Synthesis and analysis of ultra-wideband reflectarrays

The article is devoted to the problems of analysis and synthesis of dual-polarization ultra-wideband reflectarrays and is relevant for arrays of UWB elements of extended length such as Vivaldi antennas and TEM-horns. Synthesis and analysis are carried out in the approximation of a locally periodic array, when each of its elements can be assigned a Floquet cell. A review of the literature on UWB reflectarrays is carried out and it is shown that in most published works the dependence of the phase of the Floquet cell transmission coefficient on the angle of incidence and polarization of the exciting wave is not taken into account in the process of synthesis of the array. This article presents a procedure for the approximate synthesis of a dual-polarization UWB reflectarray taking into account the above effects. An approach to the analysis of the UWB RAA is proposed, based on the numerical calculation of the Floquet cell scattering matrix in combination with the successive approximations method. A comparison of the solutions at the first and second iterations is carried out, and the questions of further solution correction by increasing the order of approximation are discussed.