Study Of Reconfigurable Antenna Technology In The Application Of Passive Finding

The Electronic Countermeasure Technology has draw lots of attention and developedrapidly because of the outbreakof local war in recent years. In the field of ElectronicCountermeasure Technology, getting more accurate information of the radiation sources’direction can be more helpful to obtaining intelligence information, implementing electronicjamming and precision striking. Simultaneously, that may provide effective protection whendestroying the target. So, the technology of passive direction finding for radiation resourcesplays an important role in the field of Electronic Countermeasure field. In the passivedirection finding system, due to the diversity of the targets, their frequencies are not thesame. And the existing passive direction finding antennas can not cover enough widefrequency bands. Therefore, it has very important significance to study the passive directionfinding antennas. With the development of antenna technology, the concept ofreconfigurable antenna is proposed, and it provides a new way to solve the problem ofdesigning broadband antenna. In the article, the problem of parallel electromagneticcomputing, the frequency reconfigurable ultra-wideband antenna and the method of passivedirection finding were studied.The major research works in the article can be summarized as the follows:(1) Studied the electromagnetic optimization problem using parallel computing, anddescribed the parallel computing architecture. Due to the computational complexity andlong time’s cycle of using intelligent algorithm to optimize the electromagnetic problems,and based on the MATLAB parallel computing toolbox, the method of combining the HFSSelectromagnetic simulation software and the PSO algorithm to optimize the electromagneticproblems was presented. Then the method was applied to the design of microstriprectangular patch antenna and the optimization of PIFA antenna. The results of thesimulation shows that the method is feasible and can effectively reduce the time ofoptimization. Meanwhile, the optimization can be done automatically without any humanintervention.(2) Designed a frequency ultra-wideband antenna. Based on the printed ellipsemonopole antenna, by extending the feed line to reduce the operating frequency, afrequency ultra-wideband antenna was designed successfully using the reconfigurableantenna technology. The result of simulation by HFSS shows that the antenna covers a wideband from0.174GHz to10.9GHz, the bandwidth ratio up to62:1, and has a goodOmni-direction in the whole frequency band. The designed antenna can be widely used inradar and direction finding systems.(3) Introduced the nABD direction finding method, and proposed an advanced method.A brief introduction of nABD direction finding method was given and ideal antennas wereused to verify the method. Due to the limitation (measured angles ware over-reliance on theantenna pattern), an advanced method was proposed to expand the angle range. Then, thefrequency reconfigurable antenna designed in chapter three was introduced into theadvanced nABD method. From the results of simulation and analysis of errors, it can beconclude that the antenna can obtain high accurate angle, and the errors are less than2°.