Accurate Modeling And Simulation Of The Near-Field For Large Shipborne Array Antennas

As a new type of combat equipment,large-scale ships are an important platform related to the national economy and even national security,and the near-field distribution of large array antennas on complex ship carriers has a great significance to the electromagnetic compatibility and electromagnetic environment adaptability.Although experimental measurement is indispensable,it is undoubtedly faced with the problems of expensive and difficult.In contrast,electromagnetic numerical simulation has become a modern method for analyzing and predicting electromagnetic characteristics due to its significant advantages of flexible calculation mode and low calculation cost.However,At home and abroad,the simulation and computational analysis on the integrated model which is composed of array antennas and carrier are mainly focused on the small array antennas.In addition,some of reareaches are focus on the large-scale array antennas with simple carrie,which is not representative of the actual application scene.Moreover,the calculation results are more focused on the far-field.In view of the above problems,the Higher-Order Method of Moments(HO-MoM)and the Multi-layer Fast Multipole Algorithm(MLFMA)are theoretically introduced and accuracy verified respectively in this thesis.And then,further describe the basic theory of the hybrid algorithm,and prove its feasibility and high accuracy.The hybrid algorithm is used for simulate the near-field of the shipborne large array antennas by makeing full use of the domestic high-performance computer system.In this thesis,HO-MoM is used for the array antennas which have the characteristics of diverse structure and complex material.Then,the MLFMA is used for the large-scale ships which are consist of simple structure and single material.The hybrid algorithm of simulation in this thesis is cosisting of HO-MoM and MLFMA,which is a good mothd for the simulation of the near-field environment of large array antennas on complex carriers.In this thesis,we start with designing and modeling of the antenna and the ship model,and then the correctness of the algorithm and modeling is verified.The Higher-Order Method of Moments is used for calculate the electromagnetic characteristics of several array antennas with different sizes and different feeding modes,then,the near-field results of large array antennas in a specific region when it is placed at a specified position in a ship model are calculated by combining the Higher-Order Method of Moments with Multilevel Fast Multipole Algorithm.Hence,The near-field distribution of large shipboard array antennas is calculated.The shipborne platform in this thesis which adopts a representative large destroyer,also In the process of modeling,the error between the model and the actual ship is very smal.Moreover,the simulation scale of shipborne array antennas reaches more than 5000 at most.Finally,a breakthrough in the simulation scale of the array antennas and carrier integration model is realized.In this thesis,the electromagnetic simulation of large shipboard array antennas in different scenarios is realized,which is no longer limited to the calculation of small array antennas and simple carrier.it is possible to accurately simulate the integrated electromagnetic model of complex ship and large array antennas.