One-Dimensional Simulation with the FDTD Method

Oct 20 2020 Physics Research Project Python Electromagnetic Numerical Simulation

Boundary Condition

  1. Fixed boundary condition with hard source

  1. Fixed boundary condition with soft source

  1. Absorb boundary condition

Propagation in Medium

  1. Dielectric Medium

The reflection coefficient is $$ \varGamma = \frac{\sqrt{\epsilon_0} - \sqrt{\epsilon_r}}{\sqrt{\epsilon_0} + \sqrt{\epsilon_r}} $$ and the transmission coefficient is $$ \tau = \frac{2\sqrt{\epsilon_0}}{(\sqrt{\epsilon_0} + \sqrt{\epsilon_r})}. $$ The region where \(x > 100\) has a relative permittivity \(\epsilon_r\) of 4.

  1. Lossy Dielectric Medium

The region where \(x > 100 \) has a relative permittivity \(\epsilon_r = 4\) and electrical conductivity \(\sigma = 0.04\).

Otherwise, the theoretical decay rate in a lossy dielectric medium is given by $$ \alpha = \frac{\omega}{c_0} \sqrt{\frac{\epsilon_r}{2}} \left[\sqrt{1+\left(\frac{\sigma}{\omega \epsilon_0 \epsilon_r} \right)^2} -1 \right]^{\frac{1}{2}}. $$