A Low Phase Noise Quadrature LC VCO Using Capacitive Common-Source Coupling

Author

Soltanian, Babak ; Kinget, Peter

Author_Institution

Dept. of Electr. Eng., Columbia Univ., New York, NY

fYear

2006

fDate

19-21 Sept. 2006

Firstpage

436

Lastpage

439

Abstract

A low phase noise quadrature LC VCO with inherent tail-current shaping is presented. Two identical differential LC VCOs are locked in quadrature with a capacitor connected between their common-source nodes. This capacitor further drives the oscillators into a tail-current shaping mode, which increases their oscillation amplitude and reduces their phase noise. A multi-band 1.9 GHz differential nMOS quadrature LC VCO prototype has been fabricated in a 0.25 mum BiCMOS process. The measured phase noise is -124.4 dBc/Hz at a 1 MHz offset from a 2.07 GHz carrier while the circuit dissipates only 3 mW from a 1.5 V supply. The quadrature VCO is tunable from 1.75 GHz to 2.1 GHz and the VCO core only occupies 0.625mm²

Keywords

BiCMOS integrated circuits; MOS integrated circuits; phase noise; voltage-controlled oscillators; 0.25 micron; 1 MHz; 1.5 V; 1.75 to 2.1 GHz; 3 mW; BiCMOS process; capacitive common-source coupling; differential nMOS quadrature LC VCO prototype; oscillation amplitude; tail-current shaping; Capacitors; Circuit topology; Coupling circuits; Inductors; MOS devices; Phase noise; Signal generators; Tail; Voltage; Voltage-controlled oscillators;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Circuits Conference, 2006. ESSCIRC 2006. Proceedings of the 32nd European

Conference_Location

Montreux

ISSN

1930-8833

Print_ISBN

1-4244-0303-0

Type

conf

DOI

10.1109/ESSCIR.2006.307474

Filename

4099797