| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that there is a disadvantage that level difference is partially and remarkably generated in magnetic field intensity distribution since the number of elements of a passive element part which is a second antenna part is imbalanced in comparison with a feed element which is a first antenna part and thus, use efficiency of transmission power supplied from a reader/writer is deteriorated in the conventional technology. <P>SOLUTION: This antenna device is provided with: a substrate body approximately in the slender shape at least the surface of which is composed of an insulating material; a plurality of antenna elements which are wound in the direction perpendicular to the longitudinal direction of the substrate body on the surface of the substrate body and electrcally connected with each other; and a power supply part which is electrically connected to the antenna elements and supplies power to the antenna elements, wherein the antenna elements are divided into a first antenna part which receives power supply from the power supply part and a second antenna part which does not receive the power supply from the power supply part and the power is supplied from the power supply part to the first antenna part. <P>COPYRIGHT: (C)2009,JPO&INPIT |
