JP2008086049A - Radiowave lens antenna apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress degradation in receiving sensibility of a radiowave lens antenna apparatus in case of rainfall and snowfall, as used in combination with a hemisphere Luneberg lens and a radiowave reflector. <P>SOLUTION: The radiowave lens antenna apparatus comprises a hemisphere Luneberg lens 1, a radio wave reflector 2 with larger diameter than the lens 1, an antenna element 3, and a supporting member 4 for supporting the antenna element. Further, a means is provided for preventing damages by ice, snow and rain water comprising a first cover 5 and a second cover 6 to prevent adhesion of ice, snow, and rain water, and their retention after the adhesion to the Luneberg lens 1, in the radiowave lens antenna apparatus establised by standing upright the radio wave reflector 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a radio wave lens antenna apparatus using a Luneberg lens, and more particularly, to a radio wave lens antenna apparatus that suppresses a decrease in reception sensitivity when it rains or melts snow.

  Radio lens antenna devices using Luneberg lenses are expected as multi-beam compatible antenna devices capable of simultaneous communication with multiple communication partners, and are being offered as antenna devices for geostationary satellites replacing parabolic antennas. .

  The basic shape of a Luneberg lens made of a dielectric is a sphere, but for compactness, a hemispherical Luneberg lens and a radio wave reflector with a larger diameter than the lens (hereinafter simply referred to as a reflector) There is also a radio wave lens that has a function equivalent to a sphere by combining the two. The antenna device combined with this reflector can be installed at a position where the reflector is standing upright and looking up at a target geostationary satellite, for example, on the wall of a building or on a veranda fence. In addition, the reflector can be installed on the roof of a building with the reflector almost parallel to the ground, and the degree of freedom of installation is high.

  By the way, the antenna device using the Luneberg lens covers the outer surface of the lens with a water-resistant cover. For example, the following Patent Document 1 discloses a hemispherical radome formed integrally with a Luneberg lens, and the following Patent Document 2 and the like cover the entire antenna device including an antenna element with a radome. Is disclosed. Further, Patent Document 3 below discloses that a hemispherical lens is covered with a hemispherical cover.

  Thus, since the lens is covered with a radome or a hemispherical cover, there is no particular problem in durability even when it is wet. However, if rain that falls during use stays at the top of the lens or flows down along the surface of the lens (the outer surface of the surface protective layer), the amount of attenuation C / N (power ratio between signal and noise) is reduced. It becomes larger and the reception sensitivity of radio waves decreases. In addition, the reception sensitivity is lowered when the snow on the lens and the freezing on the lens melt and the molten water flows along the surface of the lens.

The conventional radio wave lens antenna apparatus has no consideration for such a problem, and the problem of a decrease in reception sensitivity is likely to occur. Also, the whole antenna device covered with radome
Since it is necessary to increase the thickness of the radome from the standpoint of securing strength, there are problems such as a decrease in electrical performance due to the radome, an increase in size, an increase in weight, and an increase in cost.
JP-A-50-116259 JP 2000-183645 A Japanese Patent Laid-Open No. 2002-232230 JP 2004-282718 A

  As an antenna device for a geostationary satellite using a Luneberg lens, for example, the one described in Patent Document 4 in the previous section has been proposed. This antenna device is very good as an antenna that receives radio waves from geostationary satellites, but it is easily affected by water droplets that stay or flow on the Luneberg lens during rainfall or snowmelt, and the reception sensitivity decreases. There was a problem that it was easy.

  An object of the present invention is to provide a radio wave lens antenna device that is improved in reliability by suppressing a decrease in reception sensitivity due to rain water, snow melt water, or the like.

In order to solve the above problems, in the present invention, a hemispherical Luneberg lens, a radio wave reflector having a size larger than the lens diameter along the bisector of the sphere of the lens, an antenna element, and this The radio wave lens antenna device including a holder for holding the antenna element is provided with ice / snow water preventing means for preventing rain, snow, ice from adhering to the surface of the Luneberg lens, staying after adhering, and flowing water. As for the flowing water, the flow of water to the lens surface at the position facing the antenna element is prevented.

  As a specific example of the ice / snow water prevention means, for example, a cover covering a part of the radio wave lens antenna device may be mentioned. As a preferred example of the cover, the entire Luneberg lens is covered in a state where the reflecting plate is raised from the ground, and the inclination angle of the upper part of the cover is larger than the inclination angle of the upper part of the Luneberg lens. The cover covers the top of the Luneberg lens when the reflector is level to the ground, and the tilt angle of the cover surface is larger than the tilt angle of the Luneberg lens surface. Can be considered. The tilt angle of the cover surface and the tilt angle of the lens surface are the slopes of any point on the hemispherical surface of the lens and the point where the line extending the straight line connecting the lens center and that point intersects the cover (points of comparison The angle at which the surface in contact with the surface is inclined with respect to the ground is compared.

  In addition, the cover includes a hemispherical first cover that covers the Luneberg lens in a state where the reflecting plate is raised with respect to the ground, and a second cover that covers an upper portion of the first cover. It is also preferable to make the inclination angle of the upper part of the first cover larger than the inclination angle of the upper part of the first cover. In this case, it is more preferable that the lower end of the second cover is separated from the lens and extended below the center of the lens. The inclination angle of the surface of the second cover and the surface of the first cover are such that an arbitrary point on the surface of the first cover and a line obtained by extending a straight line connecting the lens center and the arbitrary point intersect with the second cover. Are compared (the angle at which the surface in contact with each point of comparison is inclined with respect to the ground).

  The cover includes a hemispherical first cover that covers the Luneberg lens in a state where the reflecting plate is horizontal with respect to the ground, and a second cover that covers an upper portion of the first cover. It is also conceivable that the inclination angle is larger than the inclination angle of the upper part of the first cover. This can be used for an antenna device that is installed with the reflector plate horizontal to the ground.

  The ice / snow water prevention means is configured by providing a dam on the surface of the cover that covers the Luneberg lens, and the dam is above a line connecting the antenna element and the lens center and extends laterally within a predetermined range. It may be provided. In this case, the dam is constituted by any one of a concave shape, a convex shape, and a surface stepped portion. This dam has a high height from the ground above the part facing the antenna element on the cover surface, and the height from the ground is low toward both ends from there, and the surface is water repellent. Those subjected to are preferred.

  The ice / snow water prevention means may be provided between the antenna element and the Luneberg lens, and attached with a cover that covers the surface of the antenna element and the area of the Luneberg lens facing the antenna element.

  The ice / snow water prevention means may be composed of eaves protruding above the radius of the Luneberg lens and disposed on the upper portion of the Luneberg lens in a state where the reflecting plate stands with respect to the ground. The eaves may be formed by inclining the reflecting plate forward from a position where the reflecting plate stands vertically with respect to the ground, and using the inclined reflecting plate as eaves.

The ice / snow water prevention means may include those listed below.
A structure in which a cover for covering a part of the antenna device is provided, and the surface of the cover is subjected to water repellent treatment or hydrophilic treatment, or both treatments.
-A hemispherical cover that covers the Luneberg lens is provided, the top of the cover is treated with a hydrophilic treatment, and the top of the cover excluding the top is treated with water repellent treatment.
A cover that covers a part of the antenna device is provided, and a hydrophilic treatment and a water repellent treatment are performed on the surface of the cover so that the hydrophobic portion is scattered in an island shape in the hydrophilic portion. This is preferably made by making the area of the hydrophobic part larger than the area of the hydrophilic part.
-The cover is formed of synthetic resin, rubber, fiber, glass or a composite of these materials. For this, a synthetic resin, rubber, or glass foam may be used.

  In the radio wave lens antenna device of the present invention, by attaching a cover that covers a part of the antenna device, rain, snow, or ice adheres to the surface of the Luneberg lens, or stays after the adhesion or water flows to the front of the antenna element. Since the ice / snow water preventing means is provided, rainwater and melted water are prevented from adhering to and staying on the lens surface. The radio wave lens antenna device provided with a dam on the surface of the cover does not have the function of preventing rain, snow and ice from adhering itself, but rainwater and molten water flowing along the surface of the cover are guided to the dam or stopped. Thus, the flow of radio waves toward the antenna element is suppressed. Therefore, according to the present invention, the accumulation and retention of rainwater, snow, and ice is reduced, and the position where the melted water when the rainwater, snow, and ice melts greatly affects the reception sensitivity of the antenna, that is, the antenna element. To the lens surface portion at a position corresponding to is reduced, and a decrease in reception sensitivity due to flowing water is suppressed to a small level.

Embodiments of the present invention will be described below with reference to the accompanying drawings. The radio wave lens antenna apparatus according to the present invention includes a hemispherical Luneberg lens 1 (hereinafter simply referred to as a lens) shown in FIG. 1 and a radio wave reflector having a diameter larger than that of a lens along a half-section of the sphere of the lens 1. (Hereinafter simply referred to as a reflector) 2, an antenna element 3 disposed at the focal point of the lens, and a holder 4 that holds the antenna element 3.

  The lens 1 is a lens formed of a dielectric, and has an internal relative permittivity that changes from about 2 to 1 from the center toward the outside, and has a focal point near the surface forming a sphere. The lens 1 is covered and protected by a smooth hemispherical first cover 5 having a resin surface.

  The reflector 2 has a vertical and horizontal dimension larger than the outer diameter of the lens 1. In the radio wave lens antenna device of the present invention, there are a case where the reflector 2 is substantially perpendicular to the ground, a case where the reflector 2 is tilted with respect to the ground to a forward inclined posture, and a case where the reflector 2 is substantially parallel to the ground . In either case, the antenna element 3 is arranged at a position (focal point) where radio waves from a target geostationary satellite are converged.

  The antenna element 3 uses what is called LNB (low noise block). As this antenna element 3, one using a horn antenna or one having a dielectric mounted on the front of a cylindrical antenna is used. Further, as the holder 4, an arm or the like capable of fine adjustment of the element position is used.

  An example in which ice / snow water preventing means characterizing the present invention is provided in the antenna apparatus of FIG. 1 is shown in FIGS. FIG. 2 shows a radio wave lens antenna apparatus in which the reflector 2 is installed in a substantially vertical orientation with respect to the ground. The lens 1 covers the entire lens 1 and the inclination angle of the upper part of the cover is larger than the inclination angle of the upper part of the lens 1. A first cover 5 that is larger than the first cover 5 is provided so that the first cover 5 can serve as ice / snow water prevention means.

  The space 14 between the first cover 5 and the lens 1 may be a gap, but it is desirable that the space is filled with an olefin resin foam having a high expansion ratio that is very close to 1.

The surface of the first cover 5 has an inclination angle larger than the inclination angle of the lens. More preferably, the first radius from the center of the lens at the position where the lens radius is R and the angle formed with the reflector 2 is θ ₁ in FIG. Assuming that the distance to the cover 5 is R ₁ and the distance from the lens center to the first cover 5 at the position where the angle formed by the reflector 2 is θ ₂ is R ₂ , θ ₂ > θ ₁ and θ ₂ ≦ πR / In the case of 2, a shape satisfying the condition of R ₁ > R ₂ > R is preferable.

  On the other hand, FIG. 3 shows that a radiospheric lens antenna device in which the reflector 2 is installed substantially perpendicularly to the ground is provided with an aspherical second cover 6 that covers a part of the antenna device, and the surface of the second cover 6. Is made larger than the inclination angle of the surface of the first cover 5, and the second cover 6 is made to work as ice / snow water prevention means.

The second cover 6 has an outer surface with an inclination angle larger than the inclination angle of the upper portion of the lens. More preferably, the second cover 6 is from the center of the lens at the position where the lens radius is R and the angle formed with the reflector 2 is θ ₁ in FIG. Assuming that the distance to the second cover 6 is R ₁ and the distance from the lens center to the second cover 6 at the position where the angle formed by the reflector 2 is θ ₂ is R ₂ , θ ₂ > θ ₁ and θ ₂ ≦ When πR / 2, a shape that satisfies the condition of R ₁ > R ₂ > R is preferable.

  As shown in FIG. 4, if the lower end of the second cover 6 is separated from the lens 1 and extends below the center of the lens (forms the skirt portion 6a), the rainwater or ice / snow melt adheres and stays. In addition to the prevention effect, it is more preferable because the water droplets are less likely to move to the lower part of the first cover 5, and the movement of the radio waves is also inhibited from flowing due to the path of the radio waves toward the antenna element 3.

  Further, the antenna device shown in FIG. 3 may have the lower edge of the second cover 6 in contact with the surface of the lens 1 as shown in FIG. 5, and from the lens so that a gap g is formed as shown in FIG. It may be separated. When the lens is brought into contact with the lens, the wind resistance is increased. When the lens is separated from the lens, the water flowing along the second cover 6 does not easily transfer to the surface of the lens 1 (the first cover 5).

The thickness of the first cover 5 is preferably 2 mm or less, more preferably 1 mm or less in order to reduce the adverse effect on the electrical performance of the antenna.
Further, the gap between the first cover 5 and the lens 1 is desirably small in order to reduce electrical loss and maintain strength, and these may be bonded and fused.
Further, the surface of the first cover 5 may be painted.

  The second cover 6 is formed of a material that allows radio waves to pass therethrough, such as synthetic resin, rubber, fiber, glass, or a composite thereof (for example, a laminate). The material is not particularly limited, but it is desirable to use a material having a low electrical tan δ, such as a polyolefin resin.

  The second cover 6 need not be a molded product. It may be a thin sheet-like cover or a thin fabric without shape retention. Since the sheet-like cover or fabric does not receive the wind, water droplets adhering to the surface are likely to be scattered and have excellent drainage properties. On the other hand, when a transparent resin such as an acrylic resin or a polycarbonate resin is used, the bulkiness can be reduced.

  Further, the upper end of the second cover 6 may be located below the upper end of the reflector 2 as shown in FIG.

Furthermore, the thickness of the second cover 6 is preferably 2 mm or less, more preferably 1 mm or less, in order to reduce the adverse effect on the electrical performance of the antenna, similar to the first cover 5. Further, the thickness does not have to be constant, and the thickness may change as shown in FIG. By changing the thickness, the influence on the electrical performance of the antenna device can be reduced while securing the strength. Furthermore, as shown in FIG. 9, when the strength is increased by providing the vertical ribs 6c and the horizontal ribs 6d, the second cover 6 can be thinned to reduce the material cost and the weight of the cover. Although the illustrated vertical rib 6c uses a fold, the rib may be formed.

  It is preferable to seal the edge where the second cover 6 is brought into contact with the reflection plate 2 so as to prevent the rainwater from flowing inwardly. Edge sealing can be achieved by sealing with a double-sided adhesive tape or the like. On the other hand, it is preferable that the edge is fixed to the reflecting plate 2 with screws or bolts to enhance the reliability of preventing the separation. If the attachment flange 6b as shown in FIG. 10 is provided, the second cover 6 can be reliably attached with screws or bolts. Moreover, it is also possible to make it detachable using a resin bolt or the like.

  FIG. 11 shows a radio wave lens antenna apparatus in which the reflecting plate 2 is installed in a direction substantially parallel to the ground. The apparatus covers the entire lens 1, and the inclination angle of the upper part of the cover is that of the lens 1. A first cover 5 that is larger than the inclination angle of the upper part is provided, and this first cover 5 is made to work as ice / snow water prevention means.

  The space 14 between the first cover 5 and the lens 1 may be a gap, but it is desirable that the space is filled with an olefin resin foam having a high expansion ratio that is very close to 1.

The surface of the first cover 5 has an inclination angle larger than the inclination angle of the lens. More preferably, the first radius from the center of the lens at the position where the lens radius is R and the angle formed with the reflector 2 is θ ₁ in FIG. Assuming that the distance to the cover 5 is R ₁ and the distance from the lens center to the first cover 5 at the position where the angle formed by the reflector 2 is θ ₂ is R ₂ , θ ₂ > θ ₁ and θ ₂ ≦ πR / In the case of 2, the shape satisfying the condition of R ₁ > R ₂ > R is preferable because of excellent drainage.

  On the other hand, FIG. 12 shows that the radio wave lens antenna apparatus in which the reflector 2 is installed in a substantially horizontal direction with respect to the ground is provided with an aspherical second cover 12 that covers a part of the antenna apparatus. The inclination angle of the surface is made larger than the inclination angle of the surface of the first cover 5, and the second cover 12 is made to work as ice / snow water prevention means.

The second cover 12 has an outer surface with an inclination angle larger than the inclination angle of the lens. More preferably, the second cover 12 has a lens radius R in FIG. 12 and an angle formed with the reflection plate 2 from the lens center at the position θ ₁ . _{R 1} the distance to the second cover 12, the distance from the lens center at the position of the angle formed theta ₂ between the reflector 2 to the second cover 12 as _{R 2, θ 2> θ 1} and, theta ₂ ≦ .pi.R In the case of / 2, a shape satisfying the condition of R ₁ > R ₂ > R is preferable.

  FIG. 13 shows a radio wave lens antenna apparatus in which the reflecting plate 2 is installed in a substantially vertical orientation with respect to the ground, and a third portion between the antenna element 3 and the lens surface (first cover 5) at a position facing the element. A cover 15 is arranged so that the third cover 15 works as ice / snow water prevention means. The third cover 15 may be above the line connecting the antenna element 3 and the center of the lens 1. Although the shape is not particularly defined, a cylindrical shape is preferable because it is easy to attach. The third cover 15 can also be employed in an antenna device that is installed with the reflecting plate 2 oriented substantially horizontally with respect to the ground. Further, a synergistic effect can be obtained by using the third cover 15 together with the first cover 5 and the second cover 6 or 12 described above.

FIGS. 14 and 15 show a structure in which a eave is provided and the eaves function as ice / snow water prevention means. These radio wave lens antenna devices also include the elements described in FIG. FIG.
The antenna device 4 is provided with the eaves 8 projecting upward from the lens 1 in a state where the reflector 2 is arranged substantially perpendicular to the ground. The eaves 8 have a size such that the protruding amount from the reflecting plate 2 is larger than the lens radius R so as to completely cover the lens 1 in plan view.

  The radio wave lens antenna apparatus of FIG. 15 has the reflecting plate 2 tilted forward so that the upper end of the reflecting plate 2 protrudes forward from the lens 1 in a side view. Rain and snow pouring against This method has an advantage that the effects of the invention can be obtained without requiring special parts.

  16 to 18 show a radio wave lens antenna apparatus in which a dam 9 is provided on the surface of a hemispherical cover 5A (which may be the same as the first cover described above) covering the lens 1 to constitute ice / snow water prevention means. It is. The radio wave lens antenna apparatus generally protects the lens 1 by covering it with a cover, and includes a hemispherical cover 5A for that purpose. A dam 9 is provided on the outer surface of the hemispherical cover 5. The dam 9 is above the line connecting the antenna element 3 and the center of the lens 1 and extends left and right so as to have a predetermined length.

  The cover surface portion at a position corresponding to the antenna element 3 is a region through which radio waves directed to the antenna element 3 pass. Therefore, if water flowing into this region is prevented, the attenuation of the radio waves caused by the flowing water can be reduced. . In order to achieve this object, a dam 9 is provided on the outer surface of the hemispherical cover 5A to block the flow path of running water. The dam 9 is formed by the concave shape 9a shown in FIG. 17A, the one formed by the convex shape 9b shown in FIGS. 17B and 17C, and FIGS. 17D and 17E. As shown, the step portion 9c may be provided on the outer surface of the hemispherical cover 5A and the step portion 9c may be used. All have a predetermined width.

  As shown in FIG. 18, the dam 9 has a high height from the ground above the portion facing the antenna element 3, and the height from the ground gradually decreases toward both ends in the width direction from here. What has a high effect which guides flowing water to the area | region which does not hinder reception is preferable.

  The radio wave lens antenna apparatus of FIG. 19 is provided with a dam 13 on the outer surface of the hemispherical first cover 5 for suppressing water flowing to the cover surface portion at a position corresponding to the antenna element 3. Thus, not only when the reflector 2 is disposed perpendicular to the ground, but also when the reflector 2 is disposed horizontally with respect to the ground, the dam exhibits the desired effect.

  20 is a radio wave lens antenna device provided with the second cover 6 of FIG. 3 and the dam 9 of FIG. 16, and the effect of the second cover 6 that prevents adhesion and retention of rainwater, ice and snow melt, and running water Since the effect of the dam 9 that prevents the dam 9 from flowing to the position facing the antenna element 3 is synergistically exhibited, an extremely high effect can be obtained, and the amount of radio wave attenuation during rain and melting of ice and snow can be greatly reduced. .

  Water repellent treatment of the cover surface is effective as one of ice / snow water prevention means for preventing rainwater or ice / snow melt from adhering or staying. If the first cover 5 or the second cover 6 (or 12) is subjected to a water repellent treatment, the water has a large contact angle with the cover and is repelled and hardly stays on the cover surface. In particular, it is preferable to apply a water repellent treatment to the second cover 6 (or 12) having a large inclination because a large retention suppressing effect can be obtained.

  In FIG. 21, the vertex of the first cover 5 is subjected to a hydrophilic treatment to form a hydrophilic portion 10, and the upper slope other than the vertex is subjected to water repellent treatment to form a hydrophobic portion 11. This is because when water repellent treatment is applied to the surface close to the ground, the repelled water droplets do not flow, so they become polka dots and stay on the cover and have an adverse effect. It prevents the stay.

FIG. 22 shows a so-called “sea-island structure” as a coating layer formed on the surface of the first cover 5 by including a small-sized hydrophobic paint in the hydrophilic paint applied to the surface of the first cover 5. It is an example. With such a structure, water droplets repelled by the hydrophobic portion 11 (island portion) formed by the hydrophobic paint flow along the hydrophilic portion 10 (sea portion), thereby suppressing the retention of melted water of rain water, ice and snow. Can do. The hydrophobic portion 11 preferably has a diameter as small as 1 to 5 mm. Further, since the hydrophilic portion 10 temporarily forms a water film, the area ratio of the hydrophobic portion 11 is larger than the area of the hydrophilic portion 10. It is preferable to do so.

  Hydrophobic treatment may be applied to portions such as the dam 9 shown in FIGS. 17 and 18 where water drainage is particularly desired to be improved to improve hydrophobicity.

  The water-repellent treatment and the hydrophilic treatment are generally applied with a water-repellent and hydrophilic paint, but the present invention is not limited to this, and other surface modification methods may be used.

  As the above ice / snow water prevention means, for example, as shown in FIGS. 23 to 25, appropriate ones can be used in combination.

  Below, the test done in order to confirm the effect of this invention is described. In the test, radio wave lens antenna devices (examples and comparative examples) having the specifications shown in Table 1 were prepared, and using the measurement system shown in FIG. 26, the reception sensitivity (C / N) was measured every 10 minutes. Normally, since no image appears on the TV screen at C / N <6, the time when C / N ≧ 6 was investigated and the ratio to the time when C / N <6 was obtained. The results are shown in Table 1. As can be seen from Table 1, the device of the present invention has a shorter time to receive radio interference than the comparative example (a longer time for the image to appear). It turns out that it is effective in suppressing the receiving sensitivity fall by snow etc.

The perspective view which shows the outline | summary of the radio wave lens antenna apparatus used as the application object of this invention The side view which shows an example of the radio wave lens antenna apparatus of this invention Partially broken side view of another embodiment Still another embodiment of a partially broken side view Side view of yet another embodiment Still another embodiment of a partially broken side view Still another embodiment of a partially broken side view Still another embodiment of a partially broken side view A perspective view showing an example of a rib butt cover Still another embodiment perspective view Side view of yet another embodiment Still another embodiment of a partially broken side view Side view of yet another embodiment Side view of yet another embodiment Side view of yet another embodiment Side view of yet another embodiment (A)-(e) The figure which shows the cross-sectional shape of a dam (A)-(c) Front view showing the installation state of the dam Side view of yet another embodiment Side view of yet another embodiment Still another embodiment perspective view Still another embodiment perspective view Still another embodiment perspective view Side view of yet another embodiment Side view of yet another embodiment Diagram showing the measurement system used for the effect confirmation experiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Luneberg lens 2 Reflector 3 Antenna element 4 Holder 5, 5A 1st cover 6, 12 2nd cover 6a Skirt part 6b Flange 6c Vertical rib 6d Horizontal rib 7 Cover (radome)
8 eaves 9, 13 dam 9a ridge 9b ridge 9c step portion 10 hydrophilic portion 11 hydrophobic portion 14 space 15 third cover

Claims (19)

A radio wave lens antenna comprising a hemispherical Luneberg lens, a radio wave reflector larger than the lens diameter along the bisected section of the sphere of the lens, an antenna element, and a holder for holding the antenna element A radio wave lens antenna apparatus, characterized in that the apparatus is provided with ice / snow water preventing means for preventing rain, snow, ice from adhering to the surface of the Luneberg lens, or staying and flowing water after the adhesion.   2. The radio wave lens antenna device according to claim 1, wherein the ice / snow water prevention means comprises a cover that covers a part of the radio wave lens antenna device.   The cover covers the entire Luneberg lens in a state where the reflecting plate stands up with respect to the ground, and the inclination angle of the upper part of the cover is larger than the inclination angle of the upper part of the Luneberg lens. Item 3. The radio wave lens antenna device according to Item 2.   The cover includes a hemispherical first cover that covers the Luneberg lens in a state where the reflector plate stands with respect to the ground, and a second cover that covers an upper portion of the first cover. The radio wave lens antenna device according to claim 2, wherein an upper inclination angle is larger than an upper inclination angle of the first cover.   The radio wave lens antenna device according to claim 4, wherein a lower end of the second cover is separated from the lens and extends to a lower side than a center of the lens.   The cover covers an upper portion of the Luneberg lens in a state where the reflector is level with respect to the ground, and the inclination angle of the surface of the cover is larger than the inclination angle of the surface of the Luneberg lens. The radio wave lens antenna device according to 1.   The cover includes a hemispherical first cover that covers the Luneberg lens in a state where the reflector is level with respect to the ground, and a second cover that covers an upper portion of the first cover. The radio wave lens antenna device according to claim 2, wherein an upper inclination angle is larger than an upper inclination angle of the first cover.   The ice / snow water prevention means is configured by providing a dam on the surface of the cover that covers the Luneberg lens, the dam is above a line connecting the antenna element and the lens center, and is horizontally in a predetermined range. 2. The radio wave lens antenna device according to claim 1, wherein the radio wave lens antenna device is extended. The radio wave lens antenna device according to claim 8, wherein the dam is configured by any one of a concave shape, a convex shape, and a surface stepped portion.   The radio wave lens according to claim 8, wherein the position of the dam is high from the ground above a portion facing the antenna element on the cover surface, and is low from the ground toward both ends from there. Antenna device.   The radio wave lens antenna device according to claim 8, wherein a water repellent treatment is performed on a surface of the dam.   2. The radio wave lens antenna according to claim 1, wherein the ice / snow water prevention means is configured by a cover that is disposed between the antenna element and the Luneberg lens and covers a surface of the antenna element and a region facing the antenna element of the Luneberg lens. apparatus. 2. The radio wave according to claim 1, wherein the ice / snow / water prevention means includes an eaves that protrudes outward from a radius of the Luneberg lens in a state in which the reflector is raised with respect to the ground and is disposed on an upper portion of the Luneberg lens. Lens antenna device.   The radio wave lens antenna device according to claim 13, wherein the reflecting plate is tilted forward from a position standing upright with respect to the ground, and the tilted reflecting plate is also used as the eaves.   2. The radio wave lens antenna device according to claim 1, wherein the ice / snow water prevention means is configured by providing a cover that covers a part of the antenna device, and subjecting a surface of the cover to water repellency and / or hydrophilic treatment.   16. The ice / snow / water prevention means is provided with a hemispherical cover that covers a Luneberg lens, the top of the cover is subjected to a hydrophilic treatment, and the upper portion excluding the top is subjected to a water repellent treatment. Radio wave lens antenna device.   The ice / snow water prevention means is configured by providing a cover that covers a part of the antenna device, and performing a hydrophilic treatment and a water repellent treatment on the surface of the cover so that the hydrophobic portion is scattered in an island shape in the hydrophilic portion. The radio wave lens antenna device according to claim 15.   The radio wave lens antenna device according to claim 17, wherein an area of the hydrophobic portion is larger than an area of the hydrophilic portion.   The radio wave lens antenna device according to any one of claims 2 to 18, wherein the cover is formed of a synthetic resin, rubber, fiber, glass, or a composite of these materials.

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