Broadband dual‐polarized metasurface antenna with high isolation and low cross‐polarization.

This paper demonstrates a broadband dual‐polarized metasurface antenna with high isolation and low cross‐polarization using characteristic mode analysis. A wideband metasurface with stable radiation pattern is presented by splitting the edge patches into 2 × 2 sub‐array and introducing Minkowski fractal structure in the corner patches. To achieve the dual‐polarized operation, a pair of degenerate modes of the metasurface are selected, and thus high isolation and low cross‐polarization are obtained. The metasurface is excited by two slot antennas placed orthogonally. A prototype with an overall size of 1.46 λ0 × 1.46 λ0 × 0.07 λ0 (λ0 is the free‐space wavelength at center frequency) is fabricated. The proposed antenna could achieve dual‐polarization operation. The experiment results show that the −10 dB impedance bandwidths for each port are 28.9% (4.74–6.34 GHz) and 31.4% (4.62–6.34 GHz), respectively. The isolation between the two ports is higher than 31.8 dB, and cross‐polarization level is better than −28 dB. Moreover, broadside radiation performances for two ports are obtained. [ABSTRACT FROM AUTHOR]