On Crabtree´s BQSP technique for significant reduction of integration points in analyzing reflector antennas

Physical optics (PO) is commonly used for reflector antenna analysis. This is primarily due to the inherent simplicity in the PO formulation and the accuracy of PO, especially with reference to large reflectors. However, PO is computationally demanding since it involves, in general, a two dimensional numerical integration with a highly oscillatory integrand. This radiation integral can be evaluated using various numerical integration techniques which are based on either brute force approaches (Simpson´s rule, Gaussian quadrature, etc.) or modified approaches (Ludwig´s linear surface patch and Crabtree´s (1991) biquadratic surface patch (BQSP)). In the modified approach, the number of integration points are drastically reduced compared to brute force integration leading to greater efficiency in terms of computer storage and time. The application of optical path length correction, which is vital for obtaining the full computational advantage of the BQSP technique, is discussed.<>