Single-fed broadband CP bidirectional antenna with double-layer diagonally aligned plates for universal UHF-RFID applications

dc.contributor.authorDentri, Sitthichai
dc.contributor.authorPookkapund, Khanet
dc.contributor.authorLuadang, Bancha
dc.contributor.authorAkkaraekthalin, Prayoot
dc.contributor.authorPhongcharoenpanich, Chuwong
dc.date.accessioned2026-08-06T10:26:52Z
dc.date.available2026-08-06T10:26:52Z
dc.date.issued2020-01-01
dc.description.abstractThis research proposes a single-fed broadband circularly polarized (CP) bidirectional antenna operable in 840-960 MHz frequency band for readers of universal UHF-RFID applications. The proposed antenna is comprised of upper-layer conductor, lower-layer conductor, and wall patches. The upper-layer conductor consists of two diagonally aligned rectangular copper plates with a feeding gap at the center, and the lower-layer conductor is of two diagonally adjoined rectangular plates. The upper- and lower-layer conductors are adjoined with the wall patches. The diagonal alignment technique of the upper- and lower-layer plates was used to realize circular polarization and improve 3-dB axial ratio (AR) bandwidth. The double layers were deployed to improve impedance bandwidth (|S11| < -10 dB) and achieve bidirectional radiation pattern. The simulated impedance bandwidth and 3-dB AR bandwidth were 772.19-1014.6 MHz (27.13%) and 675-1000 MHz (38.80%), and the corresponding measured results were 759-1011 MHz (28.47%) and 648-1110 MHz (52.55%). The simulated LHCP/RHCP half-power beamwidth (HPBW), 3-dB AR beamwidth, and gain were 56° - 90°/54° - 92°, 60° - 104°, and 4.94 - 5.89 dBic, while the corresponding measured results were 52° - 98°/62° - 97°, 96° - 126°, and 4.28 - 5.72 dBic. As a result, the single-fed broadband CP bidirectional antenna is applicable to universal UHF-RFID readers. Besides, the novelty of this research lies in the use of diagonal alignment of conducting plates to achieve circular polarization and wider AR bandwidth.
dc.identifier.citationInternational Journal of Antennas and Propagation, 2020, 2020
dc.identifier.doi10.1155/2020/6561534
dc.identifier.issn16875869
dc.identifier.other2-s2.0-85094904470
dc.identifier.urihttps://dspace.kmitl.ac.th/handle/123456789/10499
dc.sourceInternational Journal of Antennas and Propagation
dc.titleSingle-fed broadband CP bidirectional antenna with double-layer diagonally aligned plates for universal UHF-RFID applications
dc.typeArticle

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