A low‐profile dual‐polarized heterogeneous MIMO antenna arrays with uniform beamwidth

Abstract

AbstractIn this work, a heterogeneous 6 × 4 dual‐polarized MIMO antenna array was developed to achieve antenna elements with uniform 10 dB‐beamwidth (120° ± 10°). To constrain the 10 dB‐beamwidth, two types of antenna elements are designed and properly placed in the antenna array according to the nonuniform electromagnetic coupling environment. A nonuniform aperiodic metasurface with equivalent capacitance loading effect is then proposed to compensate the inductance of the heterogeneous antenna array. It results in a low‐profile height of 0.17λL and good impedance matching over 40% bandwidth. The unit cells in the metasurface are arranged with non‐uniform spacing to achieve uniform 10 dB‐beamwidth of the antenna elements in an antenna array environment. Both simulation and measurement results validate that the proposed design achieves stable radiation patterns and uniform 10 dB‐beamwidth (120° ± 10°) over a wide frequency band of 1.8–2.7 GHz. Because of these attractive features, the proposed antenna array becomes a promising candidate for massive multiple‐input and multiple‐output base station antennas.