A 6.5mW, wide band dual-path LC VCO design with mode switching technique in 130nm CMOS

This paper demonstrates a dual path LC voltage controlled oscillator (VCO) that achieves ~65% tuning range with optimized inductor switching design. Combination of discrete and continuous tuning method reduces the gain ratio between coarse tuning path and fine tuning path which alleviates the noise and coupling issues due to high coarse tuning gain. Optimized inductor switching topology enables wideband continuous tuning from 2.74-5.37GHz. The VCO consumes 6.5 mW power from a 1.2 V supply and exhibits -123.8dBc/Hz at 3MHz offset from a 4.605 GHz carrier showing FOMT of -198.3dBc/Hz. The circuit is fabricated in 130nm CMOS process and occupies an area of 0.6mm².