EM.Tempo's adaptive mesher generates more cells in the areas that are occupied by dielectric materials, fewer cells in the free-space regions and no cells inside PEC regions. As a result, the mesh resolution and average mesh cell size differ in regions that are filled with different types of material. The variable mesh density is specified in terms of the effective wavelength inside material media.
FDTD YEE CELL GENERATOR
A fixed-cell mesh generator is also available, where you can set constant cell dimensions along the three principal axes for the entire computational domain. EM.Tempo uses a non-uniform, adaptive, voxel-based Yee mesh with a mesh density that you can customize. The FDTD computational domain must be discretized using an appropriate meshing scheme. The FDTD simulation time depends directly on the size of the computational domain and on how close you can place the PML walls to the enclosed objects. The absorbing boundaries should act such that the incident fields and waves propagate through them without any back reflection.
FDTD YEE CELL FREE
In an open boundary problem like an antenna, some kind of absorbing boundary conditions such as a perfectly matched layer (PML) must be used to emulate the free space. In a shielded structure, all objects are enclosed within a perfect electric (or magnetic) conductor box. At the boundaries of the computational domain, proper boundary conditions must be enforced. Since FDTD is a finite domain numerical technique, the computational domain of the problem must be truncated. From knowledge of the primary fields in space and time, one can compute other secondary quantities including frequency domain characteristics like scattering parameters, input impedance, far-field radiation patterns, radar cross section, etc.
![fdtd yee cell fdtd yee cell](https://slideplayer.com/slide/5311078/17/images/7/Define+Locations+of+Field+Components%3A+FDTD+Cell+called+Yee+Cell.jpg)
![fdtd yee cell fdtd yee cell](https://www.researchgate.net/profile/Stephen-Pistorius/publication/267995541/figure/fig1/AS:295338838642692@1447425674072/A-standard-Yee-Cell-for-FDTD.png)
During this process, the electric and magnetic fields are computed everywhere in the computational domain and as a function of time starting at t = 0. In the Finite Difference Time Domain (FDTD) method, a discretized form of Maxwell’s equations is solved numerically and simultaneously in both the 3D space and time.