JPH069216U - Antenna stabilizer - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention is intended to extend the lower limit of the elevation angle of the antenna to be lowered and extend the angular range of the elevation angle, and to realize a small and compact antenna stabilizer. . [Structure] The present invention constitutes an antenna stabilizer in which a radome is formed into a substantially spherical shape including a spherical shell and a cylindrical shell having a diameter smaller than the spherical shell. In addition, we constructed an antenna stabilizer with an intervening part for the antenna to intervene in the azimuth gimbal.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an antenna stabilizer for small antennas for maritime satellite communications.

[0002]

[Prior art]

 In general, an antenna system for a maritime satellite communication ship station requires that the antenna beam be constantly tracked and directed in the direction of the satellite regardless of fluctuations such as rolling and pitching of the ship. One of antenna mounts for tracking an antenna to a satellite is a so-called El / Az biaxial mount system that drives an elevation axis (El axis) and an azimuth axis (Az axis). The El / Az two-axis mount method is inferior to the three-axis type in pointing accuracy due to the delay in tracking near the zenith, but it has the feature that it can be made smaller and lighter than the multi-axis mount method.

FIG. 9 is a diagram for explaining the configuration of a conventional mount-type antenna stabilizer of this type, and FIG. 10 is a diagram for explaining the elevation operation of the antenna. 9 and 10, 1 is a base, 2 is a mount, 3 is an azimuth axis, and 4 is an azimuth gimbal. 5 is an elevation axis, 6 is an antenna, and 7 is a radome. The radome 7 is formed in a dome shape including a hemispherical shell 71 and a cylindrical shell 72 having the same diameter. S is the hull, and θ is the angular range in which the antenna 6 attached to the elevation axis 5 rotates together to raise and lower (tentatively referred to as the depression angle).

In the conventional antenna stabilizer having such a structure, the antenna 6 mounted on the azimuth gimbal rotates within the angular range of the depression angle θ about the elevation axis 5 as shown in the figure. Then, the antenna 6 is designed so that the satellite beam can be tracked by the satellite on the hull S that floats on the sea and sways, and communication using the satellite can be performed.

[0005]

As described above, in the conventional antenna stabilizer, the radome 7 has a dome shape. For this reason, the antenna beam transmitted and received by the antenna 6 is affected by the peripheral portion of the base 1 and the mounting base 2, and the depression angle of the lower limit θ min of the depression angle θ is narrowed. On the other hand, the antenna stabilizer installed on the hull S is always swaying together with the hull S floating on the sea. When the depression angle of the lower limit θmin is smaller than the swing angle α of the hull S, the antenna beam may cross the horizon H and the blind spot δ untrackable may occur due to the wobble of the hull S, as shown in FIG. .

In order to reduce the blind spot δ that cannot be tracked, the height h of the elevation axis 5 is increased, or the arm length a of the antenna 6 (the distance between the antenna 6 and the elevation axis 5) is increased to decrease the depression angle θ. It can be expanded. However, when the height h of the elevation axis 5 is increased or the arm length a is increased, the azimuth gimbal 4 and the radome 7 are correspondingly increased in size. As a result, the entire system is large and occupies a large area for mounting. Naturally, the weight is heavy and the installation work is troublesome. In particular, if the antenna system becomes large, there is a problem that it cannot be applied to small vessels less than 100 tons, which has a high proportion of vessels in Japan.

This invention has been made in order to solve such a problem of the conventional antenna stabilizer, and extends the lower limit θmin of the depression angle θ of the rotating antenna to extend the depression angle, and also to reduce the size. It aims to realize a compact antenna stabilizer.

[0008]

[Means for Solving the Problems]

 This invention is directed to an azimuth gimbal that rotates in a horizontal plane integrally with an azimuth axis supported on a base, an antenna that rotates in a vertical plane with an elevation axis provided on the azimuth gimbal as a fulcrum, an antenna and an azimuth. In an antenna stabilizer provided with a radome for covering a gimbal, the radome is formed into a substantially spherical shape consisting of a spherical shell and a cylindrical shell having a diameter smaller than this spherical shell. In addition, the antenna stabilizer is provided with an intervening part for the antenna to intervene in the azimuth gimbal.

[0009]

[Action]

 The radome that surrounds the antenna is made in the shape of a balloon with a small diameter on the cylindrical shell side, and the lower limit of the elevation angle is extended to expand the angular range in which the antenna rotates. In addition, an azimuth gimbal that is supported on the base and supports the elevation axis at the top is provided with an intervention section that allows an antenna that rotates about the elevation axis to intervene.

Therefore, even if the antenna descends while tracking the satellite and the antenna beam reaches the lower limit of the elevation angle, the propagation angle of the transmitted and received radio waves is not disturbed by the base and the periphery of the mounting base, and the elevation angle is widened. To be Also, even if the antenna beam is at the lower limit of the elevation angle and the ship sways, the antenna intervenes in the intervention section, so the blind spot that disables satellite tracking of the antenna beam can be eliminated. Furthermore, since the elevation angle axis is low and the antenna arm length is short, the antenna system structure can be made compact and compact.

[0011]

【Example】

 Embodiment 1 FIG. 1 is an explanatory view of the configuration of Embodiment 1 of the present invention, and FIG. 2 is an explanatory view of a depression angle of Embodiment 1 of the present invention. In the drawings of the embodiments of the present invention, the same parts as those of the conventional antenna stabilizer are designated by the same reference numerals, but some of the structures and functions are slightly different, so that the description will be partially overlapped and will be described in some detail.

In FIGS. 1 and 2, reference numeral 1 is a disk-shaped base. 2 is a fixed mount fixed on the base 1, 3 is an azimuth axis, 4 is an azimuth gimbal, and 5 is an elevation axis. Although not shown, the mounting base 2 is provided with a bearing, and the azimuth axis 3 is rotatably supported integrally with the azimuth gimbal 4 in the horizontal direction about the axis ZZ of the azimuth axis 3. The azimuth axis 3 and the elevation angle axis 5 are connected to a drive source such as an AC servomotor via a torque transmission mechanism such as a gear train and a belt.

Reference numeral 6 is an antenna attached to the elevation axis 5 via an arm 61, and reference numeral 7 is a radome. For the antenna 6, for example, an improved short backfire is used, and is provided with a rim 62 surrounding two large reflectors (not shown) and two small reflectors 63. Further, in the present invention, the radome 7 is formed into a substantially spherical shape, as shown in the figure, consisting of an upper spherical shell 73 and a cylindrical shell 74 having a radius r smaller than the radius R of the spherical shell 73.

Then, the base 1 is installed on the hull S such as a deck or a part of the box, and a small antenna for communication equipped with an antenna stabilizer is mounted on a ship that sails at sea. In addition, a control device for driving the drive source of the above-mentioned El / Az biaxial mount to control the tracking of the on-board antenna and a control device for various navigation such as a gyro compass for steering are also installed in the ship. There is.

The operation of the antenna stabilizer of the present invention having such a configuration will be described below with reference to FIG. As shown in the figure, the antenna 6 mounted on the hull S rotates in a vertical plane with the elevation axis 5 as a fulcrum. The upper limit θmax and the lower limit θmin of the depression angle θ are in the first quadrant and the third quadrant, and the angular range in which the antenna 6 rotates is approximately 115 degrees or more. On the other hand, the azimuth gimbal 4 on the azimuth axis 3 rotates about the axis Z-Z of the azimuth axis 3 horizontally in an angular range of about 270 degrees in the forward and reverse directions. The rotational movement in the vertical plane and the rotational movement in the horizontal direction work cooperatively, and the antenna 6 on the elevation axis 5 is displaced three-dimensionally along the inner surface of the spherical shell 73 of the radome 7.

On the other hand, based on the position information of the ship from the satellite positioning system, the control device inside the ship drives the El / Az biaxial mount three-dimensionally to program the antenna on the ship to control the satellite. To track. As a result, it is possible to transmit / receive to / from the coast earth station or another ship's earth station via the satellite. In this case, since the radome 7 of the present invention is formed into a spherical shape, as shown by the dotted line in FIG. 3, the lower limit θmin of the depression angle θ is counterclockwise by the angle λ as compared with the conventional device of the dome-shaped radome 7. To be extended. Therefore, even if the receiving antenna 6 is at the lower limit θ min position and the ship sways (see FIG. 11), it is possible to prevent the antenna beam from rising and exceeding the horizontal line H. Therefore, the blind spot δ generated when the antenna beam crosses the horizon H disappears, and at least the conventional tracking failure of the antenna 6 can be eliminated.

Second Embodiment FIG. 4 is an explanatory view of the configuration of a second embodiment of the present invention, and FIG. 5 is a side view of FIG. In the second embodiment of the present invention, the radome 7 is formed in a dome shape as in the conventional case. Instead, as shown in FIG. 5, the azimuth gimbal 4 has a flat plate portion 41 that is partially eccentric from the azimuth axis 3, and a tuning fork-like shape that is erected on the flat plate portion 41 and is bifurcated. It is composed of a holding portion 42. The lower end of the holding part 42 is connected to the eccentric part of the flat plate part 41, the holding part 42 is inclined at an angle β with respect to the axis ZZ, and the elevation axis 5 is held on the axis ZZ of the upper end. ing.

On the other hand, the arm length a of the antenna 6 is configured to be significantly smaller than that of the conventional one. Further, the height h of the elevation axis 5 is also lowered, and as a result, the entire radome 7 is made small. In the second embodiment of this configuration, when the antenna 6 rotates within the depression angle θ and reaches the position of the lower limit θmin, it intervenes in the inclined surface 43 of the β-inclined holding portion 42 of the azimuth gimbal 4. The intervention state of the antenna 6 is shown by the dotted line in FIG. As a result, the radome 7 becomes smaller, and the depression angle θ is increased in principle.

Further, FIG. 7 shows a configuration obtained by partially modifying the second embodiment of the present invention. In the configuration of the embodiment shown in FIGS. 4 and 5, the antenna 6 has a double-support structure with the arm 61, but in the case of FIG. 7, a cantilever structure is adopted. According to this modified example, there is an advantage that the structure is further simplified and the weight is reduced as the entire apparatus is made compact.

Third Embodiment FIG. 8 is a configuration explanatory diagram of a third embodiment of the present invention. In the third embodiment of the present invention, as in the first embodiment, the orientation gimbal 4 is erected on the mount 2. On the side surface of the upright azimuth gimbal 4, an intervention portion 44 having an inclined surface 43 having the same inclination angle β as in FIGS. When the antenna 6 rotates about the elevation axis 5 as a fulcrum and approaches the lower limit θ min of the depression angle θ, the antenna 6 intervenes in the intervention section 43 of the azimuth gimbal 4 as in the case of FIG. As a result, also in the third embodiment, the same effect as that of the second embodiment can be obtained.

In the above-described embodiment, the case where the mounting base 2 is provided on the base 1 and the azimuth axis 3 is supported has been described as an example, but either the mounting base 2 or the base 1 may be omitted. . Further, the present invention can be applied not only to the improved short backfire shown in the embodiment but also to a parabola type antenna.

[0022]

[Effect of device]

 The present invention includes an azimuth gimbal that rotates in a horizontal plane integrally with an azimuth axis that is supported on a base, an antenna that raises and descends in a vertical plane with an elevation axis provided on the azimuth gimbal as a fulcrum, an antenna and an azimuth gimbal. In the antenna stabilizer with a covering radome, we constructed an antenna stabilizer in which the radome was formed into a substantially spherical shape consisting of a spherical shell and a cylindrical shell having a diameter smaller than this spherical shell. In addition, we constructed an antenna stabilizer with an intervening part for the antenna to intervene in the azimuth gimbal.

As a result, unlike the conventional antenna stabilizer having a dome-shaped radome, even if the antenna beam is displaced upward due to the motion of the hull, tracking is not impossible. Also, since the elevation angle is low and the arm length is short, the azimuth gimbal and radome are also small. Therefore, it is possible to realize an antenna stabilizer in which the entire antenna system is small, the installation area is small, the weight is light and the cost is low.

Therefore, according to the present invention, it is possible to provide a small and lightweight antenna stabilizer for maritime satellite communication, which is suitable for a small ship.

[Brief description of drawings]

FIG. 1 is a configuration explanatory diagram of a first embodiment of the present invention.

FIG. 2 is an illustration of a depression angle of the first embodiment of the present invention.

FIG. 3 is an operation explanatory diagram of the first embodiment of the present invention.

FIG. 4 is a structural explanatory view of a second embodiment of the present invention.

FIG. 5 is a side view of FIG.

FIG. 6 is an operation explanatory diagram of the second embodiment of the present invention.

FIG. 7 is a side view of a modified example of the second embodiment of the present invention.

FIG. 8 is a structural explanatory view of a third embodiment of the present invention.

FIG. 9 is an explanatory diagram of a configuration of a conventional antenna stabilizer.

FIG. 10 is an operation explanatory view of a conventional antenna stabilizer.

FIG. 11 is another operation explanatory view of the conventional antenna stabilizer.

[Explanation of symbols]

 1 base 3 azimuth axis 4 azimuth gimbal 5 elevation axis 6 antenna 7 radome 43 inclined surface 44 intervention section 61 arm 71 hemispherical shell 72 cylindrical shell 73 spherical shell 74 cylindrical shell a arm length h elevation angle 5 height S hull β inclination angle δ Blind angle θ Depression angle θmax Depression upper limit θmin Depression lower limit ZZ Axial axis 3 axis

Claims (2)

[Scope of utility model registration request] 1. An azimuth gimbal that rotates in a horizontal plane integrally with an azimuth axis supported on a base, an antenna that rotates in a vertical plane with an elevation axis provided on the azimuth gimbal as a fulcrum, and the antenna and An antenna stabilizer comprising a radome for covering the azimuth gimbal, wherein the radome is formed into a substantially spherical shape including a spherical shell and a cylindrical shell having a diameter smaller than the spherical shell. 2. An azimuth gimbal that rotates in a horizontal plane integrally with an azimuth axis supported on a base, an antenna that rotates in a vertical plane with an elevation axis provided on the azimuth gimbal as a fulcrum, and the antenna and An antenna stabilizer having a radome for covering the azimuth gimbal, wherein the azimuth gimbal is provided with an intervention part for interposing an antenna.