| With the development of information technology,modern ships on the electromagnetic environment is more and more complex,electromagnetic compatibility and electromagnetic interference problem more and more prominent,and the double reflector radar antenna as a kind of ship radar’s classic structure,its anti-jamming ability needs to be improved,but the anti-jamming ability of ascension cannot significantly affect the radar antenna working frequency band.In order to realize the anti-jamming function of dual reflector radar antenna structure,a wideband FSS conical radome is studied in this paper,and it is combined with dual reflector antenna to obtain a dual reflector antenna with FSS mask with certain anti-jamming ability.However,most of the existing curved frequency selection radomes have narrow wave transmitting bandwidth,and some frequency selection radomes with wideband wave transmitting are either planar or have weak mechanical strength,so this paper carries out research on the conical wideband frequency selection radome.In this paper,the design and optimization of FSS radome elements,the layout and arrangement of FSS elements on the cone,and the overall simulation and experimental test of cassegrain antenna system with FSS radome are studied.The main research contents are as follows:(1)A bayesian optimization algorithm for solving domain scaling criterion and parallel point criterion is proposed.It is known that among all kinds of optimization algorithms,the Bayesian optimization algorithm based on the surrogate model is particularly effective for expensive and time-consuming optimization problems such as electromagnetic structure.However,with the increase of the complexity of the optimization objective and the increase of the optimization variables,the optimization effect of the traditional Bayesian optimization method is getting worse and worse.To solve this problem,this paper introduces the domain scaling criterion to speed up the convergence of the algorithm.In addition,in order to make full use of computing resources,this paper also introduces the parallel point criterion,which can collect several sample points in an optimization iteration,and then carry out the parallel calculation of several sample points,which can improve the optimization speed to a certain extent.Through the verification of numerical examples,compared with the traditional bayesian optimization algorithm,the proposed bayesian optimization algorithm based on the integrated domain scaling criterion and the parallel point criterion is greatly improved in terms of convergence speed and optimization effect.(2)Most of the curved frequency-selected radomes in the existing literature have narrow wave-through bandwidth.Some of the frequency-selected radomes with wideband wave-through are either planar or have weak mechanical strength,which is mainly due to the mutual restriction between wideband bandpass characteristics,bendability characteristics and high mechanical strength.Moreover,the conical wideband frequency selective radome designed for cassegrain dual reflector antenna is very rare.In order to realize the characteristics of broadband,bendability and high mechanical strength at the same time,a single-layer broadband FSS structure is adopted in this paper.The bearing medium is 0.1mm flexible polyimide medium plate to realize conformation of the cone,and the FSS layer is embedded in the honeycomb sandwich structure to realize the broadband characteristics and high mechanical strength.After comparison and optimization of various embedded structures,this paper determines a conical conformation of wideband frequency selective radome element structure,its-1d B bandwidth can reach12-17 GHz,its honeycomb height can reach 13 mm.(3)In view of the simulation problem of the radome of FSS,this paper combines a look-up table method with ray tracing method to deal with the analysis problem of the large FSS radome.The transmission and reflection information of the radome unit of FSS is analyzed by finite element method,and the information is stored in the form of tabular files.When the ray passes through the radome wall,Multiply the electromagnetic ray by the corresponding transmission coefficient in the table to get the electromagnetic ray passing through the cover wall,and multiply by the corresponding reflection coefficient to get the electromagnetic ray reflected through the cover wall.This analysis method balances the contradiction between simulation accuracy and speed to a certain extent.And through the construction of a simple example verification,the approximate simulation method of this paper and the finite element method analysis results are similar,small error,indicating the reliability of the approximate simulation method,and its simulation time is only one fortieth of the finite element method.(4)Based on the traditional composite process of a sandwich radome,the composite process flow of FSS radome is given,the transmittance of conical FSS radome is tested,and its anti-interference performance is quantitatively characterized and tested.Based on the working environment of the cone radome,the mechanical properties of the cone radome are tested,and the effect of deformation on the antenna system with FSS radome is analyzed by simulation. |
