A Study of Log Periodic Feeds Multiple-Beam Antenna: Offset Parabolic Reflector Antenna

Abstract

The application of an array of circular polarized log periodic dipole antennas (LPDA) as feed array for a multiple-beam antenna to cover 3.5:1 bandwidths is described. Meanwhile, the use of an array of log-periodic antennas for two kinds of arrangement: rectangular grid and hexagonal grid illumination is also presented. In comparison with the rectangular grid, hexagonal grid is more efficient in beam coverage area for synchronous-orbiting communications satellites. Enhanced feed concept is used in the LPDA feed array in order to increase gain in coverage area. Finally, the simulated results for beam contour which is excite by right-hand circular polarized LPDA of both grids and enhanced beam contour over the frequency range of 0.8 GH to 2.5 GHz are demonstrated.