Broadband unidirectional twin-element MIMO antenna scheme for mid-band 5G and WLAN laptops

• Published in: Scientific reports 2024-04, Vol.14 (1), p.9693-9693, Article 9693
• Main Authors: Luadang, Bancha, Janpangngern, Pisit, Pookkapund, Khanet, Dentri, Sitthichai, Krairiksh, Monai, Phongcharoenpanich, Chuwong
• Format: Article
• Language: English
• Subjects: 5G antenna; 639/166/987; 639/766; Antennas; Broadband antenna; Communications systems; Correlation coefficient; Coupling gap; Humanities and Social Sciences; Integrated antenna; MIMO antenna; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-60346-6

This research proposes a broadband unidirectional twin-element multiple-input-multiple-output (MIMO) antenna scheme for mid-band 5G and WLAN applications. The twin-element antenna scheme comprises two single-element antennas, and each single-element antenna consists of a T-shaped hemispherical feeding patch, left- and right-arm radiating patches, and a conjoined triangular ground plane. The twin-element MIMO antenna scheme is integrated with a laptop model functioning as the reflector. The measured impedance bandwidth (| S 11 |, | S 22 |≤ − 6 dB) are 55.32%, covering 3.4–6.0 GHz, and the measured mutual coupling (| S 12 |) is less than − 15 dB. The measured gain at the center frequency (4.5 GHz) is 4.585 dBi. Besides, the measured xz- and yz-plane cross-polarization levels are below − 25 dB and − 15 dB, respectively. The half-power beamwidth (HPBW) in the xz-plane at 3.5, 4.5, and 5.5 GHz are 99°, 92.8°, and 84.2°, and the corresponding HPBW in the yz-plane are 102°, 78°, and 102°. The measured xz- and yz-plane back lobe levels are below − 15 dB across the entire operating frequency band (3.5–5.5 GHz). The radiation pattern of the twin-element MIMO antenna scheme is of unidirectionality. Furthermore, the envelope correlation coefficient and diversity gain of the twin-element antenna scheme are  9.99 dB, respectively. The proposed broadband unidirectional twin-element MIMO antenna scheme is thus operationally suitable for mid-band 5G/WLAN communication systems. Essentially, this research is the first to propose a broadband twin-element MIMO antenna scheme for mid-band 5G/WLAN applications.