A 0.41mW Band-Tunable 6th-Order IF Filter with 40 ns Settling Time in 45 nm CMOS RFSOI

This work presents the design and implementation of a fully-differential 6th-order intermediate frequency (IF) bandpass filter (BPF) in 45 nm CMOS RFSOI. Its application targets are wake-up receivers (WuRX) that employ aggressive duty cycling. The fabricated filter with all bias circuits consumes a current of only 0.41mA from a 1V supply. Its center frequency is adaptive between 70 and 120 MHz, and the 3 dB-bandwidth is 20MHz. The BPF can settle within 40 ns. It occupies an area of 0.03mm2. To the authors’ best knowledge, this circuit provides the lowest DC-power, the lowest DC-power per pole, the shortest settling time and the fewest area for IF BPFs reported to date.