Millimeter‐wave AlGaAs/InGaAs heterojunction finite‐element monolithic microwave integrated circuit oscillators

V‐band and Ka‐band oscillators have been developed using monolithic microwave integrated circuits (MMICs). The active elements employed are AlGaAs/InGaAs heterojunction finite element transmitters (FETs) with a 0.15‐μm T‐shaped gate. The oscillators were designed with a series feedback circuit with capacitive stubs at the FET source side for generating negative resistance and a resonance circuit at the gate side. MMIC prototypes have power outputs of 4.5 dBm for a V‐band oscillator (fosc= 50.5 GHz) and 6.7 dBm for a Ka‐band oscillator (fosc= 30.6 GHz). The phase noise for the V‐band oscillator is ‐97 dBc/Hz (1 MHz off‐carrier), which is relatively small for a free‐running oscillator.