A dual band SiGe quadrature VCO design for GSM/DCS-PCS applications

A dual hand SiGe fully integrated quadrature Voltage Controlled Oscillator (VCO) for GSM/DCS-PCS applications is presented. This circuit is implemented in a 0.35μ BiCMOS SiGe process and is made of two cross-coupled differential VCOs, with integrated resonator, to ensure the quadrature outputs. At 2.7 V power supply voltage and a total power dissipation of 41.6 mW, the proposed VCO features a worst case phase noise of -8OdBuHz and -96dBr/Hz at IOW and 50kHz frequency offset respectively. Thanks to MOS capacitor switching, the VCO can be tuned over two frequency hands from 1.5 to 2 GHz with a tuning voltage varying from 0 to 2.7v.