A Compact Low-Profile Antenna for Millimeter-Wave 5G Mobile Phones

This paper presents a very low profile and simple antenna design for dual beam and dual-band operation to be employed in future 5G mobile phones operating in the millimeter-wave bands of 26.75-30.31 and 35.83-41.22 GHz. The two distinct resonances at 28 and 38 GHz are achieved using a meta-material-based structure consisting of a closed-ring resonator (CRR) and a split-ring resonator (SRR) by co-centrically combining two planar hexagonal rings; i.e., an inner split-ring resonator (SRR) and an outer closed-ring resonator (CRR). The antenna has a high gain of 4.5 dBi. The antenna also exhibits a dual-beam radiation pattern in one of its planes. The overall antenna size is 6 x 8 mm(2) and is manufactured using a low-cost PCB fabrication process. The antenna's dual-beam operation, broadband characteristics, high gain, and low profile makes it a potential candidate for future millimeter-wave mobile phones, especially in applications where space diversity is required.