A 2mA-2.5V low phase noise multi-standard VCO

This paper presents the design of a voltage controlled oscillator (VCO) for multi-standard wireless receiver covering global standards for mobile (GSM), digital communication systems (DCS), personal communication systems (PCS), and universal mobile telecommunication system (UMTS) standards. An effective frequency planning scheme that requires the VCO to tune from 3.2 GHz to 4.1 GHz and generate multiple bands using frequency division is presented. The presented VCO design employs two current mirrors for efficient current control, a specially designed inductor with quality factor (Q) of 111, and multiple noise filtering techniques to reduce flicker noise components. The proposed multi-standard VCO is designed using 0.25 mum silicon-on-sapphire (SOS) technology and consumes only 5.18 mW power at 4.1 GHz operating frequency. The VCO achieves phase noise of -132 dBc/Hz and -141 dBc/Hz at 1 MHz and 3 MHz offsets respectively resulting in figure of merit (FOM) of -197 dBc/Hz/mW.