Title :
A gate-modulated CMOS LC quadrature VCO
Author :
Cheng, Kuang-Wei ; Allstot, David J.
Author_Institution :
Univ. of Washington, Seattle, WA, USA
Abstract :
A quadrature voltage-controlled oscillator (QVCO) based on the time-varying gate-modulated coupling of two LC tank VCOs is introduced. Using a standard 0.18 mum CMOS process, the new topology is compared to the conventional series QVCO in terms of start-up loop gain, quadrature phase accuracy, phase noise, tuning range, and voltage headroom characteristics. In addition to comparable phase noise performance, the gate-modulated QVCO (GM-QVCO) also exhibits superior quadrature phase accuracy, and suitability for low power supply voltage designs that use cascode current sources and active loads. It draws 2.4 mA from a 1.8 V power supply, displays a phase noise of -122 dBc/Hz @ 1 MHz offset, and has a quadrature phase error of 0.4deg.
Keywords :
CMOS integrated circuits; UHF integrated circuits; UHF oscillators; integrated circuit noise; low-power electronics; network topology; phase noise; voltage-controlled oscillators; CMOS process; LC tank VCO; cascode current sources; circuit tuning; current 2.4 mA; loop gain; low power supply voltage design; phase noise; quadrature phase accuracy; quadrature voltage-controlled oscillator; size 0.18 mum; time-varying gate-modulated coupling; voltage 2.4 V; voltage headroom characteristics; CMOS process; Circuit topology; Coupling circuits; Displays; Low voltage; Phase noise; Power supplies; Signal generators; Tuning; Voltage-controlled oscillators; CMOS; I/Q signal generation; Voltage controlled oscillators;
Conference_Titel :
Radio Frequency Integrated Circuits Symposium, 2009. RFIC 2009. IEEE
Conference_Location :
Boston, MA
Print_ISBN :
978-1-4244-3377-3
Electronic_ISBN :
1529-2517
DOI :
10.1109/RFIC.2009.5135537
