A Miniaturized Two-Element Antenna Array With High Isolation by Using Hybrid Electromagnetic Decoupling

Abstract

A novel decoupling method combining magnetic coupling and electric coupling is proposed in this paper to design a miniaturized two-element antenna array. Different from the traditional planar decoupling structure, a three-dimensional quasi-split resonant ring decoupling structure which can realize electric coupling is introduced. The quasi-split resonant ring is composed of two meandered antenna elements printed on the top and bottom of the substrate. The other decoupling structure is composed of two parasitic patches, which realize magnetic coupling with the open end of the dipole element in the opposite plane. By properly controlling the strength of magnetic coupling and electric coupling, the induced currents can cancel each other out, thereby enhancing the isolation between adjacent ports. Compared with the antenna array employing the planar decoupling method, the size of the antenna array in this paper is significantly reduced by half. In terms of S-parameter and near-field radiation, the simulated results of the full-wave analysis are compared with the measured results. Essentially identical results successfully verify that the antenna achieves an isolation up to 27.5 dB and omnidirectional radiation mode in the resonant bandwidth of 1.76-1.80 GHz.INDEX TERMS antenna array, magnetic coupling, electric coupling, decoupling structure, parasitic patch, near-field.