Continuous Beam-Steering Low-Loss Millimeter-Wave Antenna Based on a Piezo-Electrically Actuated Metasurface

A novel antenna beam-steering technology is proposed for emerging millimeter-wave (mm-wave), broadband mobile technologies such as 5G and beyond. A high-gain (23 dBi) antenna with 30° beam steering is designed and tested at around the 38 GHz band. A Fabry–Perot type leaky-wave antenna (LWA) is employed as the main radiating structure, with a tunable high-impedance surface (HIS) used as the ground plane. The HIS phase tuning is accomplished by electro-mechanically varying the displacement between the HIS periodic metasurface layer and the ground plane using a flexure amplified piezoelectric actuator (PEA). The antenna exhibits very low loss (<1 dB) along with fast (in the order of ms.) and continuous beam steering. The measured and simulated results show close agreement and suggest that PEA-tuned, metasurface-based antennas offer a promising solution for use in future mm-wave communication systems.