Computation of radar cross section of waveguide arrays

A review of the open literature shows that not much information has been published on the radar cross-section (RCS) of waveguide arrays. An accurate method for the computation of the RCS of active waveguide arrays is presented. It combines the plane wave angular spectrum method used by Stalzer et al. (1978) to find the active element radiation pattern of an infinite phased array and the generalized scattering matrix (GSM) approach to periodic waveguide array analysis. The active scatter pattern of an element in an infinite array is obtained in terms of the reflection coefficients of the free space Floquet modes found by the GSM procedure. This active scatter pattern is employed in the computation of the RCS of a finite array by assuming that it is identical for all elements of the array and ignoring the edge effects in the process. The accuracy of this model has been validated by the good agreement observed between predictions and published test results of arrays of various sizes.