PASSIVE WIRELESS MICROPHONE

摘要

Passive wireless microphone is proposed which consisting of: passive microphone unit, consisting of: condenser microphone; connected to a high Q-factor surface acoustic wave (SAW) device, such as a SAW or STW resonator; the membrane of the capacitive microphone can be made in form of piezoelectric film and can include FR resonator (FBAR) said resonator and microphone circuit being connected to antenna, eventually the matching circuit is used and the interrogator unit (the "reader"), which interrogates the microphone unit by sending to its antenna RF signal to pump the energy into said SAW device and receives delayed response modulated by the sound vibrations. The microphone has no source of energy and operates due to energy received by antenna.