Phase Gradient Metasurface Wall Structure For Antenna Array Decoupling

A gradient metasurface wall structure operating in Ka-band is proposed. To reduce mutual coupling, side metallic walls with a designed metasurface arrays are incorporated into both sides of the unit antenna in the antenna array. These walls can also improve the performance of antenna based on the anomalous reflection. Simulation and experimental results show that the coupling coefficient reduces from -30 dB to -40 dB at the operating frequency. The 3dB beam width of the antenna is broadened from 35° to 38° in H plane and from 23.4° to 31.5° in E plane, due to the characteristic of controllable reflection direction. Because of the freedom in controlling the reflected waves and the high isolation, this gradient metasurface wall structure is of important application values in Millimeter-wave imaging system and MIMO system.