KR100745612B1 - A circular ring stack apparatus for preventing emi due to cables of the electronic equipment - Google Patents

Abstract

A circular ring stack apparatus for preventing EMI(Electromagnetic Interference) due to cables of electronic equipment is provided to reduce the amount of external radiation of the electromagnetic waves through the cables. A circular ring stack apparatus for preventing EMI due to cables of electronic equipment includes an external structure, a first metal ring(121), a second metal ring(122), a third metal ring(123), a fourth metal ring(124), and a fifth metal ring(125). The external structure includes a hole through which the cable passes. The first metal ring(121) has a predetermined first diameter, has a hole of the same size as the hole of the external structure, and is mounted on the external structure. An external circle of the second metal ring(122) has the first diameter, and an internal circle thereof has a second diameter smaller than the first diameter. The second metal ring(122) is mounted on the first metal ring(121). The third metal ring(123) has the first diameter, has a hole with the same size as the hole of the external structure, and is mounted on the second metal ring(122). An external circle of the fourth metal ring(124) has the first diameter, and an internal circle thereof has a third diameter between the first diameter and the second diameter, and is mounted on the third metal ring(123). The fifth metal ring(125) has the first diameter, has a hole with the same size as the hole of the external structure, and is mounted on the fourth metal ring(124).

Description

A circular ring stack apparatus for preventing EMI due to cables of the electronic equipment}

1 and 2 is a view showing a metal structure for reducing conventional electromagnetic interference.

3 and 4 are views showing the electromagnetic wave generation state of a general PC.

5 is a view showing a gold circular ring laminated structure device according to an embodiment of the present invention.

Figure 6 is a cross-sectional view of a metal circular ring laminated structure device according to an embodiment of the present invention.

7A and 7B show the results obtained on the frequency axis of the magnitude and the reduction ratio of the common mode current as the electromagnetic radiation source.

FIG. 8A is a diagram illustrating a coaxial filter bandstop characteristic improved according to an order. FIG.

8B is a diagram illustrating the coaxial filter bandstop characteristic of the improved result after repeating.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for reducing electromagnetic interference, and more particularly, to a metal circular ring laminated structure device for reducing electromagnetic interference of cables used in various electronic devices such as computers and electronic products.

In general, the wire-based signal and current transmission of many electronic devices and communication devices that are in use today are performed through the cable. Given the current trend of increasing the frequency of use of equipment or adjacent equipment, the frequency of electromagnetic coupling through which cables are mediated is a major design and performance issue. In particular, the current flowing through the cable from the inside of the electronic device may be sufficiently operated as an electromagnetic radiation source due to the environment formed by the enclosure, the opening, and the cable. That is, it acts as a linear antenna, causing a problem that causes malfunction of neighboring devices vulnerable to electromagnetic waves as well as internal.

The first method used in the related art to reduce electromagnetic interference is as follows.

1 is a view showing a metal structure for reducing conventional electromagnetic interference.

Referring to FIG. 1, a conventional metal structure is a method of modifying a physical structure inside an opening of an enclosure 20, and assumes a cable 10 as a wire antenna. This is a commonly proposed model in antenna literature.

This conventional method gives a corrugation to the inner surface 30 of the opening as shown in FIG. 1, which is common in previous reports of Carlson et al. Or corrugated horn research. It is used to limit the amount of current flowing out from the inside of the opening to the outside with wrinkles.

However, the biggest disadvantage of this scheme is that the corrugated structure itself must secure a certain length for the specific frequency specification, and the deformation of the inside of the opening is used, which greatly increases the overall thickness of the enclosure 20. As a result of the design of this scheme, the thickness of the PC exceeds 10cm, which is obviously not practical.

2 is a view showing another metal structure for reducing conventional electromagnetic interference.

The second method is to enclose a ferrite bead (40), which is a magnetic material, around the cable 10 as shown in FIG.

Referring to FIG. 2, when a current flows along the same line as the cable 10, a magnetic field is generated around the magnetic field. When the magnetic material is placed in the direction of the magnetic field and interferes with the magnetic flux, the current on the cable is also disturbed to act as an external radiation source. It is the principle that the power to weaken.

However, magnetic materials such as ferrite beads 40 have a high manufacturing cost and generally do not have broadband characteristics.

As such, conventionally, there are disadvantages in terms of cost or structural disadvantages to reduce electromagnetic interference.

The technical problem of the present invention is to solve the drawbacks of the prior art, the characteristics of the radiated emission (RE), conducted emission (CE), receiver of the electronic device or communication equipment that acts as a transmitter (transmitter) using a variety of frequency sources In the case of the role, it is to provide a metal circular ring laminated structure device that can realize electromagnetic compatibility (EMC) that satisfies the electromagnetic interference including the Radiated Susceptibility (RS) and Conducted Susceptibility (CS) characteristics below a predetermined level. .

In addition, the cable has been found to be a major mediator of electromagnetic coupling, and a metal circular ring stacking structure device that establishes its principles and modeling techniques to predict characteristics, and effectively and effectively prevent electromagnetic waves, based on predictions. To provide.

Metal circular ring laminated structure device according to a feature of the present invention for achieving the technical problem,

A metal circular ring laminated structure device that prevents electromagnetic interference of a cable passing through an inside and an outside of an electronic device.

An exterior structure comprising a hole for the cable to pass through;

A first metal ring having a predetermined first radius and having a hole having the same size as that of the exterior structure, and stacked on the exterior structure;

A second metal ring having an outer circle having a first radius, and having an inner circle having a second radius smaller than the first radius, and laminated on the first metal ring;

A third metal ring having the first radius and having a hole having the same size as that of the exterior structure, and laminated on the second metal ring;

 A fourth metal ring having an outer circle having a first radius, an inner circle having a third radius smaller than the first radius, and having a third radius larger than the second radius, and laminated on the third metal ring;

And a fifth metal ring having a first radius and having a hole having the same size as that of the exterior structure, and stacked on the fourth metal ring.

Metal circular ring laminated structure device according to another feature of the present invention for achieving the technical problem,

A metal circular ring laminated structure device which prevents electromagnetic interference of an electronic device and prevents electromagnetic interference of a cable passing through an outer structure having a predetermined first hole through the first hole.

A first metal ring having a predetermined first radius and having a second hole corresponding to the first hole of the exterior structure and stacked on the exterior structure;

A second metal ring having an outer circle having a first radius, and having an inner circle having a second radius smaller than the first radius, and laminated on the first metal ring;

A third metal ring having a first radius and having a third hole corresponding to the first hole of the exterior structure, the third metal ring being laminated to the second metal ring;

A fourth metal ring having an outer circle having a first radius, an inner circle having a third radius smaller than the first radius, and having a third radius larger than the second radius, and laminated on the third metal ring;

And a fifth metal ring having a first radius and having a hole having the same size as that of the exterior structure, and stacked on the fourth metal ring.

Metal circular ring laminated structure device according to another feature of the present invention for achieving the technical problem,

A metal circular ring laminated structure device which prevents electromagnetic interference of an electronic device and prevents electromagnetic interference of a cable passing through an outer structure having a predetermined first hole through the first hole.

A first metal ring having an outer circle having a predetermined first radius, and having an inner circle having a second radius smaller than the first radius, and laminated to the exterior structure;

A second metal ring having the first radius and having a second hole corresponding to the first hole of the exterior structure, the second metal ring being laminated to the first metal ring;

A third metal ring having an outer circle having a first radius, an inner circle having a third radius smaller than the first radius, and having a third radius larger than the second radius, and laminated on the second metal ring;

And a fourth metal ring having a first radius and having a third hole corresponding to the hole of the exterior structure and stacked on the third metal ring.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

In addition, when a part is said to "include" a certain component, this means that it may further include other components, except to exclude other components unless otherwise stated.

First, a description will be given of the embodiment of the present invention to explain the principle of the generation of electromagnetic waves, and briefly introduces the problem of radiating electromagnetic waves to the outside through a cable of a representative PC of the electronic device.

Referring to FIG. 3, current is flowing out of the printed circuit board 210 inside the PC 200 along the cable 10. Due to the generation of an incomplete current path such as discontinuity existing on the PCB 210, the current flowing out has a common mode as well as a differential mode. This common mode current is known to play a role of inducing electromagnetic radiation when passing through the opening 110 along the cable even if a trace amount is present.

However, since electromagnetic radiation is only a common mode, the cable may be assumed to be a wired antenna through which only the common mode flows. Referring to FIG. 4, the linear antenna has a linear structure in which the feed point 220 is located inside the PC 200 and a current is connected to the outside through the opening 110 of the enclosure 100. As shown in the figure below, the feed position does not necessarily have to be either the center of the antenna or one of both ends.

As explained in the two conventional methods, in terms of practical value, economics or efficient design, the openings should not be used, and the materials used should be as low as possible. The structure of an embodiment of the present invention reflecting this is shown in FIG. 5.

FIG. 5 is a view illustrating a gold ring ring structure device according to an exemplary embodiment of the present invention, which is configured to reduce electromagnetic interference of an electronic device cable, and FIG. 6 is a metal circular ring laminate structure device according to an embodiment of the present invention. It is a cross section

5 or 6, a metal circular ring stack 120 is attached to the outer surface of the opening 110. The cable 10 is a concentric structure passing through the center of all the metal rings 121 to 125.

The stacked structure 120 is a structure in which a plurality of metal rings 121 to 125 are stacked. The first metal ring 121 has a predetermined first radius (R _stk ) and has a hole of the same size as the hole of the exterior structure, and is laminated on the exterior structure 100 so that the holes coincide. The second metal ring 122 has a first radius of the outer circle, and the inner circle of the second metal ring 122 has a second radius r _{grv1 that} is smaller than the first radius R _stk , and is stacked on the first metal ring. The third metal ring 123 has the first radius and has a hole having the same size as that of the exterior structure, and is laminated to the second metal ring. The fourth metal ring 124 has a third radius (r _{grv2 )} whose outer circle has a first radius R _stk , and whose inner circle is smaller than the first radius and larger than the second radius, and laminated on the third metal ring. do. The fifth metal ring 125 has the first radius and has a hole having the same size as that of the exterior structure, and is stacked on the fourth metal ring 124. Here, the hole serves as a passage through which the cable 10 passes. The first radius is 320 ~ 340mm, the second radius is 110 ~ 130mm, the third radius is 160 ~ 180mm but can be variously modified.

Such a laminated structure 120 is connected to the strength that can use the coaxial filter design method, and the metal circular rings having a radius obtained according to the design method and the electromagnetic wave numerical method prediction are stacked around the cable. Giving is easy. If necessary, such a circular ring stacking structure 120 may be manufactured in one piece, only a partial part may be manufactured in one piece, and as necessary, the first metal ring 121 may be omitted, and manufacturing cost and convenience of manufacturing Can be adjusted according to gender.

When viewed from the side of the three-dimensional structure of the embodiment of the present invention can be said to be a combination of a coaxial filter and a wire antenna.

The metal rings 121 to 125 have a thick annular structure and have both an inner radius and an outer radius. However, since only the inner radius (R _grvi ) of the metal rings (121 ~ 125) is in close contact with the current and the electromagnetic coupling on the cable, their outer radius (R _stk ) were all kept constant and set to 330mm.

The metal rings 121 to 125 having different inner radii are sequentially shown as teeth and grooves. The teeth and grooves were named T _tooth and T _grv , respectively. Based on the outer surface of the enclosure, the outer end point and the common current observation point of the cable 10 are Z _{w -out} . Z _{w - crnt} , and was determined as the point of 1350mm, 1060mm to the outside. The radius of the cable 10 and the radius of the opening 110 were set to 10 mm and 20 mm, reflecting the value of the current PC cable. The current feed point and the inner end point of the cable 10 are located at 150 mm and 350 mm from the outer surface of the exterior structure 100. And the exterior structure 100 uses the size of the desktop exterior of a commercial PC.

Then, the behavior of three kinds of stacked ring structures will be described with values that show coaxial filtering characteristics over a 900 MHz band around the frequency at which the PC operates.

For convenience, the thicknesses of teeth and grooves (T _tooth , T _{grv )} were all fixed at 10 mm, and the results were checked by changing only the radius as follows. The number of grooves, or cavities, can be _regarded as the order of the _filter.The secondary filter is (r _grv1 = 120mm, r _grv2 = 170mm), and the third is (r _grv1 = 120mm, r _grv2 = 170 mm, r _grv3 = 220 mm) and 5th order (r _grv1 = 120 mm, r _grv2 = 170 mm, r _grv3 = 220 mm, r _grv4 = 270 mm, r _grv5 = 320 mm) were determined as design dimensions, respectively. There looking at the characteristics of the electromagnetic radiation can be directly used for the electromagnetic wave distribution, _w Z _- can be used for common-mode observations in _crnt.

7A and 7B sequentially show the magnitude and the reduction ratio of the common mode current which is the electromagnetic radiation source on the frequency axis.

7A and 7B show the size attenuation effect of the common mode which is the electromagnetic interference source of the laminated ring structure, and show the results before the application of the invention structure and after the application of the secondary, tertiary and fifth structures.

Throughout the experiment, the band of applied signal was defined as 100MHz ~ 1GHz and the operating frequency was 500MHz. Before applying the laminated ring structure, it can be seen that a considerable amount of electromagnetic radiation reaching 0.020 micro Ampere reaches up to 1210 mm from the inside of the PC. However, when a secondary coaxial filter laminated ring structure is introduced, an average reduction of 80% occurs over the band. The use of tertiary and fifth order structures shows partially better characteristics than the second order, but almost the same. This means that the reduction effect is already prominent from the secondary structure, and the movement almost converges to the order change. It is the result that can confirm the excellent electromagnetic interference reducing effect.

As such, it is the coaxial filter that occupies a significant portion of the electromagnetic radiation emission reduction portion. The size of the grooves or teeth of the coaxial filter can be adjusted to produce a low frequency filter (LPF), a bandpass filter (BPF), and a bandstop filter (BSF) in the microwave region. In the embodiment of the present invention, the target radiation reduction is suitable for LPF which blocks after 400 MHz band or BSF which exhibits 400 MHz to 1 GHz band blocking characteristics. The design of the filter itself can be obtained from theory, but when connected to a radiating structure, it is necessary to repeat it to bring the changing electromagnetic properties to the final design goal. Below, the values of the order-specific homes for the BSF characteristics are presented. It is the proposed value for the characteristic of filter from 1st to 5th before repetitive work only.

Coaxial filter of order 1: rgrv1 = 120mm

Coaxial filter of order 2: rgrv1 = 120mm, rgrv2 = 170mm

Coaxial filter of order 3: rgrv1 = 120mm, rgrv2 = 170mm, rgrv3 = 220mm

Coaxial filter of order 4: rgrv1 = 120mm, rgrv2 = 170mm, rgrv3 = 220mm, rgrv4 = 270mm

Coaxial filter of order 5: rgrv1 = 120mm, rgrv2 = 170mm, rgrv3 = 220mm, rgrv4 = 270mm, rgrv5 = 320mm

FIG. 8A is a diagram illustrating a coaxial filter bandstop characteristic improved according to an order. In the zeroth order without a groove, all common current modes pass through a desired band. However, it can be seen that as the order increases, the stopping characteristic is improved in the desired band. In particular, the second asymmetric filter has been found to have changed in band. Of course, when only the view of Figure 8a, the band does not seem to have a good stopband flatness, when it is taken to the 1-port structure of the radiation structure shows a remarkable improvement as shown in FIG.

FIG. 8B is a diagram illustrating the coaxial filter bandstop characteristic of the improved result after repeating, and it can be seen that the bandstop characteristic is remarkably improved.

The numerical values given in the embodiments of the present invention are only examples, and the numerical values may be variously modified in some cases.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, in the embodiment of the present invention, by providing a metal laminated circular ring structure that is easy to design and manufacture can significantly reduce the external radiation of electromagnetic waves through the cable.

Claims (6)

A metal circular ring laminated structure device that prevents electromagnetic interference of a cable passing through an inside and an outside of an electronic device. An exterior structure comprising a hole for the cable to pass through; A first metal ring having a predetermined first radius and having a hole having the same size as that of the exterior structure, and stacked on the exterior structure; A second metal ring having an outer circle having a first radius, and having an inner circle having a second radius smaller than the first radius, and laminated on the first metal ring; A third metal ring having the first radius and having a hole having the same size as that of the exterior structure, and laminated on the second metal ring;  A fourth metal ring having an outer circle having a first radius, an inner circle having a third radius smaller than the first radius, and having a third radius larger than the second radius, and laminated on the third metal ring; And a fifth metal ring having the first radius and having a hole having the same size as the hole of the exterior structure, and stacked on the fourth metal ring.  The method of claim 1, Wherein the first radius is 320 ~ 340mm, the second radius is 110 ~ 130mm, the third radius is 160 ~ 180mm characterized in that the metal ring ring structure. A metal circular ring laminated structure device which prevents electromagnetic interference of an electronic device and prevents electromagnetic interference of a cable passing through an outer structure having a predetermined first hole through the first hole. A first metal ring having a predetermined first radius and having a second hole corresponding to the first hole of the exterior structure and stacked on the exterior structure; A second metal ring having an outer circle having a first radius, and having an inner circle having a second radius smaller than the first radius, and laminated on the first metal ring; A third metal ring having a first radius and having a third hole corresponding to the first hole of the exterior structure, the third metal ring being laminated to the second metal ring; A fourth metal ring having an outer circle having a first radius, an inner circle having a third radius smaller than the first radius, and having a third radius larger than the second radius, and laminated on the third metal ring; And a fifth metal ring having the first radius and having a hole having the same size as the hole of the exterior structure, and stacked on the fourth metal ring. The method of claim 1, The first metal ring to the fifth metal ring is a metal circular ring laminated structure device, characterized in that formed integrally. A metal circular ring laminated structure device which prevents electromagnetic interference of an electronic device and prevents electromagnetic interference of a cable passing through an outer structure having a predetermined first hole through the first hole. A first metal ring having an outer circle having a predetermined first radius, and having an inner circle having a second radius smaller than the first radius, and laminated to the exterior structure; A second metal ring having the first radius and having a second hole corresponding to the first hole of the exterior structure, the second metal ring being laminated to the first metal ring; A third metal ring having an outer circle having a first radius, an inner circle having a third radius smaller than the first radius, and having a third radius larger than the second radius, and laminated on the second metal ring; And a fourth metal ring having a first radius and having a third hole corresponding to the hole of the sheathing structure, the fourth metal ring being laminated to the third metal ring. The method of claim 5, Wherein the first radius is 320 ~ 340mm, the second radius is 110 ~ 130mm, the third radius is 160 ~ 180mm characterized in that the metal ring ring structure.

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