Radiation Pattern Analysis of Reflector Antennas Using CAD Model-Based Physical Optics Method

Radiation pattern analysis is important in reflector antenna design. Mesh model based physical optics method is widely used in such circumstance. There are always geometric errors between mesh model and CAD model, and the analysis will be subjected to geometric noise, which will ultimately deteriorate its accuracy. In this paper, such analysis is implemented directly with the CAD model. The reflector expressed by Non-Uniform Rational B-Spline (NURBS) is firstly refined by NURBS operation. It does not change the original shape, but divides it into small parametric areas, named as elements. The physical optics integration performs in each element with Gauss quadrature, and finally superimposes to obtain the radiation pattern of the antenna. Several examples show that this method is effective and efficient, and it will lay a foundation for antenna shape optimization with CAD models.