A Wideband Single-Fed, Circularly-Polarized Patch Antenna with Enhanced Axial Ratio Bandwidth for UHF RFID Reader Applications

Research output: Contribution to journalJournal articleResearchpeer-review

  • Junlong Li
  • Hui Liu
  • Shuai Zhang
  • Miaohui Luo
  • Yuan Zhang
  • Sailing He

Abstract

A wideband single-fed, circularly-polarized patch antenna with enhanced axial ratio bandwidth for RFID reader application is proposed. The antenna consists of a modified half E-shaped patch, a near-field resonant parasitic (NFRP) patch, and four rotated vertical metallic plates on the ground plane. The metallic plates surrounding the main radiator of the modified half E-shaped patch antenna are fabricated vertically on the ground plane. The operating frequency of the antenna decreases substantially with the vertical metallic plates, which is important for miniaturization of RFID applications. With an elliptical slot and a cut on the modified half E-shaped patch, antenna impedance bandwidth and CP performance both improve. A truncated corner patch as an NFRP element can generate an additional CP radiation mode and further enhances the axial ratio and impedance bandwidth. The measured results show that the antenna has an impedance bandwidth of 14.2% (833-960MHz), a 3-dB AR bandwidth of 9.0% (846-926MHz), and an average gain of 7.3 dBi over a 3dB AR bandwidth. The proposed antenna has a compact size and a low profile ( 0.45λ×0.45λ×0.074λ).
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Details

A wideband single-fed, circularly-polarized patch antenna with enhanced axial ratio bandwidth for RFID reader application is proposed. The antenna consists of a modified half E-shaped patch, a near-field resonant parasitic (NFRP) patch, and four rotated vertical metallic plates on the ground plane. The metallic plates surrounding the main radiator of the modified half E-shaped patch antenna are fabricated vertically on the ground plane. The operating frequency of the antenna decreases substantially with the vertical metallic plates, which is important for miniaturization of RFID applications. With an elliptical slot and a cut on the modified half E-shaped patch, antenna impedance bandwidth and CP performance both improve. A truncated corner patch as an NFRP element can generate an additional CP radiation mode and further enhances the axial ratio and impedance bandwidth. The measured results show that the antenna has an impedance bandwidth of 14.2% (833-960MHz), a 3-dB AR bandwidth of 9.0% (846-926MHz), and an average gain of 7.3 dBi over a 3dB AR bandwidth. The proposed antenna has a compact size and a low profile ( 0.45λ×0.45λ×0.074λ).
Original languageEnglish
JournalIEEE Access
Volume6
Pages (from-to)55883-55892
Number of pages10
ISSN2169-3536
DOI
Publication statusPublished - Oct 2018
Publication categoryResearch
Peer-reviewedYes
ID: 287335342