35-40 GHZ MONOLITHIC VCOS UTILIZING HIGH-SPEED GAINP GAAS HBTS/

Design, fabrication and performance of Ka-band voltage-controlled osci llators (VCO's) are described. High-speed self-aligned GaInP/GaAs hete rojunction bipolar transistors (HBT's) as active devices and varactor diodes using the base-collector junction of the HBT structure are impl emented in the VCO's. The HBT's have an emitter area of 2 x 1.5 mum x 10 mum and incorporate a highly carbon doped base layer and a thin GaI nP hole barrier. Oscillators with center frequencies of 35, 37, and 40 GHz exhibit tuning ranges of up to 1 GHz and typical output powers of 1-3.5 dBm. Best measured phase-noise at 1 MHz off carrier is -107 dBc /Hz.