| 摘要 |
PROBLEM TO BE SOLVED: To provide a radio communication system for taking out power sufficiently from a received electric wave no matter where a radio tag might be in an electric wave receive area. SOLUTION: When a test instruction command is entered from a main control unit, a radio communication system main unit 13 feeds power to first to third antenna units 10A, 10B, 11A, 11B, 12A, and 12B in a basic mode as a test condition, and transmits electric wave to a radio tag 3. The radio tag 3 having received the electric wave transmits the data to the radio communication system main unit 13 on the basis of the received control signal by using a carrier of the electric wave as electric power. The receive signal level of the electric wave transmitted from the radio tag 3 and a reference signal level stored in the radio communication system main unit 13 are compared, and a power feeding pattern to the first to third antenna units 10A, 10B, 11A, 11B, 12A, and 12B is so changed that the receive signal level becomes larger than the reference signal level. COPYRIGHT: (C)2005,JPO&NCIPI
|
