US EPA

2934825 

Journal Article 

Electrically Large Dual-loop Antenna for UHF Near-Field RFID Readers 

Shi, Jin; Lin, L; Qing, X; Chen, Z; Tang, Hui; Zhou, L; Chu, Hui 

2013 

53-56 

WOS:000346656600022 

A dual-loop antenna is proposed to enlarge the interrogation zone of reader antennas used in near-field ultra high frequency (UHF) radio frequency identification (REM) systems. The dual-loop antenna is composed of two segmented loos with one common side and a double-sided parallel-strip line feeding network. Each loop has a uniform and single direction flowing current itself By providing reverse-direction flowing current to the two segmented loops, the strong and uniform magnetic field distribution over a large interrogation zone can be achieved. The prototype on FR4 printed borad (PCB) exhibits that the dual-loop antenna achieves the impedance matching over the frequency range from 790 to 1040 MHz and produces strong and uniform magnetic,field distribution over an interrogation zone of 308 mm x 150 mm.