Hybrid metasurface loaded tri‐port compact antenna with gain enhancement and pattern diversity

Abstract

A tri-port compact antenna loaded on hybrid metasurface (MS) with gain enhancement and pattern diversity is proposed in this article. The antenna consists of three analytically designed contorted radiators (Ant-1, Ant-2, and Ant-3). A koch-fed fractal aperture ground plane is used to improve impedance matching and port isolation, thus eliminating supplementary decoupling networks. Ant-1 is 45° tilted, operating in wideband mode. Ant-2 is one-fourth, Ant-3 is one-half in electrical lengths with L-shaped metallic contortions to achieve good matching characteristics and asserts pattern diversity. A hybrid MS (combination of conventional customized MS's) structure is loaded for gain enhancement of ≈ 8.93 dBi. Ant-1 operates at (4.97-10.63) GHz with 72.56% frequency bandwidth (FBW), Ant-2 operates at (8.5-10.4) GHz with 20.1% (FBW) and Ant-3 operates at (7.2-9.6) GHz with 28.57% (FBW). The differentiation in antenna electrical size assists compactness, reduction in mutual coupling (>17 dB), has uncorrelated radiation patterns at each port delivering far-field diversity with low ECC < 0.1. A prototype antenna of size 28.6 mm × 28.6 mm is fabricated and experimented, which are in good agreements with EM simulation and equivalent circuit model response. The proposed tri-port antenna can be a promising candidate for MIMO diversity applications.