JP3529841B2 - Snow protection device for antenna - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna snow-prevention device for preventing snow and rain from adhering to elements of an antenna installed outdoors.

[0002]

2. Description of the Related Art In a transmitting antenna or a receiving antenna for electromagnetic waves typified by television radio waves, if snow adheres to the antenna element, the weight of the accumulated snow may cause the antenna element to break and the gain to decrease. Radio disturbance such as change of directivity occurs. This tendency is significantly affected in the case of so-called solid snow with a high water content. As a measure for preventing snow from being generated on such an antenna, conventionally, a VHF, UHF, or microwave band antenna is covered with a flat or cylindrical container-like case using a hard material such as FRP or synthetic resin. Further, as for the ring antenna, the ring-shaped antenna element is surrounded by a tea-tubular hard cover formed by FRP.

[0003]

None of the snow protection devices of the prior art is effective in preventing the deterioration of the antenna performance due to snow or rain. However, since the energy propagation space for electromagnetic waves including the antenna element has a hollow structure, screws, nuts and the like are indispensable for attaching the case and the cover. Therefore, there are problems that the number of parts is increased, the structure is complicated, the mounting work is complicated, and the cost is increased due to the use of an expensive material such as FRP. In particular, in a snow protection device for a ring antenna, the antenna element has to be disassembled and mounted one by one, so that workability is poor and the antenna cannot be attached to or detached from an existing antenna. Therefore, there is a problem that the antenna cannot be easily inspected during broadcasting.

The present invention was devised to solve the above-mentioned problems, and its purpose is to prevent deterioration of the performance of the antenna due to snow and rain, and to have a simple structure. It is an object of the present invention to provide a highly practical snow protection device for an antenna that can be easily attached to and detached from, and can be implemented at low cost. The snow-prevention device according to the present invention includes a multi-element receiving ring antenna, B
The present invention can be applied to parabolic antennas such as S reception antennas, general dipole type reception antennas, and common reception antennas for co-listening and reception of electromagnetic waves.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, a snow protection device for an antenna according to the present invention includes a foamed resin molded body surrounding the antenna element, and a film-shaped waterproof cover around the foamed resin molded body. The waterproof cover is covered with foam resin
Sheet body covering the peripheral surface of the molded body and both ends of the foamed resin molded body
Has a cap-shaped part that covers the
The range is fixed to the sheet body
It When the antenna element has a ring shape or a bar shape, the foamed resin molded body is composed of a plurality of divided bodies each having a groove or slit (hereinafter referred to as a groove) corresponding to the antenna shaft and the antenna element. It is preferable. That is, according to the present invention, the foamed resin molding is an antenna sheath.
Equipped with a groove corresponding to the shaft and a groove corresponding to the antenna element
It is characterized by being composed of multiple divided bodies.
When the antenna has a cup shape or a paraboloidal shape, as represented by a parabolic antenna, the foamed resin molded body has a convex portion with a curvature corresponding to the reflective element, and the convex portion is It is preferable to have a hole having a size and shape corresponding to the main radiating element. That is,
Ming surrounds the antenna element with a foamed resin molding,
Do not cover the area around the foamed resin molded product with a waterproof membrane.
The foamed resin molding has a curvature shape corresponding to the reflective element.
A dimensional shape with a convex surface that corresponds to the main radiating element
It is characterized by having a hole.

[0006]

The present invention changes the idea that it is a necessary condition for a snow-prevention device to have a hollow effective opening surface (effective opening space) near the antenna element, and the snow-preventing effect is not a hollow structure but a solid structure. Is intended to be realized. That is, if a foamed resin is used as the solid material, the specific gravity is small. Therefore, even if it is filled up to the vicinity of the antenna element, the wavelength shortening rate of the space filled with the foamed resin is close to 1, and therefore the antenna is The changes in gain, directivity and impedance are insignificant. Since the foamed resin molded body has a low specific gravity, the strength will not be impaired by the addition of a load even if it is attached to the antenna.Furthermore, the foamed resin molded body has a higher mechanical strength than that of the specific gravity and the moisture permeability. Low and high weather resistance. Therefore, even if you use a flexible membrane waterproof cover, it can function as a stable support for it, can reduce the influence of snow, rain, ultraviolet rays on the antenna element, and can also endure environmental damage such as bird damage. Sex can also be improved. In addition, as the waterproof cover, it is made of foamed resin.
Both ends of the foamed resin molded body on the sheet body that covers the peripheral surface of the molded body
The required area of the cap-shaped body covering the
Since there are few parts, handling and equipment are easy.
At the same time, a reliable waterproof effect can be obtained.

In the present invention, when the target antenna element is a ring type or a bar type, the foamed resin molded body is composed of a plurality of divided bodies, and the antenna shaft and the antenna element are inserted into these divided bodies. The groove to obtain is provided. With such a configuration, it is not necessary to disassemble the antenna element one by one, and the antenna element can be sandwiched by the foamed resin molded body from the outside, and the outer periphery thereof can be simply wrapped with the waterproof cover, which facilitates mounting and removal. . Further, even when the antenna element has a concave shape such as a parabolic antenna, the foamed resin molding has a convex portion with a curvature corresponding to the reflecting element, and the convex portion has a hole with a dimension corresponding to the main radiating element. Since the above is provided, it suffices to load the convex surface portion into the reflective element so that the hole is fitted to the main radiating element, and wrap the outer periphery of the foamed resin molded body with the waterproof cover, and the mounting is easy. Just wrapping the parabolic antenna with a cloth sheet causes the sheet to sag due to the weight of snow, which puts a load on the radiating element.If the sheet tension is increased to reduce this, the sheet will be contacted or collided with a sharp object. It will be torn. However, in the present invention, the foamed resin molded body is filled as a backup material in the recessed portion and the outer surface of the recessed portion is covered with the waterproof cover, so that it is not deformed or stretched due to the weight of snow, and a stable snow-preventing effect is provided for a long time. be able to. In any case, the foamed resin molded product can be mass-produced into a free shape by using a mold, and cost reduction can be realized in combination with the small number of parts.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 6 show an embodiment (first embodiment) in which the present invention is applied to a snow protection device for a ring antenna. Reference numeral 1 denotes an antenna fixed to a mast 13 by a mounting bracket 14, and a plurality of ring-shaped antenna elements 11 are mounted on a shaft 10 by a supporting bracket 12 at predetermined intervals. Power supply unit 1 including
7 is connected, and a feeder or a coaxial cable 18 is connected to the power feeding unit 17. Reference numeral 2 denotes a snow protection device according to the present invention, which is a foamed resin molded body 3 or 3 divided into two pieces.
And a waterproof cover 4 for covering the foamed resin moldings 3, 3 with a snap.

For the foamed resin moldings 3 and 3, styrofoam is suitable from the viewpoints of waterproof property, dielectric property, price, etc., but in addition to this, a material with a small decrease in wavelength shortening rate and little loss. If so, a resin having another type of cell structure can be used. Foam resin molding 3,
In this embodiment, 3 has a split circular cross section so that when the mating surfaces 30, 30 are brought into contact with each other, the overall shape becomes a columnar shape. The shaft 10 is provided on each mating surface 30, 30.
A groove 31 having a shape and dimension corresponding to the half cross section of the ring-shaped antenna element 11 is penetrated in the longitudinal direction, and has a sufficient depth in the direction orthogonal to the supporting groove 31 to insert the half portion of the ring-shaped antenna element 11. Grooves 32 having a width are formed at predetermined intervals.
Furthermore, the power feeding portion 17 is provided at a portion adjacent to the groove 31.
Is formed with a groove 32 'having a depth and width sufficient to accommodate one half of the cable, and the feeder or coaxial cable 1 is provided at the end position.
A groove 33 corresponding to No. 8 is formed. Groove 3 forming a pair
2, 32 form a vacant chamber a when the foamed resin molded bodies 3, 3 are combined, and the pair of grooves 31, 31 form a hole b that contacts the outer surface of the shaft 10. Then, in the bottom of the groove 31 on the same plane as the groove 32, a recess 35 for receiving a component of the support fitting 12 of the antenna element 11, such as a screw or a nut 120, is inserted.
Is formed on the bottom side of the recess 35 so as to reach the outer edge of the mating surface 30 for obtaining a drain hole.

As the film-like waterproof cover 4, from the viewpoint of easy handling and flexibility in shape, it is preferable to use sheets having good weather resistance. The materials for these sheets are waterproof canvas or tent cloth made by waterproofing cotton or synthetic fiber cloth, inorganic fiber cloth typified by glass cloth with a waterproof coating, or resin with high weather resistance and strength. Examples thereof include films (including laminated films). It is necessary that the waterproof cover 4 has an area sufficient to surround the foamed resin moldings 3, 3 that are united together. In this embodiment, as shown in FIG. 5, the waterproof cover 4 includes a sheet portion body 40 for surrounding the peripheral surface having a width substantially equal to the length dimension of the foamed resin molded body 3 and the foamed resin molded bodies 3, 3. Two cap-like bodies 4 for covering the ends having an inner diameter approximately the same as the diameter
It consists of 1, 41. The cap-shaped body 41,
41 is located at the center of both ends of the sheet body 40, and the required area is fixed. Specifically, each of the cap-shaped parts 41, 41 has an annular part 411 continuously provided on the outer edge of the surface part 410 having a dimension and shape corresponding to the longitudinal end faces of the combined foamed resin molded products 3, 3. A required range of 411, for example, 1/4 to 1/2 of the circumferential length is sewn or adhered to the sheet body 40. On the surface portion 410 and the annular portion 411, a notch 412 for fitting with the shaft 10 is formed on the non-fixing side. The notch 412 is U-shaped in this embodiment, but may be a shape in which a circular hole is formed at the tip of a linear slit.

The seat portion body 40 for surrounding the peripheral surface can be brought into contact with and separated from a portion other than the fixing region of the cap-like body portions 41, 41 by engaging means, and preferably the free ends of the seat portion body 40 are also joined together. It can be contacted and separated by the engagement means. Although an adhesive layer may be used as the engaging means, in view of durability and the like, in this embodiment, a fiber fastener (a trade name) in which a loop thread group (female piece) and a hook thread group (male piece) form a pair : Velcro tape) is used. First, the cap-shaped body 41,
A one-side fastener 42 of a fiber fastener is attached to the outer surface of each annular portion 411 of 41. Then, the other side fastener 42 'of the fiber fastener is attached to the inner surface side of the sheet portion body 40 along both edge portions, and the annular portions 411, 4 are provided when covering the combined foamed resin molded bodies 3, 3.
It is adapted to be joined to the one-sided fastener 42. The seat portion 40 has a size such that the free ends can be appropriately wrapped, one side fastener 42 of the fiber fastener is attached to the inner surface of one free end, and the other side of the fiber fastener is attached to the outer surface of the other free end. Fasteners 42 'are attached, and in order to more reliably maintain the shape of the sheet portion body 40 and prevent separation, a binding cord 44,
44 is attached. Then, in each free end region of the sheet portion body 40, the narrow grooves 34,
A hole or a notch 401 is provided in a portion corresponding to 34, so that the water that has passed through the water drain hole formed by the unification of the thin grooves 34, 34 can be easily discharged to the outside.

7 and 8 show an embodiment (second embodiment) in which the present invention is applied to a snow protection device for a parabolic antenna.
The antenna 1 has a rod-shaped main radiating element 16 protruding from the center of a reflecting element 15 recessed in a cup shape.
It is composed of a foamed resin molded body 3 and a waterproof cover 4 which covers the foamed resin molded body 3 with a stop. The foamed resin molded body 3 is made of the same material as in the first embodiment, and has a disk-shaped base portion 36 having a diameter equal to or slightly larger than that of the reflective element 15.
In addition, the convex surface portion 3 having a curvature substantially matching the curvature of the reflecting element 15
7 is provided. A hole 370 having a diameter and a depth sufficient to accommodate the main radiating element 16 is formed in the axial direction from the top of the convex surface portion 37. The waterproof cover 4 is also made of a sheet made of the same material as that of the first embodiment, and is formed into a cap shape as a whole by connecting the annular portion 411 to the surface portion 410 having a diameter corresponding to the diameter of the base portion 36. Then, projecting pieces 414 are provided at the front end of the annular portion 411 at predetermined intervals, and the string 44 for squeezing and binding is inserted into the projecting pieces 414.

FIG. 9 shows an embodiment (third embodiment) in which the present invention is applied to a Yagi antenna for UHF reception. In the antenna 1, bar-shaped antenna elements 11 are arranged in parallel on a shaft 10, and the foamed resin moldings 3 and 3 divided into two are columnar bodies having a cross-sectionally elliptical or elliptical cross section in this embodiment. The groove 31 for supporting and the groove 32 for accommodating the element are formed in the mating surfaces 30, 30 as in the first embodiment. Since the other configurations of the foamed resin molded bodies 3 and 3 and the configuration of the waterproof cover 4 are the same as those in the first embodiment, the description thereof will be omitted to avoid duplication.

The snow protection device 2 in the first and third embodiments does not necessarily need to have a structure surrounding all the antenna elements 11 of the antenna 1. That is, as shown in FIGS. 1 and 2, one or more antenna elements 11 on the tip side of the shaft may be exposed without being covered. This is effective in reducing the wind pressure load. Further, in the first and third embodiments, the foamed resin moldings 3, 3 are divided into two, but may be divided into three or more. Although the foamed resin molded body 3 is single in the second embodiment, it is not limited to this and may be divided into two or more. Further, when the resin is a material that generates less heat during foaming, so-called in-situ foaming may be adopted in which the antenna 1 is appropriately surrounded by a mold to fill and foam the resin. Further, the groove 32 is not always required for each antenna element 1
It does not need to be separated for each one, and may be a groove having a size capable of enclosing a plurality of antenna elements.

The plurality of foamed resin molded bodies 3, 3 may be completely independent from each other, but as shown in FIG. 10, two foamed resin molded bodies 3, 3 are connected by a hinge member 36 so that they can be opened and closed. Good. This further reduces the number of parts and facilitates handling such as mounting and dismounting with respect to the antenna. As the hinge member 36, an adhesive tape is used as a strip-shaped piece having adhesiveness with the foamed resin. In addition, the plurality of foamed resin molded bodies 3, 3 are, if necessary, as shown by phantom lines in FIG. 10, the mating surfaces 30, out of the grooves 31, 32, 32 ′.
A protrusion 301 and a recess 30 for positioning or coupling
It may have 2. Further, the waterproof cover 4 in the first and third embodiments has a large number of parts, but the seat portion body 40 and the cap-shaped portion bodies 41, 41 may be separate bodies. In this case, the one-sided fastener 42 is attached to the entire circumference of the annular portion 411. In this case,
The cap-shaped parts 41, 41 are mounted on the ends of the foamed resin molded bodies 3, 3 which are united, and the seat part 40 is mounted in this state to be integrated with the cap-shaped parts 41, 41 to form a foam. The entire circumference of the resin molded bodies 3 and 3 is surrounded. Further, in a mode in which the cap-shaped parts 41, 41 are separated, the seat part 40 is mounted, and in that state, the cap-shaped parts 41, 41 are enclosed so as to wrap with both ends of the seat part 40 in a required range. You may let me. In this case, the seat body 40 may be formed in a tubular shape in advance. A string is suitable as a means for fixing the cap-shaped members 41, 41. Further, the aspect in which the cap-shaped portions 41, 41 are separated may be combined with the above-mentioned hinge structure. FIG. 11 shows this example. The two parts of the foamed resin molded body 3, 3 are preliminarily adhered to the outer periphery in the required range excluding the free end portion of the sheet portion body 40 with an adhesive. At the same time, 40 also serves as a hinge for the two foamed resin molded bodies 3, 3. In this case, the one side 42 and the other side 42 'of the fiber fastener are attached to the inner surface of the first free end and the outer surface of the second free end of the sheet member 40. Cap-shaped body 41, 41
The rims of the annular portions 411 and 411 are reversely sewn, and the binding cord 44 is passed through the hole formed thereby.
In this mode, the number of parts is small, and the mounting work is also performed by pulling the free end of the sheet portion body 40 from the state of FIG. 11 to the left and right to expand the foamed resin molded bodies 3 and 3, and sandwiching the antenna 1 therebetween.
Then, the free ends of the sheet part body 40 are overlapped and joined, the cap-shaped part bodies 41, 41 are externally fitted to both ends of the tubular sheet part body 40, and the strings 44, 44 may be squeezed and tied. Because it is easy. In the examples, foamed resin moldings 3, 3
Although the cross-sectional shape (hence the shape of the waterproof cover 4) is circular, the shape is not limited to this and may be any polygonal shape.

[0016]

Operation of the Embodiment Next, the operation of the embodiment will be described. In the first embodiment, from the state of FIG.
Attach the antenna 1 so that it sandwiches the antenna 1 from both sides. By doing so, since a plurality of flat vacant chambers a are formed by the pair of grooves 32, 32 that are open to the mating surfaces 30, 30 of the foamed resin molded bodies 3, 3, each antenna element 11 has a different shape. Each of the vacant spaces a is completely inserted, and the groove 32'32 'is used to insert the power supply unit 17. Along with that, mating surface 3
When 0 and 30 come into contact with or come close to each other, the shaft 10
Grooves 31, 31 are fitted on the outer circumference of the shaft 1, so that at least the front and rear portions of the foamed resin molded bodies 3, 3 in the longitudinal direction are in the shaft 1.
Stable support by contact with zero. Also, the groove 33,
The assembly of 33 also encloses the feeder or coaxial cable 18. This state is shown in FIG. 6, and then the waterproof cover 4 is attached. That is, the cap-shaped body 41 at both ends,
The notch portions 412 and 412 of 41 are fitted to the shaft 10, and then the annular portions 411 and 411 are externally fitted to the ends of the foamed resin molded bodies 3 and 3 which are columnar. The foamed resin moldings 3 and 3 are placed along the peripheral surface.
By doing this, the other side fastener 4 made of fiber
The seat portion body 40 and the cap-shaped portion body 41 are reliably integrated because the 2 ′ engages with the one-sided fastener 42 on the outer surface of the annular portion 411. Subsequently, if both free ends of the sheet member 40 are overlapped, the seat member 40 becomes a cylinder in close contact with the outer peripheral surfaces of the foamed resin moldings 3, 3 due to the engagement of the fiber fasteners 42, 42 ', and the cord 44 , 44 is more firmly fixed to the foamed resin molded bodies 3, 3.

In the case of the second embodiment, first, the convex surface portion 37 of the foamed resin molding 3 is loaded into the reflecting element 15. In this way, the convex surface portion 37 approaches or contacts the reflective element 15, and the main radiating element 16 is inserted into the hole 370 provided at the top of the convex surface portion 37. Therefore, the base 36 is covered with the waterproof cover 4 and the string 44 is squeezed and bound on the back side of the reflective element 15, so that a stable snow protection device as shown in FIG. 7 can be obtained.

As is clear from the above description, the snow protection device 2 of the present invention does not require disassembly of the antenna element for mounting, and does not require elements such as screws or tools for rotating the same. Therefore, it is extremely easy to use an existing antenna,
It can be installed quickly. Further, the antenna can be mounted even when the opening angle of the antenna is 70 degrees or less. Especially when applied to a transmission / reception antenna for a mini satellite, there is an advantage that the antenna can be easily inspected during broadcasting because it can be easily attached and detached. In use, as shown in FIGS. 2 to 4, the antenna element 11 is wrapped with the foamed resin moldings 3 and 3, and the foamed resin moldings 3 and 3 are covered with the waterproof cover 4. Since the foamed resin molded bodies 3 and 3 are lightweight, almost no additional load is applied to the antenna 1,
High strength for its specific gravity. Therefore, the waterproof cover 4 having poor shape retention is kept in a stable predetermined shape by the good backup action of the foamed resin moldings 3, 3, and it is possible to obtain sufficient durability and weather resistance even if snow adheres to the antenna. Element 1
It is possible to prevent snow and rainwater from adhering to 1 and irradiation of ultraviolet rays. As shown in FIG. 5, when the required range which should be the upper portion when the cap-shaped body 41, 41 is used is fixed to the sheet body 40, between the cap-shaped body 41, 41 and the sheet body 40, Since there is no gap, it is possible to accurately prevent the ingress of snow and rainwater. Further, even if moisture or humidity intrudes, the foamed resin molded bodies 3 and 3 are difficult to get wet because they do not have water absorption and hygroscopicity, and even if moisture enters the chamber a through the gap between the mating surfaces 30 and 30, The lower side of the chamber a communicates with the recess 35, and since water drainage holes are formed in the recess 35 by the thin grooves 34, 34, the water can be easily discharged to the outside.

Further, since the foamed resin moldings 3 and 3 have a small specific gravity, the reduction in the wavelength shortening rate is small. For example, in the case of styrofoam, it is about 99.1%, and the antenna has a wide band, so Considering the band, the movement of the tuning point can be practically ignored. The present inventors have made foamed resin moldings 3, 3 having a semi-cylindrical cross section by using styrofoam, and using a waterproof cloth for a tent as a waterproof cover, to form two cap-shaped parts as shown in FIG. A structure in which both ends of the sheet body are fixed was made. And when such a snow protection device was attached to a transmission five-element ring antenna for a mini satellite (diameter of about 25 cm, length of about 50 cm), the antenna gain, directivity, and antenna gain with and without the snow protection device of the present invention, The change of the impedance characteristic from 710 to 764MHz was extremely small.
If the snow protection device is not attached, the change in received voltage will be 4 to
Although a decrease of 8 dB was recognized, when the snow protection device of the present invention was attached, it was 0.5 dB or less, which was almost no decrease.

[0020]

According to the first aspect of the present invention described above, the antenna element is mounted so as to wrap it by using the foamed resin molded body, and the membrane-shaped waterproof cover is surrounded by the foamed resin molded body as a support. In addition, it is possible to achieve snow protection effects such as gain reduction prevention and directivity change prevention with a simple structure, and it can be attached and detached without the need for screws or nuts or other members or tools, and without disassembling the antenna element. Therefore, workability and work efficiency can be improved. Since the foamed resin molding is lightweight and can be mass-produced in any shape at low cost, it can easily and economically support any antenna shape such as ring type, parabolic type, bar type, etc. Combined with the small number, it is possible to obtain an excellent effect that it can be used as a highly versatile low-cost snow protection device. In addition, the waterproof cover is made of foamed resin.
Sheet body covering the peripheral surface of the molded body and both ends of the foamed resin molded body
Has a cap-shaped part that covers the
The area is fixed on the sheet body, so it is
The effect that can be prevented is obtained. According to the second aspect, there is an effect that it is possible to provide a highly practical snow protection device that is suitable for a ring type or bar type antenna and has a simple structure, easy mounting, and low cost. According to claim 3, suitable for a parabola type antenna,
An effect that a highly practical snow protection device having a simple structure, simple mounting, and low cost can be provided.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing a first embodiment of the present invention.

FIG. 2 is a vertical sectional side view of the first embodiment.

3 is a cross-sectional view taken along the line III-III in FIG.

4 is a cross-sectional view of FIG.

FIG. 5 is a perspective view showing the first embodiment in an exploded state.

FIG. 6 is a perspective view showing a state where the foamed resin molded body is mounted on the antenna in the first embodiment.

FIG. 7 is a partially cutaway side view showing a second embodiment of the present invention.

FIG. 8 is a perspective view showing a second embodiment in an exploded state.

FIG. 9 is a vertical sectional front view showing a third embodiment of the present invention.

FIG. 10 is a front view showing another embodiment of the present invention.

FIG. 11 is a perspective view showing another embodiment of the present invention.

[Explanation of symbols]

1 antenna 2 Snow protection device 3 Foamed resin molding 4 waterproof cover 10 shaft 11 Antenna element 15 Reflective element 16 Main radiating element 31 groove 32 grooves 36 base 37 convex part 40 seat body 41 Cap-shaped body 370 holes

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichi Nou, Koichi Nou 14-1 Otemachi, Kanazawa City, Ishikawa Prefecture, Japan Broadcasting Corporation Kanazawa Broadcasting Station (72) Noboru Otani 14-1 Otemachi, Kanazawa City, Ishikawa Prefecture, Japan Broadcasting Corporation Kanazawa Broadcasting Station (56) Reference JP-A-6-21714 (JP, A) Actually open 6-19304 (JP, U) Actually open 4-96103 (JP, U) Actually open 59-36607 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01Q 1/42 H01Q 1/02

Claims (3)

(57) [Claims] 1. An antenna element is surrounded by a foamed resin molded body, and the foamed resin molded body is surrounded by a film-like waterproof cover, and the waterproof cover covers a peripheral surface of the foamed resin molded body.
Cap shape that covers both ends of the sheet body and the foamed resin molded body
With the body, the required range of the cap-shaped body is
A snow protection device for antennas that is fixed . 2. The snow protection device for an antenna according to claim 1, wherein the foamed resin molding comprises a plurality of divided bodies each having a groove corresponding to the antenna shaft and a groove corresponding to the antenna element. 3. A foamed resin molded body is wrapped around the antenna element.
And surround the foamed resin molding with a film-like waterproof cover.
The snow-protecting device for an antenna , wherein the foamed resin molded body has a convex portion with a curvature corresponding to the reflecting element, and the convex portion has a hole having a size and shape corresponding to the main radiating element. .