CN210519364U

CN210519364U - Infrared transparent electromagnetic shielding structure

Info

Publication number: CN210519364U
Application number: CN201921158856.6U
Authority: CN
Inventors: 苏俊宏; 周鑫; 时凯; 徐均琪; 吴慎将; 万文博; 杨利红
Original assignee: Xian Technological University
Current assignee: Xian Technological University
Priority date: 2019-07-23
Filing date: 2019-07-23
Publication date: 2020-05-12
Anticipated expiration: 2029-07-23

Abstract

The utility model discloses an infrared transparent electromagnetic shield structure, it is fixed time in order to solve current infrared transmittance, problem that shielding effectiveness is low. An infrared transmittance model of the structure is provided, and a theoretical formula is deduced. The structure is a combination of a cross-shaped structure and a circular ring-shaped structure, and a frequency selection surface mainly composed of a plurality of same topological unit structure arrays can improve the shielding efficiency of the traditional cross-shaped structure. When the electromagnetic wave vertical incidence in the utility model provides a during topological structure, to the electromagnetic wave of 1GHz to 18GHz frequency channel have higher shielding characteristic, infrared transmittance is higher than 90% simultaneously.

Description

Infrared transparent electromagnetic shielding structure

Technical Field

The utility model relates to a frequency selective surface design field especially relates to an infrared transparent electromagnetic shield structure in electromagnetic field and periodic structure.

Background

Electromagnetic radiation is considered a fourth major nuisance. Electromagnetic radiation disturbs the balance of the environment in the body and has great harm to the health of people. Electromagnetic waves in the environment can interfere with the human immune system and lead to reduced tissue repair, possibly inducing various diseases.

Electromagnetic interference caused by electromagnetic radiation not only affects the normal life of people, but also can threaten the military confidentiality of the country. Electromagnetic waves can penetrate sensitive devices of military equipment, so that the radar of the opposite side is lost, a radio communication command system is invalid, and weapons such as guided missile artillery and the like are out of control. Therefore, finding and proposing efficient electromagnetic shielding methods to improve the protection capability of various weapon platforms is a major issue in the military field of all countries. In particular, in an optical window, in order to observe an external environment without an influence of an external electromagnetic wave on an internal electromagnetic device, it is required to have a high infrared transmittance and to effectively shield an electromagnetic wave of a certain wavelength band.

Disclosure of Invention

The utility model provides an infrared transparent electromagnetic shield structure, in order to solve current geometric topology structure at infrared transmittance when certain, the problem that shielding effectiveness is low.

In order to achieve the above object, the present invention provides a technical solution:

an infrared transparent electromagnetic shielding structure comprises an upper layer, a middle layer and a lower layer; the upper layer and the lower layer are air layers, and the middle layer is a conductive medium layer; the conductive medium layer is formed by sequentially connecting a plurality of groups of basic periodic units to form a topological structure; each basic cycle unit is formed by compounding a cross and a circular ring with the same line width, and the circle center of the circular ring is concentric with the center of the cross; the minimum positive period of the topological structure formed by the basic periodic units is 22.2277 times of the line width, and the excircle radius of the circular ring is 3/32 of the minimum positive period of the topological structure.

Further, the period of the topological structure formed by the basic periodic unit is 2222.77um, the line width of the basic periodic unit is 100um, the thickness is 20um, the radius of the outer circular ring of the circular ring is 208.38um, and the radius of the inner circular ring is 108.38 um.

Furthermore, the relative dielectric constant of the material selected by the conductive medium layer is 1.

Furthermore, the material selected by the conductive medium layer is copper.

Further, the electromagnetic wave shielding frequency band working range of the topological structure is as follows: 1GHz to 18 GHz.

Compared with the prior art, the beneficial effects of the utility model are that:

the utility model discloses a frequency selective surface structure is guaranteeing that infrared transmittance is 90%, and the linewidth is the same, in 1GHz to 18GHz frequency channel, shielding efficiency is 38dB at least, and comprehensive shielding efficiency is than traditional cruciform structure high at least 2 dB.

Drawings

FIG. 1 is a schematic view of a minimum period structure;

FIG. 2 is a schematic of a macrostructure;

FIG. 3 is a graph of S21 at 1GHz to 18 GHz;

FIG. 4 is a graph of the absolute values of the shielding effectiveness of the cruciform and new structures at 1GHz to 18 GHz;

fig. 5 is a graph of infrared transmittance measurement.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings. Wherein like elements in different embodiments are numbered with like associated elements. In the following description, numerous details are set forth in order to provide a better understanding of the present application. However, those skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances.

The present invention will be described in detail with reference to the accompanying drawings and examples.

Referring to fig. 2, a schematic view of a macrostructure of an infrared transparent electromagnetic shielding structure is shown, the structure including an upper layer, an intermediate layer, and a lower layer; the upper layer and the lower layer are air layers, and the middle layer is a conductive medium layer; the conductive medium layer is formed by sequentially connecting a plurality of groups of basic periodic units to form a topological structure. Referring to fig. 1 and 2, each basic periodic unit is formed by compounding a cross and a ring with the same line width, and the center of the ring is concentric with the center of the cross; the minimum positive period of the topological structure formed by the basic periodic units is 22.2277 times of the line width, and the excircle radius of the circular ring is 3/32 of the minimum positive period of the topological structure.

And determining an infrared transmittance formula according to the relation between the structural parameters for the designed structure.

The formula of the transmittance is as follows:

the infrared transmittance is determined to be 90% and the line width, and all the parameters of the geometric topological structure are further determined.

And (4) according to the obtained geometric structure parameters, carrying out simulation by using HFSS (high frequency transmission system), and finally obtaining the shielding effectiveness in the wave band of 1GHz to 18 GHz.

A specific example is given below, with the final parameters shown in table 1 below:

table 1:

the above table is only one embodiment of the present invention, the geometric topological structure material of the present invention is not limited to copper, the thickness t is not limited to 20um, and the line width α is not limited to 100 um.

Referring to fig. 3 and 4, the structure of the present invention is a combination of a cross structure and a circular ring structure, and the frequency selective surface mainly composed of a plurality of same topological unit structure arrays can improve the shielding effectiveness of the traditional cross structure. When the electromagnetic wave vertical incidence in the utility model provides a topological structure, to the electromagnetic wave of 1GHz to 18GHz frequency channel have higher shielding characteristic, infrared transmittance is higher than 90% simultaneously, see fig. 5.

For those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. An infrared transparent electromagnetic shielding structure is characterized by comprising an upper layer, a middle layer and a lower layer; the upper layer and the lower layer are air layers, and the middle layer is a conductive medium layer; the conductive medium layer is formed by sequentially connecting a plurality of groups of basic periodic units to form a topological structure; each basic cycle unit is formed by compounding a cross and a circular ring with the same line width, and the circle center of the circular ring is concentric with the center of the cross; the minimum positive period of the topological structure formed by the basic periodic units is 22.2277 times of the line width, and the excircle radius of the circular ring is 3/32 of the minimum positive period of the topological structure.

2. The infrared transparent electromagnetic shielding structure of claim 1, wherein the period of the topology structure formed by the basic periodic units is 2222.77um, the line width of the basic periodic units is 100um, the thickness is 20um, the radius of the outer ring of the ring is 208.38um, and the radius of the inner ring is 108.38 um.

3. The infrared transparent electromagnetic shielding structure of claim 1, wherein the dielectric layer is made of a material having a relative dielectric constant of 1.

4. The infrared transparent electromagnetic shielding structure of claim 3, wherein the conductive dielectric layer is made of copper.

5. The infrared transparent electromagnetic shielding structure of claim 4, wherein the electromagnetic wave shielding frequency band of the topological structure has an operating range of: 1GHz to 18 GHz.