Title :
Radiation characteristics of circularly polarized patch antennas mounted in a 2.45 GHz wireless ID card system
Author :
Lei Zhu ; Kirino, H. ; Joishi, I.
Author_Institution :
Matsushita-Kotobuki Electron. Ind. Ltd., Japan
Abstract :
A 2/spl times/2 circularly polarized patch antenna array is developed for the realization of noncontact data transfer between the ID card and the transmitter for a 2.45 GHz wireless ID card system. A digital phase shifter using PIN-diodes is inserted between two paired antenna elements to adjust its radiation beam compatible with application environments. Radiation characteristics with the axial ratio less than 0.5 dB and the beam shift with about 17/spl deg/, and return losses lower than -25 dB have been achieved experimentally.
Keywords :
UHF phase shifters; antenna radiation patterns; data communication; electromagnetic wave polarisation; microstrip antenna arrays; p-i-n diodes; radio equipment; -25 dB; 2.45 GHz; PIN-diodes; UHF; axial ratio; beam shift; circularly polarized patch antenna array; digital phase shifter; noncontact data transfer; radiation beam adjustment; radiation characteristics; return losses; transmitter; wireless ID card system; Antenna arrays; Antenna radiation patterns; Circuits; Optical transmitters; Patch antennas; Phase shifters; Phased arrays; Polarization; Radio frequency; Transmitting antennas;
Conference_Titel :
Antennas and Propagation Society International Symposium, 1996. AP-S. Digest
Conference_Location :
Baltimore, MD, USA
Print_ISBN :
0-7803-3216-4
DOI :
10.1109/APS.1996.549903
