| The flat-top beam antenna is a branch of a beamforming antenna,which can distribute the energy uniformly in a certain range with low sidelobe level.It is widely used in mobile communication,satellite communication,radar system and other fields.Array antennas are commonly adopted to produce flat-top beam which control the phase and amplitude of the cells in the array to focus and direct the beam.However,the antennas designed in this way are bulky in size and have complex feed systems.Dielectric lens antennas have high degree of design freedom and enable to achieve flat-top beam efficiently.In addition,it is also possible to realize the integrated design of feed antenna and lens for dielectric lens antenna.Moreover,with the advent of 3D printing technology,it also provides technical support for the design of more complex dielectric lenses.At the same time,there are some intelligence optimization algorithms that can be applied to the design of lens antennas,which free up manpower and greatly improve the design efficiency.It also allows to obtain antennas with better performance.This paper studies how to achieve the flat-top beam by all-dielectric lens antenna,and the designed lens can be fabricated by 3D printing technology.The main research contents of this paper are as follows:1.A hybrid optimization algorithm based on particle swarm optimization and genetic algorithm（PSO-GA）is used to design an E-band all-dielectric lens antenna with flat-top beam.Firstly,the initial structure of the lens is determined.Secondly,in order to ensure the search speed of the algorithm and to overcome the problem that PSO is susceptible to local optimal solution,it is studied to introduce the genetic operation of GA in PSO.PSO and GA are integrated by programing with MATLAB.Next,it is necessary to determine the objective function.Then,the integrated modeling technology based on the joint MATLAB-CST simulation is used to obtain the performance parameters of the antenna.Finally,an all-dielectric lens antenna is designed by the PSO-GA algorithm,integrated modeling technology and construction of an accurate objective function which operates at64-70 GHz.The antenna has 30°flat-top beam in both E-and H-planes,with the maximum gain of 12.87 d Bi and the sidelobe level below-10 d B.The 3D printing technology is adopted to process the lens,which has the advantages of simple processing and low cost.The measured and simulated results are generally agreed.2.A broadband all-dielectric lens antenna with flat-top beam that operates in K/Ka band is designed based on the PSO-GA algorithm and integrated modeling technology.Firstly,the structures of the feed antenna and dielectric lens are designed.Secondly,the objective function is devised to represent the flat-top beam more accurately.Thirdly,the designed lens is loaded onto the feed source.The structure of the lens is optimized and simulated by PSO-GA algorithm and integrated modeling technology.The objective function is improved by analyzing the simulation results,which further accurate its description of the flat-top beam to obtain a lens antenna with better performance.Finally,an all-dielectric lens antenna that can realize flat-top beam greater than 60°in K/Ka band is designed,which has a ripple level less than 2 d B.In addition,the antenna has a good S11,which is below-10 d B. |
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