A scaleable software-defined phased array using commercial 60 GHz chipset

Abstract

The push towards 5G networks has skyrocketed in the recent years. 5G aims to provide Gbps data rates, extremely low latency and more network capacity than was previously available. Millimeter wave (mmWave) technology provides a steppingstone for 5G networks because of its massive bandwidth from 30 GHz to 300 GHz. However, the attenuation of mmWave frequencies requires beamforming to focus the transmitted power toward the receiver. Because of this, mmWave radios use phased array technologies to alter and direct the radiation patterns. Larger phased arrays allow for even more focused beams. Unfortunately, commercial large phased arrays are not available in the market. In this project, we explore the process of combining multiple phased array modules to create larger phased arrays. Combining modules proves difficult because there are hardware discrepancies and limitations that affect the beam patterns. These include phase differences between antennas within a module and between modules. In addition, phase shifter resolution is limited by two-bit resolution which affects both the calibration process and the beam angular resolution. We combined four phased array modules from 60 GHz mmWave radios with 32 element phased array modules. Our results show that calibrating and combining phased array modules added the beam patterns constructively and created much narrower beams.