An on-off receiver array for low-power scaling of mmWave massive MIMO

Abstract

Low-power solutions are crucial for realizing the throughput gains of mmWave massive MIMO in base station to mobile links, particularly for the battery-powered handset. LNA power consumption is a significant bottleneck in scaling to large arrays at high frequencies. We propose a simplified phased array architecture for a 140 GHz receiver that uses activation switches in place of noisy phase shifters, allowing the relaxation of LNA gain requirements and, consequently, power consumption. On-off beamforming is employed, which introduces a tradeoff between aperture utilization and power efficiency. Our results show the potential for 7X power savings with approximately 40% average utilization of die area.