FDTD dispersion revisited: Faster-than-light propagation

Authors
Schneider, JB Wagner, CL
Citation
Jb. Schneider et Cl. Wagner, FDTD dispersion revisited: Faster-than-light propagation, IEEE MICR G, 9(2), 1999, pp. 54-56
Citations number
3
Categorie Soggetti
Eletrical & Eletronics Engineeing
Journal title
IEEE MICROWAVE AND GUIDED WAVE LETTERS
ISSN journal
10518207 → ACNP
Volume
9
Issue
2
Year of publication
1999
Pages
54 - 56
Database
ISI
SICI code
1051-8207(199902)9:2<54:FDRFP>2.0.ZU;2-0
Abstract
The numerical dispersion relation that governs the propagation of fields in a finite-difference time-domain (FDTD) grid was derived several years ago. In this letter a different interpretation is given for the governing equat ion. It is shown that the dispersion relation predicts faster-than-light pr opagation for coarsely resolved fields. Additionally, some spectral compone nts that were previously believed to have zero phase velocity are shown to propagate, albeit with exponential decay.