JP2001244724A - Primary radiator for two-satellite reception - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a primary radiator for two-satellite reception integrated with a pair of horns that can obtain satisfactory reception characteristic, without having to increase the maximum diameter of a surface having the openings of the horns. SOLUTION: A corrugated choke is configured on a flange 16, formed as a disk around conical horns H1, H2 with a 1st circumferential wall 11 forming a 1st groove M1, with respect to outer circumferential faces of both the conical horns H1, H2, a 2nd circumferential wall 12 forming a 2nd groove M2 with respect to the 1st circumferential wall 11, a 3rd circumferential wall 13 forming 3rd grooves M3 with respect to the 2nd circumferential wall 12, and an outer circumferential wall 14 formed along the circumferential edge of the flange 16. The 2nd and 3rd circumferential walls 12, 13 among them are integrated respectively with the outer circumferential wall 14 in the vicinity of both ends of the conical horns H1, H2 in their arrangement direction, the 1st groove M1 and 2nd groove M2 exist in the omni-azimuth of both the conical horns H1, H2 but the 3rd grooves M3 exist at only both ends of both the conical horns H1, H2 on their symmetrical axes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a primary radiator for receiving two satellites which is suitable for receiving transmission radio waves from two adjacent artificial satellites using the same parabolic reflector.

[0002]

2. Description of the Related Art Conventionally, a multi-beam antenna that receives transmission radio waves from a plurality of artificial satellites using the same parabolic reflector has been known. Here, the outer diameter is 35-50
In the case of a multi-beam antenna configured using a small home-use parabolic reflector of about cm and receiving transmission radio waves from two artificial satellites, the primary radiator 100 disposed near the focal point of the parabolic reflector is shown in FIG. As shown in FIG. 5, two horns H1 and H2 for guiding transmission radio waves from the respective artificial satellites to antenna feed units individually provided corresponding to the respective artificial satellites are arranged close to each other. ing.

[0003] For example, when a transmission radio wave (12 GHz band) from a communication satellite is received using a parabolic reflector having an outer diameter of 45 cm, two communication satellites to be received are adjacent to each other in orbit. If the beam separation of the two satellites is 4.5 degrees, the distance between the focal points of the transmission radio waves from each satellite converged by the parabolic reflector is about 20 mm, and the aperture diameter of the horn that receives the radio waves. Is 30
mm is desirable.

[0004] In other words, in order to properly receive both transmitted radio waves from two artificial satellites, it is necessary to bring the two horns close to each other so that their apertures overlap with each other. It is difficult to configure using a radiator, and as described above, the two horns H1,
The primary radiator 100 in which H2 is arranged close to and integrated is required.

However, as described above, the two horns H1 and H
Even if 2 is integrated, as can be seen from the above numerical examples,
Since it is difficult to sufficiently secure the aperture diameters of the horns H1 and H2, when such a primary radiator 100 is actually attached to a parabolic reflector and the transmission radio waves from the two adjacent satellites are received, the horns H1 and H2 become horns H1 and H2. Due to radio wave interference due to coupling between H2s, there is a case where the reception characteristics required as a satellite receiving antenna cannot be obtained.

This is because the radiated radio wave overflows out of the reflector due to the difference between the directivity of the horns H1 and H2 and the effective aperture of the parabolic reflector. This is because the lobe level becomes large and the desired side lobe characteristics cannot be satisfied.

Therefore, in order to suppress mutual interference between the horns, usually, as disclosed in Japanese Patent Laid-Open No. 10-163737, for example, grooves M1, M2 are formed around the openings of both horns H1, H2. By providing M2 (see FIG. 5), a corrugated choke for improving directivity is formed.

FIG. 5A is a front view of the primary radiator 100 as viewed from the open ends of the horns H1 and H2.
(B) is ZZ sectional drawing in (a).

[0009]

By the way, this corrugated choke can obtain better characteristics by increasing the number of steps of the groove, but as the number of steps of the choke increases, the grooves M1, M1 of the corrugated choke increase. The diameter of the surface on which M2 is provided, and hence the size of the primary radiator, increases. When the size of the primary radiator increases, not only does the primary radiator itself become heavier, but also a support or the like for fixing the primary radiator at the focal position of the parabolic antenna must be able to withstand the weight. There is a problem that the weight as a whole increases and the usability deteriorates.

In order to prevent the primary radiator from becoming too large, the number of grooves constituting the corrugated choke is usually about one or two. In this case, although a significantly improved reception characteristic can be obtained as compared with the case where no corrugated choke is provided, it has not been sufficiently satisfactory.

The present invention has been made in order to solve the above problems.
A two-satellite receiving primary radiator integrally provided with a pair of horns corresponding to each satellite in order to receive transmission radio waves from two adjacent artificial satellites using the same parabolic reflector, having a horn opening. It is an object of the present invention to obtain good reception characteristics without increasing the maximum diameter of the surface.

[0012]

According to a first aspect of the present invention, there is provided a primary radiator for receiving two satellites, wherein a corrugated choke is formed around a pair of horns in order to improve the directivity. Grooves forming this corrugated choke are formed more at both ends in the symmetric axis direction orthogonal to the arrangement direction and along the opening surfaces of the pair of horns, from both ends in the arrangement direction of the pair of horns. It is characterized by being.

That is, since the length of the pair of horns in the symmetric axis direction is about half the length in the arrangement direction, even if more grooves are formed in the symmetric axis direction, the horn of the primary radiator can be formed. Without increasing the maximum diameter of the surface where the opening was formed,
Moreover, even if the groove constituting the corrugated choke does not necessarily go around the pair of horns, and is partially formed around the pair of horns, it is possible to improve the directional characteristics of each horn.

Therefore, according to the two-satellite receiving primary radiator of the present invention, for example, an antenna feed section is provided at the end position of the waveguide continuously provided on the opposite side to the open end of each horn, and this is provided. If it is arranged near the focal point of the parabolic reflector and operated as a parabolic antenna for two-satellite reception, it can function as a satellite receiving antenna that can obtain good reception characteristics (sidelobe characteristics).

The width of the groove forming a choke around each horn may be designed in the same manner as a known choke flange. Specifically, the width of the groove is 16 to the free space wavelength λ of the radio wave to be received. 1/1 to 3/16 (λ / 16 to λ
× 3/16). Further, the depth of the groove from the opening end or the peripheral wall of each horn may be set to about one-fourth (λ / 4) of the free space wavelength λ, similarly to the known choke flange.

By the way, if a pair of horns has a disk-shaped flange around the pair of horns and a corrugated choke is formed on the flanges, foreign matter (dust) may enter the horn opening. And a cap having a simple shape, such as a circle, can be used as a cap for preventing intrusion of water or water droplets.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B show a configuration of a primary radiator to which the present invention is applied. FIG. 1A is a front view of the primary radiator viewed from an open end of a horn, and FIG. XX
Sectional view, (c) is a YY sectional view shown in (a), (d)
FIG. 3 is a sectional view of a cap for protecting the horn.
However, (c) shows only the horn forming portion.

The primary radiator 2 of this embodiment has two communication satellites (for example, JCSAT3 and JCSAT3) arranged adjacent to each other in orbit.
This is used to receive vertically and horizontally polarized radio waves transmitted from the JCSAT4) using the same parabolic reflector having an outer diameter of, for example, about 45 cm. A horn forming unit 10 having a pair of conical horns H1 and H2 for receiving the converged radio waves from the respective satellites, and transmitting the radio waves incident via the conical horns H1 and H2 to the antenna feed units 42a and 42b.
(See FIG. 2) and a main body 20 having circular waveguides D1 and D2 for guiding the horn,
Numerals 0 are integrally formed of a metal material such as aluminum die cast.

The horn forming portion 10 includes a flange portion 1 formed in a disk shape around the conical horns H1 and H2.
6, and the conical horns H1 and H2 are arranged close to each other at positions symmetrical with respect to the center of the flange portion 16 so that the outer walls of the open ends contact each other. Hereinafter, a direction orthogonal to the arrangement direction of the conical horns H1 and H2 and along the opening surface of the conical horns H1 and H2 is referred to as a symmetric axis direction.

On the flange portion 16, a first peripheral wall 11 forming a first groove portion M1 between the outer peripheral surfaces of the conical horns H1 and H2, and a second groove portion M2 is formed between the first peripheral wall 11 and the first peripheral wall M1. Are formed, a third peripheral wall 13 that forms a third groove M3 between the second peripheral wall 12, and an outer peripheral wall 14 that is formed along the periphery of the flange portion 16. .

However, the second and third peripheral walls 12 and 13 are respectively integrated with the outer peripheral wall 14 near both ends in the arrangement direction of the conical horns H1 and H2, and therefore, the first and second groove portions M1 are provided. , M2 make a round around both conical horns H1, H2, but the third groove portion M3 is located only on both ends of the symmetrical axis of both conical horns H1, H2.

The grooves M1 to M3 and the peripheral walls 11 to 14
Are formed around the two conical horns H1 and H2 to form a corrugated choke for improving directivity characteristics. The first groove M1 has a depth (height) L1 from the opening end of each of the conical horns H1 and H2, And peripheral wall 11 of second and third groove portions M2, M3
The depth (height) L2 from １４14 is 6 mm
(= Λ / 4, λ is a radio wave to be received (for example, 12.5 GHz
z), and the widths L3, L4,
L5 is 2.3 mm, 2.3 mm, 3 mm (= λ / 16
To λ × 3/16).

However, the peripheral walls 11 to 14 are all formed at the same height, and L6 is formed from the open ends of the conical horns H1 and H2.
= 1.5 mm (= λ / 16). The distance L8 between the centers of the openings of the conical horns H1 and H2 is set to 23 mm (≒ λ), and the length of the circular waveguides D1 and D2 in the central axis direction is set to the circular waveguides D1 and D2. From the boundary point between D2 and each cone horn H1, H2,
The length L9 up to the antenna feed portions 42a and 42b arranged at the end portions of the circular waveguides D1 and D2 is an odd number of the length (λg / 4) of a quarter of the guide wavelength λg of the radio wave to be received. It is set to double.

Next, the main body 20 includes circular waveguides D1, D2.
At the end (the end opposite to the horn forming part 10)
Antenna feeder 42 corresponding to each circular waveguide D1, D2
The board storage section 30 is a space for housing the receiving circuit board 40 on which the a and b are formed. And
As shown in FIG. 2, the board housing section 30 is configured to house the receiving circuit board 40 therein, and then be hermetically sealed by a lid 50 formed of a metal material such as aluminum die cast. .

Here, the receiving circuit board 40 includes antenna feed portions 42a, 42b corresponding to the circular waveguides D1, D2.
In addition to the above, a converter circuit (not shown) for converting the reception signals obtained by the respective antenna feed units 42a and 42b into a transmission signal of a predetermined frequency band (1 GHz band), and a predetermined frequency obtained by the converter circuit An output terminal T (FIG. 2) for connecting a coaxial cable with the transmission signal of the
Output circuit (not shown) for outputting to the terminal side via
Are formed on a single substrate.

The primary radiator 2 of the present embodiment is for receiving vertically and horizontally polarized radio waves transmitted from two satellites, respectively. 42b, a pair of probes Pa for taking in vertically and horizontally polarized radio waves as reception signals.
v, Pah and Pbv, Pbh are formed respectively.

The cover 50 has conductor rods 52a projecting into the circular waveguides D1 and D2 through holes formed at the center positions of the antenna feeding portions 42a and 42b of the receiving circuit board 40, respectively. , 52b projecting therefrom, and having the same diameter as the circular waveguides D1 and D2, through the through holes (not shown) formed in the receiving circuit board 40, and the circular waveguides D1 and D2
Circular ridges 54a and 54b that are electrically connected (conductive) are formed at the open end of D2.

The cover 50 has a body 2 around it.
0, a frame portion 56 for fitting is formed.
A partition wall 58 for shielding each satellite circuit (e.g., a converter circuit) formed on the receiving circuit board 40 is formed between the ridge 6 and the ridges 54a and 54b.

As described above, the primary radiator 2 of this embodiment is a two-satellite receiving antenna in which the receiving circuit board 40 is accommodated in the board accommodating section 30 of the main body 20 so that the antenna feed section and the converter circuit are integrated. (Parabolic antenna) receiving section, and in use, in order to prevent rainwater or the like from entering the primary radiator 2 through the openings of the conical horns H1 and H2, a flange is formed from the opening end side of the conical horns H1 and H2. A circular cover 60 is covered so as to cover the entire part 16.

The receiving circuit board 40 accommodated in the board accommodating section 30 and the lid 50 projecting the conductor bars 52a and 52b are provided.
Is not a main part of the present invention, and these operations and functions are described in Japanese Unexamined Patent Application Publication No. 9-2840 filed earlier by the present applicant.
02, Japanese Patent Application Laid-Open No. 9-284003, etc., and a detailed description thereof will be omitted.

Next, FIG. 3 shows that the primary radiator 2 of this embodiment integrated with the receiving circuit board 40 as described above is mounted on an offset type parabolic reflector, and the beam separation between the two satellites is 4. Assuming that the angle is 5 degrees, a measurement result obtained by measuring the side lobe characteristics for each of the satellites A and B is shown.

In FIG. 3, (a) shows a side lobe characteristic when a horizontally polarized signal from satellite A is received.
(B) shows the side lobe characteristics when a vertically polarized signal from satellite A is received, (c) shows the side lobe characteristics when a horizontally polarized signal is received from satellite B, and (d) shows 5 shows side lobe characteristics when a vertically polarized signal from satellite B is received. In each of these characteristic diagrams, the solid line represents the measurement result of the primary radiator 2 of the present embodiment, and the dotted line represents the primary result of the comparative example (the conventional device having the same number of grooves in the arrangement direction and the symmetric axis direction). Shows the measurement results of the radiator. However, in the primary radiator of the comparative example, instead of the horn forming portion 10 of the present embodiment, as shown in FIG.
Was omitted, and a horn forming portion 10a having corrugated chokes formed of only the first and second grooves M1 and M2 was used around the conical horns H1 and H2.

According to the measurement results, the primary radiator 2 of the present embodiment includes the corrugated choke by including the third groove portions M3 formed only on both ends in the symmetric axis direction of the conical horns H1 and H2. Without increasing the maximum diameter Lmax of the conical horns H1 and H2 compared to the comparative example, the side lobe characteristics better than the comparative example, particularly the relative gain in the direction of arrival of radio waves received by the other conical horns were sufficiently suppressed. It can be seen that side lobe characteristics can be obtained.

Further, according to the present embodiment, the flange 16
Is formed in a circular shape, the cover 60 that covers the circular shape can be a circular shape having a simple shape, and thus the cover 60 can be easily manufactured. As mentioned above, although one Example of this invention was described, this invention is not limited to the said Example, You can take various aspects.

For example, in the above embodiment, the primary radiator 2 provided with a pair of conical horns H1 and H2 has been described. However, the present invention is applicable to a primary radiator formed of a pyramid horn. The configuration is the same as in the example, and a similar effect can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a configuration of a primary radiator of an embodiment.

FIG. 2 is an explanatory diagram of a case where the primary radiator of the embodiment is integrated with a receiving circuit board as a receiving unit for a 2-satellite receiving antenna.

FIG. 3 is an explanatory diagram showing a measurement result obtained by measuring a side lobe characteristic of a receiving antenna using a primary radiator of an example.

FIG. 4 is an explanatory diagram illustrating a configuration of a primary radiator of a comparative example used at the time of measurement.

FIG. 5 is an explanatory diagram illustrating a configuration of a conventional primary radiator.

[Explanation of symbols]

2: Primary radiator, 10, 10a: Horn forming part, 11-
DESCRIPTION OF SYMBOLS 13 ... 1st-3rd peripheral wall, 14 ... outer peripheral wall, 16 ... flange part, 20 ... main body, 30 ... board storage part, 40 ... receiving circuit board, 42a, 42b ... antenna feeding part, 50 ... lid, 5
2a, 52b: conductor rods, 54a, 54b: ridges, 56:
Frame part, 58 ... Partition part, 60 ... Cover, D1, D2 ... Circular waveguide, H1, H2 ... Conical horn, M1-M3 ... First to first
Third groove

Claims (2)

[Claims] 1. A pair of horns that respectively receive radio waves transmitted from two artificial satellites and individually converged by the same parabolic reflector and guide them to a waveguide provided with an antenna feed unit; A corrugated choke comprising a plurality of grooves formed around openings of the pair of horns by a plurality of peripheral walls arranged at intervals from the pair of horns along the outer peripheral surface of the horn; A primary radiator for satellite reception, wherein grooves forming the corrugated choke are arranged at both ends in the arrangement direction of the pair of horns, and are symmetrical axes orthogonal to the arrangement direction and along the opening surfaces of the pair of horns. A primary radiator for receiving two satellites, which is formed in a large number at both ends in a direction. 2. The primary radiation for two-satellite reception according to claim 1, further comprising a disk-shaped flange around the pair of horns, wherein the corrugated choke is formed on the flange. vessel.