Design and characterization of a minimized planar dual‐band MIMO circular ring antenna with high efficiency

Abstract

A minimized planar dual-band multiple-input multiple-output antenna with high efficiency for the fifth-generation applications is proposed in this paper. The designed antenna is composed of two identical radiating elements and a defected ground structure (DGS). Each radiating element is made up of a circular ring, a U-shaped microstrip, a T-shaped microstrip, and an L-shaped microstrip. A rectangular microstrip with a small square stub is connected to the DGS to improve the isolation. The size of the designed antenna element is 24 mm × 15 mm. The measured reflection coefficients are less than * 10 dB in the 5G New Radio n77/n78/n79 (3.3-4.2 and 4.8-4.96 GHz). The total peak gain and efficiency are greater than 3.5 dBi and 82%, respectively. The values of calculated envelope correlation coefficient are lower than 0.015. The proposed dual-band MIMO antenna is suitable for 5 G applications.