Composite-channel InP HEMT for W-band power amplifiers

We have developed composite-channel InP-InGaAs HEMTs for W-band high power amplifier applications. The optimized 0.15 /spl mu/m T-gate device demonstrated state-of-the-art g/sub m/-I/sub max/ combination. It also showed a 1.5 V improvement in on-state and off-state breakdown over the conventional InP HEMT without degrading the RF performance. A two-stage MMIC power amplifier built on this device delivered 25 dBm output power with 17 dB linear gain at 94 GHz as measured on wafer. To our knowledge, this is the first demonstration of composite-channel HEMT at 94 GHz with excellent power performance.