ABSTRACT This paper presents a compact dual‐band MIMO antenna with enhanced isolation for smartphone applications. The basic structure of the antenna features two folded dipole elements arranged in a back‐to‐back layout, which realizes dual‐band operation. By transforming straight dipole antennas into U‐shaped folded structures and adopting a back‐to‐back configuration, the proposed antenna realizes self‐isolation in the upper frequency band, which stems from the fact that the common‐mode (CM) and differential‐mode (DM) impedances meet the mode cancellation conditions. As for the low‐frequency band, three U‐shaped slots etched into the ground plane allow for the synergistic regulation of the CM and DM impedances, meeting the cancellation conditions of both modes to attain good isolation. Experimental results demonstrate that the proposed antenna operates in dual bands covering the 3.41–3.60 and 4.95–5.40 GHz, with isolation better than 14 dB in the low band and 24 dB in the high band.
Li et al. (Fri,) studied this question.