Novel Electret Microphone

作者：Bakhoum Ezzat G^*; Cheng Marvin H M

来源：IEEE Sensors Journal, 2011, 11(4): 988-994.

DOI：10.1109/JSEN.2010.2077276

• Acoustics
• electret microphone
• magnetic field sensor
• microphone
• vibrations

This paper introduces a new type of electret microphone with an excellent dynamic range (0-120 dB SPL) and excellent frequency response characteristics over the range of 20 Hz to 20 kHz. The fundamental concept behind the new microphone is the placement of a thin PTFE (Teflon) electret membrane inside the core of a toroidal coil. As the membrane vibrates in response to the sound, a very small magnetic field is created, is picked up by the coil, and is amplified by a superconducting quantum interference device (SQUID) or by a conventional FET amplifier. Analysis and experimental results show that this new transduction mechanism results in a microphone that, while physically larger than other microphones, has substantially better performance in high-bandwidth applications.

• 出版日期2011-4