Sensitivity Analysis of Reflector Antennas and Its Application on Shaped Geo-Truss Unfurlable Antennas

This paper presents the sensitivity of far-field radiation performance with respect to reflector surface nodal displacements. The reflector surface is divided into a series of triangular elements and in any deformation state the surface can be determined by the element nodal displacements. The radiation integrals over each small element are summed to obtain the whole electromagnetic performance. With the aid of shape functions in triangular elements, the integration points inside each element are expressed as functions of element nodal displacements. Then the partial derivatives of electric far field and directivity with respect to each nodal displacement are derived. The sensitivity contour plots of maximum directivity with respect to surface nodal displacements for axis-symmetrical and offset parabolic reflectors are numerical simulated. The sensitivity is applied to a shaped geo-truss unfurlable antenna with accepted results.