Dual-band RFID tag antenna based on the Hilbert-curve fractal for HF and UHF applications Articles uri icon

publication date

  • March 2016

start page

  • 140

end page

  • 146


  • 2


  • 10

International Standard Serial Number (ISSN)

  • 1751858X (ISSN)


  • A novel single-radiator card-type tag is proposed which is constructed using a series Hilbert-curve loop and matched stub for high frequency (HF)/ultra high frequency (UHF) dual-band radio frequency identification (RFID) positioning applications. This is achieved by merging the series Hilbert-curve for implementing the HF coil antenna, and square loop structure for implementing the UHF antenna to form a single RFID tag radiator. The RFID tag has directivity of 1.75 dBi at 25 MHz, 2.65 dBi at 785 MHz, 2.82 MHz at 835 MHz and 2.75 dBi at 925 MHz. The tag exhibits circular polarisation with -3 dB axial-ratio bandwidth of 14, 480, 605 and 455 MHz at 25, 785, 835 and 925 MHz, respectively. The radiation characteristics of the RFID tag is quasi-omnidirectional in its two orthogonal planes. Impedance matching circuits for the HF/UHF dual-band RFID tag are designed for optimal power transfer with the microchip. The resulting dual-band tag is highly compact in size and possesses good overall performance which makes it suitable for diverse applications. © The Institution of Engineering and Technology 2016.


  • directional patterns (antenna) mobile antennas omnidirectional antennas radiators axial ratio bandwidth diverse applications dual band radios high frequency hf impedance matching circuits optimal power transfer radiation characteristics rfid tag antennas radio frequency identification (rfid)