A Low-Power High Order N-Path Filter With Mixed-Type Gain Implementation

A low-power high order N-path filter with mixed-type gain implementation is proposed. Thanks to the extra passive voltage gain provided by the N-path filters with 2× voltage gain, the filter achieves good noise performance and consumes low power. The simulation shows that the proposed 40MHz-band-width N-path filter implemented in 55nm CMOS achieves a 16.24 to 18.16dB voltage gain, 2.14-2.47dB NF and 27.75-29.85dBm OOB-IIP3 at a 160MHz offset from 0.2GHz to 1.2GHz, while only consuming 8.4-15.2mW at 1.2V supply.