Broadband Multi-State Electronic Impedance Tuner for On-Wafer Noise Parameter Measurement

Novel multi-state impedance tuner for use in on-wafer noise-parameter measurement system is reported. It is based on just three commercial GaAs MMIC switches that connect into or out the circuit six delay sections composed of natural and artificial transmission lines, and thus provide 36 distinct impedances at each frequency. The tuner's broadband operation (50 - 2000 MHz) was provided by optimisation of the impedance distributions using the D-optimal criterion from the design of experiments (DOE). Measurement results confirm high impedance repeatability and noise performance of the tuner.