Wireless surface acoustic wave-based proximity sensor, sensing system and method

摘要

The subject invention is related to wireless proximity sensor and sensing system for detecting the position of an object. The system includes a transceiver for providing wireless communication with a passive wireless surface acoustic wave (SAW) proximity sensor. The wireless proximity sensor receives a wireless signal from the transceiver, which powers the SAW device and in turn transmits a signal back to the transceiver that includes information about the position of an object. The wireless proximity sensor uses one or more SAW devices with a sensing element made of magnetostrictive material, in conjunction with one or more magnets and one or more targets that are positioned relative to an object. The movement of the target(s) in relation to the proximity sensor operatively produces a mechanical response due to the shift in the magnetic field of the sensing element. The sensing element in turn enhances the magnetic field of the SAW device to which it is attached, and this information is transmitted to the transceiver as information about the position of an object.