Compact microstrip antenna with forward-directed radiation pattern for RFID reader card

Author

Weigand, Steven M.

Author_Institution

WJ Commun. Inc., San Jose, CA, USA

fYear

2005

fDate

3-8 July 2005

Firstpage

337

Abstract

This paper presents a compact microstrip antenna that is compatible with PCMCIA-compatible UHF RFID reader cards. The small form factor (0.15λ×0.10λ×0.002λ) results in relatively narrow bandwidth (2% for VSWR<2) but reasonable directivity (2 dBi) in the forward direction, which is of primary importance for the maximum read-range of backscatter RFID-readers. Being a balanced antenna, the radiation pattern and input impedance are less sensitive than unbalanced antennas to hand-effects or nearby metal objects. Simulated and measured data is presented that identifies the basic properties of the antenna. Additionally, fundamental geometric dependencies are discussed.

Keywords

UHF antennas; antenna radiation patterns; directive antennas; electric impedance; microstrip antennas; radiofrequency identification; PCMCIA-compatible RFID reader cards; UHF RFID reader cards; VSWR; backscatter RFID-readers; compact antenna; directivity; form factor; forward-directed radiation pattern; hand-effects; input impedance; microstrip antenna; read-range; Antenna radiation patterns; Bandwidth; Coplanar transmission lines; Dipole antennas; Directive antennas; Impedance; Microstrip antennas; Radiofrequency identification; Shunt (electrical); UHF antennas;

fLanguage

English

Publisher

ieee

Conference_Titel

Antennas and Propagation Society International Symposium, 2005 IEEE

Print_ISBN

0-7803-8883-6

Type

conf

DOI

10.1109/APS.2005.1552011

Filename

1552011