Time-domain field response of a dielectric cylinder excited by a line source

In the last decade, considerable attention has been devoted to the analysis of time-domain electromagnetic scattering problems. The time-domain current and field response of a circular cylinder to a plane electromagnetic wave has been already studied by many researchers [1]-[4]. Recently, the transient response of a conducting cylinder to a cylindrical electromagnetic wave has also been studied by the authors [5]-[7]. The purpose of the present paper is to derive analytical expressions of the time-domain field response of a dielectric circular cylinder to a cylindrical electromagnetic wave generated by a parallel filament carrying a unit-step current. The mathematical technique employed here is similar to that in [7]. The time-domain expression of the electric field is obtained by the inverse Laplace transform of the frequency-domain eigenfunction solution. The response contains contributions of the branch cut integrals and residues corresponding to appropriately chosen integration contours.