Optimal subreflector position determination of shaped dual-reflector antennas based on the parameters iteration approach  

作　　者：Bin-Bin Xiang Cong-Si Wang Pei-Yuan Lian Na Wang You Ban 

机构地区：[1]Key Laboratory of Electronic Equipment Structure Design of Ministry of Education, School of Mechano-Electronic Engineering, Xidian University [2]Xinjiang Astronomical Observatory, Chinese Academy of Sciences

出　　处：《Research in Astronomy and Astrophysics》2019年第4期151-160,共10页天文和天体物理学研究（英文版）

基　　金：supported by the National Key Basic Research Program of China (2015CB857100);the Chinese Academy of Sciences (CAS) "Light of West China" Program (2017-XBQNXZB-021);the National Natural Science Foundation of China (Nos. 51805399 and U1737211);the Natural Science Foundation of Shanxi Province (No. 2018JZ500);supported by the Operation, Maintenance and Upgrading Fund for Astronomical Telescopes and Facility Instruments, budgeted from the Ministry of Finance of China (MOF) and administrated by CAS

摘　　要：A new method based on the parameters iteration technique has been developed to determine the optimal subreflector position for shaped Cassegrain antennas, that are distorted by gravity, to improve their electromagnetic(EM) performance. Both the features of shaped surface and the relationship between optical path difference(OPD) and far field beam pattern are employed. By describing the shaped dualreflector surface as a standard discrete parabola set, we can utilize the optical features of the standard Cassegrain system in the classical OPD relationship. Then, the actual far field beam pattern is expressed as the synthesis of ideal beam and error beam by decomposing subreflector adjustment parameters using a mechanical-electromagnetic-field-coupling-model(MEFCM). Furthermore, a numerical method for determining optimal subreflector position is presented. The proposed method is based on the iteration technique of subreflector adjustment parameters, and the optimal far field pattern is used for the iteration. The numerical solution of optimal adjustment parameters can be obtained rapidly. Results for a 25 m shaped Cassegrain antenna demonstrate that the adjustment of the subreflector to the optimal position as determined by the proposed method can improve the EM performance effectively.A new method based on the parameters iteration technique has been developed to determine the optimal subreflector position for shaped Cassegrain antennas, that are distorted by gravity, to improve their electromagnetic(EM) performance. Both the features of shaped surface and the relationship between optical path difference(OPD) and far field beam pattern are employed. By describing the shaped dualreflector surface as a standard discrete parabola set, we can utilize the optical features of the standard Cassegrain system in the classical OPD relationship. Then, the actual far field beam pattern is expressed as the synthesis of ideal beam and error beam by decomposing subreflector adjustment parameters using a mechanical-electromagnetic-field-coupling-model(MEFCM). Furthermore, a numerical method for determining optimal subreflector position is presented. The proposed method is based on the iteration technique of subreflector adjustment parameters, and the optimal far field pattern is used for the iteration. The numerical solution of optimal adjustment parameters can be obtained rapidly. Results for a 25 m shaped Cassegrain antenna demonstrate that the adjustment of the subreflector to the optimal position as determined by the proposed method can improve the EM performance effectively.

关 键 词：methods:analytical methods:numerical TELESCOPE techniques:radar ASTRONOMY 

分 类 号：P[天文地球]