JPH08181540A - Multi-beam radiator and multi-beam antenna using it - Google Patents

Abstract

PURPOSE: To realize a multi-beam radiation device and a multi-beam antenna having a feeder system in which a power supply of an amplifier is utilized with high efficiency by easily solving a problem of a power loss in the case of high power transmission and facilitating the setting of exciting distribution for a low side lobe. CONSTITUTION: A cluster comprising plural antenna elements 1-22 is used for a primary radiator of a reflection mirror antenna sending/receiving a radio wave via a reflection mirror. Then amplifiers 211-232 are connected to each antenna element and a ratio of maximum output power of each amplifier is made coincident with a ratio of exciting power given to the antenna elements 1-22. Thus, fluctuation in the communication quantity between beams is solved flexibly and the power of the amplifiers 211-232 is effectively utilized and the antenna is effective to mobile communication or the like whose communication quantity fluctuates.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-beam radiator used as a primary radiator of a reflector antenna mounted on a satellite and a multi-beam antenna using the same.

[0002]

2. Description of the Related Art With the increasing demand for satellite communication, it is required to increase the gain of an antenna mounted on the satellite to increase the communication capacity. Therefore, it is necessary to reduce the coverage area of the beam radiated from the antenna and efficiently radiate radio waves in a narrow area. Therefore, there is a need for a multi-beam satellite broadcasting system that covers a service area with a plurality of beams.

As an example, consider a multi-beam satellite communication using four beams as shown in FIG. Here, in order to effectively use the frequency, the same frequency is used every other beam. In order to effectively use this frequency, it is important to reduce the side lobe of the radiation pattern for the satellite antenna. For example, the radio wave radiated to the beam 1 needs to have low sidelobe characteristics in this region so that there is no interference with the coverage of the beam 3 using the same frequency.

As an antenna system which realizes such a low sidelobe characteristic, an antenna composed of a reflecting mirror 24 and a primary radiator 23 as shown in FIG. 3 can be considered. Here, the primary radiator is composed of four clusters 31, 32, 33, 34 as shown in FIG. Each cluster forms one beam and each has 7 beams.
It is composed of individual antenna elements. Here, the cluster 31 forming the beam 1 includes the antenna elements 1, 2, 3, 4,
Cluster 3 composed of 5, 6 and 7 forming a beam 2
2 is composed of antenna elements 6, 7, 8, 9, 10, 11, 12, and the cluster 33 forming the beam 3 is composed of antenna elements 11, 12, 13, 14, 15, 16, 17 and beam 4 The cluster 34 forming the antenna is composed of antenna elements 16, 17, 18, 19, 20, 21, and 22. In this way, one beam is formed by a plurality of antenna elements, and an appropriate excitation distribution is set for each antenna element, so that the combined pattern of them can have a low sidelobe characteristic. In addition, here, due to the requirement to increase the beam crossover level (gain at the beam-beam boundary), some antenna elements that form a cluster are shared between adjacent beams (for example, antenna elements are used). 6 and 7 are cluster 3
Used for both beam 1 formed by 1 and beam 2 formed by cluster 32).

The above concept has already been applied to many satellite-mounted multi-beam antennas. The conventional method considered as the configuration of the power feeding system is shown below. FIG.
1 is an example showing a conventional configuration of a multi-beam feeding system, in which antenna elements 1 to 22 are combined (in the case of reception) or distributed (in the case of transmission) by the feeding circuits 47, 48, 49 and 50 of the clusters corresponding to the respective beams. In the case of). Each feeding circuit is configured to use a distributor (combiner), a phase shifter, etc. so as to give a predetermined excitation distribution to the antenna elements forming each cluster. The power supply circuits 47, 48, 49 and 50 have amplifiers 201 and 20 respectively.
2, 203, and 204 are connected to amplify the transmitted and received signals. As this amplifier, a high output amplifier (specifically, a traveling wave amplifier or a solid-state amplifier) is used for transmission, and a low noise amplifier is used for reception. Further, in this power feeding system configuration, the antenna elements 6, 7, 11, 12, 16, 17 shared by the adjacent beams have the duplexers 205, 206, 20 for separating the two frequency bands.
7, 208, 209 and 210 are connected to each other. In this method, the excitation distribution of the antenna element can be freely set in the feeding circuit, and therefore, there is an advantage that an optimum low sidelobe pattern for frequency reuse can be realized for each beam. But,
This system is premised on that the frequency band of each beam is fixed and does not change, and the frequency band and communication volume cannot be flexibly changed according to the call volume of each beam.

The power supply system configuration shown in FIG. 12 makes it possible to flexibly change the frequency band and the amount of communication between beams. Here, each of the antenna elements 1 to 22 corresponds to each beam, and the feeding circuits 47 and 48 of the cluster,
FIG. 4 shows the area synthesized or distributed by 49 and 50.
The configuration is the same. However, in the antenna elements 6, 7, 11, 12, 16, 17 that are shared between the adjacent beams, it is impossible to separate the signals into the respective beams by the demultiplexer that separates in the frequency band. The simple distributors (combiners) 41, 42, 43, 44, 46 are connected.
The feeding circuits 47 and 48 are connected to the matrix amplifier 59, and the feeding circuits 49 and 50 are connected to the matrix amplifier 60. The matrix amplifiers 59, 60 are 3 dB hybrids 51, 52, 53, 54, amplifiers 55, 56, 57,
It is composed of 58. In this matrix amplifier, the input signal is equally distributed by the hybrid, amplified by the two amplifiers, and output to one port by the hybrid on the output side. As shown in the figure, even when two beams are input at the same time, the input and output are always at the same level with respect to the amplifier, and the output of each beam appears at different ports. In this case, even if there is an imbalance in the frequency band between the beams (difference in communication amount), the input to the amplifier is made uniform, so that the amplifier can always operate with high efficiency. Now, assuming that the ratio of the frequency band occupied by beam 1 and beam 3 to the whole is x (0 ≦ x ≦ 1) and the maximum output power of one amplifier is Pmax, the power supply efficiency η of the amplifier is as follows. .

Η = 2 [2 × Pmax + 2 (1-x) Pmax] / (4Pmax) = 1.0 (1) Therefore, in this example, the power supply efficiency is theoretically 100%. As described above, the power feeding system configuration of FIG. 12 is extremely effective for a satellite communication system in which the communication amount varies between beams. However, there are the following problems.

Particularly when used as a transmitting antenna,
A large amount of electric power is transmitted to the power feeding circuits 47, 48, 49 and 50, and it is often difficult to form the excitation distribution with high accuracy in terms of hardware formation. Passive intermodulation (PIM,
The nerves are sharpened in order to suppress harmonics, which affect the receiver, etc.) and multipaction (the problem that a short circuit occurs in RF due to the generation of secondary electrons, which causes a failure in high power transmission). Need to be made. Further, if flexibility is given to the frequency band, combiners (distributors) 41, 42, 43, 4 connected to the inter-beam shared element are used.
There is also a problem that losses occur at 4, 45, and 46 (half of the input to this antenna becomes a loss), antenna efficiency decreases, and heat is generated. A method of sharing elements by using a hybrid instead of a combiner is also considered, but in this case, the excitation distribution of the shared elements between beams is constrained, and it is the most suitable for low sidelobe as a cluster. The excitation distribution cannot be set. Furthermore, since the isolation between the ports of the matrix amplifier, which is ideally infinite, can be realized only to a finite value, there is a problem that a signal of one beam leaks into a cluster of another beam. In this case, the isolation characteristics between the beams are deteriorated. The isolation level between the beams largely depends on the isolation characteristics between the ports of the matrix amplifier, and thus it may not be applicable to a satellite communication system that requires very high isolation between beams.

As a conventional method of constructing a power feeding system, a configuration as shown in FIG. 13 can be considered. In this configuration, the amplifiers 61 to 82 are directly connected to the antenna elements 1 to 22, respectively. Here, all the amplifiers have the same specifications. After that, the power supply circuits 89, 90, 91, 92 are configured in cluster units, and the excitation distribution optimum for lowering the side lobes is set here. Antenna elements 6, 7, 11 shared between beams
12, 16, 17 combiners 83, 84, 85, 8
6, 87 and 88 are connected to each other. In this combiner, only half of the electric power is transmitted in the direction of the antenna element, which causes a loss here, but since the signal transmitted to this portion has a small electric power, there is no particular problem.
In the configuration of FIG. 13, particularly when used as a transmitting antenna, since the antenna element and the amplifier are directly connected, the portion for transmitting a large amount of power is short, and power loss, PIM, and multipaction which are problems in the configuration of FIG. Measures become easy. However, it is disadvantageous in terms of power supply efficiency of the amplifier. Similar to the above discussion, the maximum output power of all amplifiers is Pmax, the excitation power of the antenna elements forming the cluster is 1, and the peripheral antenna elements are α (0 <α ≦ 1), When the ratio of the frequency bands of the beams 1 and 3 is x, the power supply efficiency η is as follows. η = [2 (1 + 6α) xPmax + 2 (1 + 6α) (1-x) Pmax] / 22Pmax = 2 (1 + 6α) / 22 (2) Here, if α = 0.1 (= -10 dB), η = 1
It is 4.5%, which shows that the power supply efficiency is very poor.

[0010]

As described above, in the conventional feed system configuration of the multi-beam antenna, when the matrix feed system is used, passive intermodulation or multi-pass resulting from transmitting a large amount of power is used. However, there is a problem that it is difficult to solve the problems of power loss and power loss, and it is difficult to sufficiently reduce the side lobe because the excitation distribution of the cluster is limited in order to reduce the power loss. Further, in the case of the power feeding system configuration in which the amplifier is directly connected to the antenna element, there is a problem that the power supply efficiency of the amplifier becomes extremely low.

According to the present invention, the above problems can be solved and problems such as power loss related to high power transmission can be easily solved.
The excitation distribution can be easily set to reduce the side lobe,
An object of the present invention is to provide a multi-beam radiating device having a feeding system that can efficiently use a power source of an amplifier and a multi-beam antenna using the same.

[0012]

In order to solve the above problems, in the first invention, a plurality of antenna elements are used as a primary radiator of a reflecting mirror type antenna that transmits and receives radio waves through a reflecting mirror. The cluster is provided for each beam, an amplifier is connected to each antenna element, and the ratio of the maximum output power of each amplifier is made to match the ratio of the excitation power given to the corresponding antenna element. It is characterized by

Further, in the first invention, the ratio of the maximum output power of the amplifier connected to each of the antenna elements is represented by a simple integer ratio. In the second invention, a cluster composed of a plurality of antenna elements is used as a primary radiator of a reflector mirror antenna that transmits and receives radio waves through a reflector, and the cluster is provided for each beam, and the antenna element Part of the antenna is shared between adjacent beams, the other part is used only for one corresponding beam, and the antenna element used for only one corresponding beam is a matrix amplifier. It is characterized by being connected.

[0014]

According to the first aspect of the present invention, a cluster composed of a plurality of antenna elements is used as the primary radiator of a reflector mirror antenna that transmits and receives radio waves through the reflector. Here, an appropriate excitation distribution (excitation amplitude, excitation phase) for multiple antenna elements
Can be set, and a low sidelobe pattern required for frequency reuse between beams can be formed.
By providing this cluster for each beam, low sidelobe characteristics can be provided for each beam. An amplifier is connected to each antenna element forming the cluster,
By making the ratio of the maximum output power between the amplifiers equal to the ratio of the excitation power of each antenna element, the output power according to the excitation distribution can be generated in each antenna element.

By setting the ratio of the maximum output powers of the amplifiers to be a simple integer ratio, the output power corresponding to the excitation distribution of each antenna element represented by the simple integer ratio can be obtained. Can be generated.

In the second aspect of the invention, a cluster composed of a plurality of antenna elements is used as the primary radiator of the reflector type antenna that transmits and receives radio waves via the reflector. Here, an appropriate excitation distribution (excitation amplitude, excitation phase) can be set for a plurality of antenna elements, and a low sidelobe pattern required for frequency reuse between beams can be formed. By providing this cluster for each beam, low sidelobe characteristics can be provided for each beam.
Here, some of the antenna elements are shared between adjacent clusters, while other antenna elements are used for only one corresponding beam. An amplifier is connected to each antenna element shared by adjacent clusters to amplify the input signal. Also, for antenna elements used for only one corresponding beam, connected to the matrix amplifier,
The input signal is evenly distributed and amplified to a plurality of amplifiers in the matrix amplifier.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a feed system (multi-beam radiator) of a multi-beam antenna showing an embodiment of the first invention. In this example, as shown in FIG. 2, assuming the satellite communication by multi-beam covering the service area by four beams, the same frequency is reused every other beam (beam 1 and beam 3 have the same frequency fa, beam 2). And the beam 4 has the same frequency fb). As shown in FIG. 3, the entire antenna is composed of a reflecting mirror 24 and a primary radiator 23, and the configuration of the primary radiator is as shown in FIG. Beam 1 here,
2, 3, 4 are formed by clusters 31, 32, 33, 34, respectively, and the cluster 31 includes antenna elements 1, 2, 3,
4, 5, 6, 7 and the cluster 32 are antenna elements 6, 7,
8, 9, 10, 11, 12, the cluster 33 is the antenna element 11, 12, 13, 14, 15, 16, 17, and the cluster 34 is the antenna element 16, 17, 18, 19, 20,
21 and 22, respectively. Antenna elements are shared between adjacent beams (clusters) in order to increase the antenna gain at the crossover portion which is the boundary of beam coverage. For example, antenna elements 6 and 7 are shared by beams 1 and 2. Here, by giving an appropriate excitation distribution (excitation amplitude and excitation phase) to the seven antenna elements forming the cluster, it is possible to easily realize the side lobe reduction of each beam pattern. In particular, by reducing the side lobe level in the other beam coverage that shares the frequency, the inter-beam isolation can be increased and the frequency can be reused.

In the power feeding system configuration of FIG. 1, antenna elements 1 to 22 are connected to amplifiers 211 to 232, respectively. Each amplifier has a power supply circuit 89, 90, 91 for each cluster unit.
Connected to 92. In this power feeding circuit, an excitation distribution that realizes low sidelobe radiation directivity is set for each antenna element. For example, the power supply circuit is composed of several distributors (combiner in the case of reception), phase shifters, etc. By setting the distribution ratio and phase amount of these components, each antenna element can be excited to a predetermined frequency. Amplitude and excitation phase can be given. For the antenna elements 6, 7, 11, 12, 16, 17 shared between the beams (between clusters), combiners (distributors in the case of reception) 83, 84, 85, 86 are provided between the amplifier and the power feeding circuit. , 87, 88 are respectively connected to combine (distribute) the signals from the power supply circuits. The combiner (distributor) can be formed as a simple T-branch. This power supply system can be used for both transmission and reception. In the case of transmission, a high power amplifier (HPA) is used as an amplifier, and a traveling wave amplifier (TWT) or solid state amplifier (SSPA) is actually used. In the case of reception, a low noise amplifier (LNA) is used as an amplifier.

The method of setting the maximum output power of the amplifier will be described below in the case of the feeding system of the transmitting antenna. To reduce the side lobes, it is necessary to set the excitation distribution optimized for the antenna elements that make up the cluster. If the antenna elements are the same, the antenna element at the center of the cluster (in the example of FIG. 1, the antenna elements 4, 9, 14, 1,
If the power level excited in 9) is set to 1, it will be about -10 dB for the surrounding elements. Now, set this value to α (0 <
Let α <1). This excitation distribution is set by the feeding circuit, and the excitation phase is also adjusted in some cases. In such a situation, the antenna elements 4, 9,
Amplifiers 214, 219, 22 connected to 14, 19
4, the maximum output power of 229 is set to Pmax, and the antenna elements 1, 2, 3, 5, 6, 7, 8, 10, 11, surrounding the Pmax are set.
12, 13, 15, 16, 17, 18, 20, 21, 2
Amplifiers 211, 212, 213, 21 connected to 2
5,216,217,218,220,221,22
2, 223, 225, 226, 227, 228, 23
The maximum output power of 0, 231, 232 is αPmax.
The amplification factors of the amplifiers are all the same. In addition, the operating point (backoff level) of the amplifier is set so that the linearity of input to output is guaranteed even if all the bands are concentrated on a certain beam, and the output power at that time is defined as the maximum output power. ing. In such a situation, when the ratio of the frequency band occupied by the beam 1 (3) is x (0 ≦ x ≦ 1), the power supply efficiency η of the amplifier is expressed as follows. η = sum of output powers of all beams / sum of maximum output powers of amplifiers = [2 (1 + 6α) × Pmax + 2 (1 + 6α) (1-x) Pmax] / [(4 + 18α) Pmax] = (1 + 6α) / (2 + 9α) (3) Therefore, assuming α = 0.1 (= -10 dB), η
= 55.2%.

The following effects can be expected with the above power supply system configuration. For example, since the antenna element and the amplifier are directly connected to each other, in the case of transmission, the transmission line of high power is the minimum part, so that loss due to high power, passive intermodulation (PIM), multi-action etc. It is relatively easy to deal with the problem. For example, in order to reduce the PIM, a manufacturing method such as integral molding of a power feeding circuit is taken, but in the case of the first invention, manufacturing / manufacturing considering such a situation can be easily performed. Further, in the case of reception, the line loss from the antenna element to the amplifier can be minimized, and the deterioration of G / T (gain-to-noise temperature ratio) due to the line loss can be prevented.

Further, with the configuration of the power feeding system of the present invention, even if the communication amount varies between the beams and the frequency band is changed accordingly, a power efficiency of about 50% or more can be obtained. This is a value several times better than that of the conventional method shown in FIG. From this, it is very effective for a satellite-mounted antenna used in a satellite mobile communication system, which is expected to have a large fluctuation in communication amount.

The excitation distribution of the antenna can be freely set by the feeding circuit. Therefore, the configuration of the present invention is effective even when an optimal excitation distribution can be set for lowering the side lobe and a high isolation level between beams is required. In addition, the power supply circuit is a region where the signal is at a low power level, and there is no problem of heat generation due to line loss, and the power supply circuit can be made small, thin, and easy by using a planar circuit such as a microstrip line. Can be done.

Further, the power supply system configuration of the present invention clearly shows a method for optimizing the setting of the amplifier by the index of the maximum output power with the power supply efficiency of the amplifier as the evaluation function. From this, it is shown that there are two types of amplifiers, one for the central antenna element and the other for the peripheral antenna elements.
Therefore, it is only necessary to manufacture a large number of products having the same characteristics, and it is possible to simplify processes such as designing, manufacturing, and adjustment.

In the first invention, the same effect is obtained even if the following modifications are made. For example, in the present invention, the antenna element, the feeding line, the feeding circuit component and the like may be of any type. The effect is the same no matter what method is used.

Further, the cluster system has been described by taking the configuration of seven antenna elements as an example as shown in FIG. 4, but the same effect can be obtained by using another system such as the case of using nine antenna elements. There is. Also, regarding the sharing of the antenna elements in the adjacent clusters, the case where two antenna elements are shared is shown in FIG. 4, but this may be shared by one element. If there is an antenna element used independently for one beam among the antenna elements forming the cluster (there may be a plurality of antenna elements), the number of antenna elements shared by adjacent clusters is arbitrary. The configuration of the power supply circuit is not limited to the example shown in FIG. For example, a method of providing a frequency converter and converting to a low frequency band to configure a power supply circuit can be considered. In this case, the power supply circuit component can be easily manufactured,
There are advantages such as reduction of power supply loss.

Next, another embodiment of the first invention will be described. FIG. 5 shows the configuration of a power feeding system which is another embodiment of the first invention. Taking the case of transmission as an example, the configuration and operation of this power feeding system will be described. The antenna elements 4, 9, 14, and 19 at the center of the cluster have combiners 263, 265, 267, and 269 and distributors 264 and 2, respectively.
66, 268, 270 and four amplifiers (for the antenna element 4, amplifiers 271, 272, 273, 27
4, the antenna element 9 has amplifiers 275, 276,
277 and 278, the amplifier element 2 for the antenna element 14
79, 280, 281, 282 and amplifiers 283, 284, 285 and 286 are connected to the antenna element 19. Also, the antenna elements 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 1 around the cluster are
Amplifiers 241, 242, 243, 245, 246, and 2 are provided in 3, 15, 16, 17, 18, 20, 21, and 22, respectively.
47, 248, 250, 251, 252, 253, 25
5, 256, 257, 258, 260, 261, 262
Is connected. Here, it is assumed that the clusters are arranged as shown in FIG. The excitation power corresponding to each antenna element is supplied to the feeding circuits 89, 9 for each beam.
It is set by 0, 91, and 92, and low side lobe radiation directivity is realized in each beam. Further, similar to the configuration example of FIG. 1, the combiner 8 is used for the antenna elements 6, 7, 11, 12, 17, and 18 shared between the beams (clusters).
Signals are combined by 3, 84, 85, 86, 87, 88.

The method of setting the maximum output power of the amplifier will be described below. Similar to the configuration example of FIG. 1, it is necessary to set an optimized excitation distribution for the antenna elements that form the cluster in order to reduce the side lobes. Here, the ratio of the power level excited to the antenna element at the center of the cluster and the power level excited to the antenna elements in the periphery is N: 1 (N is an integer). Now, if the power level excited to the surrounding antenna elements is -10 dB with respect to the central element, this ratio will be 10: 1. This ratio changes depending on the degree of side lobe reduction, and in the embodiment of FIG.
We are considering the case where it becomes 1. In this case, in the embodiment of FIG. 1, the maximum output power of the amplifier connected to the central antenna element is set to N times that of the amplifier connected to the peripheral antenna elements, so that the power supply efficiency of the amplifier can be optimized.

In the configuration example of FIG. 5, instead of multiplying the maximum output power by N times, N amplifiers connected to peripheral antenna elements are arranged in parallel. With such a configuration, exactly the same power supply efficiency as in the configuration example of FIG. 1 can be obtained, and the same effect can be obtained. In addition to this, the following effects can be expected.

Further, it becomes possible to use all the same amplifiers. Therefore, the steps of designing, manufacturing, adjusting, etc. of the amplifier are further simplified, which is very effective in reducing the cost of the entire antenna.

FIG. 6 shows the structure of a feeding system of a multi-beam antenna showing an embodiment of the second invention. The multi-beam assumed here is as shown in FIG. 2, and FIG.
Consider a reflector antenna such as that shown in Figure 1 and the primary radiator shown in Figure 4.

In the feed system configuration of FIG. 6, the antenna elements 1, 2, 3, 5, 6, 7, placed around the cluster,
8, 10, 11, 12, 13, 15, 16, 17, 1
8, 20, 21, 22 are amplifiers 101, 102, 1 respectively
03, 105, 106, 107, 108, 110, 11
1, 112, 113, 115, 116, 117, 11
8, 120, 121, 122 are directly connected. The antenna elements 4, 9, 14, 19 at the center of the cluster are connected to the matrix amplifier. The antenna elements 4 and 9 are arranged in the matrix amplifier 301 and the antenna elements 14 and 1
9 are connected to the matrix amplifier 302, respectively. The antenna element connected to the matrix amplifier does not necessarily have to be the antenna element at the center of the cluster, but that antenna element is used independently for one beam (not shared by adjacent beams), The condition is that the two antenna elements connected to one matrix amplifier are operating in different frequency bands. Matrix amplifiers 301 and 302 are 3 dB hybrids 123, 124, 125 and 126 and amplifiers 104 and 1
09, 114, and 119, the input signal is evenly distributed to the amplifier, amplified, and output from the output port corresponding to the input port. The matrix amplifiers and the amplifiers include the power supply circuits 132, 133, 134, and 1 for each cluster unit.
35 is connected.

In this power feeding circuit, an excitation distribution that realizes a radiation directivity with low side lobes is set for each antenna element. For example, the power supply circuit is composed of several distributors (combiner in the case of reception), phase shifters, etc. By setting the distribution ratio and phase amount of these components, each antenna element can be excited to a predetermined frequency. Amplitude and excitation phase can be given. For the antenna elements 6, 7, 11, 12, 16, 17 shared between the beams (clusters), a combiner (a distributor in the case of reception) is provided between the amplifier and the feeding circuit.
127, 128, 129, 130, 131 and 132 are respectively connected to combine (distribute) the signals from the power supply circuits. The combiner (distributor) can be formed as a simple T-branch. This power supply system can be used for both transmission and reception.

The method of setting the maximum output power of the amplifier will be described below in the case of the feeding system of the transmitting antenna. As the excitation distribution optimized for the antenna elements forming the cluster to reduce the side lobes, the power level excited to the antenna elements 4, 9, 14, 19 at the center of the cluster is 1
And α (0 <α <1) for peripheral elements.
Here, the maximum output power of the amplifier (other than the one arranged in the matrix amplifier) directly connected to the antenna element is set to Pma.
x, an amplifier 104 arranged in a matrix amplifier,
Maximum output power of 109, 114, 119 is 0.5 Pmax
And The amplification rates are all the same. In this case, the ratio of the frequency band occupied by beam 1 (3) is x (0
The power supply efficiency η of the amplifier when ≦ x ≦ 1) is as follows. η = [2 (1 + 6α) xPmax +2 (1 + 6α) (1-x) Pmax] / [(2 + 18) Pmax] = (1 + 6α) / 10 (4) α = 0.1 (= -10 dB), η = 16%
Therefore, the power supply efficiency is improved as compared with the conventional method.
Therefore, it is effective when used in a satellite communication system or the like in which the amount of communication between beams varies.

In the embodiment shown in FIG. 6, the maximum output of the amplifier connected to the antenna element around the cluster is set to a value αPmax proportional to the excitation power of the antenna element, so that the power supply efficiency is further improved. The system is constructed. In this case, the power supply efficiency η is as follows. η = [2 (1 + 6α) xPmax +2 (1 + 6α) (1-x) Pmax] / [(2 + 18α) Pmax] = (1 + 6α) / (1 + 9α) (5) α = 0 . (1−10 dB), η = 84.2
%, And a value close to 100% is achieved.

Regarding the matrix amplifier, the number of amplifiers can be arbitrarily increased by the configuration shown in FIG. 7 or 8. By such a method, when the ratio of the excitation power of the antenna element at the center of the cluster and the excitation power of the antenna element at the periphery of the cluster is N: 1, the maximum output of all amplifiers (including those in the matrix amplifier) With the same power and amplification factor, one amplifier is connected to the antenna elements around the cluster, and a matrix amplifier is connected to the antenna element at the center of the cluster, and N amplifiers are configured therein. . With such a configuration, all the amplifiers used in the power feeding system are of the same type, which is convenient for simplifying the design and manufacturing and reducing the cost.

In the example of FIG. 6, the configuration of the power feeding system when divided into two frequency bands is shown, but the present invention is not limited to this example and can be used for various multi-beams.
For example, as shown in FIG. 9, four frequency bands (fa, f
b, fc, fd), the antenna element at the center of each cluster corresponding to four frequencies in the feeding system is connected to the matrix feeding system as shown in FIG. Similar effects are obtained.

As is apparent from the above embodiments, according to the present invention, it is possible to flexibly cope with the fluctuation of the communication amount between the beams in the mobile satellite communication or the like, and it is possible to use the power source efficiently without waste. A multi-beam feeding system can be provided. Moreover, since the amplifiers arranged in the power feeding system can be made uniform, the designing, manufacturing, and adjusting processes can be remarkably simplified, and those having excellent characteristics can be manufactured at low cost. Further, there is the same effect as the first invention, and since the antenna element and the amplifier are directly connected, P
There is an advantage that it is easy to avoid problems associated with high-power transmission such as IM and multi-packaging.

[0038]

In the multi-beam radiator and the multi-beam antenna of the present invention, since the antenna element and the amplifier are directly connected to each other, it is possible to easily prevent the occurrence of problems such as PIM and multi-passion due to the high output. It is also effective in reducing loss. In addition, since the side lobes, which are important for effective frequency use in a multi-beam satellite communication system, are implemented in the power supply circuit that transmits low power signals, the optimum excitation distribution can be set for the antenna element. Easy to do.

Further, since the isolation characteristic is not deteriorated, it is effective for use in a satellite broadcasting system or the like which requires high isolation characteristic for frequency reuse. Furthermore, it is possible to respond flexibly by changing the allocation of the frequency band when there is a change in the communication volume between the beams. In this case, the power supply efficiency of the amplifier can be used with high efficiency. Very effective in limited satellite-borne systems. Furthermore, the type of amplifier required to configure this antenna is only one type or at most two types, so the steps of designing, manufacturing, adjusting, etc. of this amplifier are greatly simplified.
It is possible to manufacture a product with good characteristics at a low cost, and it is extremely effective as an application such as a satellite antenna.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a feeding system of a multi-beam radiation device of the present invention.

FIG. 2 is a diagram showing how beams are arranged and frequency division is performed.

FIG. 3 is a diagram showing a configuration of a multi-beam antenna of the present invention.

FIG. 4 is a top view showing clusters of the primary radiator.

FIG. 5 is a diagram showing another feed system configuration of the multi-beam radiation device of the present invention.

FIG. 6 is a diagram showing a configuration of a feeding system of a multi-beam radiation device of a second invention.

FIG. 7 is a diagram showing a configuration of a matrix amplifier used in the multi-beam antenna of the present invention.

FIG. 8 is a diagram showing another configuration of the matrix amplifier used in the multi-beam antenna of the present invention.

FIG. 9 is a diagram showing another configuration example of beam arrangement and frequency division.

FIG. 10 is a diagram showing another embodiment of the matrix amplifier used in the multi-beam antenna of the present invention.

FIG. 11 is a diagram showing a feed system configuration of a multi-beam antenna according to a conventional method.

FIG. 12 is a diagram showing a feed system configuration of a multi-beam antenna according to a conventional method.

FIG. 13 is a diagram showing a feed system configuration of a multi-beam antenna according to a conventional method.

[Explanation of symbols]

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 1
2, 13, 14, 15, 16, 17, 18, 19, 2
0, 21, 22 ... Antenna element Reflector ... 24 Primary radiator ... 23 31, 32, 33, 34 ... Cluster 47, 48, 49, 50, 89, 90, 91, 92, 1
32, 133, 134, 135 ... Feeding circuit 55, 56, 57, 58, 61, 62, 63, 64, 6
5, 66, 67, 68, 69, 70, 71, 72, 7
3, 74, 75, 76, 77, 78, 79, 80, 8
1, 82, 101, 102, 103, 104, 105,
106, 107, 108, 109, 110, 111, 1
12, 113, 114, 115, 116, 117, 11
8, 119, 120, 121, 122, 201, 20
2, 203, 204, 211, 212, 213, 21
4, 215, 216, 217, 218, 219, 22
0, 221, 222, 223, 224, 225, 22
6, 227, 228, 229, 230, 231, 23
2, 313, 321 ... Amplifier 205, 206, 207, 208, 209, 210 ... Demultiplexer 41, 42, 43, 44, 45, 46, 83, 84, 8
5, 86, 87, 88, 127, 128, 129, 13
0, 131, 132, 263, 264, 265, 26
6, 267, 268, 269, 270, 314, 315
... Combiner or distributor 59, 60, 301, 302 ... Matrix amplifier 51, 52, 53, 54, 123, 124, 125, 1
26, 310, 322 ... Hybrid 311 ... Non-reflective termination

Claims (5)

[Claims] 1. A multi-beam radiation device comprising a plurality of radiation means comprising a plurality of radiation elements and a feeding circuit connected to the radiation elements via an amplifier, and a signal power ratio for feeding power to the plurality of radiation elements. A multi-beam radiation device, wherein the maximum output power ratio between the amplifiers is set to be substantially equal. 2. The radiating element that constitutes the first radiating means, part of the power amplifier and the radiating element that constitutes the second radiating means, part of the power amplifier are shared.
A multi-beam emitting device as described. 3. A cluster composed of a plurality of antenna elements is used as a primary radiator of a reflector antenna for transmitting or receiving radio waves through a reflector, and the cluster is provided for each beam, and the antenna is provided. An amplifier is connected to each element, and a ratio of maximum output power of the amplifier is matched with a ratio of excitation power given to the corresponding antenna elements. 4. The multi-beam antenna according to claim 3, wherein the maximum output power ratio of the amplifier connected to each of the antenna elements is represented by a simple integer ratio. 5. A cluster composed of a plurality of antenna elements is used as a primary radiator of a reflector antenna that transmits and receives radio waves through a reflector, and the cluster is provided for each beam and the antenna element Some are shared between adjacent beams, some are used only for one corresponding beam, antenna elements used for only one corresponding beam are connected to the matrix amplifier The multi-beam antenna is characterized by being.