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PIER PIER B PIER C PIER M PIER Letters PIER Photonics
2026-07-16
Wideband 8-Antenna Array Design for Low Profile Metal Frame 5G Smartphones
By
Rong Cao,

    Dr. Rong Cao

    Department of Electrical Engineering

    Feng Chia University

    Taiwan

    Homepage

Chun-Yi Chen,

    Dr. Chun-Yi Chen

    Department of Electrical Engineering

    Feng Chia University

    Taiwan

    Homepage

Wei-Chih Wang

    Dr. Wei-Chih Wang

    Department of Electrical Engineering

    Feng Chia University

    Taiwan, R.O.C.

    Homepage

Progress In Electromagnetics Research C, Vol. 171, 482-491, 2026
doi:10.2528/PIERC26050604 | Google Scholar

Abstract
This paper presents a compact wideband eight-antenna array for sub-7 GHz 5G smartphone applications with a low-profile metal frame. By employing a multi-near-circular open-slot configuration integrated into the system ground and metal frame, the proposed design achieves wideband operation from 3.3 to 7.125 GHz, covering 5G NR bands n77/n78/n79 and NR-U bands n46/n96, without requiring additional decoupling structures. The antenna element occupies a compact volume of 8 × 3.5 × 4 mm3, enabling a low-profile implementation compatible with modern smartphone form factors. Measured results demonstrate a 6-dB impedance bandwidth, fully covering the target bands, with inter-element isolation higher than 10 dB and an envelope correlation coefficient (ECC) below 0.1. The measured total efficiency ranges from 40% to 86% across the operating band. Furthermore, the antenna array maintains stable performance under practical conditions, including hand and battery effects. The proposed design offers a simple and effective solution for achieving wideband, low-profile, and low-correlation MIMO performance in metal-frame smartphones.
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Citation
Rong Cao, Chun-Yi Chen, and Wei-Chih Wang, "Wideband 8-Antenna Array Design for Low Profile Metal Frame 5G Smartphones," Progress In Electromagnetics Research C, Vol. 171, 482-491, 2026.
doi:10.2528/PIERC26050604
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