A Si 1.8 GHz RLC filter with tunable center frequency and quality factor

Abstract

A second-order active bandpass filter using integrated inductors was implemented in Si bipolar technology. The filter uses special techniques to make the quality factor and the center frequency tunable. For a nominal center frequency of 1.8 GHz and a quality factor of 35, the filter has 1 dB compression dynamic range of 40 dB, and draws 8.7 mA from a 2.8 V supply.