| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a loop antenna of a reader/writer whose antenna characteristic is not easily changed irrespective whether or not an installation location is near to a metallic material. <P>SOLUTION: In the loop antenna X, eight rectangle form loops 40 with the same shape are symmetrically formed in radial directions using a conductor 10, and directions of flowing currents in the conductor 10 between adjacent loops 40 are inverse. The eight loops 40 are formed in radial shapes in a way that all loop planes are parallel to a predetermined axis 60 and the center is the predetermined axis 60. At the time, in the eight loops 40, all the loop planes 20 are perpendicular to a predetermined plane 100 which perpendicularly intersects with the predetermined axis 60. At the time, the loop antenna X forms an RF tag reading plane which is an almost uniform magnetic field of circle shape as seen from an upper plane. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
