Abstract:

In this study, a decoupling radome is designed to provide a reference for solving the problem of low isolation between adjacent ports in a compactly arranged large-scale antenna array. The main body of the radome is a layer of dielectric plate with low dielectric constant and low loss, on which a periodically arranged metal patch structure is printed. By adjusting the shape of the metal patch and the distance between the radome and the antenna array, the reflected wave generated by the radome and the coupled wave in the array have the same amplitude and opposite phase,and the two cancel each other out, thereby achieving the effect of increasing the isolation between the ports in the array. The test results show that the isolation of the different polarization in the antenna array unit before loading the decoupling radome is about -20 dB, and the isolation of the same polarization is about -22 dB. After loading the radome, the heteropolarization isolation in the unit is improved by about 8 dB at 2.5~2.61 GHz.The co-polarization isolation between the units has also been significantly improved, which is improved by about 10 dB at the 2.6 GHz frequency point. Moreover,there is basically no effect on the radiation characteristics of the antenna array before and after loading the decoupling radome.

Key words: decoupling, radome, electromagnetic metamaterial, 5G, antenna array, isolation, radiation characteristics, periodic structure