ANALYSIS OF WAVE PROPAGATION IN PHONONIC CRYSTALS USING THE PLANE-WAVE EXPANSION AND SUPERCELL TECHNIQUES
Date Issued
2005
Date
2005
Author(s)
Huang, Zi-Gui
DOI
en-US
Abstract
Successful application of photonic crystals has led to a rapid growing interest in the analogous acoustic effects in periodic elastic structures called phononic crystals recently. The phenomenon of frequency band gap in the phononic crystal can be applied to the designs of filters for surface and bulk acoustic waves. The repetitive structures made up of different elastic materials can prevent elastic/acoustic waves from passing by at some specific angles or certain frequency bands. The analysis is carried out within the framework of the theorems in solid-state physics and wave equation of motion in inhomogeneous elastic media.
The methods employed in studying the wave motion in phononic crystals are based on the plane-wave expansion method and supercell technique. The formulations for elastic/acoustic wave propagation in phononic crystals are consisted of the materials with general anisotropy. The frequency band-gap features and wave propagation of surface and bulk acoustic waves in the two-dimensional phononic crystals with either square or hexagonal lattices are investigated. The concept of tunable frequency band gaps of the surface and bulk modes in the two-dimensional phononic crystals is introduced by changing the filling fraction, rotating square rods, hollow cylinders, and sectional phononic crystals. On the other hand, the supercell technique is adopted to calculate the defect modes and extended modes in phononic crystals. The technique is also used to analyze the propagating modes and couplings of waveguides in phononic crystals with acoustic channels.
It is worth noting that through a suitable design by using the plane-wave expansion and supercell techniques, the acoustic filters, mirrors, resonators, and waveguides are the possible applications in the two-dimensional phononic crystals.
Subjects
聲子晶體
平面波展開法
超晶格技術
表面聲波
徹體波
Phononic crystal
Plane-wave expansion
Supercell technique
SAW
BAW
Type
thesis
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