High-Isolation MIMO Antenna with a hybrid Decoupling Structure

The demand for improved communication quality has rapidly increased. With the advantages of high channel capacity and transmission rates, MIMO antennas have attracted significant attention in wireless communications. This research presents a High-Isolation Dual-Band MIMO Antenna using a hybrid decoupling structure and a ground stub to mitigate mutual coupling and enhance antenna performance characteristics. The proposed dual-band MIMO antenna with high isolation is designed using a hybrid decoupling method that incorporates grounded stubs and defected ground structures. The final dimension of the antenna is 58 mm × 34 mm × 1.6 mm. It covers two operating frequency bands: 2.37-3.71 GHz and 4.07-5.73 GHz, with relative bandwidths of 44.08% and 33.88%, respectively. By expanding the ground with a rectangular stub and etching a slot cut in the middle part of the metal, the antenna achieves isolation levels of over 27 dB and 42 dB in the two operating bands, respectively, and the envelope correlation coefficient (ECC) is less than 0.0025. The antenna features a simple structure, excellent omnidirectional radiation characteristics, and high isolation. It covers the 3.4–3.6 GHz and 4.8–5 GHz bands specified in the 5G spectrum standards for non-millimeter-wave antennas.