Analysis on Tunable Circularly Polarized Antenna for Applications of UHF RFID Reader Devices
Abstract: A tunable circularly polarized (CP) patch antenna based on ferrite substrate is discussed in this paper, for universal ultra-high-frequency (UHF) RF identification (RFID) applications. Such antenna is composed of top dielectric layer printed with rectangular radiation patch, middle ferrite layer, and bottom dielectric layer printed with ground plane. The ferrite layer under an applied dc magnetic bias provides the CP radiation characteristic. Most importantly, ferrite layer can tune arbitrarily the operating frequency band in a wide range covering all the worldwide operating frequency bands of UHF RFID, by adjusting the dc magnetic bias. Theoretical analysis on the reason to realize CP properties without perturbation for the radiation patch and the tunability of operating frequency are firstly presented. Numerical results demonstrate that the proposed antenna, can be arbitrarily operated from 840 to 960 MHz with a narrow impedance bandwidth of about 7 MHz, a tunable gain level ranged from −1.9 to 2.5 dBic, and a wide 3-dB AR beamwidth of 120˚ over the impedance bandwidth.
文章引用: 吴凯敏 , 赵雪峰 , 黄勇军 , 孙海斌 , 文光俊 (2015) 一种UHF RFID阅读器终端可调谐圆极化天线研究。 天线学报， 4， 1-8. doi: 10.12677/JA.2015.41001
 Welbourne, E., Battle, L., Cole, G., Gould, K., Rector, K., Raymer, S., Balazinska, M. and Borriello, G. (2009) Building the internet of things using RFID: The RFID ecosystem experience. IEEE Internet Computing, 13, 48-55.
 Chen, Z.N. and Qing, X. (2010) Asymmetric-circular shaped slotted microstrip antennas for circular polarization and RFID applications. IEEE Transactions on Antennas and Propagation, 58, 3821-3828.
 Rao, K.S., Nikitin, P.V. and Lam, S.F. (2005) Antenna design for UHF RFID tags: A review and a practical application. IEEE Transactions on Antennas and Propagation, 53, 3870-3876.
 Chen, Z.N., Qing, X. and Chung, H.L. (2009) A universal UHF RFID reader antenna. IEEE Transactions on Microwave Theory and Techniques, 57, 1275-1282.
 Wang, Z., Fang, S., Fu, S. and Jia, S. (2011) Single-fed broadband circularly polarized stacked patch antenna with horizontally meandered strip for universal UHF RFID applications. IEEE Transactions on Microwave Theory and Techniques, 59, 1066-1073.
 Pozar, D.M. (1992) Radiation and scattering characteristics of microstrip antennas on normally biased ferrite substrates. IEEE Transactions on Antennas and Propagation, 40, 1084-1092.
 Mishra, R.K., Pattnaik, S.S. and Das, N. (1993) Tuning of microstrip antenna on ferrite substrate. IEEE Transactions on Antennas and Propagation, 41, 230-233.
 Sigalov, M., Shavit, R., Joffe, R. and Kamenetskii, E.O. (2013) Manipulation of the radiation characteristics of a patch antenna by small ferrite disks inserted in its cavity domain. IEEE Transactions on Antennas and Propagation, 61, 2371-2379.
 Zervos, T., Alexandridis, A.A., Lazarakis, F., Pissas, M., Stamopoulos, D., Angelopoulos, E.S. and Dangakis, K. (2012) Design of a polarisation reconfigurable patch antenna using ferrimagnetic materials. IET Microwaves, Antennas & Propagation, 6, 158-164.
 Hwang, K.C. and Eom, H.J. (2005) Tunable notch filter of ferrite-filled grooves in parallel plates. IEEE Microwave and Wireless Components Letters, 15, 363-365.
 Huang, Y., Wen, G., Li, T. and Xie, K. (2010) Positive-negative-positive metamaterial consisting of ferrimagnetic host and wire array. Applied Computational Electromagnetics Society Journal, 25, 696-702.
 Huang, Y.J., Wen, G.J., Yang, Y.J. and Xie, K. (2012) Tunable dual-band ferrite-based metamaterials with dual negative refractions. Applied Physics A, 106, 79-86.
 Lax, B. and Button, K.J. (1962) Microwave ferrites and ferrimagnetics. McGraw-Hill, New York.
 Pozar, D.M. (2009) Microwave engineering. John Wiley & Sons, New York.