JPH0446481B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a multi-beam antenna device composed of a reflecting mirror and a plurality of feeding horns as primary radiators, and particularly relates to a multi-beam antenna device for transmitting and receiving. The present invention relates to a multi-beam antenna device for transmitting and receiving, which is commonly used in both frequency bands.

(Prior art) A multi-beam antenna device is capable of emitting independent beams to multiple service areas, and attempts to make effective use of frequency resources by allocating the same frequency to beams in different directions. It is. Therefore, in a multi-beam antenna device, it is particularly important to have a large gain within the service area and to have low side lobes to avoid interference between beams using the same frequency.

When realizing such a multi-beam antenna device using a reflecting mirror, there is a method of using a feeding horn as the primary radiator of the feeding section. A preferred example of a multi-beam antenna device using this method is Suzuki et al., "Study of multi-beam antennas for regional satellite broadcasting in the 22 GHz band," IEICE Antenna and Propagation Study Group Material A, P85-114, published February 24, 1986. There is a hybrid method reported in . This is a combination of the conventional single horn method and cluster method, and for one beam, as shown in FIG. A plurality of sub-feeding horns 52 with small opening areas are used to control the power supply. Each horn 5
1 and 52 are excited with different amplitudes and phases, and their radiation directivity is shown by the broken lines 61 and 62 in FIG.
It becomes as shown in . By adjusting the excitation distribution of each horn, a radiation directivity with a low side lobe as shown by the solid line 63 in FIG. 6 can be obtained as a whole.

This hybrid type multi-beam antenna device is designed to prevent antennas within the service area due to the large amount of power spilling over from the reflector, as seen in cluster systems that use only multiple feeding horns with small apertures for one beam. Low sidelobe radiation directivity can be achieved without the problem of reduced gain.

Consider using this hybrid multi-beam antenna device for both transmission and reception.
For example, in satellite broadcasting, the frequency bands for transmission and reception are 12 GHz (down)/17 GHz (up) in the Ku band, and 17 GHz (up) in the Ku band.
22GHz (downstream)/27GHz (upstream) are allocated. When the frequencies of transmission and reception are thus far apart, it is difficult to share the distributor and phase shifter for adjusting the excitation amplitude and phase of the feeding horn for transmission and reception. This is because if the frequency is different between transmitting and receiving, the radiation directivity of each feeding horn will be different between transmitting and receiving with the same excitation amplitude and phase, and it is necessary to obtain the required radiation directivity. This is because it is necessary to maintain the required amplitude and phase over the required frequency bands within each frequency band for transmission and reception.

Therefore, it is conceivable to use a common feeding horn, but configure the feed circuit's distributor (synthesizer) and phase shifter separately for transmission and reception. If a distributor (synthesizer) and a phase shifter are provided separately for transmission and reception in the power feeding circuit, the desired radiation directivity as shown in FIG. 6 can be achieved in both transmission and reception.

However, in such a configuration, the same number of transmit-receiver branching units as the power supply horns are required to separate the transmission and reception.
filter) is required. In other words, each feeding horn is connected to the transmitting/receiving common terminal of the transmitting/receiving duplexer, and the transmitting signal is divided into multiple signals by the distributor, passed through the phase shifter, and inputted to the transmitting side input terminal of the transmitting/receiving duplexer, and then connected to the feeding horn. The signals transmitted and received by the feeding horn are taken out from the receiving side output terminal of the transmitter/receiver duplexer, passed through a phase shifter, and combined by a combiner. Therefore, the power loss of the feeder circuit increases due to the insertion loss of the duplexer, and at the same time, the size and weight of the feeder circuit also increase. These problems become more pronounced as the number of beams increases, and are a major drawback, especially in antennas mounted on satellites.

(Problems to be Solved by the Invention) As described above, in the conventional technology, in a multi-beam antenna device with low side lobes and high gain, in which a sub-feeding horn with a small aperture area is arranged around a main feeding horn with a large aperture area, However, when attempting to use the power supply horn for both transmission and reception, there were problems in that power loss increased due to the transmission/reception duplexer and the structure of the power supply circuit became complicated.

The present invention eliminates these problems and has low side lobes and high gain, does not require a large number of transmitter/receiver duplexers in the power supply circuit, and therefore has a simple configuration and a dual transmitter/receiver with low power loss. The purpose is to provide a multi-beam antenna device.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes a main feeding horn provided facing a reflecting mirror, and a plurality of sub feeding horns arranged around the main feeding horn, each having a smaller opening area than the main feeding horn. In a multi-beam antenna device for transmitting and receiving, which is equipped with a horn and a feeding circuit connected to the main feeding horn and the sub-feeding horn, only the main feeding home is used for both transmitting and receiving, and the sub-feeding horn is used for both the sub-feeding horn for transmission and the receiving horn. It is characterized by separately providing a sub-power feeding horn.

(Function) The transmission signal distributed to multiple units from the distributor is supplied to the main power supply horn for both transmission and reception and the sub-power supply horn for transmission, and the received signal received by the main power supply horn for both transmission and reception and the sub-power supply horn for reception. is fed to the combiner via a phase shifter. In the power supply circuit, a transmission/reception duplexer is provided only for the main power supply horn, and since the auxiliary power supply horn has separate transmission and reception, it is connected to the phase shifter without going through the transmission/reception duplexer.

This multi-beam antenna device is a combination of a main feeding horn with a large aperture area and a sub-feeding horn with a small aperture area, thereby maintaining high gain within the service area and achieving low sidelobes based on the principle described above. is realized. In addition, in addition to the fact that the reflector and the main feed horn with a large aperture area are shared by the transmitter and receiver, the feeder circuit does not require a large number of transmitter/receiver duplexers, which simplifies the overall structure of the antenna system and reduces weight. is effectively reduced, and an increase in power loss due to insertion loss of the transmission/reception duplexer is also minimized.

(Embodiment) FIG. 1 is a schematic configuration diagram of a multi-beam antenna device for transmitting and receiving according to an embodiment of the present invention, in which a sub-reflector 2 is provided opposite a main reflector 1, and A primary radiator 3 is provided oppositely.

The primary radiator 3 is as shown in detail in FIG.
A main power supply horn 4 for both transmission and reception with a large opening area, and sub-power supply horns 5a to 5f for transmission and a sub-power supply horn 6 for reception arranged around the main power supply horn 4.
It consists of a to 6f. The main feeding horn 4 is arranged so that its radiation direction faces the center of the target service area. A power supply circuit 7 is connected to the main power supply horn 4 and the sub power supply horns 5a to 5f, 6a to 6f, and each power supply horn is excited by the power supply circuit 7 with a predetermined amplitude and phase, resulting in low transmission and reception. Sidelobe directivity is achieved.

FIG. 3 shows a specific configuration of the power supply circuit 7. As shown in FIG. The main power supply horn 4 for transmitting and receiving is connected to the transmitting and receiving common terminal 9 of the transmitting and receiving duplexer 8, and the transmitting side input terminal 10 of the transmitting and receiving duplexer 8 is connected to the output of the transmitting signal distribution divider 16 via the phase shifter 12. The receiving side output terminal 11 is connected via a phase shifter 13 to the input side of a synthesizer 17 for combining received signals. As the distributor 16 and the combiner 17, for example, a plurality of directional couplers, Magic T, or septum-type power dividers (combiners) can be used to realize a desired distribution ratio and combination ratio.

On the other hand, the transmitting sub-feeding horns 5a-5f are connected to the output side of the distributor 16 via phase shifters 14a-14f, respectively, and the receiving sub-feeding horns 6a-5f are connected to the output side of the distributor 16 via phase shifters 14a-14f, respectively.
6f is connected to the input side of the synthesizer 17 via phase shifters 15a to 15f, respectively.

A transmission signal from a transmitter 18 is supplied to the input end of the distributor 16, and a reception signal obtained at the output end of the combiner 17 is supplied to a receiver 19.

By adopting the configuration shown in Figures 1 to 3 above, while having the advantages of high gain and low side lobes of the conventional hybrid system, only the transmission/reception duplexer is connected to the main feed horn. A multi-beam antenna device that can be shared for transmission and reception can be realized with a very simple configuration.

By the way, in the present invention, since the sub-feeding horn is divided into one for transmitting and one for receiving, compared to the case where all the sub-feeding horns are used exclusively for transmitting or exclusively for receiving,
The degree of freedom of excitation for suppressing (or reducing) sidelobes is halved. However, sidelobe suppression, which cannot be achieved without using all the sub-feeding horns arranged around the main feeding horn, is only possible in cases where the multi-beam service area is large and covers a very wide area, such as in Japan. When the service area is a narrow and narrow area running north and south, side lobes are suppressed in only one or two directions, so this degree of freedom is practically sufficient.

FIG. 4 shows the configuration of a primary radiator in another embodiment of the present invention.
-5f and receiving sub-feeding horns 6a-6f have different opening areas and also have different center positions.

When the frequencies of transmission and reception are different, the radiation directivity of the sub-feed horn and the main feed horn differs between transmission and reception. Parameters that reduce sidelobes in a certain region include the excitation amplitude and phase of the sub-feeding horn, as well as the aperture area of the sub-feeding horn and its center position, and these optimal conditions do not match between transmission and reception. is common. Therefore, the fourth
The illustrated embodiment is effective in reducing side lobes more effectively.

Note that the present invention can be implemented with various modifications without departing from the gist; for example, the opening shapes of the main power feeding horn and the sub power feeding horn are not limited to circular shapes;
It may be a rectangle, an ellipse, etc. Further, the number of the sub-feeding horns for transmission and the sub-feeding horns for receiving do not necessarily have to be the same.

〔Effect of the invention〕

According to the present invention, a multi-beam antenna device for transmitting and receiving, which has low side lobes and high gain, and does not require a large number of transmitting/receiving duplexers in the feeding circuit, is simple in configuration, is small in weight, and has low power loss. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a multi-beam antenna device for transmitting and receiving according to an embodiment of the present invention, FIG. 2 is a front view showing the configuration of a primary radiator in the same embodiment, and FIG.
The figure shows the configuration of the power supply circuit in the same embodiment.
FIG. 4 is a front view showing the configuration of a primary radiator in another embodiment of the present invention, FIG. 5 is a front view showing the configuration of a primary radiator in a conventional multi-beam antenna device, and FIG. 6 is a front view of the same device. FIG. 3 is a diagram showing radiation directivity. 1...Main reflecting mirror, 2...Sub-reflecting mirror, 3...Primary radiator, 4...Main feeding horn for transmission and reception, 5, 5a to 5f
... Sub-power feeding horn for transmission, 6, 6a to 6f... Sub-power feeding horn for reception, 7... Power feeding circuit, 8... Transmission/reception duplexer,
9...Sending/receiving common terminal, 10...Sending side input terminal, 11
...Receiving side output terminal, 12, 13, 14a to 14
f, 15a to 15f...phase shifter, 16...distributor, 1
7...Synthesizer, 18...Transmitter, 19...Receiver.

Claims (1)

[Claims] 1. A reflecting mirror, a main feeding horn provided opposite to the reflecting mirror, and a plurality of sub feeding horns arranged around the main feeding horn, each having a smaller opening area than the main feeding horn. , in a multi-beam antenna device for transmitting and receiving, which includes a main feeding horn and a feeding circuit connected to a sub-feeding horn, the main feeding horn is used for both transmitting and receiving, and the sub-feeding horn has a sub-feeding horn for transmitting and a sub-feeding horn for receiving. A multi-beam antenna device for transmitting and receiving, characterized in that a feeding horn is separately provided. 2. The power supply circuit connects the transmission/reception terminal of the transmission/reception duplexer to the main power supply horn, and transmits the power to the transmission side input terminal of the transmission/reception duplexer and the transmission sub-power supply horn via phase shifters, respectively. A divider for signal distribution is connected, and a combiner for combining received signals is connected to the receiving side output terminal of the transmitting/receiving branching filter and the receiving sub-feeding horn via phase shifters, respectively. A transmitting/receiving multi-beam antenna device according to claim 1, characterized in that: