An electromagnetic screen observation window

Abstract

An electromagnetic shielding inspection window composed of single or multiple metal mesh and single-layer or multiple-layer thin-film optical coating of quasi-semiconductor quantum well structure, the invention is characterized in that, each layer of metal mesh is formed by single group or multiple groups of stretched filaments, any two threads of the filaments in each filament group are in the same plane and parallel from each other, the perpendicular distance between the two adjacent filaments is no greater than the 1 / 2 times of the required cut-off microwave wavelength.

Description

Technical field: [0001] The invention relates to an observation window for electromagnetic wave shielding, in particular to an electromagnetic shielding observation window composed of a metal mesh and an optical composite film with a symmetrical structure similar to a semiconductor quantum well. Background technique: [0002] The observation window used for electromagnetic wave shielding in the prior art includes materials such as wire mesh and multi-layer metal-dielectric composite multi-layer film. Wire mesh viewing windows for electromagnetic wave shielding consist of wire mesh fused into a transparent material. However, the microwave wavelength corresponding to its working cut-off frequency is not less than twice the maximum distance of the wire mesh. As the frequency increases, if you want to achieve a good shielding effect on electromagnetic waves above 1G Hz, such as above 50DB, then the metal wires must be more densely woven, the mesh is also required to be smaller,...

AI Technical Summary

Problems solved by technology

If a relatively thin multilayer metal film is used, the peak transmittance in the visible light region and the width of the highly transparent region can be greatly increased, but at this time the electrical conductivity of the metal film is significantly lower than that of the metal body material. Thin, the degree of decrease in electrical conductivity is obviously intensified. If too many layers of metal film are used, the transmittance in the visible light region will also decrease significantly and the transparent effect of the window will be lost. The above reasons also determine the ideal degree of transparency. It is difficult for the layer film to have an attenuation effect of more than 40DB for microwaves above 1G, so it cannot be used for microwave observation windows at higher frequencies

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