Evaluation of scattering in a TEM cell by the FD-TD method

The TEM cell is a fundamental tool in electromagnetic compatibility in that it permits one to simulate the effects of a plane wave incident on equipment under test in a region large with respect to the wavelength where the field is strictly TEM. The main restriction to the high-frequency operation of the cell arises from the cutoff of the first higher order mode. The new GTEM cell permits one to overcome this restriction. EMP effects upon electronic systems can be simulated to a great level of accuracy using various types of EMP simulators. Especially in the case of a large test object a theoretical analysis is very helpful for defining the threat level at the interfaces to the smaller subsystems, which may then be tested and hardened in a laboratory. In the paper the scattering of metallic object in a GTEM cell is analyzed and the results are compared with scattering with plane wave excitation. The FD-TD proves to be effective for any shape of scattering body with both sinusoidal and pulse excitation even if it is computer time consuming. A 2D analysis that reduces the computing time is therefore reported