KR20220150142A - Antenna apparatus - Google Patents

Abstract

Provided is an antenna device, which comprises a parabolic reflector; a dielectric support; a sub-reflector connected to an upper end of the dielectric support; and a waveguide connected to a lower end of the dielectric support, wherein the parabolic reflector has a curved surface with a ratio of focal length to a diameter greater than a predetermined value for high gain, and a corrugation for suppressing cross polarization is formed in one region of the dielectric support.

Description

Antenna device {ANTENNA APPARATUS}

The present disclosure relates to an antenna device.

The parabolic reflector antenna is widely used as an antenna for satellite communication. The parabolic antenna can take a high signal gain for satellite communication, and it is relatively easy to implement a wide bandwidth necessary to support a large-capacity communication speed. On the other hand, an antenna for satellite communication must satisfy the antenna radiation pattern, which is a standard recommended by the International Telecommunication Union (ITU).

The parabolic curved surface of the main reflector for obtaining a high-gain antenna signal usually has an F/D (F: parabolic focal length, D: antenna diameter) value greater than 0.25. On the other hand, if this parabolic curved surface is viewed from the side, the radio wave radiation area of the feeding horn located at the focal point of the curved surface is exposed outside the parabolic curved surface, so some of the electromagnetic waves radiated from the feeding horn are not reflected by the parabolic reflector and are not reflected on the side of the antenna. is emitted directly into The phase of the polarized wave of electromagnetic waves is reversed when it meets a conductive material such as a reflector, and the electromagnetic wave that does not reach the parabolic reflector and is directly radiated out of the main reflector is out of phase with the electromagnetic wave that arrives at the parabolic reflector. Therefore, when such a parabolic curved surface is used, the cross-polarization level radiated laterally may exceed the level recommended by the ITU. Therefore, a method capable of lowering the cross-polarization level while maintaining a high antenna gain is required.

The present invention includes an embodiment of reducing the cross-polarization level in the antenna side direction by solving the problem that a part of the electromagnetic wave radiated from the feeding horn of the reflector antenna is not reflected by the main reflector but is directly radiated to the side of the antenna.

The technical problem to be achieved by the present invention is not limited to the above-described problems, and other technical problems may be inferred from the following embodiments.

According to an embodiment, the antenna device includes: a parabolic reflector; dielectric support; a sub-reflecting plate connected to the upper end of the dielectric support; and a waveguide connected to a lower end of the dielectric support, wherein the parabolic reflector has a curved surface having a ratio of focal length to diameter greater than a preset value for high gain, and the dielectric support A corrugation for suppressing cross-polarization may be formed in one region of the .

Specific details of other embodiments are included in the detailed description and drawings.

According to the present disclosure, a focal length versus diameter antenna device for high gain forms a corrugation for cross polarization suppression in one region of a dielectric support to lower the lateral propagation level of the feed horn and finally increase the lateral cross polarization level of the antenna It can be lowered to satisfy the ITU-recommended antenna standard pattern.

The effects of the invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims.

1 shows an antenna device having a dielectric support according to an embodiment.
2 shows a top view of an antenna according to an embodiment.
3 shows a cross-section of a feed horn included in an antenna device according to an embodiment.
4 shows a cross-section of a feed horn included in an antenna device according to another embodiment.
5 shows a dielectric support on which wrinkles 162 are formed as viewed from one side.
6 shows the shape of a wrinkle according to an embodiment.
7 is a graph of gain characteristics of the antenna device using the dielectric support in FIG. 3 .
FIG. 8 shows antenna gain characteristics of the antenna device using the dielectric support of FIG. 4 , which is an embodiment.
9 and 10 show cross-sections of a dielectric support according to an embodiment.
11 shows a sub-reflective plate according to an exemplary embodiment.

Terms used in the embodiments are selected as currently widely used general terms as possible while considering functions in the present disclosure, but may vary depending on intentions or precedents of those of ordinary skill in the art, emergence of new technologies, and the like. In addition, in certain cases, there are also terms arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the corresponding description. Therefore, the terms used in the present disclosure should be defined based on the meaning of the term and the contents of the present disclosure, rather than the simple name of the term.

In the entire specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

The expression “at least one of a, b, and c” described throughout the specification means 'a alone', 'b alone', 'c alone', 'a and b', 'a and c', 'b and c ', or 'all a, b, and c'.

Throughout the specification, "corrugation" means a portion protruding from the surface of the object to the outside of the surface of the object, and there is no limitation on the detailed form thereof. become wrinkled The pleats may be integral with the object or may be detachable and mountable from the object. In addition, the material of the wrinkle may be the same as or different from the rest of the object except for the wrinkle.

Throughout the specification, "off-axis angle" refers to an azimuth angle measured with the focus of the antenna as the origin and the front of the center of the antenna as the reference axis. The directing direction of the antenna may have an off-axis angle of 0 degrees, a direction perpendicular to the antenna directing direction may have an off-axis angle of 90 degrees, and a direction behind the antenna may have an off-axis angle of 180 degrees.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

1 shows an antenna device having a dielectric support according to an embodiment.

According to an embodiment, the antenna device 1 may include a main reflection plate 100 , a sub reflection plate 120 , a dielectric support 110 , and a waveguide 130 . In the antenna device 1 shown in Fig. 1, only the components related to this embodiment are shown. Accordingly, it can be understood by those of ordinary skill in the art related to the present embodiment that other general-purpose components may be further included in addition to the components shown in FIG. 1 .

The radio wave may be fed through the inlet of the waveguide 130 , pass through the dielectric support 110 , and be reflected by the sub-reflector 120 . Since the sub-reflecting plate 120 is located at the focal point of the main reflecting plate 100 , the radio wave reflected by the sub-reflecting plate 120 is reflected back to the main reflecting plate 100 and the radio wave can be radiated in the direction of the antenna. Here, the curved surface of the main reflector 100 may be a parabolic curved surface, but is not limited thereto, and may be any curved surface having one or more focal points.

For a high gain of the antenna reflector, the F/D value, which is a ratio of focal length to diameter, may be greater than a preset value. Here, F denotes a focal length, and D denotes a diameter of the main reflector. For example, the F/D value may be set to be greater than or equal to 0.25 in order to obtain a high gain of the antenna reflector.

2 shows a top view of an antenna according to an embodiment.

The sub-reflecting plate 120 may be located at the focal point of the main reflecting plate 100 , and as the F/D value increases, the focal length compared to the diameter becomes longer, so that the sub-reflecting plate 120 is further away from the reflective surface of the main reflecting plate 100 . will lose In FIG. 2 , it can be seen that the sub-reflecting plate 120 is exposed to the outside without being covered by the main reflecting plate 100 . In this case, some of the radio waves reflected by the sub-reflecting plate 120 are not reflected by the main reflector 100 and travel to the side of the antenna, and as a result, the cross-polarization level in the side direction of the antenna may be increased. When the cross-polarization level rises above a certain level, it is impossible to comply with the antenna standard pattern recommended by the International Telecommunication Union (ITU), and communication quality and performance may be deteriorated.

The dielectric support 110 may include corrugations for suppressing cross-polarization. In other words, wrinkles for suppressing cross-polarization may be formed in one region of the dielectric support 110 . For example, the wrinkle may have a hollow cylindrical shape coaxial with the central axis of the dielectric support 110 , and may be formed to protrude from the dielectric support 110 in the direction of the central axis of the dielectric support 110 . According to an embodiment, a plurality of wrinkles may be formed on the upper end of the dielectric support 110 .

According to an embodiment, the antenna device 1 may further include a polarizer 170 connected to the waveguide 130 . According to an embodiment, the polarizer 170 may be a polarizer for circular polarization. For example, the polarizer 170 may include at least one of a septum polarizer, a corrugated polarizer, and a polarizer to which a dielectric vane is applied.

3 shows a cross-section of a feed horn included in an antenna device according to an embodiment.

The feeding horn 11 may include a dielectric support 112 , a sub-reflecting plate 122 , and a waveguide 132 . In addition, the feeding horn 11 may further include a stepped impedance matching unit 152 for impedance matching on the dielectric support 112 .

4 shows a cross-section of a feed horn included in an antenna device according to another embodiment.

The feed horn 12 may include a dielectric support 114 , a sub-reflector plate 124 , and a waveguide 134 . According to one embodiment, each of the dielectric support 114, the sub-reflector plate 124, and the waveguide 134 of FIG. 4 is the dielectric support 110, the sub-reflector plate 120, and the waveguide 130 of FIGS. 1 and 2, respectively. can correspond to each. In addition, the feeding horn 12 may further include a stepped impedance matching unit 154 for impedance matching on the dielectric support 114 .

Wrinkles 162 may be formed in one region of the dielectric support 114 . The wrinkle 162 may be formed in one region of the upper end of the dielectric support 114 . For example, the corrugation 162 may be formed to protrude from the dielectric support 114 along the central axis direction of the dielectric support 114 . According to one embodiment, the pleats 162 may have a shape in which a portion of the upper end is chamfered or filled in a hollow cylindrical shape.

According to an embodiment, a plurality of wrinkles 162 may be formed on the upper end of the dielectric support 14 . At this time, each of the plurality of pleats 162 may have a different height, and more specifically, the inner diameter of the first pleat of the plurality of pleats 162 is that of the second pleat of the plurality of pleats 162 . It may be larger than an outer diameter, and a height of the first pleat may be greater than a height of the second pleat.

In the present disclosure, the cross-polarization level may be suppressed by forming the corrugations 162 on the dielectric support 114 . In other words, it is possible to reduce radio waves that are reflected from the sub-reflecting plate 124 through the wrinkles 162 formed on the dielectric support 114 and directly radiated to the side of the antenna without being reflected by the main reflecting plate 100 . According to an embodiment, the dielectric support 114 and the corrugation 162 may be integrally manufactured so that no boundary is formed at a portion where the upper end of the dielectric support 114 and the wrinkle 162 abut by a method such as molding.

The dielectric support 114 may be any structure that exists between the sub-reflection plate 124 and the waveguide 134 and has a dielectric material. In FIG. 4 , the dielectric support 114 has a truncated upper end and a lower end shown in a cylindrical shape connected to the upper end of the truncated cone, but this is only an example, and the upper and lower ends may have different shapes, and the shape is the same. or may be different.

According to an embodiment, the dielectric constant of the dielectric support 114 may be greater than 2. For example, the dielectric material may be Teflon, alumina, ceramic, or the like.

5 shows the dielectric support 114 in which the wrinkles 162 are formed as viewed from one side. 6 shows the shape of the pleats 162 according to an embodiment.

7 is a graph of gain characteristics of the antenna device using the feed horn 11 in FIG. 3 .

As described above, since the high-gain antenna has a large F/D value, the position of the sub-reflector, which is the focal point, may protrude toward the front of the antenna as shown in FIG. 2 . In this case, among the radio waves reflected from the sub-reflector, the radio waves that do not reach the edge of the main reflector are not reflected by the main reflector and are radiated directly, which is called spill over. Referring to the graph of FIG. 7 , at an off-axis angle of 100 degrees or less, a spill over phenomenon occurs in which radio waves that are not reflected by the main reflector are directly radiated to the side of the antenna.

In FIG. 7, the Horn pattern shows the gain characteristics of only the feed horn excluding the main reflector. Therefore, the Horn pattern shows the gain characteristics of the propagation reflected by the sub-reflector through the waveguide and the dielectric support. In FIG. 7 , it can be seen that the gain of the Horn pattern is rather high in a certain range of about 100 degrees off-axis or less. Because of this, the reflector pattern representing the overall gain characteristics of the antenna device has a higher gain than ITU-R S.731-1 in a certain range of about 100 degrees off-axis or less, and thus does not meet the ITU's recommended standards.

FIG. 8 shows the antenna gain characteristics of the antenna device using the feed horn 12 of FIG. 4 .

Unlike FIG. 7 using the feeding horn 11 of FIG. 3 , the Horn pattern in FIG. 8 has a lower level in a certain range of about 100 degrees or less off-axis compared to FIG. 7 . Because of this, the reflector pattern has a lower gain than ITU-R S.731-1 in a certain range of about 100 degrees off-axis or less, and thus satisfies the ITU's recommended standards.

9 and 10 show cross-sections of a dielectric support according to an embodiment.

According to an embodiment, the dielectric support 116 may correspond to the dielectric support 110 of FIGS. 1 and 2 . In one embodiment, the dielectric support 116 may include a mounting area 16 to which the pleats 164 may be mounted. Since it is possible to attach and detach the pleats 164, the cross-polarization level can be adjusted by mounting the pleats according to the situation. According to an embodiment, a plurality of mounting regions 16 capable of mounting a plurality of pleats 164 having different heights and thicknesses may be formed. Here, the mounting region 16 may be any structure capable of mounting or detaching the pleats 164 to or from the dielectric support 116 . For example, the mounting region 16 may include a threaded structure that has a thread corresponding to the corrugation 164 and can be screwed in, a structure that fits the corrugation 164 and corrugates with the lateral pressure and frictional force of the structure, or It may have a structure capable of attaching the wrinkles 164 with an adhesive.

In FIG. 10 , the mounting region 16 is depicted as being formed at the upper end of the dielectric support 116 , but this is only one embodiment, and the mounting region 16 may be formed on the lower end of the dielectric support 116 as well as any part of the dielectric support 116 . can

11 shows a sub-reflection plate according to an exemplary embodiment.

The sub-reflective plate 124 may correspond to the sub-reflective plate 120 of FIG. 1 .

As shown in FIG. 11 , the sub-reflecting plate 124 may have a corrugated structure. According to another embodiment, the sub-reflective plate 124 may have a stepped structure. The material of the sub-reflecting plate 12 may be a metal such as aluminum.

As specific examples described in the present embodiment, the technical scope is not limited in any way. For brevity of the specification, descriptions of other functional aspects of antenna-related components may be omitted. In addition, the connections or connecting members of the lines between the components shown in the drawings exemplify functional connections and/or physical or circuit connections, and in an actual device, various functional connections, physical connections that are replaceable or additional may be referred to as connections, or circuit connections.

In this specification (especially in the claims), the use of the term "above" and similar referential terms may be used in both the singular and the plural. In addition, when a range is described, individual values within the range are included (unless there is a description to the contrary), and each individual value constituting the range is described in the detailed description. Finally, the steps constituting the method may be performed in an appropriate order unless the order is explicitly stated or there is no description to the contrary. It is not necessarily limited to the order of description of the above steps. The use of all examples or exemplary terms (eg, etc.) is merely for describing the technical idea in detail, and the scope is not limited by the examples or exemplary terms unless limited by the claims. In addition, those skilled in the art will recognize that various modifications, combinations, and changes may be made in accordance with design conditions and factors within the scope of the appended claims or their equivalents.

Claims (11)

An antenna device comprising:
parabolic reflector;
dielectric support;
a sub-reflecting plate connected to the upper end of the dielectric support; and
and a waveguide connected to the lower end of the dielectric support;
The parabolic reflector has a curved surface having a ratio of focal length to diameter greater than a preset value for high gain,
An antenna device, in which a corrugation for suppressing cross-polarization is formed in one region of the dielectric support. According to claim 1,
The preset value is 0.25, the antenna device. According to claim 1,
The lower end of the dielectric support includes a stepped impedance matching portion,
The pleats are capable of being coupled to a region of the upper end, the antenna device. According to claim 1,
The corrugation has a hollow cylindrical shape coaxial with the central axis of the dielectric support. According to claim 1,
The corrugation is formed to protrude from the dielectric support in the direction of the central axis of the dielectric support. According to claim 1,
A plurality of pleats are coupled to the upper end of the dielectric support, the antenna device. 7. The method of claim 6,
The plurality of wrinkles,
Containing a first pleat having a hollow cylindrical shape coaxial with the central axis of the dielectric support, and a second pleat having a hollow cylindrical shape coaxial with the central axis,
an inner diameter of the first pleat is greater than an outer diameter of the second pleat, and a height of the first pleat is greater than a height of the second pleat. According to claim 1,
The dielectric support includes a mounting area corresponding to the shape of the pleats,
and the pleats are mounted to the dielectric support via the mounting area. 9. The method according to any one of claims 1 to 8,
wherein the dielectric support is made of a dielectric having a permittivity greater than two. According to claim 1,
Further comprising a polarizer connected to the waveguide,
The polarizer includes at least one of a septum polarizer, a corrugated polarizer, and a polarizer to which a dielectric vane is applied. According to claim 1,
The structure of the sub-reflecting plate is any one of a stepped structure and a corrugated structure, and the material of the sub-reflecting plate is aluminum.

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