A Low-Power 2/5.8-GHz CMOS LC-VCO for Multi-band Wireless Communication Applications

A fully integrated dual-band LC voltage control oscillator designed in a 0.18-mum CMOS technology for 5.8-GHz/2.0-GHz wireless communication applications is described. The frequency band switching is accomplished with switched-inductor technique. The dual-band oscillator can be operated in 5.38~6.23 GHz and 1.78~2.07 GHz with 15% frequency tuning range. Two different inductors are used for the frequency band switching. Frequency tuning is implemented by varying the capacitance of a MOS varactor. The measured phase noise is -109 dBc/Hz @1 MHz and -112 dBc/Hz @1 MHz for frequency at 5.8 GHz and 2 GHz, respectively. This oscillator is fabricated in UMC's 0.18-mum one-poly-six-metal 1.8 V process. The power dissipation of this dual-band VCO is 11.7 and 9.3 mW for oscillation frequency of 2 GHz and 5.8 GHz, respectively