Institute of Electrical and Electronics Engineers Inc.;New York, NY: IEEE
摘要:
摘要： We report an array of piezoelectric monocrystalline silicon microphones for audio-range acoustic sensing. Thirteen cantilever-type diaphragm transducers make up the array, each having a closely spaced and precisely controlled resonant frequency. These overlapping resonances serve to greatly boost the sensitivity of the array when the signals are added; if the signals are individually taken, the array acts as a physical filter bank with a quality factor over 40. Such filtering would enhance the performance and the efficiency of speech-recognition systems. In the "summing mode," the array demonstrates high response over a large bandwidth, with unamplified sensitivity greater than 2.5 mV/Pa from 240 to 6.5 kHz. Both modes of operation rely on the precise control of resonant frequencies, often a challenge with large compliant microelectromechanical-system (MEMS) structures, where residual stress causes deformation. We mitigate these ill effects through the use of stress-compensating layer thicknesses and a stress-free monocrystalline diaphragm. For determining device geometry, we develop a simple analytical method that yields excellent agreement between designed and measured resonant frequency; all devices are within 4.5%, and four are within 0.5% (just several hertz). The technique could be useful not only for microphones but also for other low-frequency MEMS transducers designed for resonance operation at a specific frequency. 其他題名： JMEMS 出版者： New York, NY: IEEE 出版日期： 2013-02-01 出處： Journal of microelectromechanical systems, 2013-02, Vol.22 (1), p.107-114 資源來源： IEEE Electronic Library (IEL) 版權： 2014 INIST-CNRS 識別號： ISSN: 1057-7157 識別號： EISSN: 1941-0158 識別號： DOI: 10.1109/JMEMS.2012.2216505 識別號： CODEN: JMIYET
