Axial field of a symmetric paraboloidal antenna: a PO/PTD solution

Proper characterization of the radiated field along the axial direction of a symmetric paraboloidal reflector antenna is important for pencil beam applications such as ultra wideband radar systems. The challenging issues in this task is the evaluation of the edge diffracted fields from the rim of the reflector and those from other scattering structures. The goal of this study is to determine the axial-field of a symmetric paraboloidal reflector antenna using the diffraction techniques of physical optics (PO) and physical theory of diffraction (PTD). As a result, with a general spherical incident field representation, closed-form formulas are obtained for various axial field components. These formulas provide useful information on the diffraction effects of the reflector edge, and facilitate the characterization of the time-domain response of these antenna systems.<>