ANALYSIS OF ANTENNA SUPPORTING STRUCTURES

Abstract

The antennas for communication with artificial earth satellites have a complicated structure, which include high-precision mechanisms for guidance of the antennas working with the computers. Design of such large antennas for wind is rather complex. During operational condition and for proper communication, under a high design wind speed the antenna supporting structure should satisfy the stringent requirements of the antenna. In this dissertation, a paraboloidal 18-meter diameter dish antenna is considered for the analysis of antenna supporting structures. Finite element software ANSYS is used to carryout the analysis. Solid45 and mass21 elements are used to generate the mathematical model of supporting structure. Different structural configuration with truncated conical pedestal with and without ribs have been considered. Natural frequencies and maximum displacements on pedestal top have been observed to asses the suitability of supporting structure under varying soil conditions. It has been observed that the ribs do not have any significant impact on the frequency of the supporting structure. However, to achieve the displacement limits these are essential. It has been found that the stringent limits on displacement and frequency cannot be satisfied with pedestals on soil, these can be satisfied only with pedestals on hard rock.