Wideband Pulse Responses of Fractal Monopole Antennas Under the Impact of an EMP

A generalized mathematical procedure is developed for investigating wideband transient pulse responses of some fractal antennas mounted on a perfectly electrically conducting platform illuminated by an electromagnetic pulse. The numerical algorithm employed is based on the technique of time-domain integral equation solved with the method of moments. To model the junction between a monopole and a ground plane or a monopole and a solid platform, a set of new vector basis functions defined on a cylindrical surface and planar triangular patches are proposed. The Laguerre polynomials are employed as entire domain temporal basis functions to expand the unknown current in the time domain. Numerical simulations are performed to demonstrate that fractal antennas are resonant at lower frequencies than those of same-sized Euclidean counterparts. The transient response characteristics of various novel antenna configurations are shown and compared in detail.