scholarly journals Amplitude-phase distortion of the normal high-frequency shear waves in homogeneous elastic waveguide with weakly rough surfaces.

2017 ◽  
Vol 70 (2) ◽  
pp. 28-42 ◽  
Author(s):  
A.S. Avetisyan ◽  
A.A. Hunanyan
Keyword(s):  
High Frequency ◽  
Rough Surfaces ◽  
Shear Waves ◽  
Phase Distortion ◽  
Elastic Waveguide

High Frequency Ultrasound, a Tool for Elastic Properties Measurement of Thin Films Fabricated on Silicon

2011 ◽  
Vol 324 ◽  
pp. 277-281 ◽  
Author(s):  
Pierre Campistron ◽  
Julien Carlier ◽  
Nadine Saad ◽  
Jamin Gao ◽  
Malika Toubal ◽  
...  
Keyword(s):  
Thin Films ◽  
Elastic Properties ◽  
High Frequency ◽  
Shear Waves ◽  
Thin Layers ◽  
Acoustic Properties ◽  
Frequency Range ◽  
Frequency Method ◽  
Longitudinal Waves

The main goal of this work is to develop an ultrasonic high frequency method for characterization of thin layers. The development of high frequency acoustic transducers for longitudinal waves and shear waves on silicon has enabeled the characterization of thin films deposited on this substrate. Three types of transducers have been achieved : (i) single crystal LiNbOSubscript text3 Y+163° for shear waves generation, and (ii) Y+36° for longitudinal waves, bonded and thinned on silicon substrate to achieve ultrasonic transducers in the frequency range 300-600 MHz ; (iii) thin films ZnO transducers were realized due to sputtering technologies working in the frequency range 1 GHz- 2.5 GHz. Using an inversion method and a network analyser which provide the scattering S11 parameter of the transducer versus the frequency we deduce the elastic properties of films deposited on the wafer surface. Thanks to these transducers the acoustic properties of thin films such as SU-8 based nanocomposites (doped with TiO2 , SrTiO3 or W nanoparticles) will be presented. In order to achieve mechanical impedance matching between silicon and water we control the mass of the embedded particles which provide a way to adjust the elastic properties of the characterized material. In another application an Indium metallic layer have been characterized in the high frequency range. We also use this method to characterize dielectric permittivity of the ZnO transducers.

Propagating high-frequency shear waves in simple fluids

2009 ◽  
Vol 21 (1) ◽  
pp. 013105 ◽  
Author(s):  
Carlos Colosqui ◽  
Hudong Chen ◽  
Xiaowen Shan ◽  
I. Staroselsky ◽  
Victor Yakhot
Keyword(s):  
High Frequency ◽  
Shear Waves ◽  
Simple Fluids

scholarly journals Modelling of High-Frequency Roughness Scattering from Various Rough Surfaces through the Small Slope Approximation of First Order

2012 ◽  
Vol 02 (01) ◽  
pp. 1-11 ◽  
Author(s):  
Virginie Jaud ◽  
Cedric Gervaise ◽  
Yann Stephan ◽  
Ali Khenchaf
Keyword(s):  
High Frequency ◽  
Rough Surfaces ◽  
First Order

scholarly journals High Frequency Roughness Scattering from Various Rough Surfaces: Theory and Laboratory Experiments

2012 ◽  
Vol 02 (01) ◽  
pp. 50-59
Author(s):  
Virginie Jaud ◽  
Jean-Pierre Sessarego ◽  
Cedric Gervaise ◽  
Yann Stephan
Keyword(s):  
High Frequency ◽  
Laboratory Experiments ◽  
Rough Surfaces

Transformation of Rice’s small perturbation solution for rough surface scattering into the high frequency reciprocal physical and geometric optics solutions

2012 ◽  
Vol 90 (6) ◽  
pp. 557-564
Author(s):  
Ezekiel Bahar
Keyword(s):  
Small Perturbation ◽  
High Frequency ◽  
Rough Surfaces ◽  
Geometrical Optic ◽  
Low Frequency ◽  
Perturbation Solution ◽  
Physical Optics ◽  
Surface Element ◽  
Scattering Coefficients ◽  
Scatter Coefficient

A step by step transformation of the low frequency small height and slope perturbation solution into the high frequency reciprocal and dual, physical and geometrical optic solutions is presented. The familiar Kirchhoff approximations for the fields impressed by the incident plane wave upon the rough surfaces results in nonreciprocal solutions. It is shown that the surface element scattering coefficients based on the Kirchhoff approximations agree with the corresponding reciprocal physical optics solutions only at the stationary phase, specular points on the rough surfaces. While the Kirchhoff approximations and physical optics approximations are based on the characterization of the surface fields by Fresnel reflection coefficients, the corresponding surface element scatter coefficient derived for the small perturbation solution and the full wave solutions are based on the imposition of boundary conditions for the tangential components of the electric and magnetic fields. A flow graph schematically depicting the relationships between these solutions for the scattered fields is also presented.

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