Microwave VCO susceptibility to substrate noise in a fully-integrated 150 GHz SiGe HBT BiCMOS technology

Abstract

This work presents two K-band voltage controlled oscillators (VCO) implemented in a fully-integrated SiGe HBT BiCMOS technology, and analyzes their susceptibility to substrate noise. The two VCOs are identical in design, with one utilizing a spiral inductor for the resonant tank, and the other incorporating a thin film microstrip transmission line. Both VCOs exhibit significant (but different) substrate coupling behavior and performance degradation with the injection of parasitic substrate noise. An explanation of the coupling differences between the two VCOs and its relationship to VCO phase noise degradation versus control voltage, and the overall VCO design implications, are addressed.