Abstract
Recently, radio-frequency identification (RFID) has been gaining interest as a distribution management system to replace bar codes. An important difference between the RFID system and the bar code system is that, in the former, data are changeable by remote control. A system for managing gathered tags (13.56 MHz carrier wave) and a system for long-distance identification (953 MHz carrier wave) are now suitable for practical use. For continuous operation, these must integrate seamlessly. However, some disadvantages exist in long-distance identification with the 13.56 MHz carrier wave systems. To identify a gathered tag accurately, mutual interference must be suppressed. Therefore, we developed a novel emission device based on the coaxial cable leakage of a railway cellular phone service. Specifically, multiple small slots are opened on a flat shielded microstrip line. The result of an investigation into the optimum slot shape to suppress mutual interference is reported here. It is also experimentally confirmed that the proposed system can accurately identify gathered tags.
