A 0.015 mW Quasi-passive Reconfigurable Complex Band-pass Filter for Analog Baseband

Abstract

This work proposes a quasi-passive reconfigurable complex filter with harmonic rejection based on N-path filtering technique. It features extremely low power consumption and reconfigurable center frequencies. Unlike the traditional N-path filters at RF frequencies, the proposed filter achieves 3rd/5th harmonic rejection at the adjacent frequencies by cascading the N-path filters with different clock frequencies. The filter is implemented in a 55 nm CMOS technology, consumes an area of 0.24 mm² including all pads. Measured results show that the filter achieves 19 dB/34 dB harmonic-rejection ratios at 3rd/5th harmonics. At the same time, the overall power consumption is only 0.015 mW, and the measured in-band IIP3 is around 7 dBm