An Accurate Automatic Quality-Factor Tuning Scheme for Second-Order LC Filters

Author

Bahmani, Faramarz ; Serrano-Gotarredona, Teresa ; Sánchez-Sinencio, Edgar

Author_Institution

Analog & Mixed-Signal Center, Texas A&M Univ., College Station, TX

Volume

54

Issue

4

fYear

2007

fDate

4/1/2007 12:00:00 AM

Firstpage

745

Lastpage

756

Abstract

This paper presents a scheme to accurately tune the quality factor of second-order LC bandpass filters. The information of the magnitude response at the center and one of the cutoff frequencies is used to tune both the amplitude and the quality factor of the filter using two independent yet interacting loops. Furthermore, the synergic interaction between the loops makes the proposed scheme stable and insensitive to the mismatch between the input amplitudes. A chip prototype was implemented in a 0.35-mum CMOS process and consumes 4.3 mA from a single 1.3-V supply. Measurement results show that at 1.97 GHz the quality factor is tunable from 60 to 220 while the amplitude is tunable between -15 and 0 dBm with worst case quality factor and amplitude tuning accuracies of 10% and 7%, respectively

Keywords

CMOS integrated circuits; Q-factor; band-pass filters; 0.35 micron; 1.3 V; 1.97 GHz; 4.3 mA; CMOS circuits; CMOS process; Q-enhancement; automatic quality-factor tuning scheme; bandpass filters; second-order LC filters; Band pass filters; Circuit optimization; Cutoff frequency; Information filtering; Information filters; Q factor; RLC circuits; Tunable circuits and devices; Tuning; Voltage-controlled oscillators; LC bandpass filter; $Q$-enhancement; Automatic $Q$-tuning; CMOS circuits;

fLanguage

English

Journal_Title

Circuits and Systems I: Regular Papers, IEEE Transactions on

Publisher

ieee

ISSN

1549-8328

Type

jour

DOI

10.1109/TCSI.2006.888783

Filename

4155021