Four-Port Multi-Ring-Based MIMO Antenna for Wideband Applications

A simple and efficient four-port multi-ring Multiple-Input Multiple-Output (MIMO) antenna is proposed. It is intended to function in the 2.77-19 GHz wideband region, which consists of the Ku-band (12–18 GHz), X (8.2-12 GHz), and ultra-wideband (UWB) (3.1-10.6 GHz) bands. This 60×60 mm
²
antenna is developed on a FR4 substrate. Orthogonal placement of four antenna elements yields polarization diversity. At the center, the top substrate layer incorporates a Multi-Ring Decoupling Structure which improves isolation by more than 20 dB across the majority of operating bands. Thus, the antenna offered an impedance bandwidth of 16.23 GHz. Additionally, a peak gain of 6.8 dB and an efficiency ranging from 71 % to 94% are attained. The proposed MIMO antenna yielded improved MIMO diversity parameters, which include Mean Effective Gain, Diversity Gain, Total Active Reflection Coefficient, and Envelope Correlation Coefficient. The comparison of results demonstrated the novelty of the reported antenna with the recently reported MIMO antennas for the UWB and X-Ku-bands applications.