Switched inductor dual-band CMOS cross-coupled VCO

This letter proposes a high-performance CMOS dual-band voltage-controlled oscillator (VCO). The VCO consists of two cross-coupled VCOs coupled by a pair of switched inductors or LC resonators to vary the resonator's inductance. A pair of nMOSFET is used to switch high- and low-frequency bands. The VCO operates at the high-band using low resonator's inductance and the VCO operates at the low-band using large inductance. The proposed VCO has been implemented with the TSMC 0.18 mu m 1P6M CMOS technology and it can generate differential signals in the frequency range of 5.6-6.66 GHz and 4.13-4.75 and it also has comparable high output voltage swings at both low and high-frequency bands. The die area of the dual-band VCO is 0.84 x 1.1 mm(2). At the supply voltage of 0.75 V, the high (low)-band figure of merit is -193.6 (-192.3) dBc/Hz.