SiGe integrated mm-wave push-push VCOs with reduced power consumption

For use in automotive radar applications we have designed and fabricated several push-push VCOs within the frequency range 67 to 75 GHz. In this paper we present one of these oscillators which can be tuned from 71.3 GHz to 75.8 GHz. In this tuning range the measured output power is 3.5 it 0.4 dBm with an DC to RF efficiency eta = 1.6%. The measured single sideband phase noise is below - 105dBc/Hz at 1MHz offset frequency. With a reduced supply voltage the efficiency can be increased to eta = 3.5 % with an RF output power of 1.5 dBm. The circuits are fabricated in a production-near SiGe:C bipolar technology. The SiGe:C bipolar transistors show a maximum transit frequency fT = 200 GHz and a maximum frequency of oscillation max = 275 GHz. For the passive circuitry transmission-line components, MIM-capacitors and integrated resistors are used