A Millimeter-Wave Mixer-First Receiver with Non-Uniform Time-Approximation Filter Achieving $> 45\text{-dB}$ Blocker Rejection

This paper presents a non-uniform (NU) time-approximation filter (TAF) technique for a wireless receiver to reject unwanted blockers spectrally. The proposed NU-TAF leverages the alias-spreading property of NU sampling (NUS) and a TAF that approximates an FIR filter response in the time domain, achieving an overall flexible filter response with a higher attenuation factor. The filter response can be readily reconfigured by changing the NU sequence and/or the TAF waveform without adjusting the passive component value. Additionally, a quad-switch integrator is proposed to significantly reduce power consumption by sharing the current among the Gm cells. A proof-of-concept millimeter-wave receiver is implemented in 28nm CMOS. Thanks to the NU-TAF, the receiver prototype achieves >45dB blocker rejection with a 33.7-GHz carrier frequency. The EVM measures −30.9dB using a 100-MSymbol/s 64QAM signal in the presence of a 10dBc out-of-band blocker.