This paper presents a passive tag operated 920 to 925 MHz for the UHF RFID system along national standard of Thailand. This tag is a simple square loop structure with a truncation technique to achieve circular polarization. The T-Matching technique is used to achieve conjugate matching. The impedance of the tag is 18 + j150  at 922.5 MHz. The size of the antenna is 9.72 cm 9.72 cm fabricated on the FR4 substrate with thickness of 0.3 mm. The simulated results of radiation pattern is bidirectional beam with the gain of 2.53 dBic at 922.5 MHz.
(英)
This paper presents a passive tag operated 920 to 925 MHz for the UHF RFID system along national standard of Thailand. This tag is a simple square loop structure with a truncation technique to achieve circular polarization. The T-Matching technique is used to achieve conjugate matching. The impedance of the tag is 18 + j150  at 922.5 MHz. The size of the antenna is 9.72 cm 9.72 cm fabricated on the FR4 substrate with thickness of 0.3 mm. The simulated results of radiation pattern is bidirectional beam with the gain of 2.53 dBic at 922.5 MHz.