Aperture amplitude and phase control of offset dual reflectors
Aperture amplitude and phase control of offset dual reflectors
复制标题
偏置双反射镜的孔径幅度和相位控制
DOI：
10.1109/aps.1978.1147946
复制
发表时间：
1978
期刊：
影响因子：
--
通讯作者：
A. Cha
中科院分区：
文献类型：
--
作者：
V. Galindo;R. Mittra;A. Cha
在20世纪50年代早期，Galindo和Kinber首先解决了圆形反射器的双重形状反射器综合问题。给出了一个任意的饲料模式，它表明，所需的表面，通过几何光学转换成任何指定的相位和振幅模式在指定的输出孔径的饲料模式被发现的两个同时非线性常微分方程的集成。对于偏移非共轴的几何形状，然而，它表明，通过这种方法发现的方程是偏微分方程，在一般情况下，不形成一个总的微分。因此，这个问题的确切解决方案通常是不可能的。然而，它也表明，对于许多重要的问题，偏微分方程形成一个几乎全微分。因此，它成为可能产生一个光滑的副反射器的微分方程的积分，然后合成一个主反射器，给出了一个精确的解决方案，为指定的孔径相位分布。输出孔径以及输出孔径周边中的合成能量（或振幅）分布于是近似为指定值。一组具有代表性的重要的解决方案，这说明了非常好的质量，经常导致这种合成方法。这包括高增益、低旁瓣、近场卡塞格伦和不同（f/D）比反射器系统。
The dual-shaped reflector synthesis problem was first solved by Galindo and Kinber in the early 1950's for the circularly symmetric-shaped reflectors. Given an arbitrary feed pattern, it was shown that the surfaces required to transform this feed pattern by geometrical optics into any specified phase and amplitude pattern in the specified output aperture are found by the integration of two simultaneous nonlinear ordinary differential equations. For the offset noncoaxial geometry, however, it is shown that the equations found by this method are partial differential equations which, in general, do not form a total differential. Hence the exact solution to this problem is generally not possible. It is also shown, however, that for many important problems the partial differential equations form a nearly total differential. It thus becomes possible to generate a smooth subreflector by integration of the differential equations and then synthesize a main reflector which gives an exact solution for the specified aperture phase distribution. The resultant energy (or amplitude) distribution in the output aperture as well as the output aperture periphery are then approximately the specified values. A representative group of important solutions are presented which illustrate the very good quality that frequently results by this synthesis method. This includes high gain, low sidelobe, near-field Cassegrain, and different ( f/D ) ratio reflector systems.