A low-noise Ku-band AlGaAs/GaAs HBT oscillator

Design considerations, fabrication and performance results are described for a low-phase-noise Ku-band oscillator implemented using a fully self-aligned AlGaAs/GaAs heterojunction bipolar transistor (HBT). The transistor has a measured collector-current 1/f noise power density of 10/sup -19/A/sup 2//Hz at f=400 Hz for a collector current of 1.2 mA. The free-running oscillator developed represents an output power of 6 dBm at 15.5 GHz, with a single-sideband (SSB) FM noise of -65 dBc/Hz at 10 kHz off-carrier. The noise level is 24 dB lower than that for a GaAs FET oscillator, and 2 dB lower than that for a silicon voltage-controlled oscillator.<>