Research Of The Electromagnetic Shielding Characteristics And Application Of The Waveguide Cooling Hole

Electronic equipment in the course of work often be associated with heat production,completely closed shield chassis will affect the equipment in normal cooling,the surface of the chassis is usually open the heat vents.However,direct opening without any protection will reduce the chassis of the screen effect,even make the shield chassis loss of shielding ability.Considering the waveguide similar to a high-pass filter,if electromagnetic waves below the waveguide cut-off frequency,it will be lossed in the waveguide,and it can not spread within the waveguide.So add a waveguide at the opening of the chassis,it can cooling the inside components of the chassis and to ensures the shielding capacity of the chassis.Therefore,this paper uses the plane wave as the interference source,selects TLM numerical simulation algorithm,studies the electromagnetic shielding properties of the waveguide heat vents witch applied to the surface of the chassis.The main contents are included as follows:(1)Study on the electromagnetic shielding properties of a single waveguide hole which applied to the surface of the chassis.to explore the influence of the shape,length,wall thickness and polarization direction of the waveguide hole on the cutoff frequency and shielding by simulating.Then combining the field distribution of the plane wave in the waveguide,the reflection and transmission principle of the plane wave,the theory of orthogonality and the principle of cut-off waveguide in the uniform powerless transmission system and the theoretical to analysis and verification of the simulation results.And the cut-off frequency of the regular hexagonal waveguide is calculated by equating the regular hexagonal waveguide with circular waveguide.(2)Study on the electromagnetic shielding properties of arrayed waveguides which added to the surface of the chassis.Through simulation to got the influence of the factors such as shape,length,spacing,position,opening area,number of openings,plane polarization direction and other factors on the cutoff frequency of the array waveguide and the shielding effectiveness.Then,the simulation results are analyzed and validated by combining the electromagnetic shielding characteristics,resonator theory,plane wave reflection and transmission principle of single waveguide hole.(3)Study on the use of arrayed waveguide damped waveguide windows.Simulat media or conductor through the waveguide window,waveguide window installed when the gap and other factors on the waveguide window shielding characteristics of the impact.the gap generated when the installation is equivalent to rectangular waveguide,the simulation results of the installation gap are analyzed by using the rectangular waveguide theory.Finally add screws and shield pads at the installation gap.study on the influence of the number of screws and the conductivity,permeability and area of the pad on the shielding characteristics of the waveguide window,Get the best use of the parameters of the range.The results of the study contribute to the effective application of waveguide windows.