Patent ID: 8022595
Filing Date: 2011-09-20
Classification: H04R

Abstract:
1. A composite acoustic wave device having a target resonant frequency, associated with a selected polarization of acoustic displacement, the device comprising: a rigid protector plate mounted to a mechanical mount, said protector plate comprising a material having high quality acoustical characteristics, said protector plate having a driven face and a sensing face, and further having a thickness which is substantially a multiple of half wavelength of said resonant frequency; a piezoelectric plate having a thickness of substantially a multiple of half wavelength of said resonant frequency in said plate, said piezoelectric plate having an excitation face having at least one transducer electrode deposited thereupon; said electrode and at least one other electrode forming a transducer interconverting electrical and acoustical energy within said piezoelectric plate; said piezoelectric plate being supported from said protector plate forming an energy interface between said driven face and a driving face of said piezoelectric plate; said protector plate having an acoustic impedance substantially equal to the impedance of the piezoelectric material; such that a wave of said resonant frequency traveling between said excitation face and said sensing face, shall form a substantially continuous-phase wave, at substantially peak displacement amplitude, at the energy interface.