Where should the absorbing boundary be located?

Modeling the Center-Driven Dipole with Microstripes

The size and location of the absorbing boundary is determined by the Extents setting at the top of the Settings window. The default values of Extent are set to 0%, which means the mesh is tightly conforms to the geometric entities in the model. The location of the boundary depends on the maximum dimensions of the device. For example, a 50% extension around a device that is 10×10×100 would yield a mesh that is 110×110× 200. Figure 3 shows the results obtained when the boundary extent was set to 10%, the default duration changed to 24020 mm. The maximum cell size was set to default/3, minimum cell size was maximum/30. Although the simulation time decreased to only 16 minutes, the accuracy of the results was unacceptable.

Fig. 3. Input Impedance with smaller grid.