1. An antenna device comprising: a radio device for radio wave transmission or for radio wave reception; a primary radiator that has a function to radiate radio waves generated by the radio device or a function to feed received radio waves to the radio device; a parabolic reflector that reflects the radio waves radiated from the primary radiator or makes the primary radiator receive radio waves by reflecting the radio waves; a shroud that shields against unnecessary radiation radio waves among the radio w'aves radiated from the primary radiator and reflected by the parabolic reflector, or shields against radio waves requiring no reception so that the radio waves requiring no reception are not reflected by the parabolic reflector and are not received by the primary radiator; and an antenna mounting mechanism .that fits the parabolic reflector to an antenna attachment pole, wherein the shroud is arranged so as to cover at least a right and left of the parabolic reflector, the radio device and the primary radiator are arranged inside the shroud, and the antenna mounting mechanism fits the parabolic reflector to the antenna attachment pole so that the ant,enna attachment pole is located at a lateral center position of the parabolic reflector.

2. The antenna device according to Claim 1, wherein the radio device and the primary radiator are directly coupled to each other, and the radio device is arranged at a lower inside of the shroud.

3. The antenna device according to Claim 2, further comprising a support membTFthZf supports the radio device, wherein the support member is arranged inside the shroud, and thereby the radio device supported by the support member is arranged inside the shroud.

4. The antenna device according to Claim 3, wherein the radio device is fixed to the support member, and thereby a waveguide part of the primary radiator directly coupled to the radio device is directed to the parabolic reflector without being twisted.

5. The antenna device according to Claim 3 or 4, wherein the antenna mounting mechanism further includes a connection mechanism that is connected to the support member, and the support member is supported by an inside of the shroud by being connected to the connection mechanism.

6. The antenna device according to any one of Claims 1 to 5, wherein the parabolic reflector is an offset parabolic reflector. '

7. The antenna device according to Claim 6, wherein a shape of the offset parabolic reflector is a circle.

8. The antenna device according to Claim 6, wherein a shape of the offset parabolic reflector is an ellipse.

9. The antenna device according to any one of Claims 1 to 8, further comprising a radome arranged in front of the parabolic reflector.

10. A method for attaching an antenna device, wherein a shroud is provided so as to cover at least a right and left of a parabolic reflector that reflects radio waves, a radio, device for radio wave transmission or for radio wave reception is .provided inside the shroud, and a primary radiator that has a function to radiate radio waves generated by the radio device or a function to feed received radio waves to the radio device is provided inside the shroud so that 30 the parabolic reflector reflects the radio waves radiated from the primary radiator to an outside of the antenna device or reflects radio waves from an outside of thel antenna device so that the primary radiator receives the radio waves, and an antenna mounting mechanism that fits the parabolic reflector to be fitted to the antenna attachment pole so that the antenna attachment pole is located at a lateral center position of the parabolic reflector.

Technical Field

The present invention relates to an antenna device and a method for
manufacturing the same, and particularly, to an offset parabolic antenna for a
point-to-point communication line and a method for attaching the same.

Background Art

As an antenna for a point-to-point communication line, a parabolic antenna I
I
has been widely used. Particularly when a severe low side lobe characteristic is 1
15 required, an offset parabolic antenna may be used.
In Patent Literature 1, an offset parabolic antenna is disclosed in which a
worker can easily perform adjustment work of a polarization plane angle. The
Patent Literature 1 discloses a method for offsetting a position of an antenna
20 attachment pole with respect to a reflector lateral center, and mounting the offset
parabolic antenna.
While realization of the low side lobe characteristic is an important object I
in the parabolic antenna, it also becomes an important object to have a strength
25 maintaining structure in consideration of the wind pressure load resistance in
design of the parabolic antenna. Particularly, when. a technique for realizing the
low side lobe characteristic is adopted in which an unnecessary radiation shielding
plate called a shroud is provided, a wind pressure load tends to increase since a
wind receiving area becomes large with respect to a crosswind. I
It is necessary in the parabolic antenna to strengthen an antenna mounting
mechanism for mounting the parabolic antenna to the antenna attachmentpole in I
.9 order to improve a strength characteristic of the wind pressure load resistance,
factor for increasing a cost of manufacturing an antenna device:

As a method for attaching a parabolic antenna having a comparatively high
strength wind pressure load resistance; there is included an attachment method
5 . disclosed in Patent Literature 2. In the attachment method, the parabolic antenna
has a structure for covering an antenna attachment pole with a reflector mounting
part from an upper part thereof, and thereby the strength of the wind pressure load
resistance is improved.
10 Citation List
Patent Literature

Patent Literature 1 : Japanese Unexamined Patent Application Publication No.
2002- 11 1360
15 Patent Literature 2: Japanese Unexamined Patent Application Publication No.
' 201 1-82648
Summary of Invention
Technical Problem
A first problem for an offset parabolic antenna for a point-to-point
communication line is related to giving an antenna device a structure capable of
withstanding a wind pressure load. More particularly, providing the antenna
device with such a structure leads to a problem of an increase in rotation torque
25 applied to a contact surface of an antenna .mounting mechanism and an antenna
attachment pole.
For the point-to-point communication line, there has been a demand that a
plurality of antennas be installed with respect to one antenna attachment pole in
30 order to address the problem of tight communication capacity. However, in an
attachment structure to cover the antenna attachment pole with a reflector
. mounting part from the upper part thereof, which attachment structure is disclosed
in Patent Literature 2, the number of antennas that can be installed is limited.
antenna mounting are used to sandwich the pole between the metal - fittings as I
disclosed in Patent Literature 1 to increase communication capacity. Meanwhile, 1 I
in the attachment method of Patent Literature 1, the antenna mounting mechanism
must be made strong so that the antenna does not rotate with respect to the pole I
5 due to a wind pressure load applied to the antenna. This increases the degree of I
difficulty in manufacturing of the antenna mounting mechanism, and eventually
I
becomes a factor in making the manufacturing cost high.
A second problem is the problem of power loss of a primary radiator of the
10 offset parabolic antenna. In the offset parabolic antenna, a position of: the
primary radiator is offset from a reflector center position, and thus when a
structure is employed in which a radio device is arranged at a back surface of a I
reflector and is directly coupled to the primary radiator, a length of a waveguide I I
used for the primary radiator becomes long, and a bent part and a twist are 1
i
15 generated in a waveguide. This structure becomes a factor in increasing the
power loss and occurrence of cross polarization. In addition, since a structure of
the primary radiator is complicated, a manufacturing cost becomes high. i
In view of the above-described problems, an object of the present invention
20 is to provide an antenna device for which a cost is low and a strength characteristic
of wind pressure load resistance and a power loss characteristic are improved, and
a method for attaching the antenna device.

Solution to Problem
An anntena appratus according to the present invention includes: a radio
device for radio wave transmission or for radio wave reception; a primary radiator
that has a function to radiate radio waves generated by the radio device or a
function to feed received radio waves to the radio device; a parabolic reflector that
reflects the radio waves radiated from the primary radiator or makes the primary radiator or makes the primary radiator receive radio waves by reflecting the radio waves; a shroud that shields
against unnecessary radiation radio waves among the radio waves radiated from
the primary radiator and reflected by the parabolic reflector, or shields against
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are not reflected by the parabolic reflector and are not received by the primary
radiator; and an antenna mounting mechanism that fits the parabolic reflector to an
antenna attachment pole. The shroud is arranged so as to cover at least a right and
left of the parabolic reflector, the radio device and the primary radiator are
5 arranged inside the shroud, and the antenna mounting mechanism fits the parabolic
reflector to the antenna attachment pole so that the antenna attac'hment pole is
located at a lateral center position of the parabolic reflector.
A method for attaching an antenna device according to the present
10 invention includes following steps (a) and (b);
(a) providing a shroud so as to cover at least a right and left of a parabolic
reflector that reflects radio waves, providing a radio device for radio wave
transmission or for radio wave reception inside the shroud, and providing a
primary radiator that has a function to radiate radio waves generated by the radio
15 device or a function to feed received radio waves to the radio device inside the
shroud so that the parabolic reflector reflects the radio waves radiated from the
primary radiator or reflects the radio waves so that the primary radiator receives ~
the radio waves, and 1
(b) providing an antenna mounting mechanism that fits the parabolic ~
reflector to an antenna attachment pole in order for the parabolic reflector to be i fitted to the antenna attachment pole so that the antenna attachment pole is located I
I
i
at a lateral center position of the parabolic reflector.
Advantageous Effects of Invention
With the present invention, it is possible to provide an antenna device for
which a cost is low and a strength characteristic of wind pressure load resistance
and a power loss characteristic are improved, and a method for attaching the
antenna device.

Brief 1)escription of Drawings
[Fig. 11 Fig. 1 is a perspective diagram of an antenna device according to an embodiment 1.

[Fig. 21 Fig. 2 is a side cross-sectional diagram of the antenna device according to'
the embodiment 1.
[Fig. 31 Fig. 3 is an elevational diagram of the antenna device according to the
embodiment 1.
5 [Fig. 41 Fig. 4 is a perspective diagram of an antenna device according to an
embodiment 2.
[Fig. 51 Fig. 5 is a side cross-sectional diagram of the antenna device according to
' I
the embodiment 2.
[Fig. 61 Fig. 6 is a side cross-sectional diagram of an antenna device of another
10 mode according to the embodiment 2.
[Fig. 71 Fig. 7 is a perspective diagram of an antenna device according to an
embodiment 3.
[Fig. 81 Fig. 8 is an elevational diagram of the antenna device according to the
embodiment 3.
[Fig. 91 Fig. 9 is a perspective diagram of an antenna device according to an
embodiment 4.
Description of Embodiments
Embodiments of the present invention will be explained hereinafter with
reference to drawings. The following description shows preferred embodiments
of the present invention, and the scope of the present invention is not limited to the
following embodiments. In the following description, components to which the
same symbol is attached indicate a substantially similar content
(Embodiment 1 )
Hereinafter, the embodiments of the present invention will be explained
with reference to dra'wings. Figs. 1 to 3 show a perspective diagram, a side
cross-sectional diagram, and an elevational diagram of an antenna device 10
according to the embodiment 1, respectively.
The antenna device 10 is specifically an offset parabolic antenna for a
point-to-point communication line, and is provided with: an offset reflector 1; a primary radiator 2; a shroud 3; a radio device 4; and antenna mounting
mechanism 5.
The offset reflector 1 is a circular reflector, and reflects radio waves
radiated by the primary radiator 2 in a front direction. An attachment angle of the
5 offset reflector 1 is adjusted so as to reflect the radio waves radiated from the
primary radiator 2 in a horizontal direction.
The primary radiator 2 is a horn antenna formed so that a cross-sectional
area of an openin'g' end becomes gradually wider. The primary radiator 2 is
10 arranged outside an antenna opening, i.e., at a position under a lower end of the
offset reflector 1 so as not to prevent radiation of the radio waves. Here,
although the primary radiator 2 is explained as being a truncated conical horn
antenna in which a cross section of a waveguide portion is circular, a horn antenna
using a truncated pyramid-shaped waveguide whose cross section is rectangular
may be employed. The primary radiator 2 is directly coupled to an external
interface of the radio device 4 arranged inside the shroud 3.
The shroud 3 is an unnecessary radiation shielding plate arranged to realize
a low side lobe characteristic. The shroud 3 is arranged so as to cover the offset
20 reflector 1. The shroud 3 is symmetrically formed.
AS shown in Figs. 1 to 3, the shroud 3 has at least side portions (a shroud
right side surface part 3a, a shroud left side surface part 3b) that cover a right and
left of the offset reflector 1, respectively, and a bottom surface portion (a shroud
bottom surface part 3c) that connects lower ends of both of the side surface
portions. In addition, the shroud 3 is located at a lower part of the offset reflector
1, and has a back surface portion (a shroud back surface part 3d) that connects
lower back surface sides of the shroud right side surface part 3a and the shroud left
side surface part 3b.
The shroud bottom surface part 3c, which is a lower part of the shroud 3, is
formed as a flat s'urface in order to attach the radio device 4 thereto.
shroud left side surface part 3b, which are the side surfaces of the shroud 3, are
connected to each other near a vertex of an upper part of the offset reflector 1, and
they are formed by curved surfaces having bulges so as to cover a right and left of
the offset reflector 1. It is to be noted that "covering a right and left" means here
5 a shape in which the shroud right side surface pait 3a and the shroud left side
surface part 3b project from the right and left side surfaces of the offset reflector
1, respectively, to a front of the offset reflector I (in a direction of a mirror surface
of the offset reflector 1).
In addition, lower parts of the shroud right side surface part 3a and the
shroud left side surface part 3b are formed so as to taper to opposite sides,
respectively. Namely, a distance between the shroud right side surface part 3a
and the shroud left side surface part 3b is 0 at upper portions thereof since they are
connected to each other, and they bulge near middle portions thereof until the I
15 distance becomes approximately the same as a diameter of the offset reflector 1, 1
and subsequently, they taper at lower portions thereof so that the distance becomes
not more than the diameter of the offset reflector 1. Here, as a distance between
the lower parts of the .shroud right side surface part 3a and the shroud left side I
surface part 3b, a length not less than a width of the radio device 4 is maintained
so that the radio device 4 can be arranged.
The shroud right side surface part 3a, the shroud 1eft.side surface part 3b,
the shroud bottom surface part 3c, and the shroud back surface part 3d that
configure the shroud 3 may be individually designed. The shroud 3 is formed by
25 combining the shroud right side surface part 3a, the shroud left side surface part
3b, the shroud bottom surface part 3c, and the shroud back surface part 3d with .
each other.
According to the above-described configuration of the shroud 3, the shroud
3 can shield against radio waves (unnecessary radiation radio waves) radiated in
directions other than a direction (the front direction here) targeted by the offset
reflector 1 from an outside of the antenna device 10.
In, addition the shroud 3 may b formed by integrally molding the shroud right side surface part 3a,the shroud left side surface part 3b,the shroud surface part 3c, and the shroud back surface part 3d.
The radio device 4 is connected to a cable, which is not shown, and
includes an RF (Radio Frequency) circuit that generates transmission radio waves,
and a modulation circuit that modulates the generated radio waves, etc. and outputs
the modulated radio waves to the primary radiator 2 through an interface.
The radio device 4 directly coupled to the primary radiator 2 is arranged
10 inside the shroud 3. Here, the inside of the shroud 3 means an inside of a space
surrounded by the shroud 3. Since a front of the shroud 3 is in an opened state to
radiate radio waves, a region sandwiched by the shroud right side surface part 3a
and the shroud left side surface part 3b, which are the side surfaces of the shroud
3, serves as the inside of the shroud 3. Accordingly, the radio device 4 is
15 installed on an inner surface of the shroud 3 having outer and inner surfaces, and
thereby the radio device 4 is arranged inside the shroud 3.
As shown in Figs. 1 to 3, in the embodiment 1, the radio device 4 is
attached to the shroud 3, i.e., to an inner surface of the shroud bottom surface part 3c, which is a lower inside of the shroud 3, by attachment screws 7. In the
embodiment 1, four of the attachment screws 7 are inserted from a lower outside of
the shroud 3 so as to fix four corners of the radio device 4, and thereby the radio
device 4 is fixed to the lower inside of the shroud 3.
It is to be noted that a method for attaching the radio device 4 to the shroud
3 is not limited to a method for attaching it by the attachment screws 7 and that,
for example, a method for fixing it using a rivet and an adhesive may be employed.
The antenna mounting mechanism 5 is an attachment mechanism for
attaching the antenna device 10 to an antenna attachment pole 6. As shown in
Figs. 2 and 3, t h e a n t e h a device 10 is attached to the antenna attachment pole 6 by
the antenna mounting mechanism 5 so that an arrangement position of the antenna
attachment pole 6 is located at a lateral center position of the offset reflector 1.
Namely, the antenna mounting mechanism 5 is arranged at the lateral center
position of the antenna device 10. In the embodiment 1, the antenna mounting

mechanism 5 is arranged at a lateral center position of a lower back surface of the
offset reflector 1.
However, an arrangement position of the antenna mounting mechanism 5 is
not fimited to the back surface of the offset reflector 1. A position of the center
of gravity of the antenna device 10 leans downwardly as a whole since the radio
device 4 is attached to the lower inside of the shroud 3. Consequently, in order to
reduce torque generated in the antenna mounting mechanism 5, a configuration
may be employed in which the antenna mounting mechanism 5 is arranged so as to
be'installed at the back surface of the shroud 3 located at a lower part of the offset
reflector 1.
The above-,described offset reflector 1, primary radiator 2, and shroud 3 are
made of materials having conductivity, and a material covered with metal by metal
plating and a material covered with a metal sheet can be used.
In addition, the primary radiator 2 is not limited to the horn antenna, and
instead may be an antenna that radiates broad beams, such as a dipole antenna
In addition, an electromagnetic wave absorber may be further installed
inside the shroud 3. The electromagnetic wave absorber installed inside the
shroud 3 absorbs unnecessary electromagnetic waves, thereby an unnecessary
radiation shielding function of the shroud 3 can be improved, and the low side lobe
characteristic can be enhanced.
Next, an operation principle in the embodiment 1 will be explained. In
the configuration, the antenna device 10 operates as an antenna by reflecting radio
waves radiated by the primary radiator 2, which is the horn antenna, in the front,
direction by the offset reflector 1. In order to achieve the low side lobe ,
characteristic, enin in'^ surface electric field distribution of the offset reflector 1 is
adjusted so that electric field strength of an opening surface edge part of the
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12 dB). The shroud 3 operates so that no spillover occurs due to the primary
radiator 2, and so that scatter.components caused by a reflector edge part is
prevented from being externally radiated.
The shroud 3 has a strength structure for supporting the radio device 4.
The antenna mounting mechanism 5 has a structure capable of withstanding a wind
pressure load applied to the antenna. When the wind pressure load is applied to
the antenna, the antenna mounting mechanism 5 operates so that rotation torque
applied to a contact surface of the antenna mounting mechanism 5 and the antenna
attachment pole 6 becomes small.
As described above, the antenna device according to th'e embodiment 1 of
the present invention is an antenna device including: an offset parabolic reflector;
a primary radiator; a shroud; a radio device; and an antenna mounting mechanism.
Here, the antenna device is characterized in that the radio device and .the primary
radiator are fitted' inside the shroud, and that the antenna mounting mechanism and
the antenna attachment pole are fitted to a lateral center position of the offset
parabolic reflector.
More specifically, the antenna device according to the embodiment 1
includes: the radio device that generates transmission radio waves; the-primary
radiator that radiates the radio waves generated by the radio device; the parabolic
reflector that reflects the radio waves radiated from the primary radiator; the
shroud that shields against unnecessary radiation radio waves among the radio
waves reflected by the parabolic reflector; and the antenna mounting mechanism
that fits the parabolic reflector to the antenna attachment pole. Here, the antenna
device is characterized in that the shroud is arranged so as to cover at least a right
and left of the parabolic reflector, and that the radio device and the primary
radiator are arranged inside the shroud. Furthermore, the antenna device is
characterized in that the antenna mounting mechanism fits the parabolic reflector
to the antennaattachment pole so that the antenna attachment pole is located at a
lateral center position of the parabolic reflector.
The antenna mounting mechanism arranged at the lateral center of the parabolic reflector can reduce rotation torque applied to a contact surface of the mount and the antenna attachment pole due to a wind pressure load applied to the
antenna, as compared with a case where the mount is installed so as to be offset
from the lateral center of the reflector. For this reason, the antenna mounting
5 mechanism can be made to have a simpler structure, and a cost reduction can be
achieved. In addition, a structure is employed in which the radio device is fitted
inside the shroud so that the primary radiator is directly coupled to the radio
device, thereby a length of a waveguide used for the primary radiator can be
shortened, a power loss characteristic can be improved, and cost reduction can be
achieved. It is to be noted that the lateral center is not necessarily an exact
lateral center, and the lateral center may include a case of having deviation from
the exact lateral center, if the above-mentioned rotation torque is smaller as
compared with the case of being offset from the lateral center.
It is to be noted that although the antenna device 10 used for radio wave
transmission has been explained in the above, a configuration similar to that of the
antenna device 10 can be used for radio wave reception. In that case, the offset
reflector 1 reflects radio waves radiated from an outside of the antenna device 10
(particularly, radio waves radiated from the front direction of the offset reflector
20 l), and makes the primary radiator 2 receive the reflected radio waves. The
primary radiator 2 feeds the received radio waves to the radio device 4 through an
interface. The radio device 4 is a radio device for radio wave reception, and
includes a tuning circuit that takes out a target radio wave signal, a demodulation
circuit that demodulates the radio waves, etc.' The shroud 3 shields against radio
waves requiring no reception so that the radio waves that are not require to be
received (radio waves requiring no reception) among the radio waves radiated from
the outside of the antenna device 10 are not reflected by the offset reflector 1 and
are not received by the primary radiator 2. These radio waves requiring no
reception are specifically radio waves radiated from a direction other than the
front of the offset reflector 1. When a transmission antenna device (the
configura;ion thereof is, for example, as above), which is a reception target of the
antenna device 10, is present in the front of the offset reflector 1, the shroud 3 of
the antenna device 10 shields against the radio waves radiated from devices other
than the transmission antenna device. The rest of detailed configuration and
arrangement of each part of the antenna device 10 are as above.
Although in Figs. 1 to 3, the radio device 4 and the primary radiator 2 are
, directly coupled to each other, and the radio device 4 is arranged at the Lower
inside ofthe shroud, arrangement of the radio device 4 and the primary radiator 2
may not be just like this. In addition, the offset reflector 1 may not be circular.

(Embodiment 2)
An antenna device according to the embodiment 2 is characterized in that a .
support (a support member) that supports a radio device is further installed inside
the shroud 3. Hereinafter, the embodiment 2 will be explained in detail with
reference to the drawings. However, explanation of a portion already explained
in the embodiment 1 is partially omitted for clarity of the invention.

Figs. 4 and 5 show a perspective diagram and a side cross-sectional
diagram of an antenna device 20 according to the embodiment 2, respectively.
As can be'seen from Fig. 5, in the antenna device a support plate

(support member) 21 is arranged inside the shroud 3. The suppoft plate 21
supports the radio device 4, and is arranged at a lower inside of the shroud 3.

Here, the support plate 21 is fixed to the antenna mounting mechanism 5. In
a method for fixing the support plate 21 to the antenna mounting mechanism 5, it
may be fixed by attachment screws as shown in Fig. 5, or a rivet and an attachment
fitting may be used. As described above, the support plate 21 is arranged at a
lower side of the offset reflector 1 so that the radio device 4 to which the primary
radiator 2 has been directly coupled is fixed in an inclined state.
The support plate 21 has ,two support surfaces 22. One of the support
30 surfaces 22 supports a side surface (a right side surface in Fig. 5) of the radio
device 4, and theother of the.support surfaces 22 supports a lower base of the
radio device 4. Here, the support surface 22 that supports the side surface of the
radio device 4 forms an inclined surface with respect to the shroud bottom surface
part 3c so that an angle between the support surface 22 that supports the side
surface of the radio device 4 and the offset reflector 1 is larger than an angle
between the shroud bottom surface part 3c and the offset reflector 1. The radio
device 4 is installed in an inclined state by being attached to the support surface
22, which is the inclined surface. .As described above, the state of the radio
5 device 4 becomes a stably supported one by being supported by the two support
surfaces 22.
The radio device 4 can be directed to a center part of the offset reflector 1
without twisting the primary radiator 2 by attaching to the support surface 22 of
the support plate 21 the radio device 4 to which the primary radiator 2 has been
directly coupled. It is to be noted that in a method for attaching the radio device
to the support plate 21, it may be fixed by an attachment screw, or may be fixed
using a rivet and an adhesive.
The shroud 3 is a member having a main function to shield against
unnecessary radiation, and it preferably,includes a thin plate to reduce the cost or
the weight of the antenna itself. Accordingly, it may be preferable that a member
whose weight is comparatively heavy not be fixed to the shroud 3.
Therefore, as shown in Fig. 5, a configuration may be employed in which
the antenna mounting mechanism 5 supports the support plate 21. The antenna
mounting mechanism 5 shown in Fig. 5 is provided with: a reflector supporting
part 51; a pole fixing part 52; and a support supporting part 53.
The reflector supporting part 51 is a support mechanism that is connected
to the offset reflector 1 to support the offset reflector 1. In addition, the pole
fixing part 52 is a portion connected to the antenna attachment pole 6, and it has a
configuration fixable to the antenna attachment pole 6, for example, by
sandwiching and fixing the antenna attachment pole 6 from a right and left thereof.
That is, the pole fixing part 52 and the antenna attachment pole 6 are fixed by
tightening by means of a fitting, such as a bolt, in a state where the antenna
attachment pole 6 is sandwiched from a right and left thereof by the pole fixing
part 52, and thereby it becomes possible to fix the antenna device 20 and the
antenna attechment pole 6 is sandwiched from a right and lift thereof by the pole fixing part 52, and thereby it becomes possible to fix the antenna device 20 and the antenna attechment pole 6 to each other with a simple and high strength
configuration.
The support supporting part 53 is a support mechanism that is connected to
the support plate 21 to support the support plate' 21 at which the radio device 4 is
installed. One end of the support supporting part 53 is fixed to an end of the pole
1 fixing part 52 by the attachment screw 7, and the other end is connected to the
i support plate 21. Here, a through hole through which the support supporting part
I 53 is passed is provided at the shroud back surface part 3d. Therefore, the
support supporting part 53 is connected to the support plate 21 through the through
hole, and thereby a configuration can be achieved in which the support plate 21
arranged inside the shroud 3 is supported by the antenna mounting mechanism 5.
By achieving the above configuration, the support plate 21 and the radio
device 4 fixed thereto can be directly supported by the antenna mounting
15 mechanism 5 with high strength, and thus the stability of the antenna device 20 can
be improved.
It is to be noted that a method for arranging the support plate 21 is not
limited to the cases shown in Figs. 4 to 5. For example, a support 23 is arranged
at a bottom surface portion of the radio device 4 as shown in Fig. 6, and thereby it
is possible to direct the primary radiator 2 to the offset reflector 1 at an
appropriate angle without twisting the primary radiator 2 directly coupled to the
radio device 4, as in the case of the support plate 21 of Fig. 5. The support 23 is
installed at the shroud bottom surface part 3c, and has a support surface 24, which
25 is an inclined surface substantially parallel to the offset reflector 1. The bottom
surface of the radio device 4 is fixed to the support surface 24, and thereby the
primary radiator 2 installed at a top surface of the radio device 4 is directed to the
offset reflector 1.
30 A support member is not limited to the above-mentioned plate material, and
it may instead include a plurality of bar materials. The support member can be
realized by a material with sufficient rigidity to .support the radio device 4
Furthermore, it may not be the inclined.surface of the support member that the
stored is provided in a rectangular parallelepiped-shaped support member, and the
radio device 4 is put in it, whereby the radio device can be fixed to the support
member. As described above, if the radio device 4 is fixed to a certain support
member, and thereby the primary radiator 2 is directed to the offset reflector 1
without a waveguide part of the primary radiator 2 directly coupled to the radio
device 4 being twisted, the antenna device 10 can have a configuration other
than the above-mentioned configuration.
(Embodiment 3)
An antenna device according to the embodiment 3 is characterized by using
an ellipse-shaped offset reflector. erei in after, the above will be explained in
detail with reference to the drawings. However, explanations of portions already
explained in the embodiments 1 and 2 are partially omitted for clarity of the
invention.
Figs. 7 and 8 show a perspective diagram and an elevational diagram of an
antenna device 30 according to the embodiment 3, respectively. As can be seen
from Figs. 7 and 8, the antenna device 30 is provided with an ellipse-shaped offset
elliptical reflector 31.
As described above, a shape of a reflector is set to be elliptical, thereby an
effect to enliance the low side lobe characteristic can be realized without
increasing an antenna opening area, and also there is an effect of enhancing a
strength characteristic of wind pressure load resistance.
Namely, in the embodiment 3, an antenna device becomes vertically long as
a whole since the radio device 4 is arranged at a lower inside of the shroud 3.
However, it is possible to prevent the antenna device from having a vertically
longer structure by using as an offset reflector the elliptical reflector having a long
axis in parallel with horizontal' direction, and to reduce the antenna opening area.
It is to be noted that in this case as well, the antenna mounting mechanism
is attached to a lateral center position of a lower back surface of the offset
attachment pole 6.elliotical reflector 31, and connects the antenna device 30 with the antenna attachment pole 6.
(Embodiment 4)
An antenna device according to the embodiment 4 is characterized by being
further provided with a radome. Hereinafter, the above will be explained in detail
with reference to the drawings. However, explanations of portions already
explained in the embodiments 1 to 3 are partially omitted for clarity of the
invention.
Fig. 9 is a perspective diagram of an antenna device 40 according to the
embodiment 4. The antenna device 40 has a configuration newly provided with a
radome 41 at an antenna opening portion in front of an offset reflector in addition
to the antenna device 10 of the embodiment 1.
As described above, the effect of further enhancing a strength
characteristic of wind pressure load resistance can be achieved by employing a
structure having the radome in front of a shroud.
It is to be noted that as a material of the radome 41, for example, reinforced
plastics can be used as a material that does not prevent passage of radio waves and
has high strength, in addition to a glass fiber and Teflon (registered trademark)
that have high radio wave transmittance.
As explained above, the antenna device of the embodiment 4 is
characterized by being fixed to a pole in a positional relation symmetrical to the
pole. With the configuration, a structure is obtained that can reduce rotation
torque applied to a pole mounting bearing part, thus a demand for strength of wind
pressure resistance to the antenna mounting mechanism can be' reduced, and a
mount structuie to the antenna attachment pole can be made simple.
In addition, the antenna device of the embodiment 4 has a structure that is
provided with a shroud, and in which a radio device is fitted to the shroud. Since
a length of a primary radiator can be shortened by employing the structure, it
Furthermore, the length of the primary radiator can be shortened, thereby
an effect of a twist in a circular waveguide for the primary radiator, which causes
. cross polarization, can be reduced. Therefore, a cross polarization component due
5 to the effect of the circular waveguide twist can be reduced.
In addition, in a point-to-point communication line apparatus, as a direct
coupling structure of the primary radiator and the radio device is employed, a
. cable that connects the antenna and the radio device and an interface converter of
the antenna and the cable can be omitted, and thus a cost reduction can be
achieved.
Note that the present invention is not limited to the above exemplary
embodiments, and modification can be made without departing from the scope of
the invention. For example, the present invention can be carried out as an
antenna device in which the above-described embodiments have been combined.
In addition, although a case where the parabolic reflector is the offset
parabolic reflector has been explained in the above explanation, the present
invention is not limited to this. However, an effect to suppressing loss can be
obtained by using the offset parabolic reflector as the parabolic reflector.
In addition, since the parabolic reflector and the radio device are integrally
formed in the present invention, it 'is also possible to employ a transmission radio
25 device provided with the above-described features. Namely, it is also possible to
employ a radio device including: an RF circuit that generates transmission radio
waves; a primary radiator that radiates the radio waves generated by the RF.circuit;
a parabolic reflector that reflects the radio waves radiated from the primary
radiator; a shroud that shields against unnecessary radiation radio waves among
the radio waves reflected by the parabolic reflector; and an antenna mounting.
mechanism that fits the parabolic reflector to an antenna attachment pole, in which
the shroud is arranged so as to cover at least a right and left of the parabolic
reflector, the RF circuit and the primary radiator are arranged inside the shroud,and in which the antenna mechanism fits the parabolic reflector to the antenna attachment pole so that the antenna attachment pole is located at a lateral center position of the parabolic reflector.
A reception radio device can be similarly configured. Namely, it is also
possible to employ a radio device including: a demodulation circuit that .
demodulates received radio waves; a primary radiator that receives radio waves
from an outside of the radio device; a parabolic reflector that reflects radio waves
radiated from the outside to the primary radiator and makes the primary radiator
receive the radio waves; a shroud that shields the parabolic reflector from radio
waves requiring no reception among the radio waves from the outside of the radio
device; and an antenna mounting mechanism that fits the parabolic reflector to an
antenna attachment pole, in which the shroud is arranged so as to cover at least a
right and left of the parabolic reflector, the RF circuit and the primary radiator are
arranged inside the shroud, and in which the antenna mounting mechanism fits the
parabolic reflector to the antenna attachment pole so that the antenna attachment
pole is located at a lateral center position of the parabolic reflector.
Furthermore, the present invention also includes a method for
manufacturing an antenna device. This manufacturing method is specifically as
follows. Firstly, a shroud is provided so as to cover at least a right and left of a
parabolic reflector that re'flects radio waves, a radio device for radio wave
transmission or for radio wave reception is provided inside the shroud, and a
primary radiator that has a function to radiate radio waves generated by the radio
device or a function to feed received radio waves to t-he radio device is provided
inside the shroud so that the parabolic reflector reflects the radio waves radiated
from the primary radiator to an outside of the antenna device or reflects radio
waves from an outside of the antenna device so that the primary radiator receives
the radio waves. Secondly, an antenna mounting mechanism that fits the
I parabolic reflector to an antenna attachment pole is provided .in order for the
parabolic reflector to be fitted to the antenna attachment pole so that the antenna
attachment pole is located at a lateral center position of the parabolic reflector.
The antenna device can be manufactured by the above method. It is to be noted
that an execution order of the first and second steps listed above is not fixed, and
that a change of the order can be appropriately made. In addition, in the first second steps, another component of the antenna device may be provided
(arranged). For example, in the first step, a support:member may'be arranged
inside the shroud, as is done in the embodiment 2.
In addition to the above, the present invention can take the following
configurations.
(Appendix 1)
An antenna device including: a radio device for radio wave transmission or
for radio wave reception; a primary radiator that has a function to radiate radio
waves generated by the radio device or a function to feed received radio waves to
the radio device; a parabolic reflector that reflects the radio waves radiated from
the primary radiator or makes the primary radiator receive radio waves by
reflecting the radio waves; a shroud that shields against unnecessary radiation
radio waves among the radio waves radiated from the primary radiator and
reflected by the parabolic reflector, or shields against radio waves requiring no
reception so that the radio waves requiring no reception are not reflected by the
parabolic reflector and are not received by the primary radiator; and an antenna
mounting mechanism that fits the parabolic reflector to an antenna attachment
pole, wherein the shroud is arranged so as to'cover at least a right and left of the
parabolic reflector, the radio device and the primary radiator are arranged inside
the shroud, and the antenna mounting mechanism fits the parabolic reflector to the
antenna attachment pole so that the antenna attachment pole is located at a lateral
center position of the parabolic reflector.
(Appendix 2)
The antenna device according to Appendix 1, wherein the radio device and
the primary radiator are directly coupled to each other, and the radio device is
arranged at a lower inside of the shroud.
(Appendix 3)
The antenna device according to Appendix 2, further comprising a support
member that supports the radio device, wherein the support member is arranged
inside the shroud, and thereby the radio device fixed to the support member is
arranged inside the shroud.
The antenna device according to Appendix 3, wherein the radio device is
fixed to the support member, and thereby a waveguide part of the primary radiator
directly coupled to the radio device is directed to the parabolic reflector without
being twisted.
(Appendix 5)
The antenna device according to en end ices 3 or 4, wherein the antenna
mounting mechanism further includes a connection mechanism that is connected to
the support member, and the support member is supported by an inside of the
shroud by being connected to the connection mechanism.
(Appendix 6)
The antenna device according to any one of Appendices 1 to 5, wherein the
parabolic reflector is an offset parabolic reflector.
(Appendix 7)
The antenna device according to Appendix 6, wherein a shape of the offset
parabolic reflector is a circle.
(Appendix 8)
The antenna device according to Appendix 6, wherein a shape of the offset
parabolic reflector is an ellipse.
(Appendix 9)
The antenna device according to any one of Appendices 1 to 8, further
comprising a radome arranged in front of the parabolic reflector.
(Appendix 10)
A method for attaching an antenna device, wherein a shroud is provided so
as to cover at least a right and left of a parabolic reflector that reflects radio
waves, a radio device for radio wave transmission or for radio wave reception is ,
provided inside the shroud, and a primary radiator that has a function to radiate
radio waves generated by the radio device or a function to fe.ed received radio
waves to the radio device is provided inside the shroud so that the parabolic
reflector reflects the radio waves radiated from the primary radiator to an outside
of the antenna device or reflects radio waves from the outside of the antenna device so that the primary radiator receives the radio waves, and an antenna
mounting mechanism that fits the parabolic reflector to an antenna attachment pole
is provided in order for the parabolic reflector to be fitted to the antenna
position of the parabolic reflector.
(Appendix 11)
The antenna device described in any of Appendices 1 to 9, in which a radio
wave absorber is installed inside the shroud.
(Appendix 12)

An antenna device including: an offset parabolic reflector; a primary
radiator; a shroud; a radio device; and an antenna mounting mechanism, in which
the radio device and the.primary radiator are fitted inside the shroud, and in which
the antenna mounting mechanism and the antenna attachment po,le are. fitted to a
lateral center position of the offset parabolic reflector.

While the invention has been particularly shown and described with
reference to exemplary embodiments thereof, the invention is not limited to these
embodiments. It will be understood by those of ordinary skill in the art that various
changes in form and details may be made therein without departing from the spirit
and scope of the invention as defined by the claims.
This application is based upon and claims the benefit of priority from
Japanese patent application No. 2012-1 06616, filed on May 8, 2012, the disclosure
of which is incorporated herein in its entirety by reference.
Industrial ApplicabilITY
The present invention can be utilized in order to achieve a cost reduction
and to improve a strength characteristic of wind pressure load resistance and a
power loss characteristic in an antenna device and an attachment method of the
same.
Reference Signs List
OFFSET REFLECTOR
PRIMARY RADIATOR
SHROUD
SHROUD RIGHT SIDE SURFACE PART
SHROUD LIFT SIDE SURFACE PART
SHROUD BOTTOM SURFACE PART
SHROUD BACK SURFACE PART
RADIO DEVICE
ANTENNA MOUNTING MECHANISM
ANTENNA ATTACHMENT POLE 7 ATTACHMENT SCREW
ANTENN'A DEVICE 20 ANTENNA DEVICE
SUPPORT PLATE (SUPPORT MEMBER) 22 SUPPORT SURFACE
SUPPORT (SUPPORT MEMBER) 24 SUPPORT SURFACE
30 ANTENNA DEVICE
31 OFFSET ELLIPTICAL REFLECTOR
40 ANTENNA DEVICE 41 RADOME
5 1 REFLECTOR SUPPORTING PART
(REFLECTOR SUPPORTING MECHANISM)
52 POLE FIXING PART
53 SUPPORT SUPPORTING PART
(SUPPORT SUPPORTING MECHANISM)

WE CLAIM:
1. An antenna device comprising:
a radio device for radio wave transmission or for radio wave reception;
a primary radiator that has a function to radiate radio waves generated by
the radio device or a function to feed received radio waves to the radio device;
a parabolic reflector that reflects the radio waves radiated from the primary
radiator or makes the primary radiator receive radio waves by reflecting the radio
waves;
a shroud that shields against unnecessary radiation radio waves among the
radio w'aves radiated from the primary radiator and reflected by the parabolic
reflector, or shields against radio waves requiring no reception so that the radio
waves requiring no reception are not reflected by the parabolic reflector and are
not received by the primary radiator; and
an antenna mounting mechanism .that fits the parabolic reflector to an
antenna attachment pole, wherein
the shroud is arranged so as to cover at least a right and left of the
parabolic reflector,
the radio device and the primary radiator are arranged inside the shroud,
and
the antenna mounting mechanism fits the parabolic reflector to the antenna
attachment pole so that the ant,enna attachment pole is located at a lateral center
position of the parabolic reflector.
2. The antenna device according to Claim 1, wherein
the radio device and the primary radiator are directly coupled to each other,
and the radio device is arranged at a lower inside of the shroud.
3. The antenna device according to Claim 2, further comprising a support
membTFthZf supports the radio device,
wherein the support member is arranged inside the shroud, and thereby the
radio device supported by the support member is arranged inside the shroud.
4. The antenna device according to Claim 3, wherein the radio device is fixed
to the support member, and thereby a waveguide part of the primary radiator
directly coupled to the radio device is directed to the parabolic reflector without
being twisted.
5. The antenna device according to Claim 3 or 4, wherein
the antenna mounting mechanism further includes a connection mechanism
that is connected to the support member, and
the support member is supported by an inside of the shroud by being
connected to the connection mechanism.
6. The antenna device according to any one of Claims 1 to 5, wherein the
parabolic reflector is an offset parabolic reflector. '
7. The antenna device according to Claim 6, wherein a shape of the offset
parabolic reflector is a circle.
8. The antenna device according to Claim 6, wherein a shape of the offset
parabolic reflector is an ellipse.
9. The antenna device according to any one of Claims 1 to 8, further
comprising a radome arranged in front of the parabolic reflector.
10. A method for attaching an antenna device, wherein
a shroud is provided so as to cover at least a right and left of a parabolic
reflector that reflects radio waves, a radio, device for radio wave transmission or
for radio wave reception is .provided inside the shroud, and a primary radiator that
has a function to radiate radio waves generated by the radio device or a function to
feed received radio waves to the radio device is provided inside the shroud so that
30 the parabolic reflector reflects the radio waves radiated from the primary radiator
to an outside of the antenna device or reflects radio waves from an outside of thel
antenna device so that the primary radiator receives the radio waves, and
an antenna mounting mechanism that fits the parabolic reflector to be fitted
to the antenna attachment pole so that the antenna attachment pole is located at a
lateral center position of the parabolic reflector.