A new methodology to estimate E-band pHemt linearity optimum load from low microwave frequency load pull measurements

A procedure to estimate the optimum linearity load for a pHemt device working in E-band based on low microwave frequency load-pull measurements is proposed. This methodology has been used to extrapolate the optimum load for two tones linearity performances (OIP3) in 70/80GHz bands of a 4×50um pHemt device using the measured optimum load at 20, 26, 37 and 40GHz. The same procedure has been successfully validated extrapolating the optimum load for P1dB at 90GHz and comparing it with that estimated using the non linear model provided by the foundry. This has proven to well predict the P1dB at E-band in previous designs. Then, the technique has been used to extract the OIP3 optimum load over entire E-band and used for a Power Amplifier (PA) design.