| 摘要 |
<p>The present invention is directed to an apparatus and method of increasing the sensitivity of a magnetic sensor embedded in a key fob used in passive keyless entry and identification systems. The sensitivity of the sensor is increased by magnetically coupling a pair of magnetic flux concentrators at opposite ends of the magnetic core of the sensor, which is surrounded by a helical conductive coil. Addition of the magnetic flux concentrators external to the coil effectively forces a larger window of magnetic flux through the coil than was possible without them. This increases the magnetic sensitivity of the coil as a sensor in a time varying magnetic field. In a key fob/passive keyless device this results in an increased range of operation.</p> |
