An Ultra-Compact Multi-Band VCO Achieving − 196 dB FoMA with Single-Ended Tunable Active Inductor

Abstract

This paper presents a wide tuning-range LC-tank voltage controlled oscillator (VCO). To perform large frequency tuning range, the proposed circuit topology uses a tunable active inductor (TAI) for the coarse frequency tuning, while the fine-tuning is controlled only by a MOS varactor. The TAI design is based on toggling varactor arrays by which four channels are able to be selected for multi-band applications. The proposed VCO is designed in 90-nm CMOS process. Simulation results show that the VCO can operate from 760 MHz to 4.370 GHz representing an FTR of 140.74%, with a tuning gain Kvco from 654 to 1882 MHz/V. The achieved phase noise is lower than − 105 dBc/Hz at an offset frequency of 1 MHz from the carrier tuned to 2.52 GHz. The VCO core circuit draws 3.3 mA from a 1V voltage supply and occupies a small active area of (45 × 37) μm2. The fully implemented VCO provides excellent performances such as attractive FOMA value of − 196 dBc/Hz.