Experimental characterization of the impedance of balanced UHF RFID tag antennas

C. K. Stoumpos, Dimitrios Anagnostou*, Michael T. Chryssomallis

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)
649 Downloads (Pure)


An experimental procedure for the accurate characterization of the impedance of balanced tag antennas for RFID applications is reintroduced. The balanced devices that are characterized are modeledas 2-port networks and their impedance is derived from network parameters, through a rarely used equation that is preferred because it accounts for the losses of non-reciprocal structures such as imperfect test fixtures or baluns. The measurements are conducted using a test fixture for the proper excitation of the balanced devices, and its effects are removed by shifting the measurement plane to the plane of the device under test. The accuracy of the proposed method is demonstrated through the measurement of the impedance of a balanced dipole antenna, and is complemented by the measurement of the RFID ASIC chip. The experimental characterization of the impedance of an RFID tag antenna constitutes a secure way to achieve conjugate matching between the 2 devices (ie, the antenna and the RFID chip), and finally enhance the reading range of the RFID tags. Also, since RFID tags are designed to be placed directly on different surfaces, the proposed procedure is further evaluated by mounting the antenna onto 2 more surfaces.

Original languageEnglish
Pages (from-to)3127-3134
Number of pages8
JournalMicrowave and Optical Technology Letters
Issue number12
Early online date22 Sept 2017
Publication statusPublished - Dec 2017


  • balanced antenna
  • chip
  • impedance
  • integrated components
  • paper substrate
  • passive structures
  • RFIC
  • RFID
  • tag
  • wire antennas

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Experimental characterization of the impedance of balanced UHF RFID tag antennas'. Together they form a unique fingerprint.

Cite this