Research And Implementation Of Airborne VLF Automatic Antenna Feeder System Based On FPGA

The rise of China is closely related with the ocean right. In the long run, to achieve the complete marine rights and interests, China must have the strong marine forces, in which the development of the submarine known as "sea sword" is particularly important. The research will focus on How to quickly and reliably communicate with submarines based on the current technology of underwater communication.According to the relevant information, the current VLF communication stations in China are mainly two large fixed stations. However, the fixed stations easily become the primary targets of the enemy in the war. So it is a necessary and important subject to research the technology of the submarine communications on the airborne platform. For the airborne platforms, the antenna parameters are affected by environment factors and flight attitude. Above all, this thesis focus on an automatic system based on FPGA, which can improve the quality and efficiency of the system, reduce the preparation time, and improve the system survivability.The main work and innovation of this thesis includes:1Elaborated on the existing development and research of submarine communication systems and VLF transmitter antenna. Especially power combining techniques carried out a detailed analysis and comparison; to the VLF antenna radiation do some analysis and calculation;2. Antenna systems for research and theoretical calculations, to design an airborne antenna feed circuit, and then, this kind of circuit modeled by analysis and verification;3. After the hardware requirements for the analysis of the whole system, by comparing the performance and features a variety of processor and peripheral chip select FPGA build automatic tuning system, and EMC characteristics of strong electromagnetic environment for a certain amount of analysis and calculation;4On the basis of the hardware platform, using top-down, modular design methods, design of the system software. Using VHDL programming, effectively improve the program design flexibility and maneuverability;5To Achieve VLF system software and hardware integration by models and software for circuit simulation and verification. In our country, the VLF automatic antenna technology was attempted and useful research for the first time on airborne platform.In this thesis, airborne VLF communication antenna system is researched deeply. And it builds a set of hardware circuit model based on the theoretical analysis, which is controlled by the rapid automatic tuning technology of FPGA. Furthermore, the simulation results show that the system can overcome the disadvantages of the poor accuracy and low efficiency of the manual control, and greatly improve the response ability of the anti-submarine warfare and the survivability of the communication station. This will be of great practical value to enhance the overall fighting capacity of the submarine force.