JP5723999B1 - Antenna device considering the surrounding environment - Google Patents

Abstract

A small frequency sharing antenna using one antenna element for one polarization is provided. An antenna includes a reflector, a dipole element provided at a predetermined distance from the reflector, and a first parasitic element provided at a predetermined distance from the reflector. I have. Further, a second parasitic element 150a and a second parasitic element 150b provided apart from both ends of the element portion 121a and the element portion 121b of the dipole element 120 are provided. In addition, a connection member 122 that connects the element portion 121a and the element portion 121b of the dipole element 120 is provided. A signal obtained by superimposing signals in at least three frequency bands of a low frequency band having a frequency fL as a center frequency, an intermediate frequency band having a frequency fM as a center frequency, and a high frequency band having a frequency fH as a center frequency by the dipole element 120 is obtained. Sent and received. [Selection] Figure 2

Description

  The present invention relates to an antenna device in consideration of the surrounding environment.

In urban areas and downtown areas, there are places where it is difficult to install antennas for wireless communication because of considerations for local regulations and landscapes. In such an installation place, requirements differ for an antenna that conforms to the ordinance and an antenna that is suitable for a landscape. Therefore, it is necessary to develop various types of antennas suitable for each installation location.
Further, in such an installation place, it is difficult to provide a plurality of antennas even when trying to transmit and receive radio waves in a plurality of frequency bands. For this reason, frequency sharing antennas capable of transmitting and receiving radio waves in a plurality of frequency bands have been developed.

Patent Document 1 discloses a reflector, n (n ≧ 2) half-wavelength dipole antenna elements disposed on the reflection surface of the reflector, and the opposite side of each of the half-wavelength dipole antenna elements to the reflector. N parasitic elements and (n + 1) conductive plates, each half-wave dipole antenna element is disposed between the (n + 1) conductive plates, and each conductive plate is One end is opposed to the tip of each half-wave dipole antenna element, the other end is connected to the reflector, and a free space wave having a use center frequency on the low frequency side of the multi-frequency is defined as λ ₁ . A multi-frequency shared antenna is described in which the interval between adjacent half-wavelength dipole antenna elements satisfies 0.25 × λ ₁ ≦ d <0.5 × λ ₁ .

Japanese Patent Laid-Open No. 2007-60082

By the way, if the shape of the frequency sharing antenna is small, it can be easily applied even if the requirements for the antenna differ depending on the installation location. Further, it can be easily incorporated in an existing advertising device, lighting device, television viewing device, or the like.
An object of the present invention is to provide a small frequency sharing antenna using one antenna element for one polarization.

The above object, an antenna to which the present invention is applied, conductive and materials composed of a reflecting plate, a pair of element portion provided in a predetermined distance from the reflecting plate is perforated, the first frequency band a dipole element Telecommunications shape corresponding to the set of the opposite side of the reflector across the da Iporu element, provided opposite to the pair of element portions of the dipole elements, between the dipole elements, the A first parasitic element that resonates with a radio wave in a second frequency band higher than the first frequency band, and a predetermined distance from one end and the other end of the pair of element portions of the dipole element , A plurality of second parasitic elements that resonate with radio waves in a third frequency band lower than the first frequency band and a pair of element portions of the dipole element are connected to each other by an electrically conductive material. Provided and resonating Comprising a connecting member for adjusting the wavenumber, and transmitting and receiving radio waves of a plurality of frequency bands via a dipole element.
In this antenna, the plurality of second parasitic elements may be characterized in that the side far from each reflector is bent to the dipole element side.
In addition, it is possible to further include a housing that houses the reflector, the dipole element, the connection member, the first parasitic element, and the second parasitic element.

Further, in the antenna, on the side where the dipole element is provided, another pair of element portions is provided at a predetermined distance from the reflector so as to intersect with the pair of element portions of the dipole element . in one and the other dipole element shape is set corresponding to the radio frequency band, and the reflection plate across the other dipole element opposite provided opposite to the pair of the active element of the other dipole elements The other first parasitic element that resonates with the radio wave of the second frequency band and the other end of the pair of other dipole elements are determined in advance from the other dipole element. A plurality of other second parasitic elements that are provided at intervals and resonate with radio waves in the third frequency band between the other dipole elements, and a pair of other dipole elements by a conductive material Parts to each other It provided so as to continue, further comprising the other of the connecting member for adjusting the frequency of resonance of, through the other dipole elements, transmitting and receiving radio waves of a plurality of frequency bands of radio waves with different polarization dipole elements to send and receive It can be characterized by.
By doing in this way, it can be set as an array antenna for polarization sharing.
An antenna to which the present invention is applied includes a reflector made of a conductive material, a dipole element having a pair of element portions provided at a predetermined distance from the reflector, and a reflector sandwiching the dipole element And a first parasitic element provided opposite to the pair of element portions of the dipole element, and a predetermined interval from one end and the other end of the pair of element portions of the dipole element. A plurality of second parasitic elements, a connection member made of a conductive material and interconnecting a pair of element portions of the dipole element, and a side reflector provided on a side surface of the dipole element, The reflection plate, the side reflection plate, and the plurality of second parasitic elements are configured by bending a single metal plate, and transmit and receive radio waves in a plurality of frequency bands via the dipole elements.

When regarded from another point of view, the structure of the present invention is applied, possess conductive and materials composed of a reflecting plate, a pair of element portion provided in a predetermined distance from the reflection plate, the first A dipole element having a shape corresponding to a radio wave in the frequency band of (2) and a pair of element parts of the dipole element facing the dipole element on the opposite side of the reflection plate across the dipole element. A first parasitic element that resonates with a radio wave in a second frequency band higher than the first frequency band, and a predetermined interval from one end and the other end of the pair of element portions of the dipole element. A plurality of second parasitic elements that resonate with radio waves in a third frequency band lower than the first frequency band and a pair of element portions of the dipole element are connected to each other by a conductive material. So that it resonates. It has a connecting member for adjusting the frequency, and an antenna for transmitting and receiving radio waves of a plurality of frequency bands via a dipole element.
According to this configuration, the antenna can be incorporated in a structure having other functions.

  According to the present invention, it is possible to provide a small frequency sharing antenna using one antenna element for one polarization.

It is a perspective view which shows an example of the apparatus for advertisement to which 1st Embodiment is applied. It is a perspective view which shows an example of the antenna with which 1st Embodiment is applied. It is a figure which shows an example of the top view and side view of an antenna. (A) is a top view, (b) is the side view seen from the y direction in (a). It is a figure which shows the relationship between a dipole element and a connection member. (A) is a perspective view and FIG. 4 is an equivalent circuit diagram. It is a perspective view which shows the modification of the antenna with which 1st Embodiment is applied. It is a figure which shows the apparatus for illumination incorporating the antenna, the apparatus for television viewing, and the apparatus for ventilation. It is a perspective view of the antenna with which 2nd Embodiment is applied. It is a figure which shows an example of the top view and side view of an antenna. (A) is a top view, (b) is the side view seen from the y direction of Fig.8 (a). It is a perspective view which shows the relationship between a dipole element and a connection member. It is a figure which shows an example of the directivity of an antenna. (A) is directivity at frequency f _L in the low frequency band, (b) is directivity at frequency f _M in the intermediate frequency band, and (c) is directivity at frequency f _H in the high frequency band. It is. It is a figure which shows an example of the return loss of an antenna. (A) shows the case where the connecting member is used, and (b) shows the case where the connecting member is not used.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
[First Embodiment]
FIG. 1 is a perspective view showing an example of an advertising device 1 to which the first exemplary embodiment is applied.
An advertising device 1 shown in FIG. 1 is attached to a wall surface so as to protrude from the wall surface, and includes a sleeve signboard 20 that displays “Ox Bill” on the surface, and an antenna 10 inside.
The antenna 10 may be provided with a transmission / reception device that transmits and receives radio waves.
Further, an illumination device may be provided inside the sleeve signboard 20 so that characters displayed on the sleeve signboard 20 are raised at night. In this case, the power supplied to the lighting device of the sleeve signboard 20 can be branched and supplied to the transceiver.

The advertising device 1 shown in FIG. 1 has a function of transmitting and receiving radio waves by a built-in antenna 10 in addition to a function of a sleeve signboard 20.
By comprising in this way, compared with the case where the antenna 10 is provided separately from the sleeve signboard 20, the influence which it has on a landscape decreases and it becomes easy to adapt to the regulations.

FIG. 2 is a perspective view showing an example of the antenna 10 to which the first embodiment is applied.
The antenna 10 has a low frequency band having a frequency f _L (wavelength λ _L ) as a center frequency, an intermediate frequency band having a frequency f _M (wavelength λ _M ) as a center frequency, and a frequency f _H (wavelength λ _H ) as a center frequency. It is configured to resonate in at least three frequency bands of the high frequency band.

The antenna 10 includes a reflector 100, a side reflector 110, a dipole element 120, which is an example of an antenna element provided at a predetermined distance from the reflector 100 (a distance L9 in FIG. 3B described later), a reflector. A first parasitic element 140 provided at a predetermined distance from 100 (a distance L8 in FIG. 3B described later) is provided.
Furthermore, the antenna 10 includes a second parasitic element 150a and a second parasitic element 150b provided at predetermined intervals from one end and the other end of the element portion 121a and the element portion 121b of the dipole element 120. It has.
In addition, the dipole element 120 includes a connection member 122 that connects the element portion 121a and the element portion 121b.

The antenna 10 includes a casing 180 that covers and accommodates the reflector 100, the side reflector 110, the dipole element 120, the first parasitic element 140, and the second parasitic elements 150a and 150b. Also good. The housing 180 is made of a material that transmits radio waves.
In FIG. 2, the housing 180 is indicated by a broken line.

The reflector 100 and the side reflector 110 are made of a conductive material, and the outer shape of the reflector 100 is a square with four corners cut off. The side reflector 110 is provided along the sides of the reflector 100 excluding the cut four corners.
The dipole element 120 is made of a conductive material, and each includes a triangular element part 121a and an element part 121b. And the element part 121a and the element part 121b are arrange | positioned so that the vertex of a triangle may oppose. That is, the dipole element 120 is a bow tie type dipole antenna. In addition, the planar shape of the element part 121a and the element part 121b of the dipole element 120 may not be a triangle but may be a rod shape.
The connection member 122 is also made of a conductive material, and one end is connected to the element portion 121a and the other end is connected to the element portion 121b. That is, the connection member 122 connects the element part 121a and the element part 121b to each other.

The first parasitic element 140 is also made of a conductive material and has a rectangular surface shape. The first parasitic element 140 is disposed on the dipole element 120 away from the dipole element 120 along the element portion 121a and the element portion 121b. .
The second parasitic elements 150a and 150b are also made of a conductive material, and are arranged away from the dipole element 120 on a line connecting the element parts 121a and 121b of the dipole element 120.

In the antenna 10, the central portion of the dipole element 120 is a feeding point. A signal in which at least three frequency bands of a low frequency band having a frequency f _L as a center frequency, an intermediate frequency band having a frequency f _M as a center frequency, and a high frequency band having a frequency f _H as a center frequency are superimposed is transmitted and received. The

  In the following, a member with an alphabetic suffix may be displayed with the suffix omitted. For example, the element units 121 a and 121 b are referred to as the element unit 121. The same applies to other cases.

  FIG. 3 is a diagram illustrating an example of a plan view and a side view of the antenna 10. 3A is a plan view, and FIG. 3B is a side view as seen from the y direction in FIG. 3A. In addition, the top view and side view which are shown to Fig.3 (a), (b) are described according to the xyz coordinate of FIG.

  The dipole element 120 is disposed with an inclination of 45 ° from the x direction in the xy plane. That is, assuming that the y direction is on the upper side, the dipole element 120 transmits and receives 45 ° polarization.

  Note that the conductive material may be a metal such as Al or Cu, for example, the reflector 100, the side reflector 110, the dipole element 120, the first parasitic element 140, the second parasitic element 150, and the connection member 122. A metal plate can be applied. In addition, the dipole element 120, the first parasitic element 140, the second parasitic element 150, and the connection member 122 are not limited to a plate shape, and may be a metal rod. Furthermore, the dipole element 120, the first parasitic element 140, the second parasitic element 150, and the connection member 122 are made of a metal layer such as Al or Cu provided on a substrate made of a dielectric material such as glass epoxy. It may be constituted by.

As an example, the reflector 100, the side reflector 110, and the second parasitic element 150 are made of a single metal plate and bent. For this reason, a gap is provided between the side reflector 110 and the second parasitic element 150.
Therefore, the reflector 100 and the side reflector 110 are connected, and the reflector 100 and the second parasitic element 150 are also connected.
However, the reflector 100 and the side reflector 110 do not have to be connected, and the reflector 100 and the second parasitic element 150 do not have to be connected.
Furthermore, the side reflector 110 may not be provided.

Next, an example of the dimensions of the antenna 10 will be described.
As shown in FIG. 3A, the distance between both ends of the dipole element 120 is a length L1, and the first parasitic element 140 is a length L2. The length L <b> 2 of the first parasitic element 140 is a length along the dipole element 120.
The reflector 100 has a side length L5.

As shown in FIG. 3B, the side reflector 110 has a height L6 from the reflector 100. The second parasitic element 150 has a height L7 from the reflector 100.
The dipole element 120 is provided at a distance L9 from the reflecting plate 100. The first parasitic element 140 is provided at a distance L8 from the reflector 100.

For the wavelength λ _{M in the} intermediate frequency band, the length L1 between both ends of the dipole element 120 is 0.44 to 0.49λ _M , and the length L2 of the first parasitic element 140 is 0.20 to 0.20. 0.25 [lambda _M, one side length L5 of the reflector 100, 0.35~0.40λ _M are preferred.
The height L6 of the side reflector 110 is 0.15 to 0.20λ _M , the distance L9 of the dipole element 120 from the reflector 100 is 0.15 to 0.20λ _M , and the first parasitic element 140. distance L8 from the reflecting plate 100 of, 0.20~0.25λ _M, height L7 of the reflector 100 of the second parasitic elements 150, 0.25~0.30λ _M are preferred.

That is, the length L1 of 0.44～0.49Ramuda _M between the ends of the dipole elements 120, the distance L9 from the reflecting plate 100 of the dipole elements 120 because it is a 0.15～0.20Ramuda _M, dipole elements 120 is set in accordance with the frequency f _M (wavelength λ _M ) of the intermediate frequency band.

Then, the first parasitic element 140 is provided to resonate with the high frequency band radio wave, and the second parasitic element 150 is provided to resonate with the low frequency band radio wave. Yes.
In this way, radio waves in the low frequency band and the high frequency band can be transmitted and received using the dipole element 120 set in accordance with the frequency f _M (wavelength λ _M ) in the intermediate frequency band.
As will be described later, the connecting member 122 adjusts the impedance matching according to the position where the connecting member 122 is connected to the dipole element 120, and sets the resonance frequency.

FIG. 4 is a diagram illustrating the relationship between the dipole element 120 and the connection member 122. 4A is a perspective view, and FIG. 4B is an equivalent circuit diagram. In FIG. 4A, the dipole element 120 is indicated by a broken line so that the connection member 122 can be seen.
As shown in FIGS. 4A and 4B, the connection member 122 is connected to the element part 121a of the dipole element 120 and the center part of the element part 121b.

The connecting member 122 has a length L10, and the distance from the dipole element 120 of the connecting member 122 is the distance L11.
For the wavelength λ _{M in the} intermediate frequency band, the length L10 of the connecting member 122 is 0.28 to 0.33λ _M , and the distance L11 to the portion of the connecting member 122 farthest from the dipole element 120 is 0.03. ~ 0.08λ _M is preferred. The width L13, L14 of the connecting member 122, with respect to the wavelength lambda _M, it is preferable sufficiently small.
The length L10 of the connection member 122 and the distance L11 from the dipole element 120 to the farthest part of the connection member 122, that is, the shape of the connection member 122 and the element portions 121a and 121b of the dipole element 120 and the connection member 122 The connection position may be set according to the resonance frequency to be obtained.

FIG. 5 is a perspective view showing a modification of the antenna 10 to which the first embodiment is applied.
In the antenna 10 to which the first embodiment shown in FIG. 2 is applied, the upper end of the second parasitic element 150 (the side far from the reflector 100) is bent toward the dipole element 120 side. Note that the notation of the housing 180 is omitted.
The other configuration is the same as that of the antenna 10 to which the first embodiment shown in FIG.

The bent portion at the upper end of the second parasitic element 150 has a length L4 and is preferably 0.08 to 0.13λ _M with respect to the wavelength λ _M in the intermediate frequency band.
Bending the upper end of the second parasitic element 150 (the side far from the reflector 100) toward the dipole element 120 improves the radiation characteristics and return loss characteristics of radio waves in the low frequency band.

In FIG. 1, the advertising device 1 in which the antenna 10 is incorporated in the sleeve signboard 20 is shown.
FIG. 6 is a diagram showing the illumination device 2, the television viewing device 3, and the ventilation device 4 incorporating the antenna 10.
In the illumination device 2, the antenna 10 is installed inside the illumination device cover 30. In the television viewing device 3 that receives terrestrial digital broadcasting, the antenna 10 is installed inside the television viewing device cover 40 together with a terminal box 41 that receives terrestrial digital broadcasting. Further, in the ventilation device 4, the antenna 10 is installed inside the hood cover 50.

Similar to the advertising device 1 shown in FIG. 1, the lighting device 2 has the original function of lighting and the function of transmitting and receiving radio waves by the built-in antenna 10.
Similarly, the television viewing device 3 has an original function of receiving a television broadcast wave and a function of transmitting and receiving radio waves using the built-in antenna 10.
Further, the ventilation device 4 has the original function of ventilation and the function of transmitting and receiving radio waves by the built-in antenna 10.
By comprising in this way, compared with the case where the antenna 10 is provided separately, the influence which it has on a landscape decreases and it becomes easy to adapt to the regulations.
Moreover, even if it does not fulfill its original function, by using these covers and installing the antenna 10 in the interior, the influence on the landscape may be reduced or adaptation to the ordinance etc. may be facilitated. .
Note that the illumination device 2, the television viewing device 3, and the ventilation device 4 described above are examples, and the antenna 10 may be incorporated in a device having other functions with respect to the function of transmitting and receiving radio waves.

[Second Embodiment]
In the first embodiment, the radio wave transmitted and received by the antenna 10 has a single polarization. In the second embodiment, the radio waves transmitted and received by the antenna 10 are both orthogonally polarized waves.
The second embodiment is different from the first embodiment in the antenna 10, and the other parts are the same. Therefore, the antenna 10 will be described below.

FIG. 7 is a perspective view of the antenna 10 to which the second exemplary embodiment is applied.
The antenna 10 to which the second embodiment is applied is the same as the antenna 10 to which the first embodiment shown in FIG. 2 is applied, but the dipole element 130, the second parasitic elements 150c and 150d, and the connection member 132. (See FIG. 9 described later). Instead of the first parasitic element 140, a first parasitic element 141 having a different shape is provided.
Note that the second parasitic elements 150a, 150b, 150c, and 150d have their upper ends bent toward the dipole elements 120 and 130 as in the antenna 10 shown in FIG.

The dipole element 130 is provided so as to be orthogonal to the dipole element 120. The second parasitic elements 150 c and 150 d are provided apart from both ends of the dipole element 130.
The planar shape of the first parasitic element 141 is a cross shape so as to be along the dipole element 120 and the dipole element 130. That is, the first parasitic element 141 includes a first parasitic element 140 provided for the dipole element 120 in the first embodiment and a dipole element 130 added in the second embodiment. The first parasitic element provided for the second electrode is combined with the first parasitic element.
Since other configurations are the same as those of the first embodiment, description thereof is omitted.

In the antenna 10 to which the second embodiment is applied, radio waves in a plurality of frequency bands are transmitted / received via the dipole element 120, and radio waves in a plurality of frequency bands are transmitted / received via the dipole element 130. Note that the radio waves in a plurality of frequency bands via the dipole element 120 and the radio waves in a plurality of frequency bands via the dipole element 130 have different polarizations.
For example, the antenna 10 shown in FIG. 7 transmits / receives ± 45 ° polarized waves.
Therefore, signals of a plurality of frequency bands are superimposed on the dipole element 120 and transmitted / received, and signals of a plurality of frequency bands with different polarizations are superimposed on the dipole element 130 for transmission / reception.

FIG. 8 is a diagram illustrating an example of a plan view and a side view of the antenna 10. FIG. 8A is a plan view, and FIG. 8B is a side view as seen from the y direction of FIG. 8A. In addition, the top view and side view which are shown to Fig.8 (a), (b) are described according to the xyz coordinate of FIG.
In FIGS. 8A and 8B, the second parasitic element 150 is shown without being divided.
In FIG. 8B, the dipole element 120 and the dipole element 130 are provided at a distance L9 from the reflector 100. However, the dipole element 120 may be provided at a distance L9 ′ different from the distance L9 from the reflector 100. Good.

FIG. 9 is a perspective view showing the relationship between the dipole elements 120 and 130 and the connection members 122 and 132.
When dipole elements 120 and 130 are both provided at distance L9 from reflector 100, connecting member 122 and connecting member 132 intersect. Therefore, a part of the connection member 122 and a part of the connection member 132 are cut off so as not to contact at the intersection.

FIG. 10 is a diagram illustrating an example of the directivity of the antenna 10. 10A shows directivity at the frequency f _L in the low frequency band, FIG. 10B shows directivity at the frequency f _M in the intermediate frequency band, and FIG. 10C shows the frequency in the high frequency band. a directional in the f _H. Both are directivity in a horizontal plane (in the xz plane in FIG. 7).
Similar directivity is obtained at any frequency.

FIG. 11 is a diagram illustrating an example of the return loss of the antenna 10. FIG. 11A shows a case where the connection members 122 and 132 are used, and FIG. 11B shows a case where the connection members 122 and 132 are not used.
As shown in FIG. 11 (a), in the case of using the connecting member 122 and 132, predetermined three frequencies _{f L,} f M, together with the resonance at _{f H} is obtained, the return loss at the frequency _{f H} small.
On the other hand, as shown in FIG. 11B, when the connection members 122 and 132 are not used, the resonance frequency in the low frequency band and the resonance frequency in the high frequency band are the same as the connection member 122, FIG. Compared with the case of using 132, the frequency is shifted to a higher frequency side. In addition, the return loss at the frequency f _H is large.

That is, the connection members 122 and 132 have not only an effect for impedance matching in the low frequency band and the high frequency band, but also an effect of downsizing the antenna.
The antenna 10 in the second embodiment can be applied to the advertising device 1, the lighting device 2, the television viewing device 3, and the ventilation device 4 described in the first embodiment, and transmits and receives radio waves. It can be incorporated in a device having other functions with respect to the function of

As described above, in the first embodiment and the second embodiment, the dipole element 120 (dipole element 130) set based on the frequency f _M (wavelength λ _M ) that is the center frequency of the intermediate frequency band. ), A frequency sharing antenna 10 capable of transmitting and receiving radio waves in a low frequency band and a high frequency band can be realized.
Since this antenna 10 is smaller than a case where low frequency band antennas are individually configured, the antenna 10 is used by being incorporated in the advertising device 1, the lighting device 2, the television viewing device 3, the ventilation device 4, and the like. be able to. The advertising device 1, the lighting device 2, the television viewing device 3, the ventilation device 4, and the like are examples of structures. The structure is an example of an antenna device that considers the surrounding environment.
Thereby, the influence which it has on a landscape decreases and it becomes easy to adapt to the regulations.

  In the first embodiment and the second embodiment, radio waves with 45 ° or ± 45 ° polarization are transmitted and received. When using horizontal polarization and / or vertical polarization, the antenna 10 may be rotated by 45 ° around the z-axis.

  The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Advertising apparatus, 2 ... Lighting apparatus, 3 ... Television viewing apparatus, 4 ... Ventilation apparatus, 10 ... Antenna, 100 ... Reflecting plate, 110 ... Side reflector, 120, 130 ... Dipole element, 122, 132 ... connecting member, 140, 141 ... first parasitic element, 150, 150a, 150b, 150c, 150d ... second parasitic element, 180 ... casing

Claims (6)

A reflector made of a conductive material;
A dipole element have a pair of element portion provided in a predetermined distance, the shape corresponding to the radio wave of the first frequency band is set from the reflection plate,
In the opposite side to the reflecting plate across the front Symbol dipole element, provided opposite to the pair of element portions of the dipole elements, between the dipole elements, higher than said first frequency band a second frequency A first parasitic element that resonates with a radio wave of the band ;
A radio wave having a third frequency band lower than the first frequency band is provided between the dipole element and a predetermined interval from one end and the other end of the pair of element portions. A plurality of second parasitic elements that resonate ;
A connection member provided to connect the pair of element portions of the dipole element to each other by a conductive material, and to adjust a resonance frequency ;
An antenna that transmits and receives radio waves in a plurality of frequency bands through the dipole element.   2. The antenna according to claim 1, wherein each of the plurality of second parasitic elements is bent toward the dipole element at a side far from the reflecting plate.   The antenna according to claim 1, further comprising a housing that houses the reflector, the dipole element, the connection member, the first parasitic element, and the second parasitic element. . On the side where the dipole element is provided, another pair of element portions is provided at another predetermined distance from the reflector so as to intersect with the pair of element portions of the dipole element , With other dipole elements whose shape is set in response to radio waves in the frequency band ,
In the opposite side to the reflecting plate across the front SL other dipole elements, provided opposite to the pair of element portions of the other dipole element, between the other of the dipole elements, the second frequency Another first parasitic element that resonates with the radio wave of the band ;
Plural elements that are provided at predetermined intervals from one end and the other end of the pair of element portions of the other dipole element and resonate with the radio waves in the third frequency band between the other dipole elements. Other second parasitic elements,
Another connection member that adjusts the resonant frequency is provided to connect the pair of element parts of the other dipole element to each other by a conductive material ; and
The antenna according to any one of claims 1 to 3, wherein radio waves in a plurality of frequency bands having different polarizations from radio waves transmitted and received by the dipole elements are transmitted and received via the other dipole elements. A reflector made of a conductive material;
A dipole element having a pair of element portions provided at a predetermined distance from the reflector;
A first parasitic element provided opposite to the reflecting plate across the dipole element and facing a pair of element parts of the dipole element;
A plurality of second parasitic elements respectively provided at predetermined intervals from one end and the other end of the pair of element portions of the dipole element;
A connection member made of a conductive material and connecting a pair of element parts of the dipole element to each other;
A side reflector provided on a side surface of the dipole element,
The reflector, the side reflector and the plurality of second parasitic elements are configured by bending a single metal plate,
An antenna that transmits and receives radio waves in a plurality of frequency bands through the dipole element. Conducting the material consists of a reflector, have a pair of element portion provided in a predetermined distance from the reflective plate, the dipole element shape corresponding to the radio wave of the first frequency band is set The second frequency higher than the first frequency band is provided between the dipole element and the pair of element portions on the opposite side of the reflector with the dipole element in between. A first parasitic element that resonates with a radio wave of the band, and a predetermined interval from one end and the other end of the pair of element portions of the dipole element, A plurality of second parasitic elements that resonate with radio waves in a third frequency band lower than one frequency band, and a pair of element parts of the dipole element that are connected by a conductive material to resonate frequencies. The Has a connecting member for integer, a structure having an antenna for transmitting and receiving radio waves of a plurality of frequency bands through the dipole element.

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