Wideband Sub-6 GHz MIMO Antenna for Full-Screen Metal Rim Smartphones

A wideband 8-element multiple-input multiple-output (MIMO) antenna for fifth-generation (5G) smartphones with a full-screen and a metal rim is presented. A single antenna element consists of two slots, open and closed, both placed solely on the metal rim. Wideband operation is based on the interactions of multiple slot modes, their simultaneous excitation, and overlapping resonance bands. The antenna occupies only the metal rim and does not have any matching circuits or decoupling structures. This simple zero ground clearance design enables a full screen which is a highly desirable property in modern mobile devices. A prototype of the proposed antenna design is manufactured and the measurements verify that the design covers a wide frequency band of 3.4–6.1GHz, isolation over 11.7dB, and good total efficiency of 57.6–84.9%. The performance of the antenna with the user’s hand is verified with simulations.