A Broadband Quadrature-Modulator in Standard 0.13 μm CMOS

Abstract

A polyphase filtering topology is proposed which uses parallel switchable RC-networks for accurate broadband 90 • phasing. A 0.13 µm CMOS prototype using the quadrature-generation network in a direct-conversion quadrature-modulator achieves a measured image-rejection ratio of −39 dBc or better in 0.6-2.5 GHz while consuming only 66 mW from a 2.2 V single supply.