JP2000174546A - Device for preventing radio wave reflection by building, radio wave dark room and electric device vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for preventing a radio wave from being reflected by a building without using such expensive means as affixing an expensive material such as ferrite onto nearly the entire radio wave incident face of a building and without giving any adverse effect on others resulting from a reflected radio wave. SOLUTION: A building 5 is built on the ground toward the sky and a reception antenna element 1 is provided on a side wall 5a of the building 5. A non- reflective terminator 2 consisting of resistors or the like is connected to a feeding terminal of a reception antenna element 1, and a radio wave received by the reception antenna element 1 is lost in the non-reflective terminator 2. A plurality of the reception antenna elements 1 are alligned on an area of the side wall 5 of the building 5 where the reflection of a radio wave is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to
A device for preventing reflection of radio waves that interfere with reception such as V broadcast waves causing multiple reflections and generating ghosts, and a device for preventing radio wave reflection by a building having a low-noise environment and an anechoic chamber using the same. The present invention relates to an electrical equipment container.

[0002]

2. Description of the Related Art In recent years, the number of high-rise buildings has increased, and in broadcasting and communication, the reflection of radio waves from buildings and the like causes multiple reflections, and multipath noise becomes an interference wave, deteriorating the quality of broadcasting and communication. For example, in the reception of TV broadcast waves,
In the case of digital broadcasting, a ghost is generated by multipath, and a problem such as a screen not appearing occurs, and the quality of the screen is deteriorated. Also in communication, noise may degrade the quality of communication, or the communication may be disabled.

[0003] As a method of removing such an interference wave generated by reflection from a building, for example, a radio wave absorber made of ferrite or the like shaped as shown in FIG. A method of absorbing a radio wave incident on a side wall of the device has been considered. This is because the reflected waves are suppressed by absorbing a certain amount of radio waves, and the influence on normal reception is reduced.

[0004] Another method is disclosed in Japanese Patent Application Laid-Open No. 1-32.
As disclosed in Japanese Patent No. 1698 or Utility Model Registration No. 2585413, a method of arranging a metal rod in a sudare shape on a side wall of a building or the like to reflect an incident radio wave to the sky so that the radio wave is reflected to the sky, The appearance is eliminated by embedding metal rods in the concrete, and the surface is covered with a ferrite layer to absorb to some extent to weaken the radio waves. Attempts have been made to eliminate the effects of radio waves.

[0005]

In the conventional method of absorbing a radio wave by a radio wave absorber, the method of FIG.
A triangular pyramid-shaped ferrite or the like formed according to the frequency band of the radio wave to be absorbed is used as shown in the above. However, the absorption over the wide frequency band cannot be sufficiently covered, and the wide frequency band cannot be covered. The reflected wave cannot be reduced sufficiently as a whole. Further, the radio wave absorber is very expensive, and has a problem that the weight becomes heavy and the cost of the building increases.

Further, if a metal rod or the like is provided in a stepped manner on the front side of the side wall of the building, the appearance is impaired, and when reflected to the sky, it enters into an airplane or a helicopter flying in the sky as a jamming radio wave. However, there is a problem that adverse effects occur.

[0007] The present invention has been made in view of such a situation, and does not increase the cost of attaching an expensive material such as ferrite to almost the entire surface of a building from which radio waves arrive. It is an object of the present invention to provide an apparatus for preventing radio wave reflection from a building that does not adversely affect others by reflecting light.

Another object of the present invention is to provide a radio wave anechoic chamber or an electric equipment container which prevents the reflection of radio waves by using the radio wave reflection preventing device.

[0009]

According to the present invention, there is provided an apparatus for preventing radio wave reflection from a building, comprising: a building provided on the ground toward the sky; a receiving antenna element provided on a side wall of the building; And a plurality of the receiving antenna elements are arranged on the side wall of the area of the building where reflection of radio waves is prevented to prevent reflection of radio waves in the area. It has a configuration.

With this configuration, for example, the frequency band of a radio wave which is particularly susceptible to a reflected wave such as a digital broadcast wave is as high as several hundred MHz, and even if the antenna element has an electrical length of 1/4 wavelength, the wire is used. And the like can be formed by winding them into a coil, so that they can be formed at very low cost and in a small size. In addition, the radio wave arriving at that surface resonates with the antenna and proceeds to the feed end, and since the non-reflective terminator is connected to the feed end, it disappears at the non-reflective terminator and goes to another place. It does not reflect and has no adverse effect.

The receiving antenna elements are composed of two or more types of receiving antenna elements resonating in two or more frequency bands, respectively, and the two or more types of receiving antenna elements are arranged on the side wall at appropriate intervals. This makes it possible to prevent the reflection of radio waves in a wide frequency band, and in particular, it is possible to reliably prevent the reflection of two or more important wavelength bands that need to be prevented.

2. The radio wave non-reflection device according to claim 1, wherein the power supply terminal of at least one of the plurality of reception antenna elements is not terminated, and the output of the power supply terminal is connected to the radiation antenna element. The radiating antenna element is provided on the side of the building opposite to the side wall on which the receiving antenna element is provided, and a radio wave received by the receiving antenna element from the radiating antenna element is transmitted along the direction of arrival of the radio wave. By radiating the radio wave, it is possible to prevent the radio wave from being interrupted to the downstream side of the radio wave, and it is possible to transmit the radio wave to an area where viewing is difficult or an area where communication is impossible, which is preferable.

The anechoic chamber or electric equipment container of the present invention comprises:
A partition for partitioning a certain space, a receiving antenna element provided on the partition, and a non-reflection terminator for terminating a feeding end of the receiving antenna element; radio waves are reflected on the inner surface of the partition; The receiving antenna element is provided all around the inside of the partition so that the container does not become a state like a resonator. As a result, in a radio wave anechoic chamber or an electric equipment container, a strong part of the radio wave is generated due to the reflection by the partition wall, so that there is no occurrence of an error in the measurement and no malfunction of other circuits in the same electric equipment container.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an apparatus for preventing radio wave reflection by a building according to the present invention will be described with reference to the drawings. As shown in a conceptual diagram of one embodiment of the embodiment of the radio wave reflection prevention device of the present invention, as shown in FIG. The receiving antenna element 1 is provided on the side wall 5a of the antenna. As shown in FIG. 1B, a non-reflection terminator 2 composed of a resistor or the like is connected to a feed end of the reception antenna element 2. It is configured to disappear in the vessel 2. As shown in FIG. 1A, a plurality of the receiving antenna elements 1 are arranged on the side wall 5a of the area of the building 5 for preventing the reflection of the radio wave, and the reflection of the radio wave in the area is prevented. It has become. Reference numeral 6 denotes a radio wave transmitting unit.

The receiving antenna element 1 (hereinafter simply referred to as antenna element 1) includes a dipole element, a monopole element, a patch antenna element, a curl antenna element, a helical antenna element as shown in FIG. Various other shapes of antenna elements, such as a loop antenna element and a parabolic antenna element, can be used. The point is that it is only necessary to form so as to be able to receive in a desired frequency band. The antenna elements 1 are provided in a plane in a desired anti-reflection area at an interval a of about one wavelength, for example, in a direction of arrival of a radio wave for preventing reflection. By doing so, almost no reflection occurs in both regions, and no transmission occurs between the two regions and reflection occurs in the building 5. Therefore, the antenna element 1 does not need to be provided on the entire periphery of the building 5, and the object of the present invention can be achieved if it is provided only on the side facing the radio wave transmitting unit 6.

The antenna element 1 may be provided on the surface of the side wall 5a of the building 5, as shown in FIG. 1A, or may be embedded in the side wall 5a of the building 5. When buried, it is possible to prevent the reflection of radio waves without a sense of incongruity in appearance, and to provide an environmentally friendly building. When provided outside the building 5, it is possible to improve the aesthetic appearance by matching and matching the design and the color tone of the building.

The aforementioned antenna element 1 is, as described above,
Although it is formed so as to resonate in a certain frequency band, it can be formed so as to resonate in a fairly wide band frequency such as a TV band or an FM band by matching, for example, with a balun. However, in order to prevent the reflection of any radio wave in a wider frequency band, as shown in a similar conceptual diagram in FIG. 2, the first antenna element 11 for each of the different frequency bands, By arranging the second antenna element 12 and the third antenna element 13 so as to have an interval of about one wavelength in each frequency band, in any of those frequency bands, reflection is substantially obtained over the entire surface of the area. Can be prevented. That is, reflection can be sufficiently prevented even in a wide frequency band. The frequency band for preventing these reflections is set according to local circumstances. For example, especially in a band where a TV image is not reflected due to multipath such as a digital broadcast wave, radio waves in the frequency band for the digital broadcast wave are transmitted. The frequency band of the antenna element 1 can be set so as to prevent such a situation.

Further, by providing the antenna element 1 with directivity toward the transmitting part of the radio wave, the radio wave can be received particularly efficiently and the reflected radio wave can be reduced, and any one of these receiving antenna elements 1 can be used. By using the non-reflection terminator as it is without connecting the non-reflection terminator to the feeding end of the receiver, it is possible to perform high-gain reception with high sensitivity without having to install a receiving antenna.

Further, even when radio waves having different polarization planes, such as circularly polarized waves and linearly polarized waves, or vertically polarized waves and horizontally polarized waves, arrive, the antenna element 1 operates in the same manner as in the above-described correspondence to the frequency band. By using the antenna element 1 having a structure adapted to the plane of polarization of the incoming radio waves, the radio waves can be efficiently absorbed and the reflection can be prevented.

FIG. 3 is a diagram showing an application example of the radio wave reflection preventing device of the present invention. That is, in this example, a part or all of the received signal is collected and amplified by the amplifier 8 without terminating the feed end of the receiving antenna element 1 for receiving the arriving radio wave so as not to reflect the radio wave, and the amplified signal is amplified. The received signal is connected to the radiating antenna element 7, and the signal received by the receiving antenna element 1 is radiated from the back wall 5b of the building 5 (downstream of the arriving radio wave).
By thus radiating and transmitting the radio wave blocked by the building 5 again from the back side of the building 5, it is possible to receive the radio wave downstream without causing any radio interference.

As another application example of the radio wave reflection prevention device of the present invention, for example, as shown in FIG.
By providing the antenna element 1 shown in FIG. 1 around the inside of the partition wall 9a separating the antenna, radio waves in a frequency band that resonates with the antenna are absorbed by the antenna element 1 and are not reflected by the partition wall 9a. As a result, the radio wave transmitted inside is absorbed by the wall surface, so that it becomes an anechoic chamber, and can be used, for example, for measuring antenna characteristics.

FIG. 5 is a view showing still another example of the applied example. By providing the above-described antenna element 1 together with the non-reflection terminator 2 in an electric equipment container 10 for handling electromagnetic waves, Is prevented, the inside of the container 10 operates as a high-frequency resonator, and the radio wave leaked from one circuit does not sneak into another circuit or the strong electromagnetic wave leaks from the container 10.

[0023]

According to the present invention, the receiving antenna element can be formed by a metal foil pattern, a metal rod, or the like, and can be formed at a very low cost as compared with the case where an electromagnetic wave absorber is attached. Therefore, even if it is provided in a wide area of the side wall of the building, the cost does not increase, and an efficient radio wave reflection prevention device can be obtained. As a result, it is possible to solve a problem that a TV image is not displayed due to a reflected wave such as a digital broadcast wave or a ghost is hard to enter a TV receiving screen such as a UHF or a VHF.

Further, if the present invention is applied to a building or an electric equipment container shielded from electromagnetic waves, an anechoic chamber can be formed at low cost, and interference between circuits in the electric equipment container can be prevented. .

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the concept of an embodiment of a radio wave reflection prevention device according to the present invention.

FIG. 2 is a diagram illustrating the concept of another embodiment of the radio wave reflection preventing device of the present invention.

FIG. 3 is a diagram illustrating the concept of another embodiment of the radio wave reflection preventing device of the present invention.

FIG. 4 is a diagram illustrating the concept of an embodiment of an anechoic chamber of the present invention.

FIG. 5 is a diagram for explaining the concept of an application example of the radio wave reflection prevention device of the present invention.

FIG. 6 is an explanatory diagram of an example of a conventional radio wave absorber for preventing radio wave reflection.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Antenna element 2 Non-reflection terminator 5 Building 5a Side wall

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kenichi Iwai 7-5-11 Takinogawa, Kita-ku, Tokyo F-term in Yokohama, Japan 5J020 AA04 BC04 CA04

Claims (4)

[Claims] 1. A building provided on the ground toward the sky, a receiving antenna element provided on a side wall of the building,
A non-reflection terminator for terminating a feed end of the receiving antenna element, wherein a plurality of the receiving antenna elements are arranged on the side wall of the area of the building for preventing reflection of radio waves, A device to prevent radio wave reflection from buildings that prevent noise. 2. The receiving antenna element comprises two or more types of receiving antenna elements resonating in two or more frequency bands, and the two or more types of receiving antenna elements are arranged on the side wall at appropriate intervals. The apparatus for preventing radio wave reflection according to claim 1, wherein the apparatus is provided. 3. The radio wave reflection preventing device according to claim 1, wherein the power supply end of at least a part of the plurality of reception antenna elements is not terminated, and the output of the power supply end is supplied to the radiation antenna element. The radiating antenna element is provided on the opposite side of the building opposite to the side wall on which the receiving antenna element is provided, and the direction of arrival of the radio wave received from the radiating antenna element by the receiving antenna element is provided. A device to prevent the reflection of radio waves radiated along. 4. A partition for partitioning a certain space, a receiving antenna element provided on the partition, and a non-reflection terminator for terminating a feeding end of the receiving antenna element so that radio waves are not reflected inside the partition. A radio wave anechoic chamber or an electrical equipment container, wherein the receiving antenna element is provided on the entire periphery of the inside of the partition.