Design of Compact and High Isolation Dual-Polarized Antenna Array via Plasmonic Meta-Structure

Abstract

We propose a compact and high isolation dual-polarized antenna array based on plasmonic meta-structure operating at 2.58 GHz. The compact principle of the dual-polarized antenna is mainly based on spoof surface plasmon polariton (SSPP) radiation patch to support SSPP modes, which is fed by spatially coupled excitation. Due to the slow-wave feature of SSPPs, the size of dual-polarized radiation patch is reduced to 0.2λ0× 0.2λ0 , and the total antenna size is reduced to 0.39λ0× 0.39λ0 , which is much smaller than that of the traditional microstrip antenna with 0.5λ0× 0.5λ0. The cross-polarization coupling between two polarization ports can be improved to below -32 dB, showing high isolation characteristics. Besides, a 3× 3 compact antenna array is also designed, fabricated, and measured to verify the feasibility of its extension to larger-scale antenna systems. Both simulated and measured results of the proposed compact antenna and the antenna array illustrate compact profiles, good ±45° radiation performance, and high isolation levels, which have potential application values for the massive multiple-input and multiple-output (MIMO) base stations.