A 10 to 40 GHz Reflection-Mode N-Path Filter

A bandpass reflection-mode N-path filter (RMNF) with 2-GHz bandwidth and 10 to 40 GHz center-frequency tuning is presented. The design includes a broadband hybrid coupler, N-path reflectors, comprising four-phase passive mixers terminated with third-order in-phase and quadrature-phase active baseband loads, and a broadband clock-generation network. The reflectors realize an in-band open circuit and an out-of-band matched termination, providing a bandpass response in reflection mode. The filter is fabricated in the GlobalFoundries 45-nm RFSOI process. Across the 10 to 40 GHz tuning range, the bandpass filter has 18 dB/octave roll-off, 3.6–6.3 dB insertion loss, 40–20 dB out-of-band rejection, 6–12 dB noise figure, +22–+12 dBm out-of-band input-referred third-order intercept point, and 130–332 mW of power consumption.