Extremely Low-Profile Multimode Patch Antenna Pair Decoupled by Electric and Magnetic Coupling Cancellation for 5G Mobile Terminals

A novel coupling cancellation path construction decoupling method based on the electric and magnetic coupling cancellation principle and an extremely low-profile multimode patch antenna pair for 5G mobile terminals are proposed. By adopting two parasitized antenna elements with different internal couplings to form an antenna pair, two main cancellable coupling paths, including electric and magnetic couplings, can be constructed between the two feeding ports arranged at the diagonal position. The realized antenna pair can thus be isolated with multimode characteristics. To verify the validity and versatility of this decoupling method, the extremely low-profile dual-mode one-quarter patch antenna pairs, a dual-mode one-half patch antenna pair, and a multimode patch antenna pair are proposed. Benefiting from the extremely low profile of only 0.508 mm, the antenna pair can not only be competitive when directly integrated with the terminal printed circuit board (PCB) but also can be deployed in the extremely narrow gap between the terminal battery and back cover. The multimode patch antenna pair and the $4\times 4$ multiple-input–multiple-output (MIMO) antenna formed by its direct integration with the terminal PCB are fabricated and tested, and the results are acceptable. The proposed decoupling method is effective and universal, and the proposed patch antenna pair has a compact structure, extremely low profile, and high isolation and can be flexibly integrated with an actual terminal, which is very attractive to mobile terminals.