A low-cost impedance measurement method for UHF band RFID near field antenna

Author

Liao, Jiankun ; Li, Xiuping

Author_Institution

Key Lab. of Universal Wireless Commun., Beijing Univ. of Posts & Telecommun., Beijing, China

fYear

2009

fDate

16-18 Oct. 2009

Firstpage

32

Lastpage

35

Abstract

In this paper, an impedance measurement method for UHF band RFID near field reader antenna (NFRA) by using coaxial line is proposed. The coaxial line is directly connected to the balanced output port of the NFRA, and then the S parameter is obtained including NFRA and the coaxial line. The impedance can be derived by using deembedding technique which removes the effect of cascading coaxial line. Therefore, the input impedance of the NFRA can be accurately obtained. Based on the measured input impedance, the matching network can be well designed to match NFRA to 50 ohm input port. This method avoid the inaccuracy of the simulated impedance caused by dramatic variation with frequency, and final measured and simulated results agree well and therefore verify the efficiency of the method shown in this paper.

Keywords

UHF antennas; coaxial cables; electric impedance measurement; radiofrequency identification; RFID; S parameter; UHF band; cascading coaxial line; deembedding technique; impedance measurement method; near field reader antenna; Antenna measurements; Coaxial components; Electric variables measurement; Frequency; Impedance matching; Impedance measurement; Length measurement; Radiofrequency identification; UHF antennas; UHF measurements; deembedding; impedance measurement; matching network; near field reader antenna;

fLanguage

English

Publisher

ieee

Conference_Titel

Communications Technology and Applications, 2009. ICCTA '09. IEEE International Conference on

Conference_Location

Beijing

Print_ISBN

978-1-4244-4816-6

Electronic_ISBN

978-1-4244-4817-3

Type

conf

DOI

10.1109/ICCOMTA.2009.5349245

Filename

5349245