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 μm 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 × 1.1 mm². At the supply voltage of 0.75 V, the high (low)-band figure of merit is ?193.6 (?192.3) dBc/Hz.