| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an antenna device for a portable radio apparatus having an arrangement capable of simply detecting the expansion and contraction of an antenna. <P>SOLUTION: The antenna device for a portable radio apparatus is one where an antenna is expandable, and includes a tip end coil 1 provided with an antenna coil therein and a straight element 4 electrically separated from the tip end coil. The expansion and contraction state of the antenna is detected by making a first contact conductive or nonconductive with respect to a second contact in response to the contraction or expansion of the antenna section through a final end fitting 5 provided on the straight element 4, and an antenna matching characteristic of a matching circuit is switched in response to a detected result. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
