Source-injection parallel coupled LC-QVCO

Abstract

A simple source-injection parallel-coupled (SIPC) LC quadrature voltage controlled oscillator (QVCO) in which the additional noise contributions of the coupling transistors are nearly zero is proposed. The proposed topology is suitable for low phase noise and low supply voltage operation since it involves no additional transistor stacking. Compared to the conventional LC-QVCO, the SIPC topology designed for 2.4 GHz operation shows 19-12 dB improvement in phase noise at 10 kHz-1 MHz frequency offset. from the simulations based on 0.25 mum CMOS technology.