Research of Electromagnetic Field Distribution Characteristic in Complex Ship Environment
|School||Harbin Institute of Technology|
|Course||Information and Communication Engineering|
|Keywords||Electromagnetic Compatibility Multilevel fast multipole method Antenna Mutual Coupling Microwave Network|
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 .