5-6 GHz SiGe VCO with tunable polyphase output for analog image rejection and I/Q mismatch compensation

Author

Sanderson, David I. ; Raman, Sanjay

Author_Institution

Wireless Microsystems Lab., Virginia Polytech. Inst. & State Univ., Blacksburg, VA, USA

fYear

2003

Firstpage

683

Lastpage

686

Abstract

Image rejection and demodulation quality are adversely affected by in-phase and quadrature (I/Q) channel phase mismatch. This paper presents a 5-6 GHz Silicon Germanium (SiGe) voltage controlled oscillator (VCO) and integrated polyphase filter with I/Q phase imbalance compensation. The design of the VCO is discussed, including considerations for high inductor quality factor (Q) and low VCO phase noise. From a 2.5 V supply, the VCO core consumes 3 mA. The simulated phase noise at 1 MHz from the carrier is -114.6 dBc/Hz. The I/Q imbalance of the polyphase splitter is tunable by means of series output varactors. The polyphase network design can compensate for ±4° I/Q phase imbalance, which could provide approximately 15 dB improvement in image rejection in a Weaver architecture receiver.

Keywords

BiCMOS analogue integrated circuits; Ge-Si alloys; MMIC oscillators; demodulation; phase noise; semiconductor materials; varactors; voltage-controlled oscillators; 2.5 V; 3 mA; 5 to 6 GHz; BiCMOS; I/Q mismatch compensation; SiGe; VCO; Weaver architecture receiver; analog image rejection; demodulation; image rejection; inductor quality factor; phase imbalance; phase noise; polyphase splitter; series output varactors; tunable polyphase output; Analog computers; Circuits; Demodulation; Filters; Germanium silicon alloys; Inductors; Phase noise; Silicon germanium; Varactors; Voltage-controlled oscillators;

fLanguage

English

Publisher

ieee

Conference_Titel

Radio Frequency Integrated Circuits (RFIC) Symposium, 2003 IEEE

ISSN

1529-2517

Print_ISBN

0-7803-7694-3

Type

conf

DOI

10.1109/RFIC.2003.1214039

Filename

1214039