Near-Field HF-RFID and CMA-Based Circularly Polarized Far-Field UHF-RFID Integrated Tag Antenna

Abstract

This research proposes an integrated high-frequency (HF) and ultrahigh-frequency (UHF) passive radio frequency identification (RFID) tag antenna for near-field (13.56 MHz) and far-field (920–925 MHz) communication. This tag antenna is advantageous for the applications with lossy material in the near-field communication and mitigates polarization loss in the far-field communications. The HF-RFID tag antenna is of square spiral structure, and the circularly polarized UHF-RFID structure consists of a square loop radiator with cascading loop feeding and shorted stub. The structure of HF-RFID tag antenna situated inside the circularly polarized UHF-RFID tag can avoid the significant effect of the near-field magnetic coupling from the square loop. The UHF-RFID tag antenna is realized by using characteristic mode analysis for wideband circular polarization. The HF-RFID structure is conjugate-matched with NXP NT3H2111 chip, and the UHF-RFID structure is conjugate-matched with NXP G2X chip. Simulations were carried out, and an antenna prototype was fabricated. The experimental results reveal that the radiation pattern of UHF-RFID tag antenna is bidirectional with a gain of 0.31 dBic. The impedance bandwidth covers the frequency range of 903–944 MHz, and the axial ratio in boresight direction at 922.5 MHz is 1.67 dB, with the axial ratio bandwidth over 863–938 MHz. The maximum near-field and far-field reading ranges are 4.9 cm and 8.7 m. The proposed integrated dual-band passive tag antenna is operationally ideal for HF-RFID and UHF-RFID applications.

Quadri-Cluster Broadband Circularly-Polarized Sequentially-Rotated Metasurface-Based Antenna Array for C-Band Satellite Communications

“…The copolarization and cross-polarization are consistent with LHCP and RHCP radiations, respectively. The AR can be determined from equation ( 15) as [49] ( ) 20 15 The simulated IBW and ARBW were 74.57% (4 -8.4 GHz) and 56.4% (4.3 -7.63 GHz, respectively), and the measured IBW and ARBW were 87.74% (4 -9 GHz) and 57.6% (4.2 -7.6 GHz, respectively). The simulated and measured results were agreeable.…”

CMA-Based Quadruple-Cluster Leaf-Shaped Metasurface-Based Wideband Circularly-Polarized Stacked-Patch Antenna Array for Sub-6 GHz 5G Applications

“…The co-pol and cross-pol electric fields between the transmitting and receiving antennas correspond to E co−pol and E cross−pol , which in turn correspond to VOLUME 11, 2023 RHCP and LHCP. The AR is determined by equation ( 4) [30].…”

“…In [7], a 4 × 4 dipole with hexagonal-shaped parasitic patches CP antenna array achieves an IBW of 27.7% (26.26 -34.71 GHz) and 3-dB ARBW of 28.5% (27)(28)(29)(30)(31)(32)(33)(34)(35)(36). In [8], a magnetoelectric dipole CP antenna achieves an IBW of 27.2% (4.77 -6.27 GHz) and 3-dB ARBW of 42.3% (4.1 -6.3 GHz).…”

Dual‐polarized metasurface‐based monopole antenna design using characteristics mode theory for UHF RFID applications

“…In practical, the MTS layer is fixed to the underneath of antenna with plastic supporting posts at air‐gap of 0.25 λ o shown in Figure 1D. The modal analysis 71 is performed in full‐wave CST studio suite and antenna is designed in ANSYS HFSS solver. From Figure 2, it is observed that monopole antenna offers orthogonal radiation modes (mode‐1 and mode‐2).…”