A self-clocked blocker-filtering technique for SAW-less wireless applications

Abstract

A blocker filtering technique is presented that extracts the clock from the blocker for SAW-less receivers. The extracted clock is utilized to suppress the blocker without requiring any prior information of the exact location of the blocker. This clock runs at the blocker frequency and drives a notch filter that steers the blocker current away from the signal path. Implemented in a 65 nm CMOS process, the filter is able to track the blocker within 1 to 1.6 GHz and provides about 20 dB of rejection relative to the signal at the notch frequency for blockers from -40 dBm to -10 dBm.