Broadband electronic impedance tuner

A novel design of multi-state impedance tuner for an on-wafer noise parameter measurement system is presented. It is based on just three commercial GaAs MMIC switches that connect into or out of the circuit six delay sections, composed of natural and artificial transmission lines, and thus provide 36 distinct impedances at each frequency. Using the D-optimal criterion from the design of experiments (DoE), the impedance distributions were optimised over the frequency range 50-2000 MHz.