A 5.8 GHz Low-Phase-Noise LC-QVCO Using Splitting Switched Biasing Technique

Abstract

A 5.8 GHz LC-tank quadrature voltage-controlled oscillator (QVCO) is proposed for achieving low phase noise. Phase noise contributed by the tank voltage amplitude and the 1/f noise of the tail transistors were simultaneously improved when the splitting switched biasing technique was adopted. Measured results showed a tuning range from 5.09 to 6.15 GHz, a phase noise of -119.39 dBc/Hz at an offset of 1 MHz, and a phase-noise figure-of-merit of -188.21 dB, while consuming 3.06 mA for the core QVCO from a 1.6 V supply. The proposed QVCO was designed using a 0.18 mu m CMOS process.