Dual-polarized metamaterial cavity-backed antennas for mutual coupling reduction

Abstract

A novel metamaterial cavity for mutual coupling reduction of two closely positioned dual-polarized antennas is proposed in this paper. The metamaterial cavity is composed of four sets of meta-surfaces. Two sets are composed of double-layer complementary frequency selective surface and the other two are composed of double-layer complementary negative-index material. In comparison with those two antennas without the metamaterial cavity, measured results show that the isolation level of the same polarization ports (S₁₃ and S₂₄) and the cross-polarization ports (S₁₄ and S₂₃) for the proposed metamaterial cavity-backed antennas can be improved by at most 12.5 and 9.5 dB over the frequency band of 2.5–2.7 GHz, respectively. More importantly, the dual-polarized antenna array keeps other good performance such as VSWR <2 and a stable radiation pattern where the metamaterial cavity is loaded. Comparative analysis on the performance of the simulations and experiments are demonstrated. The proposed metamaterial cavity is easy to integrate with pico-base station antennas or relay antennas.

Keywords:

• Dual-polarized
• frequency selective surface
• mutual coupling
• metamaterial
• meta-surfaces
• negative-index material