. Eight error terms induced by fixtures as well as two leakage errors are derived directly from the S parameters of the calibration standards measured from the coaxial reference plane without converting S parameters to T parameters. To validate our algorithm, a microstrip device with a via hole and a coplanar waveguide transmission line are fabricated and calibrated using the present TRL calibration method and Engenʹs algorithm, respectively. The magnitudes and phases of S11 and S21 of the devices are compared. The consistency of the de-embedded results with those calibrated by Engenʹs TRL algorithm illustrates the validity of the TRL algorithm in this paper.