Title :
Coupled-mode analysis of Love waves in a filter film with periodically corrugated surfaces
Author :
Hawwa, Muhammad A. ; Asfar, Omar R.
Author_Institution :
Dept. of Eng. Sci. & Mech., Virginia Polytech. Inst. & State Univ., Blacksburg, VA, USA
Abstract :
Mode coupling of Love waves in an orthotropic thin film having periodically corrugated surfaces over an isotropic elastic half space is considered. Six modes are coupled by both surfaces by means of three simultaneous resonant conditions. On the basis of the weakness of the corrugations, the method of multiple scales is used to derive the coupled-mode equations. These equations together with relevant boundary conditions form a two-point boundary-value problem, which is solved numerically. The filter frequency response of a corrugated film designed as a stop-band filter is calculated. Enhanced filter characteristics are achieved when tapered corrugations are imposed. A narrow pass-band filter is also designed. Its high quality factor presents the fascinating features that might be realized by including the periodic corrugations in the design of SAW devices.<>
Keywords :
Love waves; Q-factor; acoustic resonators; acoustic signal processing; band-pass filters; boundary-value problems; surface acoustic wave filters; Love waves; SAW devices; boundary conditions; corrugated film; coupled-mode analysis; coupled-mode equation; design; filter film; frequency response; high quality factor; isotropic elastic half space; mode coupling; multiple scales; narrow pass-band filter; orthotropic thin film; periodically corrugated surfaces; simultaneous resonant conditions; stop-band filter; tapered corrugations; two-point boundary-value problem; Boundary conditions; Corrugated surfaces; Coupled mode analysis; Equations; Filters; Frequency response; Q factor; Resonance; Surface waves; Transistors;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
