A Compact MIMO Antenna with Improved Isolation for ISM, Sub-6 GHz, and WLAN Application

Area of Science:

• Electrical Engineering
• Electromagnetics
• Antenna Theory

Background:

• Modern wireless communication systems require compact antennas capable of multi-band operation.
• Achieving high isolation in Multiple-Input Multiple-Output (MIMO) antennas is crucial for reliable performance.
• Existing antenna designs often struggle to balance size, isolation, and multi-band capabilities.

Purpose of the Study:

• To propose and validate a compact two-element MIMO antenna.
• To achieve improved isolation for triple-band applications.
• To ensure stable gain and radiation patterns across the operating frequencies.

Main Methods:

• Design of a two-element MIMO antenna featuring a novel decoupling structure with etched slots.
• Integration of three stubs of varying lengths on each element for triple-band operation.
• Simulation and measurement of antenna parameters including S-parameters, isolation, envelope correlation coefficient (ECC), and diversity gain (DG).

Main Results:

• The antenna operates effectively at 2.4 GHz (2.29–2.47 GHz), 3.5 GHz (3.34–3.73 GHz), and 5.5 GHz (4.57–6.75 GHz) with |S11| < -10 dB.
• High isolation (>20 dB) and low envelope correlation coefficient (<0.003) were achieved.
• Stable gain and radiation patterns were observed, with a diversity gain of 9.98 dB.

Conclusions:

• The proposed compact MIMO antenna demonstrates excellent triple-band performance with superior isolation.
• The novel decoupling structure effectively enhances isolation, making it suitable for demanding wireless applications.
• The antenna's compact size and performance characteristics position it as a strong candidate for Industrial, Scientific, and Medical (ISM), 5G sub-6 GHz, and Wireless Local Area Network (WLAN) systems.