A DC to 2GHz downconverter with image rejection and high blocker tolerance for cognitive radios

Abstract

An image reject RF filter for wideband receivers is described. This image reject RF filter relies on a complex bandpass filter that can be tuned accurately over a wide frequency. Operation of this filter is demonstrated in a 0.13um CMOS technology and shown to operate from DC to 2GHz. The filter is shown to provide a minimum image rejection ratio of 62 dBc, while providing an OIP3 of at least +30dBm over the frequency band and high blocker level tolerance.