Investigation of the vivaldi array for Square Kilometer Array (SKA) application using the parallelized FDTD code GEMS on the LOFAR blue gene/L supercomputer

This paper presents the numerical simulation results of a Vivaldi 9x8x2 array. This type of arrays is being designed by ASTRON for the square kilometer array (SKA). The simulation has been carried out by using general electromagnetic solver (GEMS)-a parallelized finite difference time domain (FDTD) solver (W. Yu et al., 2005)-running on the LOFAR BlueGene/L supercomputer located at the University of Groningen. This supercomputer is one of the world´s fastest as well as largest-it has up to 6000 nodes- and the high parallelization efficiency of GEMS (-90%) makes the combination a very powerful tool for solving large complex problems in a time-efficient manner. The array parameters studied include the input impedance of the active element, coupling between the active element and those surrounding it, and the far field pattern of the same element, when the rest of the array elements are terminated with its characteristic impedance. Numerical results generated from the simulations using GEMS are presented in the paper and are compared with the measurement results.