Simultaneous Extrapolation of RCS of A Radar Target in Both Angular and Frequency Domains Based on Bivariate Padé Approximant Technique

Abstract

The radar cross section (RCS) of a target is dependent on frequency as well as angle. The method of moments (MOM) in conjunction with the bivariate Pade approximant technique is applied to predict the mono-static RCS of an arbitrarily shaped metallic target in both frequency and angular domains simultaneously. The electric field integral equation (EFIE) of the target is solved using MOM to obtain the equivalent current on the target surface. In the bivariate Pade approximant technique, the equivalent current at a given frequency and angle is expanded in the desired frequency and angle band in a binomial Taylor's series. The binomial Taylor's series coefficients are then matched via the bivariate Pade approximation to a bivariate rational function. Using the bivariate rational function, the current is obtained at any frequency and angle within the interesting frequency and angular range, which is in turn used to calculate RCS of the target. The use of this method for extrapolation of RCS has at least two significant advantages; one being obtained RCS analytical formulas and the other being a significant decrease in the amount of time required for modeling problems with large computational domains.