Study On Electromagnetic Radiation And Suppression Of PCB Based On Marx Circuit

PCB board is the most important part of electronic products,the vast majority of the electronic components of a system are based on the PCB board as a carrier to achieve their respective functions.The PCB board can be seen as a smaller version of the electronic product,so it is the most valuable research part of EMI technology.As the electronic product becomes smaller and smaller,the components of it are highly integrated in the printed circuit board.The radiation of printed circuit board determines the radiation of the entire electronic system.Once the circuit board is manufactured,The radiation performance of the product is basically determined.If we design the board without considering its EMC performance,once the products can not pass the test of EMC,the time for it to enter the market will be increased.This will increase the cost greatly.In this paper,the Marx pulse generation circuit based on avalanche triode is taken as the main research object.Firstly,introduce the influence of the components and traces of the printed circuit board on the radiation of the circuit board,and then introduce the theoretical analysis of the circuit board radiation,at last analyze the measures of reducing its radiation.The theory and design process of the Marx pulse source circuit based on the avalanche transistor are introduced in detail.The influence of the parameters of each component on the output pulse is calculated.The performance of the output wave and the radiation of the circuit boards are tested.The direction of the radiation is also plotted.Analyze the possible factors of the radiation.Combine the CST model simulation with the analyzing of the circuit board to find the method of suppressing radiation.Use the CST simulation to analyze the influence of the microstrip parameters(dielectric plate thickness,dielectric constant and microstrip width of the dielectric plate)on the radiation of the Marx pulse source circuit.To optimize the circuit board by analyzing the current distribution of re-layouting circuit.Finally,the shielding effectiveness of the shielding box is calculated,including the shielding effectiveness analysis of the single layer and the multilayer board.Reduce the amplitude of the electromagnetic radiation of the circuit board by designing the shielding box.Optimized shield box and compare the tested results with the simulation results.