Reconfigurable 28/38 GHz wideband and high isolation MIMO antenna for advanced mmWave applications

This research presents a high-performance MIMO antenna for 5G and next-generation wireless communication. Operating in the millimeter wave (mmWave) band, the antenna offers frequency and radiation pattern reconfigurability. A compact-size antenna, with dimensions of 22.5x30x0.787 mm3, exhibited peak gains of 7.5 and 6.5 dBi at 28 and 38 GHz, respectively. The envelope correlation coefficient (ECC) was improved through proper spacing and adopting a simple decoupling technique, ensuring efficient MIMO operation. Based on the evaluated reflection coefficients, bandwidths of 2.3 and 12.9 GHz at 28 and 38 GHz, respectively have been accomplished. The mutual coupling between antenna elements was minimized achieving improved isolation of -37 and -40 dB at the desired frequency bands. This corresponds to an envelope correlation coefficient and diversity gain of 1.6x10-4 and 9.99, respectively. The antenna gain was enhanced by incorporating a metasurface designed to optimize gain and improve isolation. For a single-element antenna, the gain was enhanced to 7.9 and 7.3 dBi at frequencies of 28 GHz, and 38 GHz, respectively. The antenna design incorporates frequency and pattern reconfigurability through switching selected antenna ports and patches. The proposed design's simplicity and antenna compactness make it practical for various mmWave communication systems.