Layered Dielectric Sphere

With this option a layered dielectric sphere located at the origin is taken into account with the Green’s function.

Figure 1. The GF - Specify Green's functions dialog, set to Layered dielectric sphere.
When this Green’s function is selected, the EM interaction of a layered dielectric sphere located at the coordinate system centre is taken into account. With this option it is, for example, possible to analyse a mobile phone in front of a spherical shell model of the human head very efficiently.


Configuration list
The drop-down list allows selecting between a Single dielectric sphere, a Core and a coating layer and a Core and three layers.
Note: If metal structures are included, the only options are Single dielectric sphere and Core and two layers.
Allow metal structures inside sphere
When this item is checked metallic structures can be present in the inner parts of the sphere.
Convergence criterion
Convergence criteria for the summation of the rows of Green’s functions. If this field is 0 or undefined, a sensible standard criterion is used.
Radius of the sphere / layer in metres (is scaled by the SF card). For the layers, this is the total radius of the core plus layers up to that point. The highest numbered layer is on the outside of the sphere.
Material label
Label of the material (as defined in the DI card) to be used for the core / layer.
The scaling factor that is entered by the SF card is applied to the radius. Note that the surrounding medium is defined by material label “0”. By default the values of free space is used, but these parameters can be redefined in the DI card.
The Green’s function for a homogeneous or layered dielectric sphere can be used with metallic structures (treated with the MoM) either inside or outside the sphere (but not for example a wire from inside to outside). It can be used with dielectric bodies treated with the volume equivalence principle (for example the hand of a user around a mobile phone), but the dielectric bodies must be outside the sphere.

Figure 2. Example of a sphere consisting of 4 media (core and 3 layers) indicating the layer numbering.