A Compact Strip Dipole Coupled Split-Ring Resonator Antenna for RFID Tags

A compact strip dipole coupled split-ring resonator (SRR) antenna is proposed for radio-frequency identification (RFID) tag applications. The antenna has a simple and uniplanar structure and can be designed to conjugate match to the tag chip. Design details are presented and a tag chip of impedance (33-j112) Ω at 915 MHz is used to verify the design. The simulated and measured input impedances of the prototype antenna are (34+j116) Ω and (38+j94) Ω, respectively, which are very close to the conjugate of the chip impedance. Simulated and measured radiation patterns are in good agreement and are nearly omnidirectional, especially in the H-plane. The minimum power transmitted by the reader and reflected back by the tag with detectable signals at the reader is also measured at two distances of about 1.5λ0 and 3λ0 using a commercially available reader card. The results are satisfactory.

[1]  G. F. Engen,et al.  Thru-Reflect-Line: An Improved Technique for Calibrating the Dual Six-Port Automatic Network Analyzer , 1979 .

[2]  G. Marrocco,et al.  The art of UHF RFID antenna design: impedance-matching and size-reduction techniques , 2008, IEEE Antennas and Propagation Magazine.

[3]  K. Gupta,et al.  Microstrip Lines and Slotlines , 1979 .

[4]  C. Pyo,et al.  Design of RFID tag antennas using an inductively coupled feed , 2005 .

[5]  Constantine A. Balanis,et al.  Antenna Theory: Analysis and Design , 1982 .

[6]  A. Toccafondi,et al.  Compact load-bars meander line antenna for UHF RFID transponder , 2006, 2006 First European Conference on Antennas and Propagation.

[7]  Li Yang,et al.  Design, Development and Integration of Novel Antennas for Miniaturized UHF RFID Tags , 2009, IEEE Transactions on Antennas and Propagation.

[8]  W. X. Zhang,et al.  Broadband CPW-fed RFID antenna at 5.8 GHz , 2006 .

[9]  Raj Mittra,et al.  Indirect coupling method for RFID tag antenna design , 2010 .

[10]  Klaus Finkenzeller,et al.  Book Reviews: RFID Handbook: Fundamentals and Applications in Contactless Smart Cards and Identification, 2nd ed. , 2004, ACM Queue.

[11]  S.F. Lam,et al.  Power reflection coefficient analysis for complex impedances in RFID tag design , 2005, IEEE Transactions on Microwave Theory and Techniques.

[12]  G. Marrocco.  Gain-optimized self-resonant meander line antennas for RFID applications , 2003, IEEE Antennas and Wireless Propagation Letters.

[13]  S.M. Weigand.  Compact microstrip antenna with forward-directed radiation pattern for RFID reader card , 2005, 2005 IEEE Antennas and Propagation Society International Symposium.

[14]  K. Kurokawa,et al.  Power Waves and the Scattering Matrix , 1965 .

[15]  Powen Hsu,et al.  CPW-fed folded-slot antenna for 5.8 GHz RFID tags , 2004 .

[16]  Powen Hsu,et al.  HYBRID LOOP ANTENNA FOR 2.4-GHz RFID TAGS , 2005 .

[17]  P. Nikitin,et al.  Antenna design for UHF RFID tags: a review and a practical application , 2005, IEEE Transactions on Antennas and Propagation.

[18]  Hyosang Moon,et al.  Inductively Coupled Compact RFID Tag Antenna at 910 MHz With Near-Isotropic Radar Cross-Section (RCS) Patterns , 2007, IEEE Antennas and Wireless Propagation Letters.

[19]  J. Yeo,et al.  A Passive RFID Tag Antenna Installed in a Recessed Cavity in a Metallic Platform , 2010, IEEE Transactions on Antennas and Propagation.

[20]  R. A. Burberry,et al.  Antenna problems in RFID systems , 1999 .

[21]  Yeonsik Yu,et al.  Dual-band slot-coupled dipole antenna for 900MHz and 2.45 GHz RFID tag application , 2006 .