Study On The Implementation Of3D Diffracted Gaussian Beam Analysis

Millimeter-wave and terahertz band, which ranges between the microwave and the infrared, is a band of great significance and a relatively new area in the electromagnetic spectrum study. In recent years, a large number of domestic and foreign experts devote in terahertz research. However, with the rising frequency of millimeter-wave, submillimeter and even terahertz wave, wavelength and the size of devices is getting smaller and smaller, difficulty and cost of manufacturing get increased a lot, the power capacity is sharply decreased, and the power loss of different reasons is getting much higher. All these problems become quite prominent, and it is no longer available to analyze the transmission using the microwave analysis models like the way in microstrip line, strip line, or waveguide. Terahertz quasi-optical technology analyzes the transmission using bunching electromagnetic wave propagation in space. And it has the advantages of being relatively easy to manufacture, high power capacity, working in multi-beamed and multi-polarized, little loss. Hence it is widely used in millimeter-wave and submillimeter transmission analysis and design frequency higher than100GHz.So far, the analysis method of quasi-optical technology has been widely used in submillimeter radio astronomy systems in China and abroad. And the millimeter-wave and terahertz waves has been successfully applied in radio astronomy, atmospheric remote sensing, plasma probe, material Exploration, terahertz imaging and many other areas.Till now, the commercial software most commonly used in the analysis and design of quasi-optical system is GRASP. It is based on physical optics and some other auxiliary numerical analysis method. As the software calculates with a large number of current integrations, a drawback is that the analysis is very time-consuming when more than one electrically large reflector is analyzed. Diffraction analysis of the Gaussian beam (DGBA) based on geometrical optics, developed by Queen Mary, University of London, takes the advantage of the high computing speed of geometric optics, and diffraction to improve the calculating results. But previous DGBA is only capable of two-dimensional symmetrical structured modeling, which is a major flaw in contrast with the commercial software GRASP. For example, the three-dimensional structure is clearly more sensible to save space in order to meet some tough specifications. This article makes a secondary development by using the previous2D DGBA analysis method, so that it can adapt to any3D configuration of the quasi-optical network, which is called the3D diffracted Gaussian beam analysis method. And at the end of this article, the precision of the analytical methods is verified using commercial software.