Numerical evaluation of radiation integrals for reflector antenna analysis including a new measure of accuracy

Results are presented for an investigation of popular numerical integration methods applied to the reflector antenna problem. The comparison of methods is facilitated by the introduction of a new figure-of-merit (the p-factor), which is a measure of how far out in pattern-space the results are accurate. The p-factor can also be used to determine how dense a sampling grid is required for a given pattern accuracy. Results of the comparison show that Gauss-Zirnike polynomial integration on the diameter and the trapezoidal rule on the circumference was the most accurate method tested. Somewhat less accurate but still good methods were the Gauss-Legendre/trapezoidal and Gauss-Legendre/Gauss-Legendre methods.<>