| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a radio tag communication system in which a stable communication state can be ensured from a transmitting antenna to a radio tag and from the radio tag to a receiving antenna, regardless of a position at which the radio tag is disposed. <P>SOLUTION: A radio tag communication system comprises: a transmitting antenna 21, having a circular polarization characteristics, used for transmitting a radio wave signal W toward a radio tag 1; a receiving antenna 22, which is used for receiving a radio wave signal R transmitted from the radio tag 1 and is disposed through a fixed range S where the radio tag 1 is disposed at an interval with a receiving antenna 22, having a circular polarization characteristic of inverse turns to the transmitting antenna; and an antenna for tags, having a linear polarization characteristic, provided in the radio tag 1 and used for transmitting/receiving radio wave signals from the radio tag 1 to the transmitting antenna 21 and the receiving antenna 22. <P>COPYRIGHT: (C)2009,JPO&INPIT |
