| 摘要 |
<p>An electronic device (e.g. a mobile telephone) providing wireless communication, comprising: an antenna (7; 304; 404), with an impedance, to radiate an electromagnetic field at radio frequencies; a communication circuit (301; 401) connected to the antenna (7; 303; 404) to transmit and receive the communications signals; a loudspeaker (11; 603) and a proximity sensor (302, 305, 306, 307; 402, 405, 406, 407) to provide a control signal (Vctpr) indicative of whether an object (408) is in the proximity of the device. The device is characterized in that the proximity sensor is connected to the antenna (7; 303; 404) to monitor the impedance of the antenna, to modify the control signal (Vctpr) in response to changes of the impedance, and to control the volume of sound emitted by the loudspeaker (11; 603). Thereby a single antenna is used both for providing wireless communication of e.g. speech and/or data signals, while the antenna is used to sense whether an object is present in the proximity of the antenna, thereby avoiding damage to a user's hearing due to a high sound pressure. The invention also relates to a method of detecting whether an object is in the proximity of a communication device.</p> |
