Layered protective screen

 

(57) Abstract:

The invention can be used in various branches of engineering for protection of electronic devices and staff from exposure to electromagnetic radiation (EMR) radio band. An object of the invention is to reduce the proportion reflected from layered protective screen radio frequency radiation. The goal of the project is achieved by the fact that the proposed layered protective screen, transparent in visible light, contains at least one additional layer of transparent dielectric material, which is either free from electrically conductive surface layer of the screen, or on the surface of the conductive layer or on both sides of the protective screen has at least one additional layer of transparent dielectric material. The value of dielectric permeability of the transparent dielectric layer decreases with distance from the conductive layer, and the surface resistance of the electroconductive layer is 30 to 60 Ohms/square. 4 C.p. f-crystals, 1 Il., table 1.

The invention relates to the field of radio engineering, in particular to the area of the first range, and can be used in mechanical engineering, microelectronics, aerospace and other industries to weaken AMY frequency from both external and internal radiation sources.

A device containing a layer of optically transparent material, on the outer side of which is a thin layer of electrically conductive material. The device is designed to protect electronic devices from the effects of external electromagnetic radiation [1].

The disadvantage of this device is the large proportion of reflected from the screen to radio frequency radiation.

The closest analogue, taken as a prototype, is a protective screen videodisplay terminal for attenuating electromagnetic radiation containing a layer of transparent dielectric material, on one surface of which is coated with a thin layer of electrically conductive material in contact with the ground element [2].

The disadvantage of this protective screen is a large proportion of the reflected from the screen to radio frequency radiation.

An object of the invention is to reduce the proportion reflected from layered protective screen radio Isetta fact, the proposed layered protective screen contains at least one additional layer of transparent dielectric material, and at least one additional layer of transparent dielectric material is either free from electrically conductive surface layer of the screen, or on the surface of the conductive layer or on both sides of the protective screen is at least one additional layer of transparent dielectric material. The value of dielectric permeability of the transparent dielectric layer decreases with distance from the conductive layer, and the surface resistance of the electroconductive layer is 30...60 Ohms/square. The thickness of the transparent dielectric protective layers of the screen is selected depending on the value of their dielectric constant.

In Fig. 1 (a, b, C, d) shows examples of the implementation of the proposed device layered protective screen.

The device comprises a transparent dielectric layer 1 on one side of which is coated with a conductive layer 2 having electrical contact with the grounding element 3, and at least one additional transparent layer is Rial is located on the surface of the conductive layer.

Fig. 1B is an extra layer 4 of a transparent dielectric material is free from conductive layer surface of the screen.

Fig. 1B - on both sides of the screen there is one additional layer 4 and 5 transparent dielectric material.

Fig. 1G is an additional transparent layer 4 of dielectric material is free from conductive layer surface of the screen and additional layers 5 and 6 of the transparent dielectric materials are located on the side of the electroconductive layer. The number of additional layers of transparent dielectric materials may be increased.

The device works in the following way (see Fig.1A). Electromagnetic radiation 7, radio frequency, leaning on shield, partially passes through 9, is partially reflected from 8 interfaces: air - extreme layers of the screen and the boundary layers on the inside of the screen, and also partially absorbed in the conductive coating. While a significant proportion of the incident radiation 7, of the past into the design of the screen, undergoes reflection from above the boundary layer of the protective screen, while remaining within the design and megacrania.

The table shows the comparative characteristics of options for implementing layered protective screen in comparison with the prototype for three values of the surface resistance of the electroconductive layer.

Tweed integral transmittance of visible light;

Time - transmittance of the protective screen in the range of frequencies of electromagnetic radiation 10-20 GHz;

R1 and R2 are the reflection coefficients from the two sides of the protective screen in the range of frequencies of electromagnetic radiation 10-20 GHz, see Fig.1G.

Samples 1.1-1.6 were performed according to the scheme shown in Fig.la.

Sample 1.1 - the Value of the dielectric constant of the dielectric layer 1 is equal to 7.8; surface resistance of the conductive layer 30 Ohms/square. The value of the dielectric constant of the dielectric layer 4 is equal to 7.8.

Sample 1.2 - the Value of the dielectric constant of the dielectric layer 1 is equal to 7.8; surface resistance of the conductive layer 30 Ohms/square. The value of the dielectric constant of the dielectric layer 4 is equal to 2.8.

Sample 1.3 - the Value of the dielectric constant of the dielectric layer 1 is equal to 7.8; surface electrical resistance is HH 4 equal to 7.8.

Sample 1.4 - Value of the dielectric constant of the dielectric layer 1 is equal to 7.8; surface resistance of the conductive layer 40 Ohms/square. The value of dielectric permeability additional dielectric layer 4 is equal to 2.8.

Sample 1.5 - the Value of the dielectric constant of the dielectric layer 1 is equal to 7.8; surface resistance of the conductive layer 60 Ohms/square. The value of dielectric permeability additional dielectric layer 4 is equal to 7.8.

Sample 1.6 - Value of the dielectric constant of the dielectric layer 1 is equal to 7.8; surface resistance of the conductive layer 60 Ohms/square. The value of dielectric permeability additional dielectric layer 4 is equal to 2.8.

Samples 2.1-2.3 were performed according to the scheme shown in Fig.1B.

Sample 2.1 - Value of the dielectric constant of the dielectric layer 1 is equal to 7.8; surface resistance of the conductive layer 30 Ohms/square. The value of dielectric permeability additional dielectric layer 4 is equal to 2.8.

Sample 2.2 - the Value of the dielectric constant of the dielectric layer 1 is equal to 7.8; surface with the dielectric layer 4 is equal to 2.8.

Sample 2.3 - the Value of the dielectric constant of the dielectric layer 1 is equal to 7.8; surface resistance of the conductive layer 60 Ohms/square. The value of dielectric permeability additional dielectric layer 4 is equal to 2.8.

Samples 3.1-3.3 were performed according to the scheme given in Fig.1B.

Sample 3.1 - the Value of the dielectric constant of the dielectric layer 1 is equal to 7.8; surface resistance of the conductive layer 30 Ohms/square. The value of dielectric permeability additional dielectric layer 4 is equal to 2.8. The value of dielectric permeability additional dielectric layer 5 is equal to 7.8.

Sample 3.2 - the Value of the dielectric constant of the dielectric layer 1 is equal to 7.8; surface resistance of the conductive layer 40 Ohms/square. The value of dielectric permeability additional dielectric layer 4 is equal to 2.8. The value of dielectric permeability additional dielectric layer 5 is equal to 7.8.

Sample 3.3 - Value of the dielectric constant of the dielectric layer 1 is equal to 7.8; surface resistance of the conductive layer 60 Ohms/square. The value of dielectrica the additional dielectric layer 5 is equal to 7.8.

Samples 4.1-4.3 were performed according to the scheme shown in Fig.1G.

Sample 4.1 - the Value of the dielectric constant of the dielectric layer 1 is equal to 7.8; surface resistance of the conductive layer 30 Ohms/square. The value of dielectric permeability additional dielectric layer 4 is equal to 2.8. The value of dielectric permeability additional dielectric layer 5 is equal to 7.8. The value of dielectric permeability additional dielectric layer 6 is equal to 2.8.

Sample 4.2 - Value of the dielectric constant of the dielectric layer 1 is equal to 7.8; surface resistance of the conductive layer 40 Ohms/square. The value of dielectric permeability additional dielectric layer 4 is equal to 2.8. The value of dielectric permeability additional dielectric layer 5 is equal to 7.8. The value of dielectric permeability additional dielectric layer 6 is equal to 2.8.

Sample 4.3 - Value of the dielectric constant of the dielectric layer 1 is equal to 7.8; surface resistance of the conductive layer 60 Ohms/square. The value of dielectric permeability additional dielectric layer 4 is equal to 2.8. Veligipovalante additional dielectric layer 6 is equal to 2.8.

As the table shows, the use of the proposed layered protective screen allows you to reduce the level of reflected electromagnetic radiation of radio frequency by increasing its absorption, while the share held through the radiation does not increase. The result is a decrease in the level of electromagnetic radiation, harmful effects on personnel and sensitive to electromagnetic radiation devices, on both sides of the transparent layered protective screen.

Literature

1. U.S. patent 5373102.

2. U.S. patent 5122619.

1. Layered protective screen, transparent in visible light, containing a layer of transparent dielectric material, one surface of which is coated with a conductive layer in contact with the ground element, wherein the entered at least one additional layer of transparent dielectric material, the value of the surface resistance of the electroconductive layer is 30 to 60 Ohms/square.

2. Layered protective screen on p. 1, characterized in that at least one additional layer of transparent dielectric material is an under item 1, characterized in that at least one additional layer of transparent dielectric material located on the surface of the conductive layer.

4. Layered protective screen on p. 1, characterized in that on both sides of the display has at least one additional layer of transparent dielectric material.

5. Layered protective screen according to any one of paragraphs.1-4, characterized in that the value of dielectric permeability layers of transparent dielectric materials decreases with distance from the conductive layer.