Phase-Only Synthesis of Flat Aperiodic Reflectarrays

Abstract

Abstract-A phase-only power pattern synthesis technique for flat (aperiodic) microstrip reflectarrays with elements arranged on a nonregular lattice is presented. The approach mitigates the typical design issues of reflectarray antennas related to the computational burden and to the possible occurrence of suboptimal solutions which are here even more significant due to the non-regular element lattice. This is done by a convenient two-stage procedure for choosing the starting point of the iterations and by proper representations of the unknowns of the problem. Design constraints on the element positions are also imposed to avoid overlapping as well as too large spacings. The algorithm, accelerated by parallel programming on Graphics Processing Units, has been analyzed against the cases of a pencil-beam and of a shapedbeam involving a typical South America coverage. In order to properly characterize the performance of the synthesis algorithm, it has been applied also to the design of reflectarrays with elements located on a non-regular lattice. The results show that in the case of non-regular lattice better directivities, better coverage behavior and better sidelobe levels are achievable as compared to reflectarrays characterized by a regular lattice.

Fast, Phase-Only Synthesis of Aperiodic Reflectarrays Using Nuffts and Cuda

“…The validity of the PO model for the common case of a rectangular patch has been discussed in [27]. Furthermore, the PO approach is able to take into account, although of course in an approximate way, the mutual coupling effects between each element and the surrounding reflectarray elements as well as the specular reflection from the ground plane supporting the patches.…”

“…Finally, numerical simulations have indicated that the radiation of reflectarrays synthesized under the PO model have already a good degree of matching with the radiation of the same reflectarray as evaluated by more "accurate" models [37].…”

“…On assuming each reflectarray patch to be located in the far-zone of F and under the phase-only (PO) model [27], the far-field pattern of the reflectarray can be written as…”

“…Regarding the primary source field,Ẽ f accounts for its vector aspects (assuming that the angle subtended by the reflecting surface at O is sufficiently small, see [27]), and a cos m f (θ n ) type pattern, typically sufficient for PO applications, has been assumed (θ n is defined in Fig. 2).…”

Synthesis of Sparse or Thinned Linear and Planar Arrays Generating Reconfigurable Multiple Real Patterns by Iterative Linear Programming

“…This work focuses on the synthesis of reconfigurable multiple patterns with fewer elements by selecting the common ones with optimized excitation amplitudes and phases. Some synthesis methods by using nonuniform element positions [16][17][18][19][20][21][22], or by applying thinning techniques [23][24][25], have been presented to effectively reduce the number of elements. However, these reviewed techniques are proposed for the synthesis of single-pattern arrays.…”