HIGH-PERFORMANCE HEMT WITH AN OFFSET-GATE STRUCTURE FOR MILLIMETER-WAVE MONOLITHIC MICROWAVE ICS

A process technology for a pseudomorphic high electron mobility transi stor (P-HEMT) with an offset-gate structure has been developed for mil limeter-wave monolithic microwave ICs (MMCs). A HEMT with the offset-g ate structure showed both reduced gate-to-drain capacitance and drain conductance compared with a device with a non-offset-gate structure. T he device showed a maximum available gain (MAG) of 9 dB at 77 GHz. The device was applied to a 77 GHz three-stage power amplifier, which sho wed a small-signal gain of 16.5 dB. Under preliminary life testing, th is amplifier showed a stable smalt-signal gain for over 160 hours of t esting at 175 degrees C.