Complex DC-offset cancellation circuit

Abstract

A novel DC-offset cancellation circuit that is applicable to complex filters is presented. The proposed circuit allows for a high-gain complex filter, which leads to a small chip size and low current consumption. Adopting the proposed scheme, a 10 to 73 dB gain complex filter that cancels an input referred DC-offset by more than ±100 mV is designed based on 0.18 µm CMOS technology, which dissipates 2.4 mA from a 1.8 V supply.