| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a multi-frequency antenna built in an information terminal device like a personal computer or a PDA, which has the communication sensitivity improved by resolving a lack of bandwidth in a low frequency band. <P>SOLUTION: In a two-frequency antenna, an element part 1 to which a feed point P1 is given and a ground plate 4 to which an earth point P2 is given are connected through a short-circuit part 3, and the element part 1 comprises a high frequency-side radiation element 1a connected to the short-circuit part 3 and a low frequency-side radiation element 1b which is extended so as to be folded back from an end part of the radiation element 1a and is directed to a direction opposite to the direction to which the radiation element 1a is directed, and a slit S1 having both ends opened is formed by a part 1c of the low frequency-side radiation element 1b and a narrow conductor 2a extending from the ground plate 4 to the element part 1. A coaxial cable 5 for feeding is connected to the feed point P1 in an end part of the high frequency-side radiation element 1a in the vicinity of an open part of the slit S and the earth point P2 in an edge part of the ground plate 4. <P>COPYRIGHT: (C)2007,JPO&INPIT |
