8-Path Tunable RF Notch Filters for Blocker Suppression

Periodically time-variant passive 8-path notch filters are demonstrated in 65nm CMOS technology, with a notch frequency tunable from 100MHz to 1.2GHz with a clock signal. In a 50Ω environment, filter insertion loss in the pass band is 1.4-2.8dB, while the rejection at the notch frequency is >20dB. Given their P1dB> +2dBm and IIP3> +17dBm, the filters can protect radio receivers from blocking over a wide tuning range