A variational approach to the prediction of antenna RCS

Summary form only given. Except in special circumstances, calculation of the radar cross-section (RCS) of scattering objects relies on the numerical solution of integral equations through a suitable approach, such as the method of moments. However, if the integral equations for the scattering of the electromagnetic radiation can be formulated in terms of a variational principle the effects of distortions in the scattering objects may be accounted for. In addition, if an iterative approach is adopted the RCS of bodies of size of order of a wavelength can also be calculated. This approach is often more computationally efficient than the traditional method of moments calculation. The general application of variational techniques to the calculation of radar cross-sections is reviewed. Illustrations of the technique are given by considering the scattering from a distorted dihedral corner reflector and a thin wire representing two different classes of antenna