A Compact and Multi-Coupled MIMO Antenna System Applicable to Various Electronic Devices for Sub6 GHz Design

This paper presents a multi-coupled Multiple-Input Multiple-Output (MIMO) antenna system designed for laptops, routers, and base stations, characterized by multi-band capability, compact size, low manufacturing complexity, cost efficiency, and broad applicability. The system integrates multiple antennas of identical structure, implemented on a single-layer FR4 substrate, and employs feed coupling through multiple microstrip line branches to support low-frequency bands, LTE, Sub-6 GHz, 5G FR1, and WiFi 6E. The antenna ensures stable performance across varying device sizes and placement conditions. With a compact dimension of 59 × 10 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, the design is simplified, requiring no additional passive components, thereby reducing manufacturing costs. This makes it suitable for a wide range of applications, including laptops, routers, and base station devices. The MIMO antenna system achieves isolation below -10 dB, a maximum gain of 3.63 dBi, and a maximum efficiency of 85.3%, with an Envelope Correlation Coefficient (ECC) below 0.5 within the operating frequency bands, demonstrating excellent independent operation and spatial diversity. Simulated Specific Absorption Rate (SAR) and Power Density (PD) results indicate compliance with safety standards, posing no radiation hazard to human health. Experimental results validate the system's adaptability to various devices, offering a stable, reliable, and cost-effective solution for multi-band wireless communication applications.