Radiation from aperiodic reflectarrays using optimized NUFFTs

We deal with one of the computationally most critical steps of the Phase-Only synthesis of aperiodic reflectarrays, namely, the fast evaluation of the radiation operator. We present an approach exploiting the use of a fast numerical algorithm using 2D Non-Uniform FFTs (NUFFTs) of NED (Non-Equispaced Data) type and of parallel processing on Graphics Processing Units (GPUs). A fast GPU-implementation of the NUFFT routine is achieved by exploiting a polynomial representation of the spatial and spectral windows and using the Horner polynomial calculation scheme.Numerical result highlight the performance of the developed approach.