KR20220069142A - Device for measuring electromagnetic shielding effectiveness - Google Patents

Abstract

The present invention relates to a device for electromagnetic shielding performance measurement, which includes: an electromagnetic wave transmitter generating an electromagnetic wave; an electromagnetic wave receiver receiving and measuring the electromagnetic wave; a sample support including a plate provided between the electromagnetic wave transmitter and the electromagnetic wave receiver and including an opening inside and a pedestal provided on the front side of the plate on the electromagnetic wave transmitter side for a measurement sample to be placed; and a sample fixing portion including a first frame coupled to the front of the plate with a support and movable along the support and a close contact member coupled to the first frame in the direction of the plate and in contact with the measurement sample. The first frame and the close contact member include a material with a dielectric constant of 3.5 to 4.0.

Description

Device for measuring electromagnetic shielding effectiveness

One aspect of the present invention relates to an electromagnetic wave shielding performance measuring device, and more particularly, to an electromagnetic wave shielding performance measuring device capable of measuring the electromagnetic wave shielding rate of a building material such as concrete.

Background to the present disclosure is provided herein, which does not necessarily imply known art.

In general, an electromagnetic pulse (ElectroMagnetic Pulse, EMP) is an electromagnetic shock wave generated by a nuclear explosion. It is induced through power lines and communication lines or directly applied to devices to destroy electronic circuits, which instantly paralyzes all electronic devices that operate as semiconductors, that is, military equipment, communication equipment, computers, transportation means, and computer networks, in ns units. In recent years, it is possible to destroy an enemy's industrial facilities while avoiding international condemnation of human casualties. As a result, as modern warfare is conducted by communication and weapon systems based on the electronics industry, the enemy's military communications without causing damage to people and buildings · EMP bombs capable of incapacitating all power systems, including weapon systems, and countermeasures against enemy nuclear development and high-altitude nuclear tests and attacks are required.

As a countermeasure technology to prevent electromagnetic interference, various methods such as filtering, shielding, wiring, and grounding are used. It is a method that can be used appropriately when considering the aspects.

Therefore, in order to develop a material with excellent shielding performance, an accurate shielding performance analysis must be preceded. With respect to a material having a function of shielding electromagnetic waves, the existing measurement method used to evaluate the shielding performance is to manufacture the material in the form of a structure that is actually used and measure the properties. This measurement method is a method of measuring by installing an antenna inside a structure and detecting electromagnetic waves leaking through the wall of the structure by using an antenna or a probe as electromagnetic waves are radiated.

This measurement method has the advantage of obtaining the closest measurement result to the actual situation because it approximates the structure that is finally made using the material to be evaluated. Since electromagnetic wave shielding properties are greatly affected by structural properties, it is difficult to see the properties of the material itself.

In addition, when measuring the electromagnetic shielding rate using the conventional measurement method, when measuring the electromagnetic shielding rate by the ASTM D4935 method, the thickness of the sample must be limited to 2 mm or less, so it is difficult to make or measure a sample from a material such as concrete. .

In particular, the present applicant found that when the test apparatus of Korean Patent Registration No. 10-2085038 is used, the amplitude value of the electromagnetic wave decreases with respect to the electromagnetic wave in the region with a frequency near 1 GHz, so that the dynamic range, which is a major performance indicator of the test apparatus, decreases. This made it impossible to measure a high shielding rate near 1 GHz, and also confirmed the problem that the reliability of the electromagnetic shielding rate measured in the 30 MHz ~ 1.5 GHz range, which is the measurement frequency range of ASTM D 4935, was lowered. In the frequency domain of 30 MHz to 1.5 GHz, efforts have been made to develop an electromagnetic shielding rate measurement system that can measure electromagnetic shielding performance with constant strength and high reliability.

Republic of Korea Patent No. 10-2085038

An object of the present invention is to provide an electromagnetic wave shielding rate measurement system that can measure stable intensity electromagnetic waves in a frequency range of 300 MHz to 1.5 GHz, and has excellent reliability, which has been devised to solve the problems of the prior art. it has its purpose

In addition, the electromagnetic wave shielding rate measuring system of the present invention is to provide an electromagnetic wave shielding rate measuring device that can easily measure the electromagnetic wave shielding performance of a measurement sample made of a concrete material for electromagnetic wave shielding and a system for measuring the electromagnetic wave shielding rate using the same.

In addition, it is intended to provide an electromagnetic wave shielding rate measuring device that is convenient for transporting and fixing heavy weight measurement samples and easy to operate during experiments.

One aspect of the present invention is installed in the front electromagnetic wave transmitter for generating electromagnetic waves;

an electromagnetic wave receiver for receiving and measuring the electromagnetic wave;

a plate provided between the electromagnetic wave transmitter and the electromagnetic wave receiver and having an opening therein;

A first frame coupled to a support provided in front of the plate and movable along the support, a sample fixing unit including a contact member coupled to the rear of the first frame and contacting the measurement sample;

The first frame and the contact member are an electromagnetic wave shielding performance measuring device made of a material having a relative permittivity of 3.5 to 4.0.

Here, the first frame is preferably made of phenolic resin,

Preferably, the adhesion member is made of polyacetal,

Preferably, the first frame includes an opening provided at a position in which the measurement sample is fixed.

At this time, it is preferable to include a second frame coupled to the support from the front of the first frame and including an opening in the center,

It is preferable to include an electromagnetic wave shielding room provided inside the electromagnetic wave receiving unit and including an electromagnetic wave shielding wall,

Preferably, the plate is coupled to the front of the electromagnetic wave shielding wall.

In addition, the width of the opening (W2) of the second frame is preferably 1.0 to 1.5 times the width (W1) of the opening of the first frame,

Preferably, the contact member is coupled to surround the outside of the opening of the first frame,

It is preferable to include a spaced space surrounded by the first frame, the measurement sample, and the contact member.

Another aspect of the present invention is an electromagnetic wave shielding performance measuring system for measuring the electromagnetic wave shielding performance of the measurement sample by receiving an electromagnetic wave radiated from the electromagnetic wave transmitter and passing through the measurement sample at the electromagnetic wave receiver,

an electromagnetic wave shielding chamber provided inside the electromagnetic wave receiving unit and including an electromagnetic wave shielding wall having an opening in the direction of the electromagnetic wave transmitting unit;

a sample support part coupled to the electromagnetic wave shielding wall and supporting the measurement sample; and

A first frame coupled to a support in front of the sample support and movable along the support, a sample fixing part coupled to the first frame and including a contact member in contact with the measurement sample; includes,

The first frame and the contact member are an electromagnetic wave shielding performance measuring system including a synthetic resin as a material.

In this case, it is preferable that the electromagnetic wave transmitter emits electromagnetic waves in a frequency band including 30 MHz to 1.5 GHz.

The electromagnetic wave shielding rate measuring apparatus according to an aspect of the present invention is made of a synthetic resin material such as Bakelite, and uses a frame having an opening to fix a sample for measuring the electromagnetic wave shielding rate, and uses an opening provided in the frame to receive electromagnetic waves. It is possible to measure electromagnetic waves of uniform intensity by resolving the problem of abrupt decrease in the measured values of the electromagnetic wave intensity at the frequency of 1 GHz by radiating and transmitting the measurement sample, and it is possible to secure excellent reliability in the range of 30 MHz to 1.5 GHz.

In addition, the electromagnetic wave shielding rate measuring device is provided with an adhesion member 42 made of a synthetic resin material such as polyacetal to maintain the distance between the first frame 41 and the measurement sample at a constant interval and close the opening of the first frame 41 . It has the effect of reducing the error of experimental data with excellent reliability by minimizing the effect of the reflection of electromagnetic waves incident on the measurement sample.

The electromagnetic shielding performance measurement system according to an aspect of the present invention uses an electromagnetic shielding rate measuring device having the above effect, and measures the electromagnetic shielding rate of materials that are difficult to measure with the existing electromagnetic shielding rate measurement method, such as concrete, with high reliability There are advantages to doing.

1 is a view showing a schematic configuration of an electromagnetic wave shielding performance measuring device, which is an aspect of the present invention.
2 is a diagram schematically showing the configuration of an electromagnetic wave shielding performance measuring device, which is an aspect of the present invention.
3 is a view showing a front view of the electromagnetic wave shielding performance measuring device, which is an aspect of the present invention.
4 is a view schematically showing the appearance of an electromagnetic wave shielding performance measuring device, which is an aspect of the present invention.
5 is a side view showing a state in which a measurement sample is fixed to the electromagnetic wave shielding performance measuring device, which is an aspect of the present invention.
6 is a side view showing a state in which a measurement sample is not fixed to the electromagnetic wave shielding performance measuring device, which is an aspect of the present invention.
7 is a graph showing the intensity of electromagnetic waves measured according to frequency when an existing metal jig is used as a frame.
8 is a graph showing the intensity of electromagnetic waves measured according to frequency after the material of the frame is changed to synthetic resin.
9 is a graph showing the intensity of electromagnetic waves measured by changing the material of the frame to metal and bakelite.
10 is a diagram schematically illustrating a system for measuring electromagnetic wave shielding performance, which is another aspect of the present invention.

Prior to describing the present invention in detail below, it is to be understood that the terminology used herein is for the purpose of describing specific embodiments and is not intended to limit the scope of the present invention, which is limited only by the appended claims. shall. All technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art, unless otherwise stated.

Throughout this specification and claims, unless stated otherwise, the term comprise, comprises, comprising is meant to include the stated object, step or group of objects, and steps, and any other object. It is not used in the sense of excluding a step or a group of objects or groups of steps.

On the other hand, various embodiments of the present invention may be combined with any other embodiments unless clearly indicated to the contrary. Any feature indicated as particularly preferred or advantageous may be combined with any other feature and features indicated as preferred or advantageous.

In the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. As a whole, it was described from an observer's point of view when describing the drawings, and when it is said that one component is "above/below" or "above/below" another component, it is , including the case where there is another component in the middle.

Electromagnetic wave shielding performance measuring device according to an aspect of the present invention can be used for samples of various sizes, particularly those whose size was limited by the ASTM D4935 method, which was used as a conventional electromagnetic wave shielding performance measuring method because of its thick or large size. it is a device

The measurement sample 1 used at this time is manufactured in a size and shape suitable for measurement, and the shape of the measurement sample 1 is preferably a rectangular parallelepiped shape having a flat surface, and is flat and relatively thick compared to the height and width. It is preferable to use thin specimens.

1 and 2 are diagrams schematically showing an electromagnetic wave shielding performance measuring apparatus and system according to an aspect of the present invention.

The electromagnetic wave shielding performance measuring device includes an electromagnetic wave transmitting unit 10 including a transmitting antenna that radiates electromagnetic waves to the outside, an electromagnetic wave receiving unit 20 including a receiving antenna for receiving electromagnetic waves radiated from the electromagnetic wave transmitting unit 10, an electromagnetic wave transmitting unit 10 ) and the electromagnetic wave receiver 20 are coupled to the sample support part 30 and the sample support part 30 for supporting the measurement sample 1 so that the measurement sample 1 can be provided, and the measurement sample 1 is measured. Includes a sample fixing unit 40 for fixing in position for.

In addition, it is preferable that the electromagnetic wave shielding performance measuring apparatus includes an electromagnetic wave shielding room including a receiving antenna therein, as shown in FIGS. 1 and 2 .

The electromagnetic wave shielding chamber 50 reflects or absorbs electromagnetic waves to create a first space that is not affected or less affected by electromagnetic waves from the outside, and includes at least one electromagnetic wave shielding wall capable of shielding electromagnetic waves.

The electromagnetic wave shielding room includes a receiving antenna inside. In order to minimize the measurement error that occurs when external electromagnetic waves are transmitted into the electromagnetic wave shielding room or transmitted to the receiving antenna by the reflection of electromagnetic waves inside the electromagnetic wave shielding room, the electromagnetic waves inside the wall It is preferred to have an absorber and may include a stirrer.

As the electromagnetic wave absorber, both conical and pyramidal types can be used, and any electromagnetic wave absorber generally applicable in the relevant technical field can be used regardless of shape or material.

The electromagnetic wave shielding chamber 50 reflects or absorbs electromagnetic waves to create a first space that is not affected or less affected by electromagnetic waves from the outside, and includes at least one electromagnetic wave shielding wall capable of shielding electromagnetic waves.

Two spaces of the first space and the second space may be separated from each other by the electromagnetic wave shielding wall 51 .

The first space is a space in which the receiving antenna of the electromagnetic wave receiver is installed or provided, and electromagnetic waves generated in the second space are shielded by the electromagnetic wave shielding wall 51 to prevent transmission to the first space.

The second space is a space in which the transmitting antenna of the electromagnetic wave transmitting unit is installed or provided.

The electromagnetic wave shielding wall may include an opening through which electromagnetic waves can pass. The opening is provided in the electromagnetic wave shielding wall, but the electromagnetic wave can be transmitted through the opening without being shielded.

The first space and the second space can be connected through the opening provided in the electromagnetic wave shielding wall, and the electromagnetic wave radiated from the transmitting antenna installed in the second space is not shielded through the opening and directly to the receiving antenna installed in the first space. can be transmitted. At this time, based on the intensity of electromagnetic waves measured without a shield through the opening, the electromagnetic wave shielding effect shown by the shield blocking or covering the opening can be calculated.

The size of the opening provided in the electromagnetic shielding wall is not limited, but it is preferable that the width or width (W) is 20 to 30 cm. When the width or height of the opening is larger than the corresponding range, if the size of the measurement sample (1) for shielding the opening becomes too large, the weight increases according to the volume and the measurement sample (1) cannot be stably supported. Since it has to be large, there is a problem of increasing the manufacturing cost, there is a problem in that it is difficult to transport or fix the measurement sample (1), and when the width or height of the opening is smaller than the corresponding range, the wavelength of the measurable electromagnetic wave of the electromagnetic shielding rate is limited. As the frequency range becomes narrow, there may be a problem that the usability is lowered.

Specifically, the width (W) of the opening should be at least half a wavelength (λ/2) or more of the wavelength (λ) corresponding to the frequency of the electromagnetic wave to be measured, and is configured to satisfy the following formula (1).

(Equation 1)

The electromagnetic wave shielding room 50 does not necessarily need to be a space isolated or separated from the outside, and if the electromagnetic wave shielding wall 51 is large enough so that electromagnetic waves do not affect it, it is possible that at least one side is an open space.

For example, when measuring shielding performance against electromagnetic waves having a frequency of 600 MHz, the width (or height) of the opening is configured to be 0.25 m or more. Due to the nature of electromagnetic waves, in a space made of metal, the opening acts like a waveguide to block or pass a specific frequency. At this time, the frequency of the electromagnetic wave that can pass through the opening is determined by the width of the opening, and when the width and the wavelength of the electromagnetic wave are equal to or 0.5 times, the frequency is passed. Resonance occurs when the width of the opening is 3λ, 2λ, λ, 1/2λ, 1/4λ, 1/8λ, etc., and the resonance effect is particularly large at λ and 1/2λ. Therefore, when an opening narrower than a half-wavelength of the wavelength corresponding to the frequency is provided, that is, when Equation 1 is not satisfied, the electromagnetic wave is blocked, so that the electromagnetic wave shielding performance cannot be measured.

The electromagnetic wave transmitter 10 may include an electromagnetic wave generator and a transmitting antenna, and electromagnetic waves generated at a desired frequency by the electromagnetic wave generator may be radiated to the outside through the transmitting antenna.

As the transmit antenna, various types and types of antennas may be used, but it is preferable to use a log periodic antenna (LP antenna).

The transmitting antenna may be installed by a tripod, etc., and it is preferable to install it at a height similar to the opening provided in the electromagnetic wave shielding wall.

The transmitting antenna can be installed in a vertical direction and a horizontal direction depending on the installation direction, and can be freely converted into vertical and horizontal directions.

The transmitting antenna is preferably capable of emitting electromagnetic waves having a frequency in the range of 30 MHz to 1.5 GHz, and the size is not limited.

The electromagnetic wave receiving unit 20, including a receiver and a receiving antenna, receives the electromagnetic wave generated and radiated by the electromagnetic wave transmitting unit 10 to the receiver through the receiving antenna.

The antenna is characterized in that it can perform both roles without distinguishing between transmission and reception with respect to radio waves of a suitable frequency, and is provided as a pair.

That is, when one antenna is used as a transmit antenna, the other antenna can be used as a receive antenna, and it is preferable that the structure of the transmit antenna and the receive antenna are the same.

It is preferable that the receiving antenna be installed at the same height as the transmitting antenna, and it is preferable that an opening of the electromagnetic wave shielding wall is provided between the transmitting antenna and the receiving antenna.

The electromagnetic wave shielding performance measuring device supports and fixes the measurement sample (1), which is the target of measuring the electromagnetic wave shielding rate, and is configured to reduce losses or errors in the process of electromagnetic waves passing through the measurement sample (1). The sample support unit (30) and a sample fixing unit 40 .

3 is a view schematically showing a state in which the sample fixing part 40 and the sample support part 30 are viewed from the front.

The sample support unit 30 serves to support the measurement sample 1 for measuring the electromagnetic wave shielding ability at a measurement position, and includes a plate 31 , a pedestal 32 , and a gasket 33 .

The plate 31 (Plate) is coupled to the periphery of the opening of the electromagnetic wave shielding wall and includes an opening through which electromagnetic waves can pass. The plate 31 may be made of a metal material that does not transmit electromagnetic waves and reflects electromagnetic waves from the surface.

The plate 31 is positioned between the electromagnetic wave transmitter 10 and the electromagnetic wave receiver 20. Hereinafter, the electromagnetic wave transmitter 10 direction is the front of the plate 31, and the electromagnetic wave receiver 20 direction is the plate 31. Define the rear.

The pedestal 32 serves to support the lower portion of the measurement sample 1 so that the measurement sample 1 can be positioned at a position corresponding to the opening of the plate 31 , and its shape is not limited, but the length in the horizontal direction It is preferable to have a structure in the form of a cuboid having

For the pedestal 32, it is preferable to use a material that has a strong electromagnetic wave transmission property and has a low electromagnetic wave-reflecting property from the surface, for example, it is preferable to use a synthetic resin material. 32) and use polyacetal material.

The pedestal 32 is positioned under the opening of the plate 31 and is coupled to the plate 31 so that the measurement sample 1 mounted on the pedestal 32 covers or matches the opening of the plate 31, and the plate 31 It is installed in the direction of the electromagnetic wave transmitter 10 from the front surface of the plate 31 .

4 is a view showing the external appearance of the sample fixing part 40 and the sample support part (30). The pedestal 32 may be provided to extend long to one side when viewed from the front as shown in FIG. 3 , and a bearing 46 may be provided on the bottom so that the user can easily move or adjust the position of the measurement sample 1 . can

The measurement sample 1 mounted on the pedestal 32 by the bearing 46 can be easily moved on the pedestal 32 .

In addition, the gasket 33 is provided at the portion in which the outside of the opening of the plate 31 and the measurement sample 1 come into contact with each other to bring the measurement sample 1 and the plate 31 into close contact, and transmit the measurement sample 1 through. It prevents one electromagnetic wave from being lost to the gap between the plate 31 and the measurement sample 1 or generating an error, thereby enabling high-reliability measurement.

The sample support part 30 may further include a panel 34 in addition, and the panel 34 is installed between the plate 31 and the electromagnetic wave shielding wall to facilitate the attachment and detachment of the sample support 30 and the electromagnetic wave shielding wall. can

At this time, the panel 34 is selectively installed between the plate 31 and the electromagnetic wave shielding wall, and similarly, the panel 34 includes an opening at a position corresponding to the opening provided in the plate 31 and the electromagnetic wave shielding wall.

The sample support unit 30 coupled to the electromagnetic wave shielding wall includes an opening at the same position as the opening of the electromagnetic wave shielding wall, and a hole connecting the outside and the inside of the electromagnetic wave shielding room. At this time, the shape of the opening provided in the electromagnetic wave shielding wall and the sample support unit 30 coupled thereto is not limited, but preferably a rectangular or square shape, and the width or width of the opening may be defined as W0.

The measurement sample 1 having an area equal to or greater than the area of the opening may be disposed in front of the opening by the sample support 30 . The placed measurement sample 1 is placed on the pedestal 32 to cover the opening, and it is preferable to place it so as to completely cover the opening when viewed from the front.

The sample fixing unit 40 is a means for fixing the measurement sample 1 supported on the sample supporting unit 30 , and is coupled to the supporting unit 44 in a state in which it is coupled to the sample supporting unit 30 , the length of the supporting unit 44 . It serves to attach the measurement sample 1 to the sample support unit 30 according to the movement of the frame, including the first frame 41 movable along the direction.

The sample fixing unit 40 includes a first frame 41 , a second frame 43 , and a contact member 42 .

The first frame 41 is coupled to the front side of the plate 31 by a support 44 , and preferably has a ring shape including an opening of the same size or smaller than that of the measurement sample 1 in the center. In one embodiment of the present invention, the first frame 41 including a square-shaped opening and a square-shaped opening therein is coupled to four supports 44 in the vicinity of each vertex, and the portion coupled to the support 44 It has a structure that is movable in the longitudinal direction of the support 44 along the support 44 according to the operation of the distance adjusting screw 45 located in the middle of the.

5 and 6 are views showing the sample support part 30 and the sample fixing part 40 as viewed from the side. 5 shows a state in which the first frame 41 is moved in the direction of the measurement sample 1 and is in close contact with the measurement sample 1 to fix the measurement sample 1, and FIG. 6 is the first frame 41 measured It is moved in the opposite direction of the sample (1), indicating a state in which the measurement sample (1) is not fixed.

When the first frame 41 is moved in the direction of the measurement sample (1), it is in close contact with the measurement sample (1) to fix the measurement sample (1), and when the measurement sample (1) is moved in the opposite direction, the measurement sample ( The measurement sample (1) can be moved or replaced by being spaced apart from 1).

The width of the opening provided in the inner center of the first frame 41 may be defined as W1, and W1 is made smaller than the width of the measurement sample 1 .

In addition, the first frame 41 may be made of a synthetic resin or a reinforced plastic material, for example, may include any one or more of phenolic resin (including novolak resin and resol resin) and polyacetal resin, , preferably a phenolic resin containing a fabric such as cloth inside, for example, phobaiklite is preferably used.

Phenolic resins have a smaller specific gravity than metals, but have excellent mechanical strength, resistance to heat, and good electrical properties and processability.

In particular, since it has high electrical insulation and low electromagnetic wave absorptivity, it has the advantage that it has very little influence on the results of electromagnetic wave related tests. It is suitable for use as the first frame 41 because it does not reflect electromagnetic waves from the surface or cause disturbance (disturbance) well, and thus it is suitable for use as the first frame 41, and the reliability of the electromagnetic wave shielding rate measurement experiment can be improved.

The phenolic resin preferably has a dielectric constant of 3.5 to 4.5, preferably 3.5 to 4.0, and more specifically, the phenolic resin preferably has a dielectric constant of 3.5 to 4.5 at 3 GHz and 3.5 to 4.0 at 10 GHz.

When the relative permittivity of the phenolic resin is greater than 4.5, absorption or reflection of electromagnetic waves may occur, so there is a problem in that the reliability of the measurement data of the electromagnetic wave shielding ratio is lowered.

Hereinafter, when the term "permittivity of a material" is used in this specification, it is used to include relative permittivity, which means the permittivity of a dielectric when the permittivity of vacuum is set to 1.

The second frame 43 is provided in front of the first frame 41 and coupled to the support 44 , and preferably has a ring shape including an opening having a size smaller than or equal to that of the measurement sample 1 in the middle.

In one embodiment of the present invention, the second frame 43 including a square-shaped opening and a square-shaped opening therein is coupled to four supports 44 in the vicinity of each vertex, and a portion coupled to the support 44 According to the operation of the distance adjusting screw 45 located in the middle of the first frame 41 has a movable structure.

The width of the opening provided in the inner center of the second frame 43 may be defined as W2, and W2 is preferably larger than W1, and the ratio is 1 to 1.5 times, preferably 1 to 1.1 times. .

When the ratio of W2 and W1 is smaller than the corresponding range, W2 becomes small, and there is a problem in that it is difficult for the user to check the position and movement state of the first frame 41 when the distance adjusting screw 45 is operated, and the electromagnetic wave to be transmitted Incident conditions may become unfavorable, and when the ratio of W2 and W1 is greater than the corresponding range, economical efficiency is deteriorated and W1 becomes small, so there may be a problem in that the wavelength of the measurable electromagnetic wave is limited.

More specifically, W2 and W1 must be designed to be larger than the opening in the wall, and W2 can be provided to be larger than W1, so that the electromagnetic wave input environment can be improved. However, if the ratio is designed to exceed 1, 1 times, although the second frame 43 occupies too large a space, there is a limit in which an advantageous effect does not additionally occur.

The second frame 43 is preferably made of a synthetic resin material, and preferably made of the same phenolic resin as the first frame 41 .

The adhesion member 42 is coupled to the rear surface of the first frame 41 , that is, the measurement sample 1 side surface of the first frame 41 , and is coupled to the measurement sample 1 according to the movement of the first frame 41 . It comes into contact and serves to fix the measurement sample (1).

The contact member 42 is preferably formed in a rectangular parallelepiped shape and may be fastened to the first frame 41 using a screw.

The adhesion member 42 is preferably coupled to surround the periphery of the opening provided in the interior of the first frame 41, and in a preferred embodiment of the present invention, four adhesion members 42 are provided around the opening in the square shape. The enclosing array is enclosing and concatenated.

The thickness of the adhesion member 42 is various, and it is also possible that the adhesion member 42 is combined in two or more layers. When the adhesion member 42 is in close contact with the measurement sample 1 according to the thickness of the adhesion member 42 and the number of adhesion members 42 coupled to the first frame 41, the first frame 41 and the measurement sample ( 1) The distance between them can be adjusted, for example, at intervals of 5 cm, 10 cm, 15 cm or 20 cm, and the distance between the adhesion member 42 and the measurement sample 1 is within 2 cm, preferably It is preferably within 1 cm.

If the surface of the first frame 41 and the measurement sample 1 is too close, if the heavy sample is moved to the installation location, there may be a problem that the work is not performed smoothly due to the narrow space. increases, and the safety of the operator may occur due to the drop of the sample.

The adhesion member 42 is preferably made of a synthetic resin, for example, polyacetal resin is preferably used.

Polyacetal material has excellent mechanical properties, fatigue resistance, chemical resistance, small friction coefficient, and low wear resistance, so it is used for various machine parts and electrical parts. Measurement error can be reduced by not reflecting.

When the adhesion member 42 and the measurement sample 1 are in close contact with each other, a separation space surrounded by the adhesion member 42 is provided between the surface of the measurement sample 1 and the rear surface of the first frame 41, The electromagnetic wave transmitted through the opening of the first frame 41 passes through the separation space and transmits the measurement sample 1 through the incident surface of the measurement sample 1 .

At this time, it is preferable that the adhesion member 42 surrounding the side surface of the first space is made of a synthetic resin or a reinforced plastic material, for example, polyacetal.

It is preferable that a material having a relative permittivity of 3.5 to 4.0, preferably 3.6 to 3.9 is used for the contact member 42, and when the relative dielectric constant of the contact member 42 is out of the corresponding range, reliability is lowered when measuring the electromagnetic wave shielding rate can be

7 and 8 show the frequency of electromagnetic waves with the direction of the antenna in the vertical direction and the horizontal direction in a state where the materials of the first frame 41 and the second frame 43 expressed in a jig are different from bakelite and a metal material. It is a graph showing the intensity of electromagnetic waves measured from the receiving antenna while changing

9 is a graph showing the intensity of electromagnetic waves measured using a frame made of a metal material and a frame made of a synthetic resin material in a range of 600 MHz to 2 GHz.

When the first and second frames 43 made of a metal material were used, a phenomenon in which the intensity (y-axis) of electromagnetic waves rapidly decreased in the region near 1 GHz was observed, and the first and second frames made of synthetic resin, bakelite, In the case of using the two frames 43, the above phenomenon did not occur in the region near 1 GHz, and a phenomenon in which the intensity of the electromagnetic wave rapidly decreased in the region near 1.6 GHz was observed.

In the ATSM D 4935 test method, the standard frequency range for measuring the electromagnetic wave shielding rate and electromagnetic wave shielding performance is in the range of 30 MHz to 1.5 GHz, so when the first and second frames 43 made of metal are used, it is observed in the 1 GHz range. There is a problem in that the reliability of the measured electromagnetic wave intensity and electromagnetic wave shielding rate data is deteriorated due to the decrease in electromagnetic wave intensity. However, when the first and second frames 43 made of synthetic resin are used, the Since a decrease in intensity is not observed, data reliability for the electromagnetic wave shielding performance test is improved.

In addition, an embodiment of the present invention uses a measurement sample (1) that surrounds the side of the metal tape. Since the foam gasket is provided along the side surface of the measurement sample 1, it is incident through the incident surface provided on the front side of the measurement sample 1, and then exits from the inside of the measurement sample 1 to the side of the measurement sample 1 The foam gasket blocks the electromagnetic waves and the electromagnetic waves that enter the inside of the measurement sample 1 from the external diffuse reflection can be measured, so that the measurement error can be reduced and reliability can be improved.

The electromagnetic wave shielding performance measuring system according to another aspect of the present invention includes an electromagnetic wave shielding performance measuring device for measuring the electromagnetic wave shielding performance, for example, the electromagnetic wave shielding rate, of a measurement sample (1) made of a target material or material to be measured to be.

10 is a diagram schematically showing an electromagnetic wave shielding performance measuring system.

The electromagnetic wave shielding performance measurement system generates electromagnetic waves using a signal generator that generates electromagnetic waves according to a frequency input in advance and a transmitting antenna that amplifies and radiates signals, and the radiated electromagnetic waves are fixed electromagnetic shielding performance measurement samples It propagates to the incident surface of (1).

The electromagnetic wave passes through the inside of the measurement sample 1 except for a part reflected from the incident surface of the measurement sample 1, and exits to the transmission surface located opposite to the incident surface. The intensity is reduced by being reflected from the surface or absorbed inside the sample.

The electromagnetic wave that has passed through the pendulum surface travels through the air and is received by the receiving antenna, and the receiving unit and the control PC detect the signal, measure and record the intensity of the transmitted wave, and convert it into data.

The intensity of the electromagnetic wave measured through the sample can be expressed as EUT (equipment under test), and the intensity of the electromagnetic wave measured at the receiving antenna and the receiving unit by removing the measurement sample (1) and propagating in the air under the same frequency condition is REF ( Reference), REF-EUT, which is the difference between EUT and REF, can be referred to as SE (Shielding effectiveness).

A preferred embodiment of the present invention is a device for supporting and fixing the measurement sample (1), including the sample support unit 30 and the sample fixing unit 40 of the electromagnetic wave shielding performance test device described above, which is the frequency band of the electromagnetic wave to be measured at 30 MHz A constant electromagnetic wave intensity can be obtained at ~ 1.5 GHz, so the reliability of the electromagnetic wave shielding performance is excellent.

Specifically, the electromagnetic wave shielding performance measurement system comprises an electromagnetic wave shielding chamber 50, an electromagnetic wave transmitting unit, an electromagnetic wave receiving unit, and a sample fixing device.

The electromagnetic wave transmitter preferably includes a signal generator and a transmitting antenna in order to generate and radiate electromagnetic waves at a desired frequency. As the transmit antenna, various types and types of antennas may be used, but it is preferable to use a log periodic antenna (LP antenna).

The electromagnetic wave receiving unit may include a receiving antenna and a spectrum analyzer, and may measure electromagnetic waves emitted from the electromagnetic wave transmitting unit through the receiving antenna. Although various types and types of antennas may be used as the receiving antenna, it is preferable to use the same type of antenna as the aforementioned transmitting antenna, for example, it is preferable to use a log periodic antenna (LP antenna).

The signal generator, transmitting antenna, receiving antenna, and spectrum analyzer are recommended to receive signals using a coaxial cable. It is not limited as long as it does not interfere with the measurement, and it is preferably outside the electromagnetic wave shielding room 50 .

The distance between the transmitting antenna and the receiving antenna is preferably 3m, 5m or 10m, preferably 3m. Specifically, it is preferable that the distance between the measurement sample 1 and the transmitting antenna is about 2 m and the distance between the measurement sample 1 and the receiving antenna is about 1 m.

If the distance between the transmitting antenna and the receiving antenna is too close, the effect of the near-field effect increases and it may be difficult to accurately measure the electromagnetic wave shielding performance. There is a growing problem.

The signal generator receives a signal through a control PC, etc. and generates an appropriate electromagnetic wave, and the generated electromagnetic wave is radiated by a transmitting antenna, and the transmitting antenna is installed in a vertical or horizontal direction to radiate electromagnetic waves to the surroundings.

The radiated electromagnetic wave passes through the sample fixing unit 40 and is transmitted to the receiving antenna, and the receiving antenna is installed in the same axial direction as the transmitting antenna in the vertical or horizontal direction to receive the signal and transmit it to the receiving unit connected to the receiving antenna.

The sample fixing device serves to fix the measurement sample 1 to the opening provided in the electromagnetic shielding chamber 50 while positioning the measurement sample 1 between the transmitting antenna and the receiving antenna, and the sample support part 30 of the aforementioned electromagnetic shielding performance test device. and a sample fixing unit 40 .

In the electromagnetic wave shielding performance measurement system according to this aspect, electromagnetic waves that are radiated and incident on the incident surface of the measurement sample (1) do not reach the receiving antenna completely due to factors other than reflection or absorption by the measurement sample (1). It includes a sample support part 30 and a sample fixing part 40 in order to minimize The presence of the member 42 can prevent electromagnetic wave loss, and in particular, has the effect of greatly reducing electromagnetic wave loss in the 1 GHz portion and improving reliability.

Specifically, the gasket 33 prevents electromagnetic wave penetration or loss in a small space between the sample and the sample support unit 30, and the first and second frames 43 are made of a synthetic resin material to form the first and second metal materials. The loss in the 1GHz range compared to the use of the second frame 43 is eliminated, and the foam gasket provided on the outer periphery of the incident surface and the edge of the incident surface of the measurement sample 1 is utilized, thereby minimizing the influence of other electromagnetic waves.

Features, structures, effects, etc. exemplified in each of the above-described embodiments may be combined or modified for other embodiments by those of ordinary skill in the art to which the embodiments belong. Accordingly, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

1: measurement sample
10: electromagnetic wave transmitter
20: electromagnetic wave receiver
30: sample support part
31: plate
32: pedestal
33 : gasket
34: panel
40: sample fixing part
41: first frame
42: adhesion member
43: second frame
44: support
45: distance adjusting screw
46: bearing
50: electromagnetic shielding room
51: electromagnetic wave shielding wall

Claims (12)

an electromagnetic wave transmitter installed in the front to generate electromagnetic waves;
an electromagnetic wave receiver for receiving and measuring the electromagnetic wave;
a plate provided between the electromagnetic wave transmitter and the electromagnetic wave receiver and having an opening therein;
A sample fixing unit including a first frame coupled to a support provided in front of the plate and movable along the support, a contact member coupled to the rear of the first frame and contacting the measurement sample;
The first frame and the adhesion member are electromagnetic wave shielding performance measuring device made of a material having a relative permittivity of 3.5 to 4.0. According to claim 1,
The first frame is an electromagnetic wave shielding performance measuring device made of phenolic resin. According to claim 1,
The adhesion member is an electromagnetic wave shielding performance measuring device made of polyacetal. 4. The method of claim 2 or 3,
The first frame is an electromagnetic wave shielding performance measuring device including an opening provided at a position where the measurement sample is fixed. 5. The method of claim 4,
Electromagnetic wave shielding performance measuring apparatus including a second frame coupled to the support in front of the first frame, the second frame including an opening in the center. 6. The method of claim 5,
The electromagnetic wave receiving unit is provided inside, and the electromagnetic wave shielding performance measuring device comprising an electromagnetic wave shielding room including an electromagnetic wave shielding wall. 7. The method of claim 6,
Electromagnetic wave shielding performance measuring device in which the plate is coupled to the front of the electromagnetic wave shielding wall. 8. The method of claim 7,
The width (W2) of the opening of the second frame is 1.0 to 1.5 times the width of the opening (W1) of the first frame. 4. The method of claim 3,
The adhesion member is an electromagnetic wave shielding performance measuring device that is coupled to surround the outside of the opening of the first frame. 10. The method of claim 9,
Electromagnetic wave shielding performance measuring apparatus comprising a separation space surrounded by the first frame, the measurement sample, and the contact member. An electromagnetic wave shielding performance measuring system for measuring the electromagnetic wave shielding performance of the measurement sample by receiving an electromagnetic wave radiated from the electromagnetic wave transmitter and passing through the measurement sample at the electromagnetic wave receiver,
an electromagnetic wave shielding chamber provided inside the electromagnetic wave receiving unit and including an electromagnetic wave shielding wall having an opening in the direction of the electromagnetic wave transmitting unit;
a sample support part coupled to the electromagnetic wave shielding wall and supporting the measurement sample; and
A first frame coupled to a support in front of the sample support and movable along the support, a sample fixing part coupled to the first frame and including a contact member in contact with the measurement sample; includes;
The first frame and the adhesion member are electromagnetic wave shielding performance measurement system comprising a synthetic resin as a material. 12. The method of claim 11,
The electromagnetic wave transmission unit is an electromagnetic wave shielding performance measurement system that radiates electromagnetic waves in a frequency band including 30 MHz to 1.5 GHz.

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