ASYMMETRIC COMPOSITE ACOUSTIC WAVE SENSOR

摘要

A composite acoustic wave device provides improved protection from environmental factors while maintaining high electrical characteristics and dynamic range is provided. The device comprises a rigid protector plate having high quality acoustical characteristics and a thickness which is a multiple of half wavelength of the resonant frequency. A piezoelectric plate is coupled to the protector plate, is supported therefrom, and forms an energy interface therewith. The piezoelectric and protector plates are dimensioned such that a wave of resonant frequency traveling between the excitation face and the loaded/sensing face, forms a substantially continuous- phase wave, at substantially peak amplitude, at the energy interface. By doing so the device decouples the electrical thickness of the wave device from the mechanical thickness thereof.