JP2812283B2 - Reflector antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflector antenna for tracking a target by an amplitude comparison method, and more particularly to a reflector antenna having a primary radiator for tracking circularly polarized waves.

[0002]

2. Description of the Related Art There is a reflector antenna that receives a circularly polarized wave component of a circularly polarized wave signal or a linearly polarized wave signal as a tracking signal because it is not necessary to perform polarization tracking. This type of reflector antenna has a primary radiator for tracking circularly polarized waves. A reflector antenna including such a primary radiator for tracking circularly polarized waves is disclosed in, for example, Japanese Utility Model Application Laid-Open No. 1-1070.
No. 6 (invention name: tracking antenna).

FIGS. 4A and 4B are configuration diagrams of a reflector antenna according to the prior art, wherein FIG. 4A is a schematic diagram, and FIG.
It is R2 sectional drawing.

In this reflector antenna, a reflector 1 whose radio wave reflecting surface has a parapolar shape or an offset parabolic shape receives a radio signal R received from a target such as an opposed antenna or the like, as a primary radiator 2, 6A1, 6A2. Reflect toward 6B1 and 6B2. The radio signal R may be a circularly polarized wave or a linearly polarized wave. 1 such as horn antenna
The secondary radiator 2 sets the center of radio wave radiation at a position O near the focal point on the mirror axis z of the reflecting mirror 1 so that the antenna gain becomes substantially maximum in the mirror axis z direction. Here, the radio signal R received by the primary radiator 2 is converted into the main signal beam M and the primary radiator 6.
Radio signal R received by A1, 6A2, 6B1 and 6B2
Is defined as a tracking signal beam T. The primary radiator 2 sends the received main signal beam M as a main signal such as a wireless communication signal to a receiver (not shown) or the like, and the main signal is used for its intended purpose.

[0005] The primary radiators 6A1, 6A2, 6B1 and 6B2 are antennas for receiving circularly polarized signals using a horn antenna or the like, and have substantially the same performance.
The primary radiators 6A1 and 6A2 are two primary radiators for elevation angle tracking, and the primary radiators 6B1 and 6B2 are two primary radiators for horizontal angle tracking. It is a radiator.
The primary radiators 6A1, 6A2, 6B1 and 6B2 are planes (xy) passing through the position O near the focal point and perpendicular to the mirror axis z (x axis: horizontal axis with respect to the mirror axis z, y axis: mirror axis) They are arranged at positions (0, d), (0, -d), (d, 0), and (-d, 0) separated from the position O on the plane (vertical axis with respect to z) by a distance d. That is, the primary radiators 6A1 and 6A2 and the primary radiators 6B1 and 6B2 are symmetrically arranged with respect to the position O near the focal point.

As described above, primary radiators 6A1 and 6A
When each of 2, 6B1 and 6B2 is offset from the position O near the focal point by the distance d, the primary radiator 6A
The maximum antenna gain direction (hereinafter, also referred to as the maximum gain direction) of the radiation pattern (secondary radiation pattern) from the reflector 1 by the antennas 1, 6A2, 6B1 and 6B2 is in the elevation direction from the mirror axis z in the direction opposite to the offset. The angle differs by an angle αE and an azimuth angle βE. These angles are determined by the dimensions of the reflector 1, the reflector 1 and the primary radiator 6A1.
And the like, and the characteristics of the primary radiator 6A1, etc. FIG. 4A shows only the antenna maximum gain directions of the primary radiators 2 and 6A1 and the difference αE thereof.
The primary radiators 6A1, 6A2, 6B1 and 6B2 convert the received tracking signal beam T into linearly polarized waves, and
Occurs _A1, T _A2, T _B1 and T _B 2 (not shown), respectively, and sends these tracking signals to the power supply circuit 4.

The power supply circuit 4 includes primary radiators 6A1 and 6A
In response to the tracking signals T _A1 and T _{A2 from A2} , a sum signal (T _A1 + T _A2 ) = ΣA and a difference signal (T _A1 −T _A2 ) = ΔA of the tracking signal T _A are generated. The sum signal ΣA and the difference signal ΔA are signals for tracking control of the reflecting mirror 1 in the elevation direction.
The feeding circuit 4 is responsive to the tracking signal T _B1 and T _B2 from the primary radiator 6B1 and 6B2, the tracking signal T _B
Signal (T _B1 + T _B2 ) = ΣB and the difference signal (T _B1 −T _B
B2 ) = ΔB. The sum signal ΣB and the difference signal ΔB are tracking control signals of the reflecting mirror 1 in the azimuth direction.

A tracking control circuit (not shown) includes an elevation angle error signal ΔA / ΣA and a horizontal angle error signal ΔB
/ ΣB to 0, that is, the tracking signal T
The elevation angle and the azimuth angle of the reflecting mirror 1 are controlled so that the amplitudes of _A1 and T _A2 coincide with the amplitudes of T _B1 and T _B2 , respectively.
Finally, when the elevation angle error signal ΔA / ΣA and the horizontal angle error signal ΔB / ΣB both become 0, the target direction is the mirror axis z direction, that is, the antenna gain by the primary radiator 2. Is the maximum direction. As described above, the reflecting mirror 1 is controlled so that the amplitudes of the tracking signals T _A1 and T _{A2 and} the amplitudes of T _B1 and T _B2 are equal.
This tracking method is called an amplitude comparison method.

FIG. 5 is a schematic diagram of a secondary radiation pattern by the primary radiators 6A1 and 6A2 of the reflector antenna of FIG. This figure shows a state where the primary radiators 6A1 and 6A2 are both for right-handed circular polarization.

FIG. 5 shows that the primary radiator 6A1 is arranged at a point (0, d) on a (xy) plane which is a vertical plane including a mirror axis.
The secondary radiation pattern when the primary radiator 6A2 is arranged at the symmetry point of the primary radiator 6A2, that is, at (0, -d), is schematically shown by a plurality of equal antenna gain lines. As can be seen, despite the fact that the primary radiators 6A1 and 6A2 are arranged symmetrically with respect to the horizontal plane (xz plane) including the mirror axis, each of the primary radiators 6A1 and 6A2 is used. The maximum gain direction of the secondary radiation pattern is the horizontal plane (xz plane)
Is not symmetric with respect to That is, the maximum gain direction of the secondary radiation pattern by the primary radiator 6A1 is in the + direction of x, 1
The maximum gain direction of the secondary radiation pattern by the secondary radiators 6A2 is slightly shifted in the-direction of x, and the primary radiators 6A1 and 6A
The maximum gain direction of the secondary radiation pattern by A2 rotates counterclockwise when viewed from the back of the reflecting mirror 1. As a result, the locus of a line connecting points where the antenna gains of the secondary radiation patterns by the primary radiators 6A1 and 6A2 coincide with each other, that is, the “crosspoint locus XP” is shifted counterclockwise from the x-axis. ing.

The locus XP of the cross point is substantially orthogonal to the line connecting the antenna gain maximum points of the primary radiators 6A1 and 6A2, and is linear. According to the simulation result by the calculation of the secondary radiation pattern, the maximum gain direction of the secondary radiation pattern by the primary radiators 6A1 and 6A2 is the angle α in the elevation (y) direction with respect to the mirror axis z.
E, the angle βE also in the horizontal (x) direction.
The angle tan-1 (βE / αE) of the cross point trajectory XP deviated from the x-axis was about 11 °.
The above-described phenomenon that the cross point locus XP shifts is peculiar to the case where the primary radiator for circular polarization is used, and is not seen when the primary radiator for linear polarization is used. When the primary radiators 6A1 and 6A2 are for left-handed circularly polarized waves, the trajectory XP of the cross point shifts clockwise from the x-axis. Primary radiators 6B1 and 6B for azimuth tracking
The primary radiator 6 is also rotated by 90 ° for the primary radiator 6.
A phenomenon similar to that of A1 and 6A2 occurs.

FIGS. 6A and 6B are diagrams for explaining the feeding circuit 4 of the reflector antenna in detail. FIG. 6A is a detailed block diagram of the feeding circuit 4A of the first example, and FIG. 6B is a diagram of the feeding circuit 4B of the second example. FIG. 4C is a detailed block diagram, and FIG. 4C is a waveform diagram for explaining tracking signal processing by the power supply circuit 4B.

First, referring to FIG. 6A, the power supply circuit 4A is composed of hybrids 41 and 42 using a waveguide, a strip line or a coaxial line. The hybrid 41 includes a tracking signal T _A1 from the primary radiator 6A1.
The input to the port P1, enter the tracking signal T _A2 from the primary radiator 6A2 to port P2, resulting sum signal _{(T A1 + T A2) =} ΣA tracking signal T _A to the port P3, the tracking signal T
_A difference signal of _A (T _A1 −T _A2 ) = ΔA is generated at the port P4. Hybrid 42 having the same configuration as hybrid 41
It is a tracking signal T _B1 from the primary radiator 6B1 port P1
And the tracking signal T _B2 from the primary radiator 6B2 is input to the port P2, and the sum signal of the tracking signal T _B (T _B1 + T _B2 )
= Occur ΣB the port P3, the difference signal (T tracking signal T _B
B1− T _B2 ) = ΔB at port P4.

Next, referring to FIGS. 6B and 6C, the power supply circuit 4B includes high frequency (RF) switches 43 and 44 and a signal processing circuit 45. The RF switch 43 alternately switches the tracking signals T _A1 and T _A2 from the two primary radiators 6A1 and 6A2 every time T0,
_A tracking signal DA which is a time-division tracking signal _TA1 and _TA2 is generated. The signal processing circuit 45, in response to the tracking signal D _A, produces a sum signal ΣA and difference signal ΔA of the tracking signal T _A is the data for elevation control of the reflector 1. The RF switch 44 alternately switches the tracking signals T _B1 and T _B2 from the two primary radiators 6B1 and 6B2 at every time T0, and the tracking signal D which is the time-division tracking signals T _B1 and T _{B2.
Produces B.} The signal processing circuit 45, the tracking signal D also responds to _B, and the azimuth angle control data of the reflecting mirror 1 tracking signal T
A sum signal ΣB of _B and a difference signal ΔB are generated.

[0015]

In the above-mentioned conventional reflector antenna, when a primary radiator for circular polarization is used for tracking, the primary radiator is perpendicular to the mirror axis z (y-axis). ) Even if they are symmetrically arranged above, the maximum antenna gain direction is shifted not only in the elevation direction but also in the horizontal (azimuth) direction. Therefore, the locus XP of the cross point also becomes a locus in a direction deviated from the x-axis. Similarly, even if the primary radiator is arranged symmetrically on the horizontal axis (x-axis) with respect to the mirror axis z, the maximum antenna gain direction is shifted not only in the horizontal direction but also in the elevation direction. As a result, so-called crosstalk occurs in which the primary radiator also outputs its own tracking signal for orthogonal control to the output terminal.

As described above, when the stalk is generated, the elevation angle error signal ΔA / ΣA includes not only the elevation angle error but also the azimuth angle error. Similarly, the azimuth angle error signal ΔB / ΣB
Includes not only the pointing angle error in the azimuth direction but also the pointing angle error in the elevation direction. For this reason, the antennas (reflector and primary radiator) are not drawn straight in the direction of the target, but are drawn in a detour in a curved manner. In this way, the antenna tracking control bypasses the curved path,
The pull-in speed is deteriorated, and when the target is a fast-moving moving body, tracking of the target may become difficult. Therefore, in receiving the tracking signal, it is necessary to reduce the crosstalk and the deviation of the locus of the cross point in the primary radiator in the orthogonal direction, which causes the crosstalk.

[0017]

SUMMARY OF THE INVENTION A reflector antenna according to the present invention comprises a reflector for reflecting a received radio signal and a main reflector arranged so that an antenna gain is substantially maximized in a direction of a mirror axis of the reflector. A primary radiator for signal and a symmetrically arranged mirror reflector in a direction deviating from the mirror axis in a horizontal plane including the mirror axis such that an antenna gain with respect to a circularly polarized wave component of the radio signal becomes substantially maximum; An azimuth tracking primary radiator that generates an azimuth tracking signal from a circularly polarized component of the radio wave signal received from the radiator, and deviates from the mirror axis in a vertical plane including the mirror axis. In two directions, the antenna gains for the circularly polarized wave components of the radio wave signal are symmetrically arranged so as to be almost maximum, and two signals for raising the elevation angle are generated from the circularly polarized wave component of the radio wave signal received from the reflecting mirror. 1 set A reflector antenna comprising: an elevation tracking primary radiator; and a feeder circuit for generating a tracking control signal in response to the azimuth tracking signal and the elevation tracking signal. The primary radiators are respectively positioned in planes slightly inclined from the horizontal plane about the mirror axis so that the trajectory of the cross point, which is the trajectory of the points where the antenna gains are equal to each other, almost coincides with the vertical plane. And the two primary radiators for elevation tracking are arranged so that the trajectory of a cross point, which is the trajectory of a point having the same antenna gain, substantially coincides with the horizontal plane. They are respectively arranged in planes whose surfaces are slightly inclined.

In the reflector antenna, each of the primary radiator for azimuth tracking and the primary radiator for elevation tracking may include:
It is possible to adopt a configuration in which the radio wave emission axis is directed outward at an angle with respect to the mirror axis.

[0019]

Next, the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of a reflector antenna according to the present invention.
FIGS. 3A and 3B are configuration diagrams of an embodiment of the present invention, in which FIG.
FIG. 3A is a cross-sectional view taken along line X1-X2 of FIG.

This reflector antenna comprises the same reflector 1, the primary radiator 2 for the main signal beam M and the feeder circuit 4 as the prior art reflector antenna shown in FIG. The primary radiators that receive the polarization component as the tracking signal beam T include the primary radiators 3A1, 3A2, and 3B.
1 and 3B2. Primary radiators 3A1 and 3A
2 is a set of two primary radiators for tracking elevation angles.
B1 and 3B2 form a set of two for azimuth tracking. Primary radiators 3A1, 3A2, 3B1 and 3B2
Are the primary radiators 6A1, 6A2, 6B1 and 6 in FIG.
B2 has the same function and performs the same operation, but is arranged at a different location.

In other words, the primary radiators 3A1 and 3A2 for elevation tracking pass by the distance O in the y-axis direction from the position O on the xy plane which is a vertical plane including the mirror axis z, passing through the position O near the focal point. Further, they are arranged symmetrically at positions (d1, d) and (-d1, -d) apart from each other by a distance d1 in the x-axis direction. That is, the primary radiator 6A1 in FIG.
And 6A2, primary radiators 3A1 and 3A3
A2 is moved clockwise in the x-axis direction by d1.
In this reflector antenna, the primary radiators 3A1 and 3A
By arranging 2 as described above, the maximum gain direction of the secondary radiation pattern can be turned clockwise about angle tan ^-1 (d1 / d) about mirror axis z when compared with the reflector antenna of FIG. Is rotated. Now, the angle αE in the elevation direction in the maximum gain direction of the secondary radiation pattern by the primary radiators 3A1 and 3A2 is generally a very small angle. Therefore, when the primary radiators 3A1 and 3A2 are rotated clockwise from the position of the primary radiators 6A1 and 6A2 in FIG. 4 by the distance d1, the azimuth generated at the position of the primary radiators 6A1 and 6A2 in FIG. The shift angle βE in the maximum gain direction in the angular direction can be corrected, and the shift in the maximum gain direction in the x-axis direction can be eliminated. At this time, the value of d1 / d may be set to about (βE / αE).

As described above, primary radiators 3A1 and 3A
When A2 is arranged, the direction of the maximum antenna gain in the secondary pattern of the tracking signal T is corrected to the position of the angle βE = 0 ° with respect to the azimuth direction, and the maximum antenna gain direction by the primary radiator 2 with respect to the elevation angle. Are different directions by the angle αE. As a result, primary radiators 3A1 and 3A
2, the cross-point locus XP of the equal antenna gain point coincides with the y-axis, and does not cause crosstalk. When primary radiators 3A1 and 3A2 are for receiving left-hand circularly polarized signals, primary radiators 3A1 and 3A2 are used.
At an angle tan ^-1 (β
E / αE).

Primary radiators 3B1 and 3 for azimuth tracking
B2 is also located at a position rotated by 90 ° with respect to the primary radiators 3A1 and 3A2 for elevation tracking, so that 1
The only difference is that they are orthogonal to the secondary radiators 3A1 and 3A2. That is, the primary radiators 3B1 and 3B2 for azimuth tracking pass the position O near the focal point and are separated by a distance d in the x-axis direction from the position O on the (xz) plane which is a horizontal plane including the mirror axis z. , (D, -d1) and (-d,
In d1), they are arranged symmetrically to each other. That is, as compared with the primary radiators 6B1 and 6B2 in FIG. 4, the primary radiators 3B1 and 3B2 are moved clockwise by d1 in the y-axis direction. This reflector antenna, the maximum gain direction of the secondary radiation pattern by placing the primary radiator 3B1 and 3B2 as described above, as compared with the reflector antenna of Figure 4, the angle about the mirror axis z tan ^{- 1} (d1 / d)
(Not shown) is rotated clockwise. Therefore,
Primary radiators 3B1 and 3B2 are replaced with primary radiators 6B of FIG.
By rotating clockwise by a distance d1 from the positions 1 and 6B2, it is possible to correct the shift angle in the elevation direction of the maximum gain direction generated at the position of the primary radiators 6B1 and 6B2 in FIG. Direction deviation can be eliminated. As a result, the cross point locus XP (see FIG. 5) of the equal antenna gain points in the azimuth direction coincides with the y-axis, and no crosstalk occurs.

The primary radiators 3A1, 3A2, 3B1 and 3B2 receive the tracking signals T _A and T _B (see FIG. 6).
Are respectively converted into linearly polarized waves and sent to the feed circuit 4. The power supply circuit 4 supplies a tracking signal T as in the conventional example of FIG.
_A sum signal of _A (T _A1 + T _A2 ) = ΣA, difference signal (T _A1 −
T _A2 ) = ΔA, Sum signal of tracking signal T _B (T _B1 + T _B2 ) =
ΣB and the difference signal (T _B1 −T _B2 ) = ΔB. As the power supply circuit 4, of course, the power supply circuit 4A or 4B shown in FIG. 5 can be used.

FIG. 2 shows a second embodiment of the reflector antenna according to the present invention.
FIGS. 3A and 3B are configuration diagrams of an embodiment of the present invention, in which FIG.
FIG. 2 is a sectional view taken along line Y1-Y2 of FIG. FIG. 3 is FIG.
FIG. 9 is a diagram of a secondary radiation pattern of the reflector antenna according to the embodiment.

Referring to FIG. 2, this reflector antenna is a circularly polarized tracking signal comprising a reflector 1, a primary radiator 2 for the main signal beam M, and a feeder circuit 4, which are the same as the reflector antenna of FIG. For the amplitude comparison method using the beam T of FIG. Also, the primary radiator 5 in this reflector antenna
A1 and 5A2 correspond to the primary radiators 3A1 and 3A2 for elevation tracking in FIG. 1, respectively, and the primary radiators 5B1 and 5B2 for azimuth tracking correspond to the primary radiators 3B1 and 3B2 respectively in FIG. I do. Primary radiator 5
A1, 5A2, 5B1 and 5B2 have the same functions and perform the same operations as the primary radiators 3A1, 3A2, 3B1 and 3B2 in FIG. 1, but the arrangement position and the arrangement method are different.

Primary radiators 5A1 and 5A for elevation angle tracking
Reference numeral 2 denotes a position passing through the vicinity O of the focal point and separated from the position O on the (xy) plane which is a vertical plane including the mirror axis z by the distance d3 in the y-axis direction and further by the distance d4 in the x-axis direction. (D4, d3) and (-d4, -d3) are arranged symmetrically to each other. At the same time, the primary radiators 5A1 and 5A2 point the radio wave radiation axis (perpendicular to the opening surface of the primary radiator) outward at an angle with respect to the mirror axis z. Also,
The tracking signal beam T is a right circular polarization signal. Also in the reflector antenna of FIG. 2, similarly to the embodiment of FIG. 1, the maximum antenna gain direction by the primary radiators 5A1 and 5A2 is set to the angle αE with respect to the mirror axis z in the (yz) plane. , The distance d3, d4, the direction of the radio wave radiation axis of the primary radiators 5A1 and 5A2 are set.

Primary radiators 5B1 and 5 for azimuth tracking
B2 is a position passing through the position O near the focal point and separated by a distance d3 in the x-axis direction from a position O on the (xz) plane which is a horizontal plane including the mirror axis z and further separated by a distance d4 in the y-axis direction ( (d3, -d4) and (-d3, d4). At the same time, primary radiator 5B1
And 5B2 have the aperture plane with respect to the mirror axis z
It is oriented at the same outward angle as A1 and 5B2. This one
Since the secondary radiators 5B1 and 5B2 are arranged only at orthogonal positions to the primary radiators 5A1 and 5A2,
The primary radiators 5A1 and 5A can be changed only by changing the coordinate axis by 90 °.
It has the same function and operation as A2.

FIG. 3 shows the reflector antenna of FIG.
Specifications are frequency about 15 GHz, diameter of reflector 1 = 1500
mm, focal length ≒ 550 mm, d3 ≒ 30 mm and d4 ≒ 6 mm in the primary radiators 5A1 and 5A2,
The graph shows the secondary radiation pattern characteristics in the elevation angle α direction when the radio wave radiation axes of the primary radiators 5A1, 5A2, 5B1 and 5B2 are directed outward by about 50 ° with respect to the mirror axis z. At this time, the beam width (3 dB width) of the main signal beam M is 1 °.
The tracking signal beam T (5A1 and 5A
Regarding 2), since the primary radiators 5A1 and 5A2 are not set at the focal point of the reflecting mirror 1 and the radio wave radiation axis is not parallel to the mirror axis z, the beam width becomes ≒ 2 °.
Has spread. In addition, the tracking signal beam T has a wider beam width, and the gain change in the portion of the radiation pattern near the mirror axis z is gentler than the gain change of the main signal beam M, and the null state is clear. It is not a pattern. The radiation characteristic of this tracking signal beam T is
This produces an effect of increasing the pull-in angle of the tracking signal beam T.

[0031]

As described above, according to the present invention, the two azimuth tracking primary radiators are arranged such that the trajectory of the cross point, which is the trajectory of the line connecting the points having the same antenna gain, is the reflection mirror. Two elevation radiating primary radiators are respectively arranged in planes slightly inclined from a horizontal plane including the mirror axis about the mirror axis so as to substantially coincide with a vertical plane including the mirror axis. The trajectories of the cross points, which are the trajectories of lines connecting points having the same antenna gain, are almost coincident with the horizontal plane, and are respectively arranged in planes slightly tilting the vertical plane about the mirror axis. Therefore, the locus of the cross point of the primary radiator can be made coincident with a desired axis, and crosstalk can be eliminated. As a result, when the target tracking of the amplitude comparison method is performed using this reflector antenna, the direction control time of the reflector can be shortened, and even if the target is a moving object, the target tracking is easy. Is generated.

[Brief description of the drawings]

1A and 1B are configuration diagrams of a first embodiment of a reflector antenna according to the present invention, wherein FIG. 1A is a schematic diagram, and FIG. 1B is a cross-sectional view taken along line X1-X2 of FIG.

FIGS. 2A and 2B are configuration diagrams of a reflector antenna according to a second embodiment of the present invention, wherein FIG. 2A is a schematic diagram and FIG. 2B is a cross-sectional view taken along line Y1-Y2 of FIG.

FIG. 3 is a diagram of a secondary radiation pattern of the reflector antenna according to the embodiment of FIG. 2;

4A and 4B are configuration diagrams of a reflector antenna according to a conventional technique, wherein FIG. 4A is a schematic diagram and FIG. 4B is a cross-sectional view taken along line R1-R2 of FIG.

5 is a diagram schematically showing secondary radiation patterns by primary radiators 6A1 and 6A2 of the reflector antenna of FIG.

6A and 6B are diagrams illustrating in detail a power supply circuit 4 of the reflector antenna of FIG. 4; FIG. 6A is a detailed block diagram of a power supply circuit 4A of a first example, and FIG. 6B is a detailed block diagram of a power supply circuit 4B of a second example; FIG. 3C is a waveform diagram for explaining tracking signal processing by the power supply circuit 4B.

[Explanation of symbols]

1 Reflector 2,3A1,3A2,3B1,3B2,5A1,5A
2,5B1,5B2,6A1,6A2,6B1,6B2
Primary radiator 4, 4A, 4B Feeding circuit 41, 42 Hybrid 43, 44 RF switch 45 Signal processing circuit

Claims (4)

(57) [Claims] 1. A reflector for reflecting a received radio signal, a main signal primary radiator arranged so that an antenna gain becomes substantially maximum in a direction of a mirror axis of the reflector, and The antenna gain for the circularly polarized wave component of the radio signal is symmetrically arranged so as to be substantially maximum in a direction off the mirror axis in the horizontal plane including the circularly polarized wave component of the radio wave signal received from the reflecting mirror. An azimuth tracking primary radiator that forms a set of two azimuth tracking signals;
In a direction deviating from the mirror axis in a vertical plane including the mirror axis, the antenna gains for the circularly polarized wave components of the radio signal are symmetrically arranged so as to be almost maximum, respectively. A pair of primary radiators for elevation tracking that generate an elevation tracking signal from a circular polarization component, and power supply for generating a tracking control signal in response to the azimuth tracking signal and the elevation tracking signal A trajectory of a cross point, which is a trajectory of a line connecting points at which the two antennas have the same antenna gain, substantially coincides with the vertical plane. Thus, two primary radiators for elevation tracking are arranged in planes slightly inclined from the horizontal plane about the mirror axis. Is black As the locus of points substantially coincides with the horizontal plane, reflector antenna, characterized in that it is arranged to be about the mirror axis in the plane slightly inclined the vertical plane. 2. The azimuth tracking primary radiator and the elevation tracking primary radiator, respectively, have their radio wave radiation axes directed outward with respect to the mirror axis. The reflector antenna according to claim 1. 3. The reflector antenna according to claim 1, wherein the power supply circuit is configured by a hybrid. 4. A power supply circuit comprising: a first RF switch that alternately switches and outputs an azimuth tracking signal from two azimuth tracking primary radiators; and a first RF switch. A first signal processing circuit for performing signal processing on the tracking signal to generate the tracking control signal for azimuth control;
A second RF switch for alternately switching and outputting elevation angle tracking signals from the plurality of elevation elevation tracking primary radiators; and a signal processing unit for the elevation signal by processing the tracking signal from the second RF switch. The reflector antenna according to claim 1, further comprising a second signal processing circuit that generates the tracking control signal.