Dual-fed wideband MIMO antenna system design for 5G applications with increased gain with superstrate

Abstract

In this study, a compact microstrip MIMO antenna system design with broadband for fifth generation (5G) mobile applications, also known as the next generation, is presented. The proposed antenna system consists of two identical log-periodic dipole antennas (LPDA) placed at an angle of 90° to each other. LPDAs, each consisting of 5 element arrays, are designed with Rogers RT5880 dielectric material with a thickness of 0.508mm and a relative permeability of 2.2. The total size of the MIMO antenna system is determined as 20x20 mm2, where each LPDA's size is 4.15x13 mm2. The proposed antenna system offers impedance bandwidth in the 28 GHz resonance and frequency range of 26.2-30.4 GHz. However, an isolation level above 25 dB was achieved without the need for any additional structure between MIMO elements. To increase the gain value, a superstrate with 1.52 mm height and relative permeability of 3 was also added on the MIMO antenna system. Thus, a gain increase of over 50% was achieved for the whole operating band with this superstrate. With this top layer added, an increase of over 50% has been achieved in the recommended antenna gain for the entire operating band. All the designs and simulations in the study were carried out with the moment based HyperLynx 3D EM package program. © 2021 IEEE.