Symmetry properties of electromagnetic planar arrays: Long-wave approximation and normal incidence

We analyze in this paper symmetry properties of planar arrays in long-wave approximation and for normal incidence. Using group-theoretical methods we define all the possible magnetic groups for such structures. For some practical cases, we calculate the scattering matrices for nonmagnetic and magnetic arrays and discuss their properties.

For planar electromagnetic arrays in the long-wave approximation and normal incidence, we have defined all the possible nonmagnetic and magnetic groups of symmetry. We have analyzed the role of unitary and antiunitary elements of symmetry groups in the scattering matrix structure and discussed a method of matrix calculations.