A universal measurement system for microwave power transistors

We describe a measurement system for model parameter extraction and full characterization of power transistors in frequency and time domain. It provides bias dependent linear S parameters, power transfer characteristics, intermodulation data, and RF waveforms in dependence on harmonic load tuning. The power level exceeds 30 dBm for highly mismatched devices. The system is for full on-wafer operation including all calibration steps. Examples of measurements, e.g. RF-I/V curves, are presented for low-voltage GaInP/GaAs HBTs. These experimental results are confirmed by a scaleable large-signal HBT model, which demonstrates both usefulness of the measurement system and performance of the nonlinear model