A 5G smartphone-oriented dual-band dual-antenna system designed via characteristic mode theory and surface current analysis

Abstract In this research, a compact dual-band dual-antenna system with mutual coupling reduction based on characteristic mode theory and surface current distribution for 5G mobile terminals is proposed. The edge-to-edge distance between two antennas is only 5 mm. The dimensions of the antenna syste...

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Main Authors: Zhaozhi Gu, Wenhan Li, Shibao Li
Format: Article
Language:English
Published: Nature Portfolio 2025-07-01
Series:Scientific Reports
Subjects:
Online Access:https://doi.org/10.1038/s41598-025-12308-9
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author Zhaozhi Gu
Wenhan Li
Shibao Li
author_facet Zhaozhi Gu
Wenhan Li
Shibao Li
author_sort Zhaozhi Gu
collection DOAJ
description Abstract In this research, a compact dual-band dual-antenna system with mutual coupling reduction based on characteristic mode theory and surface current distribution for 5G mobile terminals is proposed. The edge-to-edge distance between two antennas is only 5 mm. The dimensions of the antenna system are 6 mm × 34 mm (approximately 0.07λmin × 0.41λmin, where λmin corresponds to the lowest operational frequency). The design comprises two modified inverted-F antenna elements with parasitic feeding, which are arranged in a back-to-back configuration. A defected ground structure (DGS) and a neutralization line (NL) are employed for decoupling in the lower (3.3–3.6 GHz) and upper (5.1–5.9 GHz) bands, respectively, achieving isolation levels of |S₂₁|< –25.5 dB and < –23.3 dB. The proposed system demonstrates compact geometry, low-cost fabrication, and scalability for array applications. This study presents a systematic design methodology that integrates characteristic mode analysis with current distribution optimization. The proposed approach enables direct translation of current distributions into physical antenna parameters, effectively eliminating empirical trial-and-error processes while establishing a reproducible design paradigm for future antenna development.
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issn 2045-2322
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publishDate 2025-07-01
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spelling doaj-art-c8bcd8f576794d03abb2f9954dcb0ce32025-08-20T04:01:52ZengNature PortfolioScientific Reports2045-23222025-07-0115111210.1038/s41598-025-12308-9A 5G smartphone-oriented dual-band dual-antenna system designed via characteristic mode theory and surface current analysisZhaozhi Gu0Wenhan Li1Shibao Li2School of Oceanography and Space Informatics, China University of Petroleum (East China)School of Oceanography and Space Informatics, China University of Petroleum (East China)School of Oceanography and Space Informatics, China University of Petroleum (East China)Abstract In this research, a compact dual-band dual-antenna system with mutual coupling reduction based on characteristic mode theory and surface current distribution for 5G mobile terminals is proposed. The edge-to-edge distance between two antennas is only 5 mm. The dimensions of the antenna system are 6 mm × 34 mm (approximately 0.07λmin × 0.41λmin, where λmin corresponds to the lowest operational frequency). The design comprises two modified inverted-F antenna elements with parasitic feeding, which are arranged in a back-to-back configuration. A defected ground structure (DGS) and a neutralization line (NL) are employed for decoupling in the lower (3.3–3.6 GHz) and upper (5.1–5.9 GHz) bands, respectively, achieving isolation levels of |S₂₁|< –25.5 dB and < –23.3 dB. The proposed system demonstrates compact geometry, low-cost fabrication, and scalability for array applications. This study presents a systematic design methodology that integrates characteristic mode analysis with current distribution optimization. The proposed approach enables direct translation of current distributions into physical antenna parameters, effectively eliminating empirical trial-and-error processes while establishing a reproducible design paradigm for future antenna development.https://doi.org/10.1038/s41598-025-12308-95G MIMODual-antenna systemCharacteristic mode theorySurface current distributionNeutralization line (NL)Defected ground structure (DGS)
spellingShingle Zhaozhi Gu
Wenhan Li
Shibao Li
A 5G smartphone-oriented dual-band dual-antenna system designed via characteristic mode theory and surface current analysis
Scientific Reports
5G MIMO
Dual-antenna system
Characteristic mode theory
Surface current distribution
Neutralization line (NL)
Defected ground structure (DGS)
title A 5G smartphone-oriented dual-band dual-antenna system designed via characteristic mode theory and surface current analysis
title_full A 5G smartphone-oriented dual-band dual-antenna system designed via characteristic mode theory and surface current analysis
title_fullStr A 5G smartphone-oriented dual-band dual-antenna system designed via characteristic mode theory and surface current analysis
title_full_unstemmed A 5G smartphone-oriented dual-band dual-antenna system designed via characteristic mode theory and surface current analysis
title_short A 5G smartphone-oriented dual-band dual-antenna system designed via characteristic mode theory and surface current analysis
title_sort 5g smartphone oriented dual band dual antenna system designed via characteristic mode theory and surface current analysis
topic 5G MIMO
Dual-antenna system
Characteristic mode theory
Surface current distribution
Neutralization line (NL)
Defected ground structure (DGS)
url https://doi.org/10.1038/s41598-025-12308-9
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