Decoupling Design Based on Metasurface Superstrate for Millimeter Wave Antennas

A high port isolation millimeter wave antenna array with compact size is proposed in this paper. The center distance between the two E-shaped patches is only 3.2mm, about 0.28 wavelength at center frequency, which will generate a strong mutual coupling. In order to suppress the coupling, a metasurface superstrate consisting of the split-ring resonators is designed, which is placed on the top of the antenna element. The simulation results show that the port isolation of the decoupled antenna array can be improved to over 25dB in the operating frequency range of 24.25-27.5GHz, which demonstrates the effectiveness of the proposed decoupling method.