Noise properties of SiGe heterojunction bipolar transistors

In this paper, we present a SiGe HBT featuring very attractive LF noise properties with excess corner noise frequency lower than 1 kHz. Concerning the high frequency noise, we report noise figure <1 dB at 10 GHz for an abrupt HBT and of 0.5 dB at 2 GHz for an optimized gradual HBT. Finally, SiGe HBT allows the realization of a microwave oscillator in the 4.7 GHz range, featuring very low phase noise behavior -135 dBc/Hz at 10 kHz offset frequency.