Effects of Periodic Geometric Error of AstroMesh Reflector Surface on Radiation Pattern and Its Elimination Method
ZONG Ya-li;WANG Wei;WANG Cong-si;ZHANG Yi-qun;Key Laboratory of Electronic Equipment Structure Design of Ministry of Education,Xidian University;
Since curved antenna surface is approximated by flat facets,the electromagnetic( EM) properties of an AstroMesh reflector are determined by the size and shape of the facets. A period disturbance technique is presented to decrease the grating lobe level generated by periodic geometric approximation error. At first,the periodicity of the error and the effects of the periodicity on EM properties are studied. Secondly,tw o strategies are developed to disturb the periodicity of the error, one is to introduce radial direction disturbance parameters,and the other is to change the shape of the rings. At last,an optimization model is built to obtain few er segments,proper disturbance parameters and better EM performance. Numerical examples show that the presened method can eliminate the grating lobes level w ithout decreasing the gain and increasing the structural complexity of AstroMesh antennas.