Geometric symmetry, electric symmetry and magnetic planes of symmetry in a model can be
exploited to reduce runtime and memory requirements.
Symmetry in a model applies to the method of moments (MoM) and all hybrid techniques where the MoM is involved, but not in conjunction with the multilevel fast multipole method (MLFMM).
A symmetric model without geometric symmetry defined is not guaranteed to have a symmetric
mesh. Such a setup leads to non-symmetric current distributions on the structure.
Geometric Symmetry
The structure must be symmetric concerning the symmetry plane, while the sources may be
arbitrarily located.
Electric Symmetry
To define an electric symmetry plane, the following must be true:
The model must be geometric symmetry at the plane.
The electric current density must be anti-symmetric.
The magnetic current density must be symmetric.
For example, a physical interpretation of an electric symmetry plane is a plane which can be
replaced by a perfect electric conductor (PEC) wall without changing the field distribution.
The tangential component of the electric field and the normal component of the magnetic
field are zero at such a plane.
Figure 1. Electric symmetry plane
Magnetic Symmetry
To define a magnetic symmetry plane, the following must be true:
The model must be geometric symmetry at the plane.
The electric current density must be symmetric.
The magnetic current density must be anti-symmetric.
For example, a physical interpretation of a magnetic symmetry plane is a plane which can be
replaced by a perfect magnetic conductor (PMC) wall without changing the field distribution.
The normal component of the electric field and the tangential component of the magnetic
field are zero at such a plane.
