Compact circular MIMO antenna with defected ground structure (DGS) for improved isolation in 5G sub-6GHz mobile systems

Al Gburi, Ahmed Jamal Abdullah and Megahed, Amany A. and Elabd, Rania Hamdy (2025) Compact circular MIMO antenna with defected ground structure (DGS) for improved isolation in 5G sub-6GHz mobile systems. Results in Engineering, 27. pp. 1-14. ISSN 2590-1230

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Abstract

This work introduces a compact circular MIMO antenna designed specifically for sub-6 GHz 5 G mobile applications. The antenna features two circular radiating elements arranged orthogonally to each other, incorporating a circular ring and additional side stubs to enhance both bandwidth and impedance matching. A partially slotted ground plane with curved cuts is employed to reduce capacitive effects and further extend the operational bandwidth. The design is implemented on an FR4 substrate with compact dimensions of 0.3λ₀ × 0.6λ₀ × 0.0242λ₀ at 4.5 GHz, achieving a wide impedance bandwidth of 3.0 to 6.5 GHz—covering major 5 G frequency bands such as n77, n78, and n79. To improve port isolation, a rectangular defected ground structure (DGS) is introduced, effectively reducing mutual coupling down to -53 dB. Both simulated and experimental results show excellent isolation performance (ranging from -15 dB to -55 dB), high radiation efficiency of up to 95 %, and a peak gain reaching 11.5 dBi. Evaluation of MIMO characteristics—including Diversity Gain (DG), Envelope Correlation Coefficient (ECC), and Total Active Reflection Coefficient (TARC)—confirms the antenna’s suitability for multiport systems. Additionally, Specific Absorption Rate (SAR) analysis demonstrates compliance with safety standards for handheld device integration. Overall, the proposed antenna offers a robust solution for modern sub-6 GHz 5 G communication systems.

Item Type:	Article
Uncontrolled Keywords:	Circular shaped antenna, Mutual coupling (MC), MIMO, Defected ground structure (DGS), Specific absorption rate (SAR), Wide band, 5G Sub 6GHz, Mobile systems
Divisions:	Faculty Of Electronics And Computer Technology And Engineering
Depositing User:	Sabariah Ismail
Date Deposited:	17 Aug 2026 07:56
Last Modified:	17 Aug 2026 07:56
URI:	http://eprints.utem.edu.my/id/eprint/30240
Statistic Details:	View Download Statistic

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