Low-Noise, Tunable Gaas Bipolar Oscillator

Varactor tuned oscillators using GaAs heterojunction bipolar transistors (HBTs) covering the frequency range 2.7-6.2 GHz are reported. These oscillators have the widest electronic tuning range so far reported for HBT oscillators. The oscillators have a phase noise of -105 dBc/Hz at 100 kHz offset which is the lowest phase noise so far obtained with a broadband HBT oscillator.