GaN-HEMT nonlinear modeling of single-ended and Doherty high-power amplifiers

A large-signal model for 120W high power packaged pre-matched transistor utilizing TriQuint´s TQGaN25HV HEMT technology is presented. It is composed of an array of unit-cell nonlinear EEHEMT models representing the high power GaN transistor die and EM based models for the input/output pre-matching circuits relaying the transistor die pads to the package leads. This model offers accurate small-signal and large-signal performance prediction at the package leads reference plane, as well as, when used in 50Ω matched evaluation boards of 120W single-ended and 240W Doherty PA´s. The model is validated in S-band against measured data, offering good prediction of Doherty PA key parameters, backoff efficiency and saturated peak power.