A Blocker-Tolerant mm-Wave MIMO Receiver with Spatial Notch Filtering Using Non-Reciprocal Phase-Shifters for 5G Applications

This work reports a highly-linear blocker-tolerant mm-wave MIMO receiver front-end for 5G and beyond-5G applications. The proposed architecture enhances the RX linearity performance by establishing a mm-wave spatial notch filter (SNF) at the LNA output. The SNF incorporates a low-loss non-reciprocal phase-shifter architecture that can be turned off in the absence of spatial blockers. A 27-31GHz four-element MIMO receiver prototype is implemented in a 45nm SOI technology and exhibits an in-notch IP1dB of -7.8dBm with up to 41dB spatial blocker rejection. Through significant cancellation of co-channel wideband blockers, the RX achieves an EVM of -32.6dB, while receiving a wideband 256-QAM 100MS/s desired signal.