| 摘要 |
<P>PROBLEM TO BE SOLVED: To receive radiowave signals of a wide signal level in an antenna device which receives the radiowave signal by resonanting a vibrator with the radiowave signal, and converting the resonant motion to an electrical signal. <P>SOLUTION: The antenna device includes: a vibrator which receives an external magnetic field, and displaces while having a characteristic to vibrate with a predetermined natural frequency; and an antenna unit 10 with a conversion means which converts motion of the vibrator to an electrical signal. It is provided with: a sensitivity change means 107 which changes displacement degree for the external magnetic field of the vibrator; and a speed control means 102 which outputs an AGC signal to the sensitivity change means 107 according to the taken-in electrical signal. <P>COPYRIGHT: (C)2010,JPO&INPIT |
