| With the continuous development of RF technology, chip technology and big data analysis, aimed at improving the quality in people lives and lifestyles of innovative new equipment have been gradually developed. It also contributed to the rapid development of various automatic detection technology, especially in the automotive field autopilot. Cars autopilot technology to change people life, will be a landmark, especially the frequent traffic accidents in China, its significance will become more and more apparent. However, there are some difficulties in this technology, such as large-scale application detection radar device, radar to improve the performance to reduce the volume. The present paper proposes a method, using the Rotman lens to replace the traditional radar antenna feeding network in order to simplify the structure and improve the performance of the radar antenna equipment.First of all, the paper introduces the history and current development of Rotman lens, and presents the design goals with the actual application requirements. Besides, it discusses the characteristics of wide band of Rotman lens array antennas, and the principle of comparative analysis of the Vivaldi antenna array unit as its RF-termination. Finally, we have completed this Vivaldi antenna analysis and design simulation. Based on the principle of optical path, which satisfies the design equation of Rotman Lens, we find the initial value that accord with the goals of Rotman lens performances, the size of parametric qualitative analysis and the final results in theory.The Rotman lens design and implementation depending on the single electromagnetic simulation software is unachievable. But the paper adopted a software package to realize calculations, modeling and simulation:MATLAB-HFSS-API. It gives the MATLAB to comput its geometric artwork, and electromagnetic simulation software HFSS to implement in modeling and simulation. Before the simulation model, we need to refine the processing, such as terminating at the port connected with a virtual matching resistor and Rotman lens array unit-Vivaldi antenna. After the completion of the overall simulation Rotman lenses, based on the analysis of simulation results, the model has been optimized, and ultimately reached the design target.By the processing test, this Rotman lens antenna is identical with the results of simulation, and the return loss is maintained at less than-10dB over a wide frequency range, and in the scanning angular range its gain remains stable. |
