The singularity expansion method as applied to perpendicular crossed wires

The singularity expansion method (SEM) makes it possible to determine the time domain scattering from a conducting object in terms of a summation of damped sinusoids. SEM is used to calculate the current and charge induced on a system of two perpendicular crossed thin cylinders (wires) representing a crude model of an aircraft. The induced current and charge are obtained by varying the parameters of the problem. The time domain response of one particular geometry is obtained by SEM and compared to that determined by the more conventional frequency domain analysis and Fourier inversion. The results are found to agree within a few percent difference. The singularity expansions for the wire currents and charges are expressed in terms of the complex natural frequencies, vector current modes, coupling vectors, and coupling coefficients. The variation of these quantities with changes in the wire configuration is presented.