Printed symmetric inverted‐F antenna with a quasi‐isotropic radiation pattern

This article presents a tag antenna with a quasi-isotropic radiation pattern operating in the UHF band to eliminate the shadow zone in RFID systems. The proposed tag antenna has a symmetric inverted-F structure with a bent section and is printed on a 50 μm-thick PET substrate for easy and low-cost fabrication. The detailed design parameters of the antenna were optimized using a Pareto genetic algorithm in conjunction with the IE3D EM simulator. The optimized antenna shows 3.2% fractional bandwidth for S11 < −10 dB, more than 87% efficiency in the operating frequency band, and less than 6 dB gain deviation. The measured reading range between the tag and reader is between 1.4 and 2.2 m. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 927–930, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23247

[1]  Tomoyuki Hiroyasu,et al.  The new model of parallel genetic algorithm in multi-objective optimization problems - divided range multi-objective genetic algorithm , 2000, Proceedings of the 2000 Congress on Evolutionary Computation. CEC00 (Cat. No.00TH8512).

[2]  David E. Goldberg,et al.  Genetic Algorithms in Search Optimization and Machine Learning , 1988 .

[3]  Keskilammi,et al.  Using text as a meander line for RFID transponder antennas , 2004, IEEE Antennas and Wireless Propagation Letters.

[4]  Yahya Rahmat-Samii,et al.  Electromagnetic Optimization by Genetic Algorithms , 1999 .

[5]  K. Carver,et al.  Measured mutual coupling between microstrip antennas , 1981 .

[6]  Kourosh Mahdjoubi,et al.  Mutual coupling between circular disc microstrip antennas , 1987 .

[7]  Martin Fischer,et al.  Fully integrated passive UHF RFID transponder IC with 16.7-μW minimum RF input power , 2003, IEEE J. Solid State Circuits.

[8]  Kin-Lu Wong,et al.  Mutual coupling computation of probe‐fed circular microstrip antennas , 1995 .

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

[10]  Ikmo Park,et al.  Broadband RFID tag antenna with quasi-isotropic radiation pattern , 2005 .

[11]  Antti Ruhanen,et al.  Contactless radiation pattern measurement method for UHF RFID transponders , 2005 .

[12]  C. Soras,et al.  Analysis and design of an inverted-F antenna printed on a PCMCIA card for the 2.4 GHz ISM band , 2002 .

[13]  C. Dehollain,et al.  Remotely powered addressable UHF RFID integrated system , 2005, IEEE Journal of Solid-State Circuits.

[14]  Glenn S. Smith.  An analysis of the Wheeler method for measuring the radiating efficiency of antennas , 1977 .

[15]  H. A. Wheeler.  The Radiansphere around a Small Antenna , 1959, Proceedings of the IRE.

[16]  W. Kiranon,et al.  Simple and accurate formula for the resonant frequency of the circular microstrip disk antenna , 1995 .

[17]  Y. Tikhov,et al.  Impedance-matching arrangement for microwave transponder operating over plurality of bent installations of antenna , 2004 .

[18]  Hosung Choo,et al.  On the Wheeler cap measurement of the efficiency of microstrip antennas , 2005, IEEE Transactions on Antennas and Propagation.

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

[20]  Hang Wong,et al.  Accordion shape monofilar axial mode helix for RFID reader , 2006 .