Transient response computation of spheroidal objects using impedance boundary conditions

The transient response of imperfectly conducting and permeable spheroidal objects is determined using the impedance boundary conditions. Since the impedance boundary conditions are not known in the time domain, the frequency domain analysis is used to formulate the problem. The use of impedance boundary conditions relates conveniently the solution to the object´s physical parameters and simplifies the computations. For highly conducting objects a simplified method is used to determine numerically the frequency domain data, which utilizes the numerical code for perfectly conducting objects. The excitation is assumed to be due to a periodic pulse train and generated by a small circular loop antenna. The procedure for the computation of the transient response, at very low excitation frequencies, is presented and the response forms for different object parameters and orientations are computed.