A Research And Design Of Stopping Vehicles System Based On High Power Microwave Technology

Based on the development of high-power microwave technology,the vehicle forcing system can be applied to the critical parts to prevent terrorist attacking the post,protection of the fleet and the recovering suspect’s vehicles and other occasions,It has many characteristics.such as rapid deployment,concealed attack,no collateral damage and attacking multiple targets,These characteristics will make it become the very importent force of public safety equipment in the future,So it’s very important to do this research.In this paper,we first study the response characteristics of ECU which is the key technology in microwave system under microwave radiation,and we find that the ECU of engine controls the fuel injection to inject the fuel several times accidentally under the microwave pulse.A phenomenon which corresponding ignition signal will be a lost occurs,which resulted that air-fuel ratio is less than the ideal air-fuel ratio k = 14.7 in the engine cylinder,when air-fuel ratio is up to a certain degree which fuel ratio is too heavy in the engine cylinder,the spark plug can’t achieve to ignite the fuel,and engine flames out.Based on the response characteristics of ECU under microwave radiation,I analyze microwave radiation power which causes the ECU disorder.According to analysis of electromagnetic coupling,we find the corresponding relations that radiation electric field which causes the ECU disorder on the engine cover;Then,I calculate coupling efficiency which sensor cable receives from radiation field,when their aperture area is equal,the relation between aperture’s long side and direction of incident electric field determines coupling degree,when they are mutual perpendicular,the coupling is strongest,when they are parallel,the coupling is weakest,the coupling changes from 20 dB to 40 dB according to the difference of frequency.The coupling efficiency of square aperture is between them.Ordinary RF microwave source can not reach the MW level of power,so the ultra-high power magnetron is chosen as a high-power microwave radiation source.The magnetron’s anode pulse voltage is 30 kV,its peak power is 450 kW,coaxial connector L29 which power capacity is bigger than L16 is chosen as cable connector.And controlled vehicle stop system is designed.The power density of radiation’s far-field of the system is analyzed.The equivalent radiation power is about 10 MW,the peak of the maximum radiation field is 12.0kV/m.And the whole system has carried out the physical experiment.The experiment solves the problem of microwave ignition.The RF microwave is received by omnidirectional receiving antenna,then it goes through 2 attenuators,the attenuation is 60 dB,peak-peak value from digital oscilloscope is 140 mV and the equivalent radiated power is 6.8MW,the error between design value and measured value is 1.7dB which is acceptable,the design goal is achieved.The experiment proves that high-power magnetron can use in system of stopping vehicles.