论文部分内容阅读
对于任何通信系统而言,天线能否正确发射和接收有效信号是人们最为关心的问题。对于点对点的激光通信系统而言,由于激光与电波迥然不同的特点,在天线系统的设计上更需严格要求。在空间光通信系统中,光学天线是一个物镜系统,通过折射、反射和折射-反射光学系统实现,目前应用比较广泛的是牛顿系统、格林系统以及卡塞格伦系统。讨论了卡塞格伦天线系统,该系统的结构(双反射式)决定了存在遮挡比造成光能量浪费的潜在问题,也就是所谓的渐晕现象。另一个问题是像差,也就是卡塞格伦天线系统要获得良好的像质必须以牺牲视场为代价。基于这两点提出了减小渐晕的几种新方案,并从减小像差上进行了理论分析。
For any communication system, the antenna can transmit and receive valid signals correctly is the most concern. For point-to-point laser communication system, due to the very different characteristics of the laser and radio waves in the antenna system design more strict requirements. In the space optical communication system, the optical antenna is an objective system, which is realized by the refraction, reflection and refraction-reflection optical systems. At present, the widely used are the Newton system, the Green system and the Cassegrain system. The Cassegrain antenna system is discussed. The structure of the system (dual reflection) determines the potential problem of light energy wasting due to the occlusion ratio, which is known as vignetting. Another problem is that aberrations, that is, Cassegrain antenna systems, have to come at the expense of the field of view for good image quality. Based on these two points, several new schemes to reduce the vignetting are proposed, and the theoretical analysis is made on the reduction of aberrations.