High-Isolation 5G Repeater Antenna Using a Novel DGS and an EBG

Abstract

Repeaters have been widely used to improve communication quality and extend the coverage areas of wireless communication systems. However, mutual coupling between the Tx and Rx antennas significantly deteriorates the performance of repeater systems. This work presents a high-isolation repeater antenna operating in a frequency range of 3.6–3.7 GHz in a 5G communication system. Perpendicularly arranged microstrip patch antennas are used because this arrangement can lead to greater isolation than a parallel arrangement. However, the perpendicular arrangement results in radiation pattern distortion due to the ground mode. A novel defected ground structure (DGS) is developed to suppress the ground mode and simultaneously reduce the mutual coupling between the Tx and Rx antennas. An electromagnetic bandgap (EBG) is additionally employed to further increase isolation. The measurement results of a fabricated repeater antenna show no radiation pattern deformation and an isolation improvement of 28 dB over the repeater antenna without the DGS and EBG.

Enhancing gain and isolation of a quad-element MIMO antenna array design for 5G sub-6 GHz applications assisted with characteristic mode analysis

“…A foundational concept of CMA involves the weighted aggregate of perpendicular eigencurrents can be used to represent the entire current brought forth by an advancing electromagnetic field going via a structure that conducts electricity or a framework that emits . These eigencurrents depend on both the excitation vector and the geometry and material of the structure 28 , 29 . Equation ( 13 ) shows the entire current, and the influence of eigencurrents on the whole current are determined by modal coefficients of weight .…”