A 1.1–8.2 GHz tuning range In-phase and Quadrature output DCO design in 90 nm CMOS technology

Abstract

This paper presents a high-frequency wide tuning range Digital Control Oscillator (DCO) with In-phase and Quadrature outputs designed using a 90nm CMOS process with 1.2 V power supply. The proposed design operates in the frequency range of 1.1-8.2GHz. The designed ring oscillator with digital control inputs attains high oscillation frequencies by applying negative delay inputs to the transistors in parallel to the conventional static CMOS inverter. The stage delay of the ring oscillator with the proposed design is less than the conventional static CMOS inverter and the skewed delay inverter cell. At 2.02GHz oscillation frequency, the measured phase noise is -90.43dBc/Hz at an offset of 1 MHz and -117.64dBc/Hz at an offset of 10MHz. Keywords-Digital Control Oscillator (DCO), All-DigitalPhase Lock Loop (ADPLL), skewed delay, high frequency, wide tuning range, ring oscillator.I.