TiMeW
Newbie level 2
Hi,
I am working with the FDTD method. I read a lot of time that the FDTD method in his "simple" form cannot deal with metals. I understand that it is due to the negative relative permittivity. Indeed my MATLAB code was not working for these values of permittivity.
I would like to understand why but not on a programming point of view (I can see why it is diverging when the equations are discretized). I put a pdf file where I derived the curl equations needed for the FDTD from the Maxwell equations and the constitutive relations:
View attachment Question.pdf
My questions are the following:
1) Does the problem come from the assumption made for the constitutive relation? Is it really not valid for metals?
2) If the problem lies in the constitutive relation, using the FDTD to describe semiconductors is maybe also a mistake because no material is stricly non dispersive (in time).
3) I would like to know if I linked correctly the n k parameters with epsilon and sigma.
Thanks in advance,
TW
ps: I wrote it in Latex because I could not make the equations work directly on the internet page...
I am working with the FDTD method. I read a lot of time that the FDTD method in his "simple" form cannot deal with metals. I understand that it is due to the negative relative permittivity. Indeed my MATLAB code was not working for these values of permittivity.
I would like to understand why but not on a programming point of view (I can see why it is diverging when the equations are discretized). I put a pdf file where I derived the curl equations needed for the FDTD from the Maxwell equations and the constitutive relations:
View attachment Question.pdf
My questions are the following:
1) Does the problem come from the assumption made for the constitutive relation? Is it really not valid for metals?
2) If the problem lies in the constitutive relation, using the FDTD to describe semiconductors is maybe also a mistake because no material is stricly non dispersive (in time).
3) I would like to know if I linked correctly the n k parameters with epsilon and sigma.
Thanks in advance,
TW
ps: I wrote it in Latex because I could not make the equations work directly on the internet page...