A postprocessing method based on high-resolution spectral estimation for FDTD calculation of phononic band structures

• Published in: Physica. B, Condensed matter Vol. 405; no. 10; pp. 2444 - 2449
• Main Authors: Su, Xiao-Xing, Li, Jian-Bao, Wang, Yue-Sheng
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.05.2010; Elsevier
• Subjects: Band structure of solids; Condensed matter; Condensed matter: structure, mechanical and thermal properties; Eigenfrequencies; Energy band structure; Exact sciences and technology; Finite difference time domain; Finite difference time domain method; High-resolution spectral estimation; Iterative methods; Lattice dynamics; Mathematical analysis; Mathematical models; Other topics in lattice dynamics; Phononic crystal; Physics; Spectra; Phononic crystal; High-resolution spectral estimation; Finite difference time domain; Energy band structure; Time domain method; Fast Fourier transforms; Spectral resolution; Digital simulation; Time series; Eigenfrequency; Iterative methods; Finite difference method
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2010.03.005

If the energy bands of a phononic crystal are calculated by the finite difference time domain (FDTD) method combined with the fast Fourier transform (FFT), good estimation of the eigenfrequencies can only be ensured by the postprocessing of sufficiently long time series generated by a large number of FDTD iterations. In this paper, a postprocessing method based on the high-resolution spectral estimation via the Yule–Walker method is proposed to overcome this difficulty. Numerical simulation results for three-dimensional acoustic and two-dimensional elastic systems show that, compared with the classic FFT-based postprocessing method, the proposed method can give much better estimation of the eigenfrequencies when the FDTD is run with relatively few iterations.