JP2011010191A - Antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna that is provided with a structure suitable for the installation near indoor windows and a function to transmit/receive both vertically and horizontally polarized waves.SOLUTION: The antenna includes an antenna element 10 wherein the feeding conductor 30 of skeleton slot antenna element is inclined at a specified angle in the plane including a frame-like conductor 20. The ratio between main polarized wave component level and cross polarized wave component level is regulated by the tilt of the feeding conductor 30.

Description

  The present invention relates to an antenna that can be suitably used as a repeater antenna device provided to cover an indoor area particularly in a mobile communication system or the like.

In land mobile communication systems, it is required to enable communication in indoor areas where radio waves are difficult to reach. Therefore, a repeater antenna device for satisfying such a requirement is proposed by, for example, Patent Document 1.
This repeater antenna device includes an outdoor antenna, an indoor antenna, and an antenna coupling means for amplifying the received signal of the outdoor antenna and transmitting it to the indoor antenna, and amplifying the received signal of the indoor antenna and transmitting it to the outdoor antenna. Yes. The outdoor antenna transmits and receives radio waves to and from the base station, and the indoor antenna transmits and receives radio waves to and from portable terminals that move indoors. Therefore, if this repeater antenna device is used, communication between an indoor portable terminal and an outdoor base station becomes possible.

Japanese Patent Laid-Open No. 08-331028

The above repeater antenna device requires a work for attaching the outdoor antenna to the outside of the building and a work for drawing a cable (coaxial cable, optical cable, etc.) connected to the outdoor antenna indoors. Become. Moreover, since the installation of the outdoor antenna on the side of the building will damage the exterior of the building, the installation of the outdoor antenna may be avoided from the building owner.
Therefore, it is conceivable to install an antenna corresponding to the above-mentioned outdoor antenna at an indoor window. In this case, the antenna is required to have a design that takes aesthetics into consideration, specifically, a design that is transparent and downsized so as not to block the view of the outside of the window.

  On the other hand, in the current land mobile communication system, technological innovation for improving the data communication speed is advanced, and as a result, one communication carrier uses various communication methods. One example is to divide communication methods between different polarizations such as horizontal polarization and vertical polarization. When the repeater antenna device is applied to a communication system operated in a form like this example, the repeater antenna device needs to have a function of transmitting and receiving both horizontally polarized waves and vertically polarized waves. When the repeater antenna of the repeater antenna apparatus is installed near an indoor window, a transparent and miniaturized design is also required for the repeater antenna.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an antenna having both a structure suitable for installation at an indoor window and a function capable of transmitting and receiving both vertical and horizontal polarized waves Is to provide.

  The present invention includes an antenna element in which a feeding conductor portion of a skeleton slot antenna element is inclined at a predetermined angle in a plane including a frame-like conductor portion of the antenna element, and intersects with a main polarization component by the inclination of the feeding conductor portion. Provided is an antenna characterized by defining a level ratio of polarization components.

The antenna may further include a reflector having a lattice structure disposed on the back of the antenna element.
Moreover, the cylindrical antenna cover with transparency which accommodates the said antenna element and reflector can be further provided. In this case, it is desirable to form the reflector in an arc shape in order to reduce the antenna diameter.

The present invention provides a first antenna element applied to a first frequency f1, a second antenna element applied to a second frequency f2 (> f1), the first antenna element and the second antenna element. Is also provided with support means for supporting each in a form that can be individually pivotally displaced along horizontal concentric circumferences of radii r1 and r2 (> r1), respectively.
In this antenna, each of the first and second antenna elements has a configuration in which a feeding conductor portion of the skeleton slot antenna element is inclined at a predetermined angle within a plane including the frame-shaped conductor portion of the antenna element, The level ratio of the main polarization component and the cross polarization component is defined by the inclination of the conductor portion.

  In this antenna, reflectors having a lattice structure are respectively disposed on the back portions of the first and second antenna elements as necessary.

The present invention relates to a first antenna element applied to a first frequency f1, a second antenna element applied to a second frequency f2 (> f1), and the second antenna element to the first antenna. Also provided is an antenna comprising supporting means for supporting in a form that can be pivotally displaced along the periphery of the element.
In this antenna, each of the first and second antenna elements has a configuration in which a feeding conductor portion of the skeleton slot antenna element is inclined at a predetermined angle within a plane including the frame-shaped conductor portion of the antenna element, The level ratio of the main polarization component and the cross polarization component is defined by the inclination of the conductor portion.

  The antenna includes first and second reflectors having a lattice structure disposed on the back of the first and second antenna elements, the first and second antenna elements, and the first and second antenna elements, respectively. And a cylindrical antenna cover having transparency that accommodates the reflector. In this case, the antenna cover is disposed so as to be located on a circumference that is concentric with the circumference that is the trajectory of the second antenna element, and the second reflector extends along the antenna cover. In order to make it, it is formed in an arc.

  The antenna according to the present invention can be applied to both vertical and horizontal polarized waves despite being a simple configuration based on a skeleton slot antenna element, and is small and transparent. . Therefore, it can be suitably used as a repeater antenna that is installed especially at an indoor window.

It is a conceptual diagram which shows the antenna element of the conventional skeleton slot antenna. It is a characteristic view which shows the directivity in the horizontal surface of the skeleton slot antenna shown in FIG. It is a conceptual diagram which shows the antenna element of the antenna which concerns on the 1st Embodiment of this invention by which the inclination-angle of the electric power feeding conductor part was set to about 45 degrees. It is a characteristic view which shows the directivity in the horizontal surface of the antenna of FIG. It is a conceptual diagram which shows the antenna element of the antenna which concerns on the 1st Embodiment of this invention by which the inclination angle of the electric power feeding conductor part was set to about 60 degrees. It is a characteristic view which shows the directivity in the horizontal surface of the antenna of FIG. It is a perspective view which shows the antenna which concerns on the 2nd Embodiment of this invention. It is a characteristic view which shows the directivity in the horizontal surface of the antenna of FIG. It is a perspective view which shows the antenna which concerns on the 3rd Embodiment of this invention. It is a perspective view which shows the antenna which concerns on the 4th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 illustrates an antenna element of a conventional skeleton slot antenna. This antenna element 1 includes a rectangular frame-shaped conductor portion 2 constituting a radiation slot and a feeding conductor portion interposed between one opposing side 2a, 2a (along the y-axis) of the frame-shaped conductor portion 2. 3 (along the x-axis).
In the skeleton slot antenna including this antenna element 1, the level of the vertical polarization component that is the cross polarization component is significantly lower than that of the horizontal polarization component, as shown in FIG. In addition, the directivity pattern for each polarization component is also greatly different.

  3 and 5 show the antenna element 10 constituting the antenna according to the first embodiment of the present invention. In the antenna element 10, the frame-shaped conductor portion 20 and the power supply conductor portion 30 correspond to the frame-shaped conductor portion 2 and the power supply conductor portion 3 shown in FIG. 1, respectively. The feeding conductor portion 30 of the antenna element 10 is provided so as to be inclined by an angle θ with respect to the x axis in the plane including the frame-like conductor portion 20, and in this respect, the conventional skeleton slot antenna shown in FIG. The configuration of the antenna element 1 is different.

In the antenna element 10 shown in FIG. 3 and the antenna element 10 shown in FIG. 5, the inclination angle θ of the feed conductor portion 30 is set to θ≈45 ° and θ≈60 °, respectively. Therefore, in the antenna element 10 of FIG. 3, the level of the vertical polarization component, which is a cross polarization component, increases as shown in FIG. Further, in the antenna element 10 of FIG. 5, as shown in FIG. 6, the level and directivity of vertical polarization can be made close to that of horizontal polarization.
As described above, the inclination angle θ of the feed conductor portion 30 defines the level ratio between the main polarization component (horizontal polarization component in the present embodiment) and the cross polarization component (vertical polarization component in the present embodiment). Therefore, it is appropriately set so as to obtain a desired level ratio.
Note that the inclination angle θ of the power supply conductor portion 30 is set in a range of 45 to 80 ° from a practical viewpoint.

  Since the antenna of this embodiment can be applied to both horizontally polarized waves and vertically polarized waves as described above, for example, the horizontally polarized waves are applied to communication according to a certain communication method, and the vertically polarized waves are separated. It is also possible to cope with a communication mode such as applying to communication according to the above communication method.

By the way, in the repeater antenna device provided to cover the indoor area, as described above, between the first repeater antenna used for transmission / reception with the base station and the indoor portable terminal. And a second repeater antenna that is used to perform transmission / reception at. For the reasons described above, the first repeater antenna is preferably installed at an indoor window. In that case, the design is aesthetically pleasing, specifically, it is transparent so as not to obstruct the view outside the window. And a miniaturized design is required.
Since the antenna according to the present embodiment includes the antenna element 10 whose basic configuration is the configuration of the skeleton slot antenna element 1 of FIG. 1, it can be configured in a small size and has transparency. Therefore, the antenna according to the present embodiment can be suitably used as the first antenna that is installed near an indoor window.

FIG. 7 shows a second embodiment of the present invention having a configuration in which a reflector 40 is arranged on the back of the antenna element 10. The reflector 40 has a lattice structure in which wire conductors are cross-arranged, and is provided in a plane parallel to the plane including the antenna element 10. The reason why the reflector 40 has a lattice structure is to make the reflector 40 transparent.
The antenna of the present embodiment including the reflector 40 has a horizontal directivity as shown in FIG. 8, that is, a unidirectional directivity in which the back lobes of both polarizations are suppressed. Therefore, if this antenna is used as the first antenna of the repeater antenna device, unnecessary interference radio waves can be prevented from being radiated indoors, and the quality of communication can be improved.

  In addition, in the antenna which concerns on the said 1st, 2nd embodiment, the antenna cover which covers the circumference | surroundings is provided as needed. In that case, a highly transparent antenna cover is used. When the antenna cover is used for the antenna according to the second embodiment, in order to reduce the antenna diameter, the reflector is formed in an arc shape and the arc surface is aligned with the arc surface of the antenna cover. It is desirable.

  FIG. 9 shows an antenna according to a third embodiment of the invention applied to two frequencies. This antenna includes two antenna elements 10-1 and 10-2 having a configuration according to the antenna element 10 of FIG. 7, and two reflectors 40-1 and 40 having a configuration according to the reflector 40 of FIG. -2.

  The sizes of the antenna elements 10-1 and 10-2 are set so as to adapt to the first frequencies f1 and f2 (f1 <f2), respectively, and the reflectors 40-1 and 40-2 are respectively It is formed to have a size corresponding to the size of the antenna elements 10-1 and 10-2. Therefore, according to the antenna of the present embodiment, the radio wave having the frequency f1 can be transmitted and received by one antenna unit including the antenna element 10-1 and the reflector 40-1, and the antenna element 10-2 and the reflector. The other antenna unit including 40-2 can transmit and receive a radio wave of frequency f2.

  The one antenna unit is disposed on a planar circular table 50-1, and the other antenna unit is disposed on a planar annular table 50-2 arranged concentrically around the table 50-1. It is arranged. The tables 50-1 and 50-2 are pivotally supported by a base (not shown) so that they can rotate independently of each other about a common axis.

When the antenna of the present embodiment is used as the first antenna of the repeater antenna device, the one antenna unit is turned by the turning operation of the table 50-1 (displacement on the circumference of the radius r1). The main beam direction of the antenna unit can be adjusted to the direction of the base station according to the frequency f1, and the turning displacement of the other antenna unit by the turning operation of the table 50-2 (on the circumference of the radius r2) The main beam direction of the antenna unit can be matched with the direction of the base station related to the frequency f2.
In addition, also in the antenna which concerns on this embodiment, the antenna cover which covers each said antenna unit is provided as needed. Of course, a highly transparent antenna cover is used.

FIG. 10 shows an antenna according to a fourth embodiment of the present invention in which the antenna according to the third embodiment is improved. 10, the code | symbol common to the element corresponding to the component shown in FIG. 9 is attached | subjected, and the concrete description about them is abbreviate | omitted.
In the antenna of the present embodiment, the antenna element 10-1 is fixedly supported on the table 50-1 ′ formed at the center of the planar circular base 60, and the reflector combined with the antenna element 10-1. 40-1 'is fixedly supported on the outer peripheral side of the base 60, and the antenna element 10-2 and the reflector 40-2 are fixedly supported on the annular table 50-2. This antenna is provided with a cylindrical antenna cover 70 covering the antenna elements 10-1 and 10-2 and the reflectors 40-1 ′ and 40-2.

  The annular table 50-2 is supported by the base 60 so as to be able to rotate around the table 50-1 ′. The center axis of the antenna cover 70 coincides with the common center axis of the tables 50-1 and 50-2. And reflector 40-1 'is formed in circular arc shape so that the circular arc internal peripheral surface of the antenna cover 70 may be followed.

When the antenna of this embodiment is used as the first antenna of the repeater antenna device, the main beam direction of one antenna unit including the antenna element 10-1 and the reflector 40-1 ′ is related to the frequency f1. The base 60 is positioned so as to be in the direction of the base station, and then the main beam direction of the other antenna unit including the antenna element 10-2 and the reflector 40-2 is turned by rotating the table 50-2. It is adjusted to the direction of the base station related to the frequency f2.
At this time, the rotation range of the table 50-2 is a range in which the reflector 40-1 ′ can be prevented from entering the front area of the antenna element 10-2 (for example, each main beam of one antenna unit and the other antenna unit). It is desirable that the rotation angle of the table 50-2 when the directions coincide with each other is limited to a rotation range of about ± 45 ° with a rotation angle of 0 ° as a base point.

According to the antenna of this embodiment, the diameters of the tables 50-1 and 50-2 can be made smaller than that of the antenna of the embodiment shown in FIG. Since the diameter can be reduced, further miniaturization can be achieved.
Also in this embodiment, a highly transparent antenna cover 70 is used.

  The present invention is not limited to the above embodiment, and can include various modifications. For example, instead of the reflector 40 shown in FIG. 7, the reflectors 40-1 and 40-2 shown in FIG. 9, and the reflectors 40-1 ′ and 40-2 shown in FIG. It is also possible to use a reflector.

10, 10-1, 10-2 Antenna element 20 Frame-shaped conductor part 30 Feeding conductor part 40, 40-1, 40-1 ', 40-2 Reflector 50-1, 50-1', 50-2 Table 60 Base 70 Antenna cover

Claims (11)

An antenna element in which a feeding conductor portion of a skeleton slot antenna element is inclined at a predetermined angle within a plane including a frame-shaped conductor portion of the antenna element;
An antenna characterized in that a level ratio of a main polarization component and a cross polarization component is defined by an inclination of the feeding conductor portion.   The antenna according to claim 1, further comprising a reflector having transparency disposed on a back portion of the antenna element.   3. The apparatus according to claim 2, further comprising a cylindrical antenna cover having transparency for accommodating the antenna element and the reflector, wherein the reflector is formed in an arc shape so as to follow the antenna cover. Antenna described in.   The antenna according to claim 2, wherein the reflector has a lattice structure.   The antenna according to claim 2 or 3, wherein the reflector is formed of an electromagnetic wave shielding film. A first antenna element applied to the first frequency f1,
A second antenna element applied to the second frequency f2 (>f1);
Supporting means for supporting the first antenna element and the second antenna element in a form that can be individually swung and displaced along horizontal concentric circles having radii r1 and r2 (> r1), respectively.
Each of the first and second antenna elements has a configuration in which a feeding conductor portion of the skeleton slot antenna element is inclined at a predetermined angle within a plane including the frame-shaped conductor portion of the antenna element. An antenna characterized in that the level ratio of the main polarization component and the cross polarization component is defined by.   The antenna according to claim 6, further comprising transparent first and second reflectors respectively disposed on the back portions of the first and second antenna elements. A first antenna element applied to the first frequency f1,
A second antenna element applied to the second frequency f2 (>f1);
Supporting means for supporting the second antenna element in a form that can be pivotally displaced along the periphery of the first antenna element;
Each of the first and second antenna elements has a configuration in which a feeding conductor portion of the skeleton slot antenna element is inclined at a predetermined angle within a plane including the frame-shaped conductor portion of the antenna element. An antenna characterized in that the level ratio of the main polarization component and the cross polarization component is defined by. The first and second reflectors having transparency disposed on the back portions of the first and second antenna elements, the first and second antenna elements, and the first and second reflectors, respectively. A cylindrical antenna cover having transparency to be accommodated;
The antenna cover is disposed so as to be located on a circumference concentric with a circumference that is a turning displacement locus of the second antenna element,
9. The antenna according to claim 8, wherein the second reflector is formed in an arc shape so as to follow the antenna cover.   The antenna according to claim 7 or 9, wherein the first and second reflectors have a lattice structure.   The antenna according to claim 7 or 9, wherein the first and second reflectors are formed of an electromagnetic wave shielding film.

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