In many electromagnetic modeling problems you need a boundary condition that simply absorbs all the incoming radiation. For problems of this nature, an absorbing boundary condition (ABC) is often chosen that effectively minimizes wave reflections at the boundary. EM.Tempo uses Convolutional Perfectly Matched Layers (CPML) for absorbing boundary conditions. The boundary CPML cells in the project workspace are transparent to the user. But, in effect, multiple rows of CPML cells are placed on the exterior side of each face of the visible domain box.
Click here to learn more about the theory of '''[[Perfectly Matched Layer Termination]]'''.
Click here to learn more about '''[[Advanced CPML Setup]]'''.
===Modeling Planar Structures of Infinite Extents===
=== Excitation Waveform & Frequency Domain Computations ===
When an FDTD simulation starts, your project's source starts pumping energy into the computational domain at t > 0. [[Maxwell's Equations|Maxwell's equations ]] are solved in all cells at every time step until the solution converges, or the maximum number of time steps is reached. A physical source has a zero value at t = 0, but it rises from zero at t > 0 according to a specified waveform. [[EM.Tempo]] currently offers four types of temporal waveform:
# Sinusoidal