A new traveling wave expansion for the UTD analysis of the collective radiation from large finite planar arrays

In this paper, a new and improved traveling wave (TW) expansion is introduced for the efficient uniform geometrical theory of diffraction (UTD) analysis of the collective radiation from large finite planar arrays. The array distribution which can be obtained by using the method of moments (MoM) solution of the governing array integral equation was represented, in the recent past, in terms of a discrete Fourier transform (DFT) based TW expansion because it was found to be highly compact. The DFT is superseded in this paper by the new TW expansion in which a highly compact sequence of TWs adequately represents the array distribution. It is seen that the TW expansion requires a total number of terms which are typically less than 1% of the total number of array elements, which is far less than the required DFT terms for the same accuracy.