Abstract
A semi-analytical method for finding the elastic modes propagating along the edge of an anisotropic semi-infinite plate is presented. Solutions are constructed as linear combinations of a finite number of the corresponding infinite plate modes with the constraint that they decay in the direction perpendicular to the edge and collectively satisfy the free boundary condition over the edge surface. Such modes that are confined to the edge can be used to approximate solutions of acoustic ridge waveguides whose supporting structures are sufficiently far away from the free edge. The semi-infinite plate or ridge is allowed to be oriented arbitrarily in the anisotropic crystal. Modifications to the theory to find symmetric and antisymmetric solutions for special crystal orientations are also presented. Accuracy of the solutions can be improved by including more plate modes in the series. Numerical techniques to find modal dispersion relations and orientation dependent modal behavior, are discussed. Results for ridges etched in single crystal Silicon are found to be in good agreement with Finite Element simulations. It is found that variations in modal phase velocity with respect to crystal orientation are not significant, suggesting that anisotropy may not be a critical issue while designing ridge waveguides in Silicon.
Highlights
The acoustic ridge waveguide has applications in many fields like microwave engineering and ultrasonics
Finite element simulations were done in ANSYS to verify the calculated mode propagation velocities
A semianalytical method for finding the approximate solution of the elastic equations in a ridge waveguide made of an anisotropic crystal was presented
Summary
The acoustic ridge waveguide has applications in many fields like microwave engineering and ultrasonics. Due to the low velocity of acoustic waves, compared to electromagnetic waves, miniature scale acoustic transmission lines can be fabricated at microwave frequencies for use in filters and resonators. An acoustic transmission line made from a vertical ridge etched in silicon is of special interest because of its ease of fabrication and small footprint. The modes of a ridge waveguide decay perpendicular to the edge surface and exhibit strong confinement to the free edge. This makes the ridge waveguide suitable for making low-loss acoustic transmission lines. The symmetric mode of the ridge shows little dispersion over a wide frequency range and is similar to surface waves
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
