Truncated Floquet wave full-wave analysis of large phased arrays of open-ended waveguides with a nonuniform amplitude excitation

Recently, an efficient hybrid asymptotic-method of moments (MoM) approach has been proposed for the analysis of large periodic planar arrays of elements excited with equal amplitude and linear phase. The aforementioned method, which is based on a Floquet wave diffraction representation of the array Green\´s function (AGF), is here extended to treat arrays with tapered amplitude excitation. To this end, the asymptotic AGF is refined by introducing additional "slope" diffraction contributions. An appropriate "fringe" integral equation, solved via a MoM scheme, provides the effects of array truncation in addition to the infinite array solution. The dimension of the corresponding linear algebraic system is independent of the number of elements of the array. Numerical results are provided to prove the accuracy and the efficiency of this method with respect to an ordinary element-by-element MoM.