Wideband Self-decoupled Dual Antennas for 5G MIMO Operation in Smartphone

Two wideband self-decoupled dual antennas for the fifth-generation (5G) multiple-input, multiple-output (MIMO) operation in a smartphone are presented. The dual antennas are composed of a differential mode (DM) antenna and a common mode (CM) antenna. They are integrated into the same radiator for size reduction. Their feeding positions are arranged asymmetrically on the radiator, and the high isolation and low envelope correlation coefficients (ECCs) can be obtained without the need of an external decoupled structure. For the first example, the dual antennas are integrated into the rectangular radiator and have a size of 5 x 39 mm
²
(about 0.05λ x 0.43λ) for operating at 5G n78 band (3.3-3.8 GHz). The dual antennas show an acceptable isolation of better than 12 dB and their ECC is much less than 0.05 in the operating frequency band. The second example follows the design rule of the first example. The dual antennas are integrated into the T-shaped radiator and show a high isolation of more than 20 dB in the 5G n77 band (3.3-4.2 GHz). Details of the two wideband self-decoupled dual antennas are presented and discussed.