A uniform phase noise QVCO with a feedback current source

Abstract

A novel integrated quadrature voltage controlled oscillator (QVCO) with a feedback current source is presented in this paper. Benefiting from the current adjusting function of the feedback current source, the proposed QVCO exhibits a uniform phase noise over the entire tuning range. This QVCO is implemented in 65-nm CMOS technology. The measurement results show that it draws less than 3-mA average current from a 1.2-V supply and the phase noise is less than −110 dBc/Hz @1MHz offset over the entire tuning range. The fluctuation of phase noise @1MHz offset from the center frequency of 2.84-GHz to 3.27–GHz is less than 1 dBc/Hz, which validates the correctness of the proposed current source feedback technique.