Gain Enhancement of a Dual-Polarized U-Shaped Aperture Antenna Using Metamaterial-Embedded Aluminum Plane for 5G Applications

This paper introduces a compact, high-gain dual-polarized U-shaped aperture antenna designed for 5G communication systems, highlighting the impact of a metamaterial-embedded aluminum plane placed beneath the lower substrate. Dual polarization is achieved through two U-shaped apertures, which also improve impedance matching and coupling efficiency. The antenna is built using two substrates separated by an air gap, with orthogonal feed lines below the lower substrate powering a square radiating element situated beneath the upper substrate. The U-shaped apertures, etched into the ground plane above the lower substrate, facilitate efficient coupling of electromagnetic waves. Thanks to the integration of the metamaterial (MTM)-embedded aluminum plane, the antenna exhibits a significant performance boost: the operational bandwidth is extended from 500 MHz to over 800 MHz, the inter-port isolation improves from 26 dB to over 32 dB, the realized gain increases from 6.27 dBi to 9.35 dBi, and the radiation efficiency improves from 77% to over 90%. Simulation results show that the metamaterial-patterned aluminum plane significantly enhances the antenna’s gain by almost 3 dB, while the design also demonstrates excellent port isolation and over 90% radiation efficiency. All design and simulation steps were carried out using both CST and HFSS software, and RO4003C was chosen as the substrate material (thickness: 0.813 mm, dielectric constant: 3.5).