A fast analysis of the transient radiation from reflector antennas excited by pulsed beams

Abstract

This paper presents a fast analysis of the transient radiation from large reflector antennas which are excited by a pulsed feed. This development employs a superposition of a set of time domain (TD) complex source beams (CSBs), or TD-CSBs, as basis function to represent a pulsed feed which excites a reflector antenna. Each TD-CSB undergoes reflection and diffraction in a manner analogous to rays from a pulsed point source, at an external position in real space, when they are incident on the reflector. This reflection and diffraction of real rays can be found via the previously available TD version of the uniform geometrical theory of diffraction (UTD), or TD-UTD. That TD-UTD is analytically continued here to allow the point source to reside in complex space because the latter generates a CSB. The resulting CSB-TD -UTD overcomes the field singularities of the conventional TD-UTD at ray caustics, while retaining all their advantages of the UTD. The total field of the reflector is given by a superposition of the fields of each CSB-TD-UTD. The speed and validity of the proposed method is demonstrated via examples.