Airborne Antenna Optimization Based On Domain Decomposition Method Of MoM

Airborne antenna system design is an important research topic in the field of electromagnetics.The early-warning radars installed on airborne platforms can be efficiently deployed anywhere because of the high mobility of aircraft.Thus the detection distance of radars will sharply increase.However,the aircraft structure will affect the performance of the antenna due to its complex electromagnetic scattering property,which contributed to the antenna radiation pattern distortion.If the antenna and the aircraft platform can be integrated as a whole in the simulation,then the antenna would achieve the best performance by optimizing efficiently based on the analysis of disturbed characteristics of the airborne antenna at the initial stage of the antenna design.In order to solve the problems of large calculation and long computation time in the process of accurate and integrated simulation of airborne antenna systems,the use of higher-order method of moments and parallel computing method can reduce the number of unknowns and increase the calculation speed.In this thesis,the domain decomposition method is used to separate the large-scale electromagnetic problem into several small problems.This method can overcome the imitations of computer size on the method of moments(Mo M)because the simulation can be carried out as long as the platform computing capability meets the requirements of the largest sub-domain calculation.At the same time,the domain decomposition method is also combined with the out-of-core solver method to expand the scale of the calculation.The sub-domain impedance matrix data will be stored on hard disk,thus reducing memory space occupancy.What is more,the improved Particle Swarm Optimization(PSO)algorithm is applied in the optimization.With the advantages of simple algorithm model,strong search ability and well stability,the solution to the multi-scale complex optimization of the airborne platform antenna converges to the optimal solution quickly and accurately.According to the method above,the whole model is divided into several carrier sub-domains and one antenna sub-domain during the optimization of airborne antenna in this thesis.Then calculate each part and iterate to the complete solution.Subsequently,data concerned like the impedance matrix of the carrier sub-domain can be stored into the hard disk.For the follow-on subsequent optimization of the airborne antenna,only the antenna part needs to be recalculated since the carrier part is not adjusted.Finally,the new solution generated by iteration is used to guide the next optimization until it meets the design goals.This method avoids repeated calculations of the carrier part in the optimization process,which not only reduce the optimization time greatly but also lower the memory requirements for calculation platform.Thus,the problem of integrate simulation and optimization of airborne antenna can be solved.