A Miniaturized RHCP Slot Antenna for Wideband Applications including Sub-6 GHz 5G

Mohammed, Atyaf H, Alnahwi, Falih M, Al-Yasir, Yasir and Ekpo, Sunday Cookey ORCID: https://orcid.org/0000-0001-9219-3759 (2025) A Miniaturized RHCP Slot Antenna for Wideband Applications including Sub-6 GHz 5G. Technologies, 13 (6). 254. ISSN 2227-7080

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Abstract

The rapid development of 5G and next-generation wireless systems has increased the demand for antennas that support circular polarization (CP), wide frequency coverage, and compact size. Achieving wideband CP performance in a low-profile and simple structure remains a key challenge for modern antenna designs. In response to this, this paper presents a compact wide-slot antenna with a single feed, offering a wide operational bandwidth and circularly polarized radiation. The proposed design is excited by a 50 Ohm microstrip feed line, and it is fabricated on (54×50×1.6 mm3) FR4 dielectric substrate. On the bottom side of the dielectric substrate, the ground plane is engraved to form a square-shaped radiating slot. The shape of the tuning stub of the antenna is modified in order to attain wide impedance bandwidth and axial ratio bandwidth (ARBW). The modifications include inserting a rectangular strip and thin horizontal strips to the tuning stub after tapering its upper corner. On the other hand, the radiating slot is appended by two rectangular stubs. The radiation of the resulted structure has a right-hand circular polarization (RHCP). The measured results of the proposed antenna show a -10dB impedance bandwidth equal to 78% (2.65 GHz, 2.08-4.73 GHz), whereas its broadside 3-dB ARBW is 71.6% over the frequencies (2.31 GHz, 2.07-4.38 GHz), which is compatible with various wireless communication applications. Furthermore, the peak value of the measured gain is equal to 4.68 dB, and its values is larger than 2 dBi along the operational bandwidth of the antenna.