On the interaction of electromagnetic fields with wire cagestructures

The authors address the problem of the interaction of electromagnetic fields with wire cage structures. The two canonical shapes considered are cubes and cylinders. The motivation for this work comes from a need to investigate electromagnetic field coupling (transient or broadband CW) to communication facilities or buildings with metallic rebar elements in the perimeter walls. Coupling calculations are performed by using NEC-2 computer codes and the experiments were performed at the Swiss MEMPS facility. MEMPS is a hybrid type of nuclear electromagnetic pulse (NEMP) simulator consisting of an impedance loaded elliptical structure with either a transient or a broadband CW excitation. Both types of excitations have been used in experimentally studying the coupling characteristics. In the case of cylindrical wire cage structures, both polarizations, i.e., incident electric field and incident magnetic field parallel to the cylinder axis, have been investigated. Good agreement is seen between the computed and measured result