| The amount of facilities which used on the ships for communication grows faster and faster in recent years,the information flow-rate between each war system grows rapidly due to the explosive increase of the information content. Based on this trend,to respond to the request of the ages,promoting the communication quality becomes the one task that has to do in modern naval warfare.The current ship communication system is restricted to the conditions of the original system,deficiencies of many techniques have been exposed naturally.However the antenna system plays an important role in ship communication system,Therefore, object of this paper is the shipboard wide band antenna, which focuses on the open sleeve antenna.Common form of shipboard wide band antenna is shortwave antenna.The key point of this research is broadbandization and miniaturization of shipboard shortwave antenna.In this paper,some known methods,such as increase the diameter of vibrator,design a broadband matching network for a shortwave antenna,loaded components in design, are applied to single whip antenna and the sleeve antenna.At the same time, the structure and performance of open sleeve antenna are suitable for the shipboard.Also these features and results are analyzed and calculated here,including some influence factors should be taken into consideration.The author's main work done is as follows:1.Around the shipboard shortwave antenna issue,this article summarizes some common structure and the characteristics of shortwave antenna after understanding the spread mode and parameters of shortwave antenna.And according to the requirements in the practical application of shortwave antenna selection is roughly presented;2.Taking single whip loaded antenna and double-fold loaded antenna as examples,this paper uses FEKO for these two kinds of antenna simulation and calculation,get the VSWR and gain of theses antennas.In the same time,the intervention influence between ground wave and sky wave in the process of actual transmission is also reckoned with;3.Sleeve monopole antenna is analyzed by FDTD,then open sleeve antenna is proposed here.This paper discusses the influence of different number of the parasitic vibrator,a top-loaded sleeve antenna is proposed on this basis to meet the requirements of miniaturization and broadbandization.At last, the analysis method to solve the irregular shape of limited ground is given. |
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