Time-domain analysis on the scattering from a reflector antenna based on high frequency approximations

The presented work is motivated by the needs of transient EM analysis in the booming applications of ultra-wide-band or short pulse antenna system for target identifications and remote sensing, where reflector antennas are apparently good candidates and have been widely used. In this paper, We develops an Analytic Analysis of Transient Scattering from a reflector antenna Illuminated by an Incident Plane Wave and another case a quasi-analytic TD solution is presented to perform a transient analysis of scattering from a parabolic reflector antenna when it is illuminated by a general astigmatic Gaussian Beam (GB). A closed-form analytic solution is thus developed for predicting the early-time transient EM fields scattered from a second-order surface truncated with an arbitrary edge boundary when it is illuminated by a transient impulsive plane wave and addition analysis employs physical optics (PO) approximation and utilizes analytic time transform (ATT) to treat the complex time delays resulted from GB's complex phase variations along its propagation in a frequency domain (FD).