An Accelerated TD-NFPO Method for Computing Near-Field Scattering of a Parabolic Antenna

To address the issue of computational time in near-field scattering analysis of electrically large scatterers, a time-domain near-field physical optics (TD-NFPO) method based on spatial symmetry is proposed. This method is employed to compute the temporal near-field scattering signals along the axis of symmetry of a parabolic surface. Based on the theoretical formulation of the TD-NFPO, it is derived that the total scattered field of a parabolic structure is four times that of its 1/4-section scattering field. The efficiency and accuracy of this method are validated through numerical experiments. The accelerated TD-NFPO method based on the high-frequency approximation algorithm is well suited for the near-field time-domain scattering analysis of large-aperture parabolic antennas, providing some assistance in electromagnetic compatibility issues for radio telescopes.