A Novel Design for Compact Multiband MIMO Antennas

This paper presents a compact multi-band MIMO antenna design. By employing slot-coupled feeding and slotting on the radiating patch, the low-frequency mode of the antenna element is excited, achieving a miniaturized design. The proposed antenna element structure has dimensions of only 0.26λ×0.26λ, and it can generate three operating bands at 2.53 GHz, 4.73 GHz, and 7.05 GHz. The overall size of the 2-element MIMO antenna is just 0.56λ ×0.41λ, with a very compact element spacing. Simulation results indicate that the MIMO antenna achieves radiation gains of 4.3 dBi,4.0 dBi, and 6.2 dBi at 2.53 GHz, 4.73 GHz, and 7.05 GHz, respectively. The isolation at the operating frequencies is 52 dB, 15 dB, and 18 dB, respectively. This MIMO antenna features a highly compact size and excellent isolation. Index Terms—MIMO antenna, multiband, high isolation