Fu Research And Synthesis Of Reflector Antenna

Shaped reflector antennas have a wide range of applications in many areas, such as the air search radar, airborne radar of ground tracking and satellite communications. In this paper, based on geometrical optics (GO) and physical optics (PO), electrically large reflector antennas are studied for beam-forming with optimization algorithms. Deformation of the reflecting surface, the best permutation and combination of multiple feeds and dual-reflector shaped are studied respectly.The main contents of this article are as follows:Firstly, for the air defense weapon system to intercept low-altitude and low altitude targets, the environment is very complex. In order to reduce the impact of ground clutter on the antenna system, by reducing the reflector antenna on the side of the first sidelobe level, the interference of ground and surface features is reduced. Meanwhile, the ability of the weapon system to intercept low-altitude and low altitude targets are improved. With this application background, there are some requirements for the reflector antenna with beam-shaping. NURBS is used to model the arbitrary shaped reflector antennas. By changing the reflective surface of the control points corresponding weight, the shape of the reflecting surface is modified to achieve the purpose of beam-shaping. Simulated results verify its feasibility.Secondly, the research focused on the reflector antenna with beam-shaping. By defocusing characteristics analysis of reflector antenna feeds, and solving a set of optimal feed arrangement, a multi-beam antenna covering the territory of China is designed, which meets beam-shaping requirements.Finally, three types of Gregorian, Cassegrain and Ring-focus of dual-shaped reflector antenna are introduced. The ideas are based on geometrical optics, according to the law of reflection and the law of conservation of energy. Forming shaped-equation was obtained. The direction of the main reflector and sub-reflector surface shape was converted to the main aperture field distribution of the reflecting surface. Shaped ring-focus antenna is modeled as an example, and the typical band is simulated. An example was given to achieve the caliber of its high efficiency and good polarization discrimination.The main work of this thesis is concentrated on the design and simulated methods of shaped-beam reflector antenna, expecting through the analysis of simulation examples to solve the problems that encountered in practical work.