Array inspired wideband and high gain antenna with enhanced pattern diversity for 5G mm wave networks

This paper presents a four-port MIMO antenna array designed for future 5G millimeter-wave applications. Initially, a single antenna element is developed by loading two semi-circular stubs onto a basic rectangular patch to enhance the impedance bandwidth. To further improve the antenna's performance, a three-element array is designed and optimized for high-performance characteristics. Subsequently, the array is extended to a four-element MIMO configuration for diverse applications. The proposed antenna system is designed and analyzed using Rogers TMM-4 substrate with a thickness of 1.52 mm. This substrate is selected due to its low loss and dielectric properties similar to those of FR-4. The performance of all three antenna designs is evaluated in terms of S-parameters, gain versus frequency, radiation patterns, and radiation efficiency. Additionally, MIMO performance parameters are studied for the MIMO antenna configuration. The proposed antennas operate in the millimeter-wave frequency band ranging from 24.4 to 27.9 GHz. Beyond return loss and operational bandwidth, the array also offers high gain, and the investigation of MIMO performance metrics demonstrates excellent characteristics. To verify and validate the simulated results, hardware prototypes of both the standalone and array antennas are fabricated and measured. The measured results show good agreement with the simulated data. Finally, the performance of the proposed antenna is compared with recently published work. The results and comparison confirm that the proposed antenna features a compact size and simple structural configuration, while offering wide bandwidth, high gain, and acceptable MIMO parameter values. These attributes make the proposed antenna a strong candidate for integration into upcoming 5G devices operating in the millimeter-wave spectrum.