Closely Placed Single-Layer Patch Antenna Array With Self-Decoupling Using Hybrid Modes

In this paper, a novel single-layer patch antenna is presented, designed to excite dual resonant modes for bandwidth expansion. By arranging these elements into an array, the mutual coupling between them is effectively suppressed by exploiting their inherent modes. This design strategy effectively suppresses mutual coupling in the antenna array without the need for additional decoupling structures. Instead, modifications in the physical placement of closely spaced antenna elements achieve high isolation. Within −10 dB of impedance bandwidth, an isolation greater than 25 dB is achieved by the array, with an antenna profile of 0.017 λ₀. Both simulation and experimental results demonstrate a strong correlation, affirming the design's effectiveness. The antenna array is capable of operating within the n78 band from 3.34 to 3.48 GHz, characterized by advantages such as high radiation efficiency, high isolation, and a low profile.