Supply voltage switching dual-band SiGe HBT VCOs using a dual-band resonator with inductor-loaded varactor diodes

A supply voltage switching dual-band SiGe HBT VCO for the next generation multi-band and multi-mode wireless radios is presented. It employs a single dual-band resonator with inductor-loaded varactor diodes and achieves a dual-band performance by switching a supply voltage. High performance and miniaturized size can be expected since no additional VCOs, resonators, matching elements, control voltages or circuits are required. The implemented 0.35-mum SiGe HBT VCO has achieved a tuning range from 0.82 to 1.04 GHz for a V_CC of 3.5 V and from 2 to 2.54 GHz for a V_CC of 5 V. The phase noise at 100 kHz offset is -111 dBc/Hz at 0.93 GHz center frequency and -112 dBc/Hz at 2.27 GHz center frequency. This is the first report on the dual-band VCO with a single dual-band resonator switched by a supply voltage.