Fully-integrated bipolar differential VCOs at 2.95 and 5.7 GHz

Two fully integrated differential Si bipolar voltage controlled oscillators (VCOs) are described. The VCOs are implemented at 2.95 GHz and at 5.7 GHz. The measured tuning range is 11.5% for the 2.95 GHz and 6.7% for the 5.7 GHz VCO with a tuning voltage from 0 to 3 V. The measured phase noise at 3 MHz offset from the carrier is -111 dBc/Hz for the 2.95 GHz design and -105 dBc/Hz for the 5.7 GHz design. Both VCOs operate from a standard 3 V supply and the power consumption for both designs is approximately 30 mW with an average output power of -11 dBm. All VCOs are implemented in a f/sub T/=25 GHz bipolar process.