Highly efficient 4‐port self‐decoupled multiple‐input multiple‐output antenna pairs operating in n46 band for 5G smartphone applications

Abstract

A highly efficient self-isolated multiple-input multiple-output (MIMO) antenna system functioning in the n46 5G NR band (5.15–5.925 GHz) for smartphone implementation is discussed in this paper. The system is made up of two blocks of vertically printed antenna pairs, placed at the exact center of the side frames of the smartphone. Each block comprises of a self-isolated antenna pair with two inverted L-shaped radiators facing each other, a T-shaped isolating element, and a U-shaped structure placed at the back of the radiators, and is attached to the ground plane. A simple coaxial feeding structure is deployed to excite the L-shaped radiators. The T-shaped structure placed between the two radiators has a crucial role in minimizing the mutual coupling between the two radiators, and its arm serves as a radiator. The self-isolated antenna pair functions from 5.10 to 5.98 GHz, covering the entire n46 band (5.15–5.925 GHz) with over −16.8 dB isolation in the complete operating bandwidth. The parametric investigation of some ideal parameters and the antenna pair evolution stages to obtain the final structure is examined for a superior understanding of the functioning of the proposed MIMO smartphone system. The proposed self-decoupled antenna pair MIMO system operates with a very high radiation efficiency and gain in the complete operating bandwidth, with radiating efficiency, total efficiency, and peak gain greater than 92%, 85%, and 6 dB respectively. The lowest obtained envelope correlation coefficient (ECC) value is 0.025 between the two elements in the antenna pair, which is very low when compared with the ideal value of 0.5. Various other parameters like channel capacity loss (CCL), mean effective gain (MEG), total active reflection coefficient (TARC), and diversity gain (DG) of the proposed system are also calculated and examined with the experimental results to study the diversity performance of the proposed MIMO smartphone system. A prototype of the proposed 4-port MIMO smartphone system is fabricated and various parameters are examined. The coherence between the measured and the experimental outcomes stipulates that the proposed system is a capable contender for application in the upcoming 5G handheld devices.