Research On Radiation Disturbance Suppression Technology Based On Electromagnetic Band Gap In Marine Very High Frequency Band

Marine very high frequency communication equipment is important for safety of navigation,and the electromagnetic environment of its installation position is very complex because electronic equipment is intensive,therefore it is vulnerable to interference.In order to ensure the normal operation,electromagnetic compatibility standards of marine electronic equipment put forward strict requirement for radiation disturbance limitation in marine very high frequency band(156~165MHz),the limitation from 54dB?V/m dropped to 24dB?V/m.Existing technology is not enough to achieve the targeted suppression of radiation in this band,same as the stringent limitation imposed on the whole testing band,which makes the electromagnetic compatibility design of marine electronic equipment cost more.Due to the special radiation limitation in marine very high frequency band,a novel electromagnetic band gap structure with spiral line bridges is proposed to suppress the radiation in PCB.The main research contents are as follows:(1)The electromagnetic disturbance source signal is analyzed briefly,the influence of PCB parasitic parameters on the electromagnetic disturbance is researched by CST,and the radiation pattern of PCB is simulated and analyzed.(2)The radiation mechanism of Simultaneous switching noise in PCB is researched by CST,the characteristics and insufficiencies of traditional SSN suppression methods is analyzed,and the mechanism of electromagnetic band gap is studied.(3)A novel electromagnetic band gap structure with spiral line bridges which stop band is contain marine very high frequency band is proposed,and the equivalent circuit is built.The influence of PCB layers distance and material's relative permittivity on characteristics of electromagnetic band gap stopband is studied,and the stopband characteristic is analyzed by simulation and experimental.(4)The influence of common factors in PCB design on characteristics of electromagnetic band gap stopband is analyzed by simulation and experimental,the effect of electromagnetic band gap on radiation suppression is researched by CST.The stopband of proposed electromagnetic band gap structure contain marine very high frequency band,the insertion loss at 160 MHz for double,four and five units are-29 dB,-56 dB and-72 dB respectively.Proposed electromagnetic band gap has good suppression effect for electromagnetic disturbance in power net,and also applicative for the radiation problem caused by this.