1.8 GHz tunable filter in Si technology

Abstract

An active filter using integrated inductors has been implemented in Si bipolar technology. The filter has a second-order bandpass response, with quality factor tunable through Q enhancement and center frequency tunable through reactance multiplication. For a nominal center frequency of 1.8 GHz and a quality factor of 35, the filter has a 1 dB compression dynamic range of 40 dB, and draws 8 mA from a 3 V supply.