A broad-band quadrature-modulator in standard 0.13μm CMOS

A polyphase ltering 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 measured image-rejection ratio of -39dBc or better in 0.6-2.5GHz while consuming only 66mW from a 2.2V single supply.