Simulation Research Of Emc For Shipborne HF Surface Wave OTHR

High Frequency Surface Wave Radar(HFSWR) transmitting a vertical polarization of electromagnetic wave, the path of this wave is curved when spread along the air-water interface, with a diffraction effect High Frequency Surface Wave Radar could detect and track targets over the horizon, in a great value on both military and civilian.Shipborne High Frequency Surface Wave OTH Radar can greatly enhance the ship's warning distance and improve its mobility.However, the ship's complex superstructure will have great impact on electromagnetic properties of the HF antenna which installed on the ship.The antennas on ship will also interfere with each other. HF antenna radiate electromagnetic energy, is is a class of interference source, which produce complex electromagnetic environment on ship and will impact ship's EMC. How to predict and judge the impact is an important issues need to be carefully considered when design a ship.Have a test on the real ship is a basic mehod to study the ship's EMC,but this mothed not only spend both manpower and resources cost,but also need a lot of time. With the rapid development of electromagnetic numerical computation and computer technology, the numerical simulation technology becomes a useful method.Method of moments(MoM) above all numerical methods is widely used for its high precision,but because of its low efficiency, people developed multilevel fast multipole algorithm(MLFMA),which can greatly improve the computational efficiency.In this paper, MLFMA has used to reaserch the electromagnetic compatibility of ship with High Frequency Surface Wave OTH Radar.The theory of MoM and MLFMA were studied detailedly at first, Studied the radiation of HF antenna and analysised the matters needing attention when it installed on a ship platform with limited space.To ensure simulation results fit the actual electromagnetic environment,it is very important to found accurate electromagnetic model of a ship,electrically small metal structure make hardly influence on propagation characteristic of electromagnetic wave,such the model need simplify in order to enhance the computational efficiency.This article utilized a professional electromagnetic calculation software to establish a full-scale ship model and simulate the ship's electromagnetic environment,analysised the EMC of the ship with HFSWR,including the electromagnetic properties of HF antennas, the surface current on ship and the electric field's change characteristics of sensitive areas and so on. Finally through validity check, verified the accuracy of simulation results. This article studied HF distribution characteristic of shipbome HF Surface Wave OTH Radar, provided theoretical basis for further study on optimizate the layout of HF antenna and electromagnetic safety of ship design,therefore this paper has some certain theoretical value.