Design And Implementation Of183/325GHZ Dual-Channel System

Millimeter and sub-millimeter wave systems are gradually used to the field of astronomy, remote sensing, satellite communications, and terahertz imaging. Quasi-optical technology is an important means of analysis and design of millimeter and sub-millimeter systems.This thesis first describes the characteristics of Gaussian optics,then the basic formula of Gaussian beam transmission and conversion is deduced in detail, and technical background of Gaussian beam is introduced. Afterward, it gives a review on the design methods for Quasi-optical dual-channel Systems, including the design of dual-channel system, design of dichroic, design of Cassegrain antenna and integrated design. This part of the contents is the theoretical derivation for quasi-optical system design based on the Gaussian optics theory. This part focuses on the ellipsoidal reflector design, frequency selective surface design theory and mirrors placed in the core of the integrated design, and the design in the paper is simulated by SiMatrix. Meanwhile, mature commercial GRASP quasi-optical simulation software is also used to verify the accuracy of SiMatrix. Then, the thesis describes the program and test equipment that will be used.The main work of the author is designed a183GHz/325GHz dual-channel quasi-optical system based on the given feed. And result simulated by SiMatrix is analyzed to find if the design meet the requirement. And the result simulated by GRASP is used to verify the accuracy of the result simulated by SiMatrix.Double large frequency bandwidths, miniaturizing system and high efficiency are three merits of the designed and fabricated double-path multi-reflector QON. It was found that the teat result were in accord with the simulation data quite well which indicates that the integrated design method and simulation method are very accurate.This paper explores the design and simulation methods in quasi-optical systems under terahertz frequencies by combining a variety of different simulation methods to verify the accuracy of the simulation. This is in line with the general guidelines of engineering design. It has a certain sense of guidance of design of quasi-optical systems and frequency selective surface.