JP2000252741A - Multiple-satellite adaptive receiving antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increasing form a beam newly even when the number of satellites increases by making the lateral size of an array antenna of lane antennas along a stationary track wide enough to actualize directivity by which relative gains of a side lobe have nearly equal values. SOLUTION: The width of the lateral side of the array antenna of plane antennas along the stationary track is set to length or its integral multiple for actualizing the directivity by which the relative gains of the side lobe have nearly equal values so as to reduce the interference of broadcasting satellites at a 6 deg. interval and communication satellites at a 4 deg. interval on the stationary track with adjacent satellites. To this antenna, row noise block converters (LNB) 2 are connected by the subarrays of the array antenna 1 and the LNBs 2 perform frequency conversion by a common local signal oscillator 3 and output IF signals 4. The IF signals 4 after having their delay quantities set by a beam forming circuit are put together.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiving antenna for satellite broadcasting (BS and CS) from a geosynchronous satellite in a geosynchronous orbit, and to a plurality of receiving antennas capable of simultaneously receiving radio waves from many satellites with one receiving antenna. It is related to a receiving antenna for satellites and is a technical field of a phased array antenna.

[0002]

2. Description of the Related Art Parabolic antennas are mainly used for current satellite broadcasting (BS, CS) reception. However, considering future trends, from the viewpoint of effective use of geosynchronous orbit and effective use of frequency resources, it is considered that broadcasting may be performed from more satellites in the future than in the present. In the current parabolic antenna, the reflector is common, and the feeding point is multiplied to form a multi-beam. At present, antennas with a diameter of 45 cm are generally used for consumer antennas.
In Japan, it becomes physically and technically difficult to increase the number of power supply points when the number of satellites further increases from the current four satellites. Further, the position of the feeding point is further away from the focal point, which is disadvantageous in terms of antenna efficiency.

[0003]

In contrast to a parabolic antenna, with a planar antenna, the antenna surface can be divided into subarrays to form a plurality of receiving systems, and the combined directivity can be adjusted by adjusting the phase of each receiving system. Can be formed in any direction. Low noise block converter (LN
After distributing the intermediate frequency (IF) output of B), many beams can be formed simultaneously since beam forming can be performed individually. Therefore, an object of the present invention is to provide a multi-beam receiving antenna that realizes a multi-beam receiving antenna utilizing the features of the planar antenna and realizes a configuration for reducing the cost as a receiving antenna for consumer use. Things.

[0004]

In order to achieve this object, a receiving antenna for multiple satellites according to the present invention is provided as a planar antenna array antenna capable of receiving 12 GHz band satellite broadcasting from a plurality of geostationary satellites in geosynchronous orbit. In the configured multi-satellite receiving antenna, the width of the side of the array antenna in the horizontal direction along the geosynchronous orbit by the planar antenna is a satellite adjacent to the broadcasting satellite and the communication satellite at an interval of 6 degrees on the geosynchronous orbit. In order to reduce the interference with the side ropes, the relative gain at the side ropes is set to a length for realizing directivity with which substantially the same value is obtained or a length that is an integral multiple thereof.

In a preferred embodiment, in order to be able to receive satellite broadcasts from the plurality of geostationary satellites in a geosynchronous orbit, the tilt angle of the antenna is set such that the tilt angle center in the normal direction of the antenna is arbitrary. It is characterized in that it is configured to be realized by a uniaxial beam tilt substantially along a trajectory in a range of ± 20 degrees in longitude.

Furthermore, in a preferred embodiment, even if the width of the side of the antenna along the track is 37.1 ± 0.5 cm and the tilt angle is in the range of ± 20 degrees, no grating lobe is generated. The sub-array spacing of the array antenna is less than or equal to 0.745λ,
The array antenna is configured by performing phase control for each sub-array in which the orbital direction is one element and the vertical direction is n elements.
Here, λ is a wavelength corresponding to the highest frequency of receivable 12 GHz band satellite broadcasting, and n is a plurality of positive integers. Still further, in a preferred embodiment, when the sub-array interval is 0.745λ or more,
The number of the sub-arrays is set to 15 to constitute an array antenna.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the accompanying drawings, and then some of the specific examples of the present invention will be described. Beam control of the receiving antenna Since it is not possible to predict what kind of satellite configuration will be in the future, the factor that determines the range of the beam control of the receiving antenna is the range in which the current four satellites in Japan can be received. It is mentioned as a basic condition. Fig. 1 shows the positional relationship between the geosynchronous orbit and the current four satellites as viewed from the receiving point (Tokyo). The horizontal axis of the figure indicates the geosynchronous orbit and the tangent to the geosynchronous orbit around 127 degrees east longitude. Relationship. The vertical axis is an axis orthogonal to the horizontal axis, and represents the difference between elevation angles. In consideration of such a spatial relationship, the range of the beam tilt of the receiving antenna is about 40 degrees between the outer satellites as an angle on the horizontal axis (almost azimuth direction), and the angle range on the vertical axis (almost elevation direction). Can be said to cover 0.3 degrees. Since the vertical axis direction has a small angle difference of 0.3 degrees, two-dimensional beam control is not necessary, and it can be seen that it is only necessary to realize one-axis control that tilts the beam on the horizontal axis up to ± 20 degrees. .

Regarding the width of the planar antenna in the control axis direction Assuming that one side of the planar antenna is arranged along the horizontal axis in FIG. 1 (referred to as the width of the array antenna), the width of the horizontal axis Introduce elements of satellite interference. If only the current four satellites are received, 124 degrees east longitude using the same frequency band and linear polarization (JCSAT-
The antenna width may be determined so that the interference between 4) and 128-degree (JCSAT-3) CS satellites is reduced. FIG.
(A) is the directivity when the width is set to 32 cm (excitation distribution is a general uniform excitation), and a satellite angle of about 4.4 degrees at a 4-degree interval viewed from the antenna is located at the null point of the directivity. Interference can be reduced.

On the other hand, in the case of the present multi-satellite receiving antenna, although it is intended to receive satellite broadcasting in the future, since the satellite arrangement is undecided, not only CS (communication satellite) but also BS
It is determined that it is appropriate to select the width of the antenna under the condition that the condition that the interference between them is small including the (broadcast satellite) is satisfied. In order to reduce interference to both adjacent satellites of the 6-degree interval BS and the 4-degree interval CS, it is necessary to lower the relative gain to the adjacent satellites. FIG. 2B shows the directivity when the antenna width satisfies this condition and the antenna width is 37.1 cm. The side lobe gain at an angle of 6.6 degrees for BS and 4.4 degrees for CS is obtained. Both -18
dB. If the relative gain needs to be further reduced, the length may be an integral multiple of 37.1 cm. FIG. 2 (c) shows the antenna width and 4.4 in the 12 GHz band.
It is a calculation result which shows the relationship with the side lobe relative gain of each direction 6.6 degrees. From this figure, the antenna width is 37.
It can be seen that, within a range of 0.5 cm (approximately 0.2λ) in each of the upper and lower directions with respect to 1 cm, both directions are −17 dB or less, and the relative gain values can be substantially equal. Hereinafter, a further measure of the present invention will be described by adopting the shortest length of 37.1 cm in the receiving antenna corresponding to a plurality of satellites.

[0010] An array of antennas for the beam control axis will be discussed based on the beam tilt angle with respect to the element arrangement and the phase control unit of the 37.1 cm wide antenna adopted in the item. When antennas are arrayed, usually, when the maximum tilt angle (θ) is determined, the element spacing (sub-array spacing: d) that does not generate grating lobes in the directivity at this tilt angle is determined by the following formula. d <(1 + sin (θ)) ⁻¹ · λ (λ is a wavelength) If θ = 20 degrees, d <0.745λ, and the wavelength is 12.75 GHz, which is the highest frequency of CS targeting λ. In this case, d <17.53 mm. In this case 37.1
Although the number of divisions of the antenna of cm is 21.1, 22 is an integral number of units to be arrayed, and in this case, the unit of phase control is one element. FIG. 3 is an image of an array antenna array. FIG. 3A shows an antenna in which the number n of elements in the orbital direction is 1 and 22 subarrays of k elements are arranged in the vertical direction.

Reducing the number of sub-arrays It is important to simplify the receiving antenna, which leads to cost reduction. Consider a method that can reduce the number of subarrays obtained in the above items. In the item, grating lobes are not generated. However, even if grating lobes are generated, the number of sub-arrays can be reduced as long as interference from unintended satellites can be reduced. FIG.
FIG. 9 is a diagram showing a level relationship between a relative gain of a main lobe and a grating lobe with respect to the number of antenna divisions. As the number of divisions decreases, gain loss of a main lobe (white triangle mark) increases and grating lobes (white circles) occur. The level of (mark) also becomes large and is not practical. From this figure, it can be seen that the main lobe has the lowest gain reduction and the generation amount of the grating lobe is small.
Is considered to be the most practical. Where the number of divisions is 15
Is composed of 30 radiating elements having a width of 37.1 cm with 30 elements,
In the case where the number of elements n = 2 in the orbital direction is the unit of the subarray (see FIG. 3B), the subarray interval is substantially one wavelength. The generation level of the grating lobes for this division number 15 is -8.5 dB, and there is a high possibility that interference will occur if the division level is not changed.

FIG. 5 shows an angle (about -4) at which a grating lobe occurs when the number of divisions is 15 and the tilt angle is 20 degrees.
0 degree) and the angle difference between the satellite orbit at that angle. As can be seen from the figure, the satellite orbit moves away from the beam control axis (horizontal axis) as the distance from the center increases. At a grating lobe angle of -40 degrees, there is an angle difference of 1.2 degrees. Since this angle difference is substantially the angle difference in the elevation direction, the relative gain of the great globe in the satellite orbit can be further reduced by the directivity in the elevation direction. Considering the relative gain of the antenna in the orbit direction with reference to -20 dB, the vertical direction (elevation direction)
It is sufficient to set the antenna length such that a relative gain of -11.5 dB can be obtained with the above directivity. FIG. 6 shows the directivity of the grating lobe with respect to the length in the vertical direction (elevation direction) of the antenna. The length at which the relative gain of -20 dB in total at 1.2 degrees is 120 cm.

The length of the vertical side obtained in the item is the width of the side in the horizontal direction.
It is unbalanced compared to 7.1 cm, and a method for shortening this is considered. As can be seen from FIG. 6, since the directivity is sharp, the relative gain can be significantly reduced by only slightly increasing the angle difference. If an angle difference is made within a small range in which the gain of the main lobe is reduced, the relative gain can be reduced, which can be used to shorten the length of the antenna in the vertical direction. When the axis of the beam tilt is offset by 0.5 degrees (translation) away from the satellite orbit, the length is 120 cm.
It can be seen that the length can be reduced to 80 and several cm. Further, considering the satellite arrangement in the actual satellite orbit, since there is no satellite at the peak position of the grating lobe, a margin for interference can be further expected. Incidentally, when the length in a state where the -15 dB grating lobe range is offset by 0.5 degrees (the shaded portion in FIG. 5) is estimated, the length can be reduced to 70 cm.

Regarding Configuration of Plural Beam Forming As a method of forming a plurality of beams by an array antenna by examining items 1 to 3, beam forming by phase control in IF band (1 to 2 GHz band) frequency-converted by LNB for each subarray. Is easy in terms of a circuit. Each L
A beam can be formed in a target (satellite) direction by distributing the IF output from the NB according to the number of beams, giving a required delay amount to each by a delay line, and performing in-phase synthesis. When the center direction of the antenna is set to 127 degrees east longitude, the tilt angle from the receiving point to each satellite is determined.
By preparing a beam forming circuit formed by a fixed delay line for each satellite, reception can be performed for a plurality of satellites.
In the beam forming by the delay lines, all the delay lines can be accurately manufactured with the length of the strip line on the same printed circuit board, so that the mass productivity is high and the cost can be reduced. Since the angle of the satellite is different in each place, if boards for various angles are prepared, it is possible to cope with them by combining boards of necessary angles.

FIG. 7 is a diagram showing polarization angles and maximum angle deviations in various parts of Japan. In a CS using linear polarization, the orthogonal polarization relationship must be adjusted to the polarization of the target satellite. In the multi-beam parabolic antenna, the polarization of the primary radiator is mechanically combined with each other because the separation from the adjacent channel cannot be sufficiently obtained. In a planar antenna, the plane of polarization is determined by the arrangement of the radiating elements. Therefore, even if the receiving antenna is adjusted to the polarization of one satellite, the signal is received with the polarization shifted from the other satellites. Therefore, a function of electrically adjusting the polarization is required. However, there is no problem because it is easy to electrically perform polarization matching from the output signal of the receiving system with orthogonal polarization.

FIG. 8 is a vector diagram showing the relationship of polarization.
Assuming that the polarization of the target satellite is H and V, and each output of the orthogonal polarization receiving system when the reception is performed with the polarization plane of the receiving antenna inclined by θ is Hr and Vr, Each output is as follows: Hr = Hcos θ + Vsin θ Vr = −Hsin θ + Vcos θ Both outputs of Hr and Vr can be obtained as outputs of H and V by the following linear addition and subtraction processing if there is no non-linearity in the receiving system. H = Hr sin θ + Vr cos θ V = Hr cos θ−Vr sin θ Therefore, in the receiving antenna for multiple satellites of the present invention, each sub-array antenna is configured as an orthogonal receiving antenna.
For a circularly polarized wave, a signal received by the circularly polarized wave receiving system can be equivalently obtained by adding a 90-degree phase difference between the signals of the orthogonally polarized wave related receiving system and combining them.

The description of each item is completed above, and a specific configuration example of the present invention will be sequentially described. FIG. 9 is a block diagram showing the overall configuration of a receiving antenna for a plurality of satellites according to the present invention. For each sub-array of the array antenna 1 using a planar antenna, an LNB (Low Noise Block Converter) 2 is provided.
Is connected. The LNB 2 performs frequency conversion by a common local signal oscillator 3 and outputs an IF (intermediate frequency) signal 4. For example, if the antenna is composed of 15 sub-arrays, there are 15 receiving systems. The amount of delay of the IF signal 4 is set for each input terminal in the next beam forming circuit (blocks 5, 6, and 7 in this example) so that the same phase condition is obtained in the target direction (tilt angle θ) in accordance with the number of beams. After being synthesized. In the synthesized signal, the signal from the target direction has a correlation of 1 and is in-phase added to increase the amplitude. Otherwise, the correlation is almost random and the amplitude approaches zero. Therefore,
The resulting signal is a pair of orthogonal IF signals equivalent to a beam formed in the direction of the target satellite. In the case of the linearly polarized CS signal, the orthogonally polarized outputs 8 and 9 of the beam forming circuit 5 are output.
Is added and subtracted between signals by the polarization control circuit 11 in the next polarization synthesis circuit 10, and the output 12 in which the orthogonal components mixed together are reduced (in this figure, horizontal or vertical polarization corresponding to the channel). Output of one of the components). In circularly polarized BS reception, the beamforming circuit first forms a circularly polarized reception signal in a hybrid and then forms a beam in the beamforming circuit, or the beamforming forms a hybrid circularly polarized reception signal after beamforming. Performs the conversion from the orthogonal polarization signal to the circular polarization reception output 13. Output 12
Alternatively, the 13 output signals correspond to the corresponding CS, BS
It becomes an IF signal to the tuner.

FIG. 10 is a block diagram showing a more specific configuration. In the case where an array antenna in which the beam control axis direction of the planar antenna is divided into n sub-arrays and m beams are formed and received, FIG. FIG. 3 is a configuration block diagram assuming the following. “A” and “b” in the code are attached as symbols indicating that they are orthogonally polarized. The antenna is composed of n sub-Aire antenna receiving systems 21-1 to 21-n. Each receiving system receives the signal with the orthogonally polarized wave receiving sub-array antenna and two LNBs and converts the signal into an IF signal. The sub-array antenna receiving system 21-1 includes the antenna 25-1 and the LN
B26-1a and 26-1b. Similarly,
The n-th sub-array antenna receiving system 21-n includes an antenna 25-n, LNBs 26-na, and 26-nb. All of the constituent LNBs perform frequency conversion with a signal obtained by dividing a signal of a common oscillator 36 by a distributor 37. Quadrature IF output 27- of sub-array antenna receiving system 21-1
1a and 27-1b from the sub-array antenna receiving system 21-
The n orthogonal IF outputs 27-na and 27-nb are distributed to the following IF band distribution systems 22-1 to 22-n, and are distributed to m distributors 29-1a / b to 29-na / b according to the number of beams. And 30-1a-1 to m / 30-1b-1 to m are output. Other systems have the same configuration. Each bias T28
Is a part for supplying power to each LNB 26. The beam forming card interfaces 23-1 to 23-m are parts corresponding to multi-signal connectors for supplying IF signals to the beam forming cards 24-1 to 24-m, and two sets corresponding to each polarization. Consists of parts. 23-1
In the example, 31-1a is a group of n signals of 30-1a-1 to 30-na-1 among the IF signals of each sub-array reception system, and 31-1b is a sub-array reception system. Of the IF signals, 30-1b-1 to 30-nb-1
Are grouped in a line. Other systems have the same configuration. The beam forming cards 24-1 to 24-m are 2
It is composed of one beam forming circuit and one polarization combining circuit. A description will be given taking 24-1 as an example. Beam forming circuits 32-1a and 32-1 for forming a beam for each polarization
-1b for beam forming and outputs 33-1a and 33-1b
Get. These two outputs are signals in a state where the orthogonal polarization components from the desired satellite leak into each other if the polarization planes of the antennas do not match. The two signals are electrically polarized by a next polarization combining unit 34-1 to obtain a vertical polarization output signal 35-1a and a horizontal polarization output 35-1b with a high degree of separation between polarizations. The same applies to 24-2 to 24-m.

FIG. 11 is a diagram showing the configuration of a beam forming circuit, in which a delay line 42-n is provided for n IF signals 41-1 to 41-n.
In-phase synthesis is performed by the n synthesizer 43 via 1 to 42-n. Each delay amount of the delay lines 42-1 to 42-n is configured by a delay line that provides a delay amount determined for each beam direction to be formed (tilt angle from the radiation direction of the antenna).

FIG. 12 is a diagram showing a specific example of the polarization synthesis circuit. The H 'polarization component 51 and the V' polarization component 52, which are two signals having an orthogonal relationship, are input signals, and the V polarization output 72 is first. Will be described. The V polarization output 72 is obtained by multiplying the output 55 of the two-way divider 53 of the H ′ polarization component 51 with the sin θ output 65 of the ROM table 63 by the multiplier 59 and the output 66 resulting from multiplication.
And an output 57 obtained by multiplying the output 57 of the two-way divider 54 of the V ′ polarization component 52 by the multiplier 61 with the cos θ output 64 of the ROM table 63 by the in-phase adder 70.

The H polarization output 73 is the H ′ polarization component 51 2
The output 56 of the distributor 53 is converted by the multiplier 60 into the ROM table 6.
Output 67 resulting from multiplication with the cosθ output 64 of 3
The output 58 of the V ′ polarization component two-divider 54 is obtained by adding a multiplier 62 to the sin θ output 65 of the ROM table 63 and an output 69 resulting from the multiplication by an antiphase adder 71.
Cosθ output 64 and sinθ output 65 of ROM table 63
Is a coefficient for the angle difference θ between the polarization plane of the antenna and the polarization plane of the radio wave from the desired satellite.
Is equivalently acting as an attenuator (amplitude adjuster).

Therefore, the beam forming card can be manufactured as a dedicated card by determining the delay dose and the polarization angle θ when the receiving point and the target satellite are determined.

Although several embodiments and specific configuration examples have been described in detail above, the present invention is not limited to these, and various modifications and changes can be made within the scope of the invention described in the appended claims. Variations will be obvious to those skilled in the art.

[0024]

According to the present invention, it is possible to realize a multi-beam antenna using a planar antenna capable of simultaneously receiving four current satellites, and even if the number of satellites increases in the future, all antennas of BS and CS can be broadcasted by one antenna. It can be receivable. Since the beam formation for the target satellite is a phase control method using a delay line in the IF band, by adding a card (substrate) for each beam, it is possible to increase the number of beams and receive even if the number of satellites increases in the middle. be able to. In addition, a card in which a delay line is formed on one substrate is excellent in mass productivity and can be manufactured at a low cost.

[Brief description of the drawings]

FIG. 1 is a diagram showing a positional relationship between a geosynchronous orbit and four existing satellites as viewed from a receiving point (Tokyo).

FIGS. 2A and 2B are diagrams showing the directivity of an antenna. FIG. 2A shows the directivity when the width (aperture) is 32 cm, and FIG. 2B shows the directivity when the width (aperture) is 37.1 cm. (C) is a diagram showing the relationship between the width of the antenna and the relative side lobe gain in each direction of 4.4 degrees and 6.6 degrees.

FIG. 3 is a diagram showing an image of an array antenna.

FIG. 4 is a diagram showing the relationship between the number of antenna divisions and the relative gains of a main lobe and a grating lobe.

FIG. 5 is a diagram illustrating a relationship between an angle difference between a satellite orbit and a beam tilt axis.

FIG. 6 is a diagram illustrating the directivity of a grating lobe with respect to the length in the vertical direction (elevation angle direction) of an antenna.

FIG. 7 is a diagram showing polarization angles and maximum angle deviations in various parts of Japan.

FIG. 8 is a vector diagram showing a relationship of polarization.

FIG. 9 is a block diagram showing an overall configuration of a receiving antenna for multiple satellites according to the present invention.

FIG. 10 is a block diagram showing a more specific configuration shown in FIG. 9;

FIG. 11 is a diagram illustrating a configuration example of a beam forming circuit.

FIG. 12 is a diagram illustrating a specific configuration example of polarization combining.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Array antenna 2 LNB (Low Noise Block Converter) 3 Common local oscillator 4 LNB output IF signal 5, 6, 7 Beam forming circuit 8, 9 Orthogonal polarization output of beam forming circuit 5 10 Polarization combining circuit 11 Polarization control signal 12 Linearly-polarized (horizontal / vertical) output IF signal 13 Circularly-polarized output IF signal 21-1 to 21-n: Sub-array antenna receiving system 22-1 to 22-n: IF band distribution system 23-1 to 23-m : Beam forming card interface (maximum number of beams is m) 24-1 to 24-m: Beam forming card 25-1 to 25-n: Sub array antenna 26-1a / b to 26-na / b: LNB 27-1a / b to 27-na / b: IF signal transmission line 28-1a / b to 28-na / b: bias T 29-1a / b to 29-na / b: m distributor 30-1a-1 to 30-1 -m: m distributor 29-1a
Output 1 to m 30-1b-1 to 30-1b-m: m distributor 29-1b
Outputs 1 to m 30-na-1 to 30-na-m: m distributor 29-na
Outputs 1 to m 30-nb-1 to 30-nb-m: m distributor 29-nb
Outputs 1 to m 31-1a: output 1 of m distributors 29-1a to 29-na
(Terminal) 31-1b: output 1 of m distributors 29-1b to 29-nb
(Terminal) 31-ma: m output m of distributors 29-1a to 29-na
(Terminal) 31-mb: m output of m distributors 29-1b to 29-nb
(Terminals) 32-1a / b to 32-ma / b: beam forming circuit 33-1a: output of beam forming circuit 32-1a 33-1b: output of beam forming circuit 32-1b 33-ma: beam forming Output of the circuit 32-ma 33-mb: Output of the beam forming circuit 32-mb 34-1 to 34-m: Polarization synthesis circuit 35-1a: Vertical polarization output of the polarization synthesis circuit 34-1 35-1b: Horizontally polarized wave output of the polarization combining circuit 34-1 35-ma: Vertically polarized wave output of the polarization combining circuit 35-m 35-mb: Horizontally polarized wave output of the polarization combining circuit 35-m 36: Common locality of LNB Oscillator 37: 2n distributor 38-1 to 38-2n: output of distributor 17 39-1 to 39-2n: external local input terminal of LNB 41-1 to 41-n: IF input terminal 42-1 to 42- n: delay line 43 n synthesizer 44 Output terminal 51 H 'polarization input terminal 52 V' polarization input terminal 53, 54 In-phase two distributor 55, 56 Distribution output of in-phase two distributor 3 57, 58 Distribution output of in-phase two distributor 4 59, 60, 61 , 62 Multiplier 63 ROM table 64 Numerical corresponding signal of cos θ of ROM table 65 Numerical corresponding signal of sin θ of ROM table 66, 67, 68, 69 Multipliers 59, 60, 61, 6
2 outputs 70 In-phase adder 71 Negative-phase adder 72 V (vertical) polarization output 73 H (horizontal) polarization output

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaru Fujita 1-10-11 Kinuta, Setagaya-ku, Tokyo Inside the Japan Broadcasting Corporation Broadcasting Research Institute (72) Inventor Takao Murata 1-10-11 Kinuta, Setagaya-ku, Tokyo No. Japan Broadcasting Corporation Broadcasting Research Institute (72) Inventor Junji Kumada 1-10-11 Kinuta, Setagaya-ku, Tokyo Japan Broadcasting Corporation Broadcasting Research Institute F-term (reference) 5J021 AA09 AA11 AB06 CA04 DB06 EA04 FA10 FA14 FA16 FA17 FA24 FA32 GA02 GA05 GA06 HA02 HA07 JA05

Claims (4)

[Claims] 1. A method for detecting 12 geostationary satellites from a geosynchronous orbit.
In a receiving antenna for a plurality of satellites, which can receive a GHz band satellite broadcast and is configured as an array antenna using a planar antenna, a width of a lateral side of the array antenna using the planar antenna along the geostationary orbit is 6 degrees on a geostationary orbit. In order to reduce both the interference between the broadcast satellite at intervals and the communication satellite at intervals of 4 degrees to the adjacent satellites, the relative gains at the side ropes are set to a length for realizing directivity that can obtain substantially the same value as each other, or an integral multiple of the length. A receiving antenna for a plurality of satellites, wherein the receiving antenna has a length. 2. The receiving antenna according to claim 1, wherein
In order to be able to receive satellite broadcasts from the plurality of geosynchronous satellites in a geosynchronous orbit, when the tilt angle of the antenna is set to an arbitrary longitude with the tilt angle center in the normal direction of the antenna,
A receiving antenna for a plurality of satellites, wherein the antenna is configured to be realized by a one-axis beam tilt substantially along an orbit in a range of ± 20 degrees. 3. The receiving antenna according to claim 2, wherein
The width of the side of the antenna along the track is 37.1 ± 0.5
cm, the sub-array spacing of the array antenna is equal to or less than 0.745λ so that no grating lobe is generated even when the tilt angle is in the range of ± 20 degrees, the orbital direction is one element, and the longitudinal direction is The array antenna is configured by controlling the phase for each sub-array composed of n elements, where λ is the wavelength for the highest frequency of the receivable 12 GHz band satellite broadcasting, and n is a plurality of positive integers. Characteristic receiving antenna for multiple satellites. 4. The receiving antenna according to claim 2, wherein
A multi-satellite receiving antenna, wherein the number of sub-arrays is 15 when the sub-array interval is 0.745λ or more.