A Novel Dual-Antenna Structure for UHF RFID Tags

A novel dual-antenna tag structure for UHF radio-frequency identification (RFID) systems is proposed. It is formed by two linearly tapered meander dipole antennas that are perpendicular to each other and connected to the slightly modified tag chip. One of the antennas is for receiving, while the other is for backscattering. The input impedance of the receiving antenna is designed to be conjugate matched to the highly capacitive chip impedance for the maximum power transfer. Meanwhile, the backscattering antenna is alternatively terminated by an open or a short circuit to modulate the backscattered field. By making the input impedance of the backscattering antenna real-valued, the maximum differential RCS may be achieved leading to a longer read range and better reliability. With the aid of the design of experiments (DOE) technique, the proposed dual-antenna structure is designed to fit within a compact area of 32.8 × 32.8 mm2 while keeping relatively low mutual coupling between the two antennas. The impedance, receiving, and backscattering performances of the proposed dual-antenna structure are measured and simulated, and they agree very well. Also, it is demonstrated that the proposed dual-antenna structure outperforms the conventional single-antenna tag design in every respect.

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

[2]  Lauri Sydanheimo,et al.  Radar cross-section analysis for passive RFID systems , 2006 .

[3]  G. Derringer,et al.  Simultaneous Optimization of Several Response Variables , 1980 .

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

[5]  Kenny Q. Ye,et al.  Critical Values of the Lenth Method for Unreplicated Factorial Designs , 2000 .

[6]  Hosung Choo,et al.  Design of UHF small passive tag antennas , 2005, 2005 IEEE Antennas and Propagation Society International Symposium.

[7]  D. Staiculescu,et al.  Design rule development for microwave flip-chip applications , 2000 .

[8]  D. Staiculescu,et al.  Design and optimization of 3-D compact stripline and microstrip Bluetooth/WLAN balun architectures using the design of experiments technique , 2005, IEEE Transactions on Antennas and Propagation.

[9]  Xi Chen,et al.  Circularly Polarized Stacked Annular-Ring Microstrip Antenna With Integrated Feeding Network for UHF RFID Readers , 2010, IEEE Antennas and Wireless Propagation Letters.

[10]  G. Iannaccone,et al.  Design criteria for the RF section of UHF and microwave passive RFID transponders , 2005, IEEE Transactions on Microwave Theory and Techniques.

[11]  C. K. Krichbaum,et al.  Radar Cross Section Handbook , 2013 .

[12]  P.V. Nikitin,et al.  Theory and measurement of backscattering from RFID tags , 2006, IEEE Antennas and Propagation Magazine.

[13]  Ilaria De Munari,et al.  Design of a Low-Power Digital Core for Passive UHF RFID Transponder , 2006, 9th EUROMICRO Conference on Digital System Design (DSD'06).

[14]  Martin Vossiek,et al.  Design and optimization of amplitude-modulated microwave backscatter transponders , 2010, German Microwave Conference Digest of Papers.

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

[16]  Narayanaswamy Balakrishnan,et al.  ANALYZING UNREPLICATED FACTORIAL EXPERIMENTS: A REVIEW WITH SOME NEW PROPOSALS , 1998 .

[17]  K. V. S. Rao,et al.  Helical antenna for handheld UHF RFID reader , 2010, 2010 IEEE International Conference on RFID (IEEE RFID 2010).

[18]  Aggelos Bletsas,et al.  Improving Backscatter Radio Tag Efficiency , 2010, IEEE Transactions on Microwave Theory and Techniques.

[19]  Xianming Qing,et al.  A Universal UHF RFID Reader Antenna , 2009, IEEE Transactions on Microwave Theory and Techniques.

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

[21]  R. Green,et al.  The general theory of antenna scattering , 1963 .

[22]  R.A. Rodriguez-Solis,et al.  Analysis of a CPW Fed Annular Slot Ring Antenna using DOE , 2006, 2006 IEEE Antennas and Propagation Society International Symposium.

[23]  Hsueh-Jyh Li,et al.  Impedance loading state determination for UHF Passive RFID Applications , 2007, 2007 IEEE Antennas and Propagation Society International Symposium.

[24]  T. J. Warnagiris,et al.  Performance of a meandered line as an electrically small transmitting antenna , 1998 .

[25]  H. Kurss,et al.  Minimum-scattering antennas , 1965 .

[26]  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.

[27]  Dong Sam Ha,et al.  An overview of passive RFID , 2007, IEEE Communications Magazine.

[28]  L. Roselli,et al.  Concurrent Circuit-Level/System-Level Optimization of a 24 GHz Mixer for Automotive Applications Using a Hybrid Electromagnetic/Statistical Technique , 2007, 2007 IEEE/MTT-S International Microwave Symposium.

[29]  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.

[30]  Klaus Finkenzeller,et al.  RFID Handbook: Radio-Frequency Identification Fundamentals and Applications , 2000 .

[31]  M. O. White.  Radar cross-section : measurement, prediction and control , 1998 .

[32]  K. Wu,et al.  Novel design strategy for passive UHF RFID tags , 2010, 2010 14th International Symposium on Antenna Technology and Applied Electromagnetics & the American Electromagnetics Conference.

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

[34]  D. van der Weide,et al.  Radar Cross-Section Analysis of Backscattering RFID Tags , 2007, IEEE Antennas and Wireless Propagation Letters.

[35]  D. Staiculescu,et al.  Conformal Magnetic Composite RFID for Wearable RF and Bio-Monitoring Applications , 2008, IEEE Transactions on Microwave Theory and Techniques.

[36]  Pavel Nikitin,et al.  Differential RCS of RFID tag , 2007 .

[37]  Roger F. Harrington,et al.  Electromagnetic scattering by antennas , 1963 .