JPH11163585A - Electromagnetic wave control board - Google Patents

Abstract

(57) [Problem] To provide an electromagnetic wave control plate having frequency selectivity independent of polarization of an electromagnetic wave. SOLUTION: An electromagnetic shield plate 10 provided with a sheet glass 1 which is a base material having transparency to visible light and a plurality of loop antenna elements 2 made of a conductive material provided on the surface of the base material. The electromagnetic wave having a desired frequency can be amplified and attenuated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave control plate for amplifying or attenuating an electromagnetic wave having a predetermined frequency according to the purpose. The present invention relates to a light-transmitting electromagnetic wave control plate made of glass or the like that can be amplified or attenuated and that can transmit visible light, and a laminated electromagnetic wave control plate obtained by laminating the same.

[0002]

2. Description of the Related Art With the rapid spread of mobile communication devices in recent years, communication failures due to mutual interference between various mobile communication devices inside buildings and high-frequency EMC problems have been highlighted. As a countermeasure against such high-frequency noise interference, measures such as installing an electromagnetic wave shielding material between the inside and outside of the building or between rooms partitioned by walls, etc., or installing a director if the receiving sensitivity is poor. Is effective, but a function of shielding the high-frequency noise or guiding a required electromagnetic wave to a glass plate or a transparent resin plate used for a window or a door provided for daylighting is provided. This is not easy in terms of technology and cost.

[0003]

Accordingly, there has been a strong demand for the development of a technique and a plate material that can shield high-frequency noise at low cost without sacrificing the transparency of visible light.

On the other hand, if the entire building or the entire room, including the window glass for lighting, is shielded, information cannot be transmitted to the outside using electromagnetic waves propagating in the space. It has been necessary to use an electromagnetic wave shielding material having frequency selectivity that can shield only unnecessary electromagnetic waves and transmit other electromagnetic waves in a part of a building or a room.

Here, as means for imparting such frequency selectivity to an electromagnetic wave shielding material, a frequency selectivity in which antenna elements such as dipole antennas which resonate at a specific frequency are arranged at a specific interval on the same plane is used. Has been proposed.

However, since electromagnetic waves radiated from mobile communication equipment or the like have a fixed polarization plane, it is difficult to obtain a sufficiently satisfactory shield characteristic with a dipole antenna that is a polarization-dependent antenna. there were.

[0007] In view of the above situation, a technical problem of the present invention is to provide an electromagnetic wave control plate having frequency selectivity independent of the polarization of electromagnetic waves.

[0008]

That is, the present invention uses a loop antenna that does not depend on the direction of polarization as an antenna element and eliminates the polarization dependence of an electromagnetic wave shielding material using a conventional diball antenna. Another object of the present invention is to provide a technique of laminating electromagnetic wave shielding plates having different polarization angles from each other to substantially eliminate polarization dependence.

According to the present invention, there is provided an electromagnetic wave control base including a base having transparency to visible light, and a plurality of loop antenna elements made of a conductive material provided on the surface of the base. , An electromagnetic wave control plate characterized in that it can be configured to amplify or attenuate electromagnetic waves of a desired frequency.

Further, according to the present invention, there is provided an electromagnetic wave control plate, wherein a feed point of the loop antenna element is short-circuited in the electromagnetic wave control plate.

According to the present invention, there is provided any one of the above-mentioned electromagnetic wave control boards, wherein the loop antenna element has a circular or polygonal shape.

According to the present invention, in any of the above-mentioned electromagnetic wave control plates, a loop antenna element group having a different radius is additionally arranged substantially concentrically or at a predetermined interval between the elements, and An electromagnetic wave control plate having a plurality of loop antenna element groups having different dimensions on a plane is obtained.

Further, according to the present invention, in any of the above-mentioned electromagnetic wave control boards, a plurality of the above-mentioned electromagnetic wave control bases are laminated, and the dimensions of the constituting antenna elements are different between the respective laminated electromagnetic wave control bases. The electromagnetic wave control plate characterized by the above is obtained.

Further, according to the present invention, at least three electromagnetic wave control bases each having a plurality of linear antenna elements made of a conductive material provided on the surface of a base material having transparency to visible light. An electromagnetic wave control plate comprising: at least three electromagnetic wave control bases, wherein the polarization angles of the linear antenna elements of the electromagnetic wave control bases are different from each other between the laminated electromagnetic wave control bases, and the electromagnetic wave of a predetermined frequency is determined according to the purpose. Is obtained so as to amplify or attenuate the electromagnetic wave.

Further, according to the present invention, there is provided an electromagnetic wave control plate wherein the dimensions of the antenna elements constituting the electromagnetic wave control plate are different between the respective electromagnetic wave control substrates to be laminated.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

First, the principle of operation of the electromagnetic wave control plate of the present invention will be described.

The size of the antenna element operating at a specific frequency (wavelength: λ) used in the electromagnetic wave control plate of the present invention can be obtained by the following equation (1).

[0019]

(Equation 1)

Here, ε _re is the equivalent relative permittivity of the antenna including the conductor and the base material. When used as the director of the present invention, a value slightly smaller than the value obtained by the above equation (1) may be used. Further, in the present invention, the operating bandwidth can be controlled by the interval between a plurality of antenna elements arranged on the same plane.

The material of the antenna element used in the present invention is desirably one having a small pure resistance component. If this value is large, the characteristics are deteriorated, which is not preferable.

Next, a specific example of the electromagnetic wave control plate of the present invention will be described.

FIG. 1 is a plan view showing an electromagnetic wave control plate according to a first embodiment of the present invention. Referring to FIG. 1, the electromagnetic wave control plate 10 is configured by arranging a plurality of loop antenna elements 2 on a plate glass 1.

The electromagnetic wave control plate 10 according to the first embodiment
Is specifically manufactured as follows. Thickness 1
(Mm) A loop antenna made of copper foil with a radius of 16 (mm) and a width of 0.5 (mm) on a square plate glass 1 having a side length of 300 (mm) and a short-circuited feed point. The element 2 was arranged, and a sample (hereinafter, referred to as a first sample) of an electromagnetic wave control plate including only one electromagnetic wave control base was obtained.

FIGS. 2A and 2B are plan views showing an electromagnetic wave control plate according to a second embodiment of the present invention. FIG.
Referring to (a), a plurality of linear antenna elements 3a, 3b, 3c are respectively arranged on three glass sheets 1 to form electromagnetic wave shielding plates 4a, 4b, 4c, respectively. Next, as shown in FIG. 2B, the electromagnetic wave control plate 20 is configured such that the polarization planes of the linear antenna elements 3a, 3b, 3c of the electromagnetic wave shield plates 4a, 4b, 4c, which are the electromagnetic wave control bases, are 60
It is configured by laminating differently.

The electromagnetic wave control plate 20 according to the second embodiment
Is specifically manufactured as follows.

The thickness is 1 (mm) and the length of one side is 300
(Mm) Three plate-shaped glass sheets 1 each having a square shape are prepared, and linear antenna elements 3a, 3b, 3c made of copper foil having a length of 85 (mm) and a width of 1 (mm) are prepared on the sheet glass 1. 2 (a)
The three electromagnetic wave shielding plates 4 are arranged as shown in FIG.
a, 4b, and 4c are laminated so that the polarization planes of the antenna elements are different from each other by 60 degrees, and a sample of a laminated electromagnetic wave control plate (hereinafter, referred to as a laminate)
A second sample) was obtained.

FIGS. 3A and 3B are plan views showing an electromagnetic wave control plate according to a third embodiment of the present invention. FIG.
Referring to (a), a plurality of loop antenna elements 5a are arranged on two glass sheets 1 and a plurality of loop antenna elements 5b each having a diameter larger than the loop antenna element 5a are arranged on the other. The electromagnetic wave shields 6a and 6b are electromagnetic wave control substrates. Next, FIG.
As shown in (b), the electromagnetic wave control plate 30 is configured by stacking the respective electromagnetic wave shield plates 6a and 6b.

The electromagnetic wave control plate 30 according to the third embodiment
Is specifically manufactured as follows.

The thickness is 1 (mm) and the length of one side is 300
(Mm) square glass sheets 1 were prepared, and one of them had a short-circuited radius of 16 (mm) and a width of 0.
The loop antenna element 5a made of 5 (mm) copper foil is
On the other one, a loop antenna element 5b having a radius of 25 (mm) is arranged as shown in FIGS. 3 (a) and 3 (b) to form electromagnetic wave shielding plates 6a and 6b, which are laminated to control electromagnetic waves. A sample of the plate 30 (hereinafter, referred to as a third sample) was obtained.

As described above, in the first to third embodiments, the electromagnetic wave control characteristics of each of the obtained samples were measured using the measuring system shown in FIG. As shown in FIG. 4, each electromagnetic wave control plate sample 7 was placed between a transmitting antenna 8 and a receiving antenna 9 connected to a network analyzer 11 and measured.

FIGS. 5 and 6 show typical frequency characteristics. FIG. 5 shows the frequency characteristics of the electric field reception intensity when the first sample is interposed with the transmission / reception antenna directly connected as a reference. According to this figure, 3
A region A where an increase of about [dB] is observed and a region B where an attenuation of 30 [dB] or more are observed can be confirmed. This shows the same characteristics even when the polarization plane is changed.

FIG. 6 shows the frequency characteristics when the third sample is placed, as in the case of FIG. 5, and it can be seen that there is attenuation at two frequencies. Also in this case, the characteristics do not depend on the plane of polarization.

From the above measurement results, the electromagnetic wave control plates according to the first to third embodiments of the present invention can obtain excellent frequency-selective electromagnetic wave control characteristics irrespective of the plane of polarization of the irradiated electromagnetic wave. I understand.

FIG. 7 is a plan view showing an electromagnetic wave control plate according to a fourth embodiment of the present invention, and shows a modification of the electromagnetic wave control plate according to the first embodiment. As shown in FIG. 7, the electromagnetic wave control plate 40 is an electromagnetic wave control plate 40 having two types of loop antenna elements 12 and 13 having different dimensions on the same plane of one sheet glass 1. With the electromagnetic wave control plate having such a configuration, the same effect as that shown in the similar first to third embodiments can be obtained.

[0036]

As described above, according to the present invention,
By providing a plurality of loop antenna elements made of a conductive material on the surface of a base material that transmits visible light, it is possible to provide an electromagnetic wave control plate that is independent of the polarization plane and has frequency selectivity. .

According to the present invention, each electromagnetic wave control plate having a plurality of linear antenna elements made of a conductive material is laminated on the surface of a base material having transparency to visible light. By arranging and laminating the polarization planes of the linear antenna elements so as to be different from each other between the electromagnetic wave control plates, it is possible to provide an electromagnetic wave control plate independent of the polarization plane and having frequency selectivity.

Further, according to the present invention, it is possible to provide an electromagnetic wave control plate having a plurality of frequency selectivity independent of the polarization plane by stacking a plurality of electromagnetic wave control plates operating at different frequencies. it can.

Further, according to the present invention, by providing a plurality of loop antenna element groups having different dimensions on the same plane, it is possible to provide an electromagnetic wave control plate having a plurality of frequency selectivities independently of the plane of polarization and simultaneously. be able to.

[Brief description of the drawings]

FIG. 1 is a plan view showing an electromagnetic wave control plate according to a first embodiment of the present invention.

FIG. 2A is an exploded view showing an electromagnetic wave control plate according to a second embodiment of the present invention. (B) is a top view of the electromagnetic wave control board of (a).

FIG. 3A is an exploded view showing an electromagnetic wave control plate according to a third embodiment of the present invention. (B) is a top view of the electromagnetic wave control board of (a).

FIG. 4 is a diagram showing a measurement system for measuring the electromagnetic wave control characteristics of each sample.

FIG. 5 is a diagram showing frequency characteristics of a first sample.

FIG. 6 is a diagram illustrating frequency characteristics of a third sample.

FIG. 7 is a plan view showing an electromagnetic wave control plate according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sheet glass 2, 5a, 5b, 12, 13 Loop antenna element 3a, 3b, 3c, Linear antenna element 4a, 4b, 4c, 6a, 6b Electromagnetic wave shield plate 7 Electromagnetic wave control plate sample 8 Transmitting antenna 9 Receiving antenna 10, 20 , 30,40 Electromagnetic wave control board 11 Network analyzer

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yuro Sato 6-7-1, Koriyama, Taishiro-ku, Sendai-shi, Miyagi-ken Tokin Co., Ltd.

Claims (7)

[Claims] 1. A substrate having transparency to visible light,
An electromagnetic wave control base including a plurality of loop antenna elements made of a conductive material provided on a surface of the base;
An electromagnetic wave control plate configured to amplify or attenuate electromagnetic waves of a desired frequency. 2. The electromagnetic wave control plate according to claim 1, wherein
An electromagnetic wave control plate, wherein a feed point of the loop antenna element is short-circuited. 3. The electromagnetic wave control plate according to claim 1, wherein the loop antenna element has a circular or polygonal shape. 4. The electromagnetic wave control plate according to claim 1, wherein a loop antenna element group having a different radius is additionally arranged substantially concentrically or at a predetermined interval between the elements. An electromagnetic wave control plate comprising a plurality of loop antenna element groups having different dimensions on the same plane. 5. The electromagnetic wave control plate according to claim 1, wherein a plurality of said electromagnetic wave control bases are laminated, and a dimension of an antenna element to be formed is between each of said laminated electromagnetic wave control bases. An electromagnetic wave control plate characterized in that: 6. An electromagnetic wave control plate formed by laminating at least three electromagnetic wave control bases each having a plurality of linear antenna elements made of a conductive material on a surface of a base material having transparency to visible light. Wherein the polarization angles of the linear antenna elements of the at least three electromagnetic wave control substrates are different from each other between the laminated electromagnetic wave control substrates, so that electromagnetic waves of a predetermined frequency can be amplified or attenuated according to the purpose. An electromagnetic wave control plate, characterized in that: 7. The electromagnetic wave control plate according to claim 6, wherein
An electromagnetic wave control plate, characterized in that the dimensions of the constituting antenna elements are different between the laminated electromagnetic wave control substrates.