An mmWave FZP-Based Phased Array

The development of millimeter-wave phased array based on the digital beamforming architecture needs to overcome a physical-level challenge due to the contradiction between the massively integrated TR devices and the compact volume for thermal dissipation. In this work, we demonstrate an analog beamforming solution based on a reconfigurable Fresnel-zone-plate (RFZP) antenna for 28-GHz phased array. The proposed RFZP including 16x8 unit cells based on active frequency selective surface (FSS) with varactor diodes to implement a continuous 180 degrees phase tunability. The measured scan ranges up to +/- 50 degrees and +/- 30 degrees at horizontal plane and vertical plane, respectively. The proposed RFZP antenna is an attractive solution for millimeter-wave beamforming.