JPH08307139A - Satellite antenna device for mobile installation - Google Patents

Abstract

(57) [Summary] [Purpose] By omitting the tracking mechanism in the elevation direction,
(EN) Provided is a satellite antenna device for mounting on a mobile body, which is capable of reducing mounting height, downsizing and manufacturing cost, and avoiding deterioration of electrical characteristics. [Structure] The fixed part (11) fixed with the center line (V) orthogonal to the bottom surface (2) of the housing, and this fixed part with the degree of freedom of rotation around the center line of this fixed part. The rotating part (12) supported by the fixed part (2), the antenna body part (1) fixed on the rotating part, and the rotating mechanism for rotating the rotating part (12) around the center line (V). It has and. Antenna body (1)
As a telescopic mechanism (50) for expanding and contracting the distance between the rotating part (12) and the rotating part (12) in order to change the elevation angle of the first cylindrical body (51) whose root part is fixed on the rotating part (12). , Antenna body
A second cylindrical body (55) whose root portion is rotatably fixed to the bottom surface of (1) and whose tip portion fits with the tip portion of the first cylindrical body (51); And a mechanism (51, 56, 57, 60) for discretely changing the fitting depth of the cylindrical bodies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile-vehicle-mounted satellite antenna device used as a vehicle-mounted satellite broadcast receiving antenna device and the like, and more particularly to downsizing the entire antenna device by simplifying a tracking mechanism. The present invention relates to an antenna device for mounting on a mobile body, which is inexpensive.

[0002]

2. Description of the Related Art With the spread of satellite broadcasting in recent years, various kinds of vehicle-mounted satellite broadcast receiving antenna devices have been studied. In this type of antenna device, since it is attached to the top of a vehicle running on a road with a height restriction, how to reduce the height is one of the important technical problems. Further, since the size of the top of a vehicle in which this type of satellite broadcast receiving antenna is installed is limited, how to reduce the installation area is also an important technical issue. In order to reduce the height of the antenna, a planar array antenna having a tilt angle in the elevation direction is considered promising.

A further characteristic point of the vehicle-mounted satellite receiving antenna device is that the satellite to be received is not only a mobile satellite, but even if this is a geostationary satellite, the direction of the vehicle is constantly changing as the vehicle travels. Since it changes, an automatic tracking mechanism for always pointing the antenna body toward the satellite is required. Such an automatic tracking mechanism is realized by a combination of an azimuth angle control mechanism that controls the azimuth angle of the antenna body and an elevation angle control mechanism that controls the elevation angle of the antenna body.
Such an automatic tracking mechanism occupies a considerable part of the manufacturing cost of the entire satellite broadcasting receiving system including the electric circuit parts such as the converter and the tuner, and increases the height and area of the antenna device. Simplification is one of the important technical issues.

The above-mentioned automatic tracking mechanism is described in Japanese Patent Application Laid-Open No. 5-7108 entitled "Antenna device for mobile object" according to the prior application of the present applicant.
No. 6,086,045. This automatic tracking mechanism includes a support, a base substrate supported on the support while having a degree of freedom of rotation about a vertical line, and an electric motor that rotates the base substrate with the vertical line as a rotation axis. A tracking mechanism in the azimuth direction including a rotating mechanism including the rotating mechanism is included. The antenna body is supported on the base substrate with a degree of freedom of rotation about a horizontal straight line as a rotation axis. The automatic tracking mechanism further includes an elevation-direction tracking mechanism including an electric motor for rotating the antenna main body on a horizontal straight line on the base substrate.

The azimuth angle of the antenna body needs to be controlled over 360 ° as the vehicle travels,
It is considered realistic to realize this by a rotating mechanism including an electric motor. In contrast, when targeting geostationary satellites such as broadcasting satellites, the control of the elevation angle of the antenna body is
The control range is comparatively limited because it is sufficient to cope with changes in the latitude of the region in which the vehicle is running and the inclination of the road within a range of ± 5 ^o .

For this reason, as an antenna device for receiving satellite broadcasting, the directivity in the elevation direction of the antenna main body is set to be wide in advance, and a uniaxial tracking system that only controls the azimuth angle is adopted, thereby making the entire receiving system. Attempts have been made to make the economy economical. As for the planar array antenna that directs such a single-axis tracking method, if necessary, the "vehicle-mounted satellite broadcasting reception single-layer leaky wave guide" announced in the Technical Report of the Institute of Electronics, Information and Communication Engineers held in May 1993. See Hirokawa et al.'S paper entitled “Tube Slot Array Antenna” (A.P. 93-25).

[0007]

In the conventional uniaxial tracking method described above, the antenna gain decreases and the S / N decreases as the directivity in the elevation angle direction is widened so as to cope with the change in latitude and the inclination of the road. There is a problem of causing deterioration of image quality. Therefore, if a biaxial control method including elevation angle control is adopted, the tracking mechanism becomes complicated, and the height and installation area of the antenna device increase, and the manufacturing cost of the entire receiving system also increases. .

That is, as shown by the satellite antenna device for mounting a moving body of the above-mentioned prior application, it is necessary to mount an elevation angle tracking mechanism including an electric motor on the base substrate. This means that the elevation tracking mechanism and the azimuth tracking mechanism are three-dimensionally arranged in the height direction, and as a result, the mounting height of the entire antenna device increases. Further, since the elevation tracking mechanism mounted on the base substrate becomes a load of the azimuth tracking mechanism arranged outside the base substrate, there is a problem that the electric motor and the power transmission mechanism are large and expensive. Therefore, one object of the present invention is to provide a satellite antenna device for mounting on a mobile body, which enables miniaturization of the entire antenna device, reduction of mounting height, and reduction of manufacturing cost.

[0009]

SUMMARY OF THE INVENTION An antenna device of the present invention for solving the above-mentioned problems of the prior art is a fixing portion fixed to the bottom surface of a housing with their center lines orthogonal to each other, and this fixing portion. A rotating part supported by this fixed part in a state of having a rotational degree of freedom around the center line, and a rotating part supported by a rotating part in a state of having a rotational degree of freedom around a straight line orthogonal to the center line of the fixed part The antenna main body portion and the rotating mechanism for rotating the rotating portion around the center line of the fixed portion are provided. Between the appropriate part of the rotating part and the appropriate part of the antenna main body, one or a plurality of expansion / contraction mechanisms for changing the elevation angle of the antenna main part by expanding / contracting the distance between the two parts are installed.

In the above-mentioned expansion / contraction mechanism, the first cylindrical body whose root portion is fixed on the rotating portion is rotatably coupled to the bottom surface of the antenna body, and the tip portion is the first cylindrical body. It is provided with a second cylindrical body fitted with the tip portion and a mechanism for discretely changing the fitting depth of these first and second cylindrical bodies, or on the upper surface of the rotating part and with this rotation. A pinion fixed substantially horizontally to the upper surface of the section, a rack having a root portion rotatably coupled to the bottom surface of the antenna body and a tip portion engaging with the pinion, and a mechanism for rotating the pinion. I have it.

[0011]

According to the mobile device mounting antenna device of the present invention,
The elevation angle tracking control is omitted in order to realize the miniaturization of the entire antenna device and the reduction of the manufacturing cost. The deterioration of the electrical characteristics due to the omission of the tracking control of the elevation angle is reduced by manually operating the expansion / contraction mechanism prepared in advance to set the optimum elevation angle according to the latitude of the usage area.
For example, if intended for use in Japan, 0 for the region centered on the Kanto ^o, Tohoku north of -5 ° for the area of discrete by a spacer so on +5 ^o for Kansai south of the region Elevation angle is set.

According to the antenna device for mounting a moving body of the present invention,
The expansion / contraction mechanism for expanding / contracting the distance between the rotating part and the antenna main body is realized by a combination of two cylindrical bodies whose fitting depths can be changed, or a combination of a pinion and a rack. Therefore, it is much simpler and smaller than the conventional rotating mechanism of the base substrate using the electric motor, and the mounting height of the satellite antenna device as a whole can be reduced, the size can be reduced, and the manufacturing cost can be reduced.

[0013]

1 is a sectional view showing a characteristic part of a satellite antenna device for mounting on a moving body according to an embodiment of the present invention. This satellite antenna device has a structure in which an antenna body 1 is rotatably held around a vertical line V in a watertight housing body including a metal bottom plate 2 and a resin radome 3. Has become. This antenna body 1 is composed of a one-layer leaky wave waveguide slot array antenna,
A tilt angle of 52 ^o is set in the elevation direction. For details of this one-layer leaky-waveguide slot array antenna, see Technical Report of IEICE Technical Report AP 93 if necessary.
-23-35 (Science Technical Report VOL.93, No.40)

This mobile unit mounting antenna device further comprises:
The stationary unit 11 and the rotating unit 12 are provided. Fixed part 11
Has a cylindrical shape having a center line coinciding with the vertical line V, and is fixed to the metallic bottom plate 2 of the housing by a plurality of screws 6. The rotating portion 12 has a center line that coincides with the vertical line V, and the thin plates 13 and 14 having a low friction coefficient such as tetrafluoroethylene (TFE) and the bearing 15 are interposed between the rotating portion 12 and the fixed portion 11. By this, while being supported by the fixed portion 11 while having a degree of freedom of rotation around the vertical line V.

This mobile unit mounting antenna device further comprises:
A support member 4 and a support portion 7 for fixing the antenna body 1 to the rotating portion 12 are provided. The peripheral portion of the lower surface of the support portion 7 is fixed to the upper surface of the rotating portion 12.

A V-shaped groove 16 is formed on the outer peripheral surface of the rotating portion 12.
Are formed in plural. A belt 17 having a plurality of V-shaped grooves formed on its inner peripheral surface is engaged with these V-shaped grooves 16. The belt 17 is also formed in the V-shaped groove formed on the outer peripheral surface of the pulley that is coaxially fixed to the rotation shaft of the azimuth motor (not shown) fixed on the bottom plate 2 on the right side of the drawing. Engaged. Therefore, with the rotation of the azimuth motor, the rotating unit 12 rotates via the belt 17 with the vertical line V as the rotation axis, and the tracking of the antenna body 1 in the azimuth direction is performed. The groove formed on the outer peripheral surface of the rotating portion 12 is not limited to the V-shaped groove 16 and may be, for example, a vertical groove.

A further characteristic point of this satellite antenna device is that each of the fixed portion 11 and the rotating portion 12 serves as the fixed portion and the rotating portion of the slip ring.
That is, the transmission ring 18 fixed to the fixed portion 11 side
A slip ring is formed by the transmission ring 19 fixed to the rotating portion 12 side and the plurality of armatures 20 held slidably with respect to each of the transmission rings 18 and 19. ing. Through this slip ring, operating power is supplied to the converter 21 mounted on the back surface of the antenna body 1.

The expansion / contraction mechanism 50 for controlling the elevation angle of the antenna body 1 includes a first cylindrical body 51, a second cylindrical body 55, and a set screw 60. The first cylindrical body 51 has its root side fixed to the rotating portion 12 and a pair of openings (52 _1, 52 ₂ ) formed so as to face the left and right sides of the tip portion thereof.
have. The second cylindrical body 55 has its root side connected to the stopper 10 fixed to the back surface of the antenna body ₁ via a pin 10 ₁ , and its tip side inserted into the first cylinder 51. . On both left and right sides of the second cylinder, the opening pair groups (56 ₁ , 56 ₂ ) and (5
7 ₁ , 57 ₂ ) ... Are formed.

An appropriate one of the pair of openings formed in the second cylindrical body 55 is communicated with the pair of openings (52 _1, 52 ₂ ) formed in the first cylindrical body 52, and a set screw is set therein. The depth of insertion of the second cylindrical body 55 into the first cylindrical body 52 is fixed by penetrating 60 and screwing. By setting and changing this insertion depth, the elevation angle of the antenna body 1 can be set and changed. For example, when the elevation angle of the antenna body 1 is set to any one of −5 ^° , 0 ° and + 5 °, the aperture pair groups (56 ₁ , 56 ₂ ) and (57 _1, 57 ₂₎
... should be formed.

The extension / contraction mechanism 50 can also be formed on the upper surface of the support portion 7. In addition, this expansion / contraction mechanism is attached to the rotating unit 1.
It can also be installed obliquely on the upper surface of 2 or the upper surface of the support portion 7. Further, in order to ensure the stability of the elevation angle control of the antenna body 1, the expansion / contraction mechanism may be composed of a plurality of parts that function in conjunction with each other.

FIG. 2 is a sectional view showing the structure of a satellite antenna device for mounting on a moving body according to another embodiment of the present invention. In this figure, the components designated by the same reference numerals as in FIG.
Since they are the same as the components already described in relation to, the duplicated description thereof will be omitted.

In the satellite antenna device for mounting on a moving body of this embodiment, the expansion and contraction mechanism for controlling the elevation angle of the antenna body 1 is different from that of the first embodiment described above. That is,
The expansion / contraction mechanism 70 for controlling the elevation angle of the present embodiment is an expansion / contraction mechanism that uses a rack and pinion, and is provided between the upper surface of the rotating portion 12 and the stopper 10 fixed to the back surface of the antenna body 1. A rack 71 and a pinion 72 engaged with the rack 71 and fixed in position;
A handle 73 for rotating the pinion 72 is provided.

In the mobile-body-mounted satellite antenna device of this embodiment, the handle 73 is used to rotate the pinion 72 in a predetermined direction by a predetermined number of rotations to move the rack 71 up and down in the figure by a predetermined distance. By doing so, the elevation angle of the antenna body 1 can be set to a desired value. The expansion / contraction mechanism 70 may be provided on the upper surface of the support portion 7, or may be obliquely provided on the upper surface of the rotating portion 12 or the upper surface of the support portion 7. Further, in order to secure the stability of the elevation angle control of the antenna body 1, the expansion / contraction mechanism can be composed of a plurality of parts that function in conjunction with each other.

The satellite antenna apparatus shown in the embodiments of FIGS. 1 and 2 typically includes a reception level detecting section for detecting the level of the received radio wave received by the antenna body 1 from the satellite. Then, preferably, the rotating unit 1 is arranged so that the level of the received radio wave detected by the receiving level detecting unit becomes maximum.
After rotating 2 in the direction angle direction, the distance is expanded or contracted so that the level of the received radio wave becomes maximum.

FIG. 3 is a plan view of 52 in the elevation direction shown in FIGS.
C with the reference antenna when the antenna body 1 having a tilt angle of 0 ° is installed at an angle of 0 ° or ± 5 ° from the horizontal plane.
The experimental data of the / N ratio difference are shown. When the antenna body 1 is installed horizontally, the C / N ratio is 1 dB and the angular width is about 7 °, which covers about 1/3 of the Japanese archipelago. Also, this angular width is the far directionality of the right-handed circularly polarized component in the tilt plane.
It is almost as wide as the dB beam width. Due to the tilted installation of the antenna body 1, the zenith angle characteristic of C / N ratio is about 5 overall.
° It is changing. As illustrated in each of the above embodiments, it is understood that these three inclination angles 0 ° and ± 5 ° can cover almost the entire area of the Japanese archipelago.

[0026]

As described in detail above, according to the satellite antenna device for mounting a mobile unit of the present invention, the size of the entire antenna device and the manufacturing cost can be reduced by omitting the elevation angle control. It Deterioration of electrical characteristics due to this is mitigated by manually operating the expansion / contraction mechanism prepared in advance according to the latitude of the usage area and changing the elevation angle of the antenna main body. According to the experimental data shown in FIG. 3, when it is assumed to be used in Japan, it is 0 ^o for the area centering on Kanto, -5 ° for the area north of Tohoku, and -5 degrees for the area south of Kansai. By setting a +5 ^o discrete elevation angle, it is possible to cover almost the entire area of the Japanese archipelago.

According to the present invention, the expansion and contraction mechanism for changing the elevation angle of the antenna main body is realized by two cylindrical bodies having mutually variable fitting depths or a combination of a rack and a pinion. . Therefore, compared with the conventional device that controls the elevation angle using the electric motor mounted on the base substrate,
The mounting height of the antenna can be reduced, the size can be reduced, and the manufacturing cost can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a main part of an embodiment of a satellite antenna device for mounting on a moving body according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a main part of an embodiment of a satellite antenna device for mounting on a moving body according to another embodiment of the present invention.

FIG. 3 is experimental data of C / N ratio difference obtained when the antenna main body shown in each of FIGS. 1 and 2 is installed at an angle of ± 5 ° and 0 °.

[Explanation of symbols]

 1 Antenna main body 2 Bottom of housing 3 Radome 4 Antenna main body support 7 Support 9 Expansion / contraction mechanism V Center line of fixed part 50,70 Expansion / contraction mechanism 51 First cylinder 55 Second cylinder 71 Rack 72 Pinion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Motonobu Moriya 2-6-3 Otemachi, Chiyoda-ku, Tokyo Inside Nippon Steel Corporation

Claims (4)

[Claims] 1. A fixed portion fixed to a bottom surface of a storage body with its center line orthogonal to each other, and a rotation supported by this fixed portion with a degree of freedom of rotation around the center line of the fixed portion. Part, an antenna body supported by the rotating part in a state of having a degree of freedom of rotation around a straight line orthogonal to the center line of the fixed part, and rotating the rotating part around the center line of the fixed part. In a moving body mounting antenna device having a rotating mechanism, the antenna is installed between an appropriate portion of the rotating portion and an appropriate portion of the antenna body to expand or contract the distance between the two portions. One or a plurality of expansion / contraction mechanisms for changing the elevation angle of the main body, the first cylindrical body having a root portion fixed on the rotating portion,
A second cylindrical body having a root portion rotatably coupled to the bottom surface of the antenna body and a tip portion fitted to the tip portion of the first cylindrical body, and the first and second cylindrical bodies. And a mechanism for discretely changing the fitting depth of the mobile antenna. 2. A fixed portion fixed to the bottom surface of the storage body in a state where the center lines are orthogonal to each other, and a rotation supported by the fixed portion with a degree of freedom of rotation around the center line of the fixed portion. Part, an antenna body supported by the rotating part in a state of having a degree of freedom of rotation around a straight line orthogonal to the center line of the fixed part, and rotating the rotating part around the center line of the fixed part. In a moving body mounting antenna device having a rotating mechanism, the antenna is installed between an appropriate portion of the rotating portion and an appropriate portion of the antenna body to expand or contract the distance between the two portions. One or a plurality of expansion / contraction mechanisms for changing the elevation angle of the main body, wherein the pinion is fixed on the upper surface of the rotating section and substantially horizontally to the upper surface of the rotating section, and the root is formed on the bottom surface of the antenna main body. The parts are rotatably connected Rutotomoni tip portion said pinion and a rack which engages, mobile mounted satellite antenna apparatus characterized by comprising a mechanism for rotating the pinion. 3. The antenna main body according to claim 1, wherein the antenna main body is a planar array antenna having a tilt angle of approximately 50 ^° or more in an elevation angle direction, and a plurality of predetermined discrete values regarding expansion / contraction amount of the distance are The angles between the antenna body and the rotating part are 0 ^o , -5 ^o and +5.
A satellite antenna device for mounting on a mobile body, which is set to a value set to one of °. 4. The antenna body according to any one of claims 1 to 3, wherein the antenna main body includes a converter on a back surface thereof, and the fixed portion and the rotating portion also serve as a slip ring that forms a power feeding path for the converter. A feature is a satellite antenna device for mounting on mobile units.