Doped-channel heterojunction structures for millimeter-wave discrete devices and MMICs

AlGaAs/InGaAs/GaAs-type heterostructures with one or two channels have been used to fabricate both discrete devices and monolithic amplifiers for millimeter-wave operation. The authors report that 0.25- mu m*50- mu m discrete devices delivered a power density of 1 W/mm with 2.9-dB gain and 25% efficiency at 60 GHz. A 100- mu m monolithic single-stage amplifier demonstrated a record 40% efficiency at 32 GHz, and a two-stage monolithic amplifier achieved a record 31.3% efficiency with 72-mW power and 13-dB gain at 32 GHz.<
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