The effect of RF-driven gate current on DC/RF performance in GaAs pHEMT MMIC power amplifiers

This paper describes RF-driven gate current effects on the dc/RF performance of 0.15-μm (gate length) 2-mil (substrate thickness) GaAs pseudomorphic high-electron mobility transistor (pHEMT) monolithic microwave integrated circuit power amplifiers (PAs). High gate current is generated in PAs under RF drive at room temperature. A long-term lifetest of PAs with various gate currents induced by RF drive was performed to investigate the effect of RF-driven gate current on dc/RF performance in GaAs pHEMT PAs. Accordingly, an empirical model was developed to predict the dc/RF performance of V-band PA modules by the end of life (EOL). This information is crucial for system engineers in order to budget sufficient output power so that the system can still maintain performance capability by EOL.