A very wide-tuning range 5-GHz-band Si bipolar VCO using three-dimensional MMIC technology

The first completely integrated, wide-tuning range 5-GHz-band 0.5-/spl mu/m Si bipolar transistor voltage-controlled oscillator (VCO), based on three-dimensional MMIC technology, is presented. A 33% frequency tuning range from 4.02 to 5.35 GHz is obtained at the collector voltage of 3 V because the base-emitter resistance of the active transistor works like a varistor with a large ratio. Furthermore, the oscillation frequency is remarkably linear against the controlled base bias. The achieved phase noise is -108 dBc/Hz at 1 MHz offset from the carrier.