Dissertation
Dissertation > Transportation > Waterway transport > Marine Engineering > Various types of vessels > Military ships ( warships ) > General issues

Research of Electromagnetic Field Distribution Characteristic in Complex Ship Environment

Author WuXiaoChuan
Tutor DengWeiBo
School Harbin Institute of Technology
Course Information and Communication Engineering
Keywords Electromagnetic Compatibility Multilevel fast multipole method Antenna Mutual Coupling Microwave Network
CLC U674.70
Type Master's thesis
Year 2010
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There is a large number of ship navigation systems and wireless communication complexity lined platform on which electromagnetic environment extraordinarily complex communication system ( receiver , transmitter ) frequency coverage as small as a few kilohertz , big enough to 40GHz. In recent years, a large number of studies published to solve complex TV antenna structure analysis of the problem . For the layout of the carrier antenna , the metal structure ( chimneys , masts etc. ) on the antenna performance and electromagnetic compatibility problems ship are very complex calculation , the antenna radiation pattern and a large number of model coupling antenna design and arranged to provide critical information . Many theoretical approaches such as scattering theory , mutual coupling theory can be used to solve the antenna near metal structures and interactions . However , large complex antenna platform analysis and calculation of the radiation pattern often is both difficult and time-consuming , and sometimes impossible. Therefore , the use of numerical methods or evolutionary theory estimates are good solution. In order to solve the multi-antenna carrier platform electromagnetic compatibility (EMC) , this paper utilizes automatic hierarchical multilevel fast multipole algorithm (MLFMA), and a detailed analysis of the algorithm principle and implementation process. Then introduced the model in two ways , and gives a typical ship model building . Secondly, this paper analyzes the ship on deck 3 ~ 30MHz frequency range of the antenna pattern and degree of coupling . In order to analyze the coupling between the antenna characteristics , this paper, microwave network theory gives an arbitrary degree of isolation between antennas expression. Based on multilevel fast multipole algorithm , analyze and simulate the shipboard HF whip antenna radiation far field pattern and different frequency , antenna height, horizontal and vertical distances , polarization and other conditions of the coupling strength . Finally, the paper discusses the complex platform antenna radiation characteristics of near-field electromagnetic field strength and compared in different shape hull superstructure , antenna position , the number of antennas and transmit power antenna radiation characteristics, which for shipboard HF communication antennas design and layout to provide a reference standard . In addition, this paper, based on the antenna mutual coupling matrix eigenvalue decomposition algorithm optimized antenna layout algorithm to optimize the layout of shipboard antenna provides a reasonable , feasible plan .

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