Algorithm for currents reconstruction using the FFT iterative method and a lattice of the spectrum

Abstract

The knowledge of the equivalent currents of an antenna could become one of the most important aspects during its design process. This information can be obtained by knowing the currents obtained from the radiated field of the antenna. As this is usually measured in the near field region, is necessary to obtain a relationship between near field and equivalent currents. Basically, the process described in a previous paper obtains the far field from the near field measurements and with this far field calculates the plane wave spectrum. If this process is followed the maximum resolution achievable is 1 lambda. The reason for such a poor resolution is the use of only the visible spectrum. However, we need this non-visible spectrum to achieve a better resolution. For this reason we propose in this paper the combination of two techniques to obtain the non-visible spectrum. These techniques are the fft iterative method and the second technique is using the lattice of the spectrum to improve results. The use of both increases considerably the resolution of the reconstruction