Content deleted Content added
m Task 18 (cosmetic): eval 81 templates: del empty params (2×); hyphenate params (3×); cvt lang vals (1×); |
Video on numerical dispersion. |
||
Line 150:
=== Weaknesses of FDTD modeling===
[[File:Numerical dispersion of a pulse signal in 1D FDTD.ogg|thumb|right|290px|[[Numerical dispersion]] of a square pulse signal in a simple one-dimensional FDTD scheme. [[Ringing artifacts]] around the edges of the pulse are heavily accentuated ([[Gibbs phenomenon]]) and significant distortion is present. This artifact is a direct result of the discretization scheme.<ref name="taflove05"/>]]
* Since FDTD requires that the entire computational ___domain be gridded, and the grid spatial discretization must be sufficiently fine to resolve both the smallest electromagnetic wavelength and the smallest geometrical feature in the model, very large computational domains can be developed, which results in very long solution times. Models with long, thin features, (like wires) are difficult to model in FDTD because of the excessively large computational ___domain required. Methods such as [[eigenmode expansion]] can offer a more efficient alternative as they do not require a fine grid along the z-direction.<ref name="phot_cad" />
* There is no way to determine unique values for permittivity and permeability at a material interface.
| |||