JP3406192B2 - Multi-frequency transmission system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-frequency transmission system which amplifies a plurality of signals in one frequency band or a plurality of frequency bands, synthesizes the amplified signals and transmits the amplified signals.

[0002]

2. Description of the Related Art FIG. 10 is a block diagram showing a configuration of a conventional multi-frequency transmission system, and FIG. 11 is a configuration diagram of a satellite communication ground station provided with this multi-frequency transmission system. 10 and 11, the multi-frequency transmission system includes a plurality of amplifying devices 4, 5, 8, 9, 10 for amplifying a plurality of signals in one frequency band (for example, 30 GHz), and these amplifying devices 4, 4. From the power feeding device 2, a synthesizing device 7 for synthesizing the signals amplified by 5, 8, 9, 10 and a power feeding device 2 for inputting the signal synthesized by the synthesizing device 7 through the connection waveguide 6. The antenna 1 is provided with which the output signal is input and transmitted via the connection waveguide 6b. A connecting waveguide 6 is provided between the amplifiers 4, 5, 8, 9, 10 and the synthesizer 7.
1, 62, 63, 64 and 65 are connected respectively.

A plurality of amplifiers 4, 5, 8, 9, 10 and a synthesizer 7 are installed in a lower communication room 12 (ground) of a satellite communication ground station as shown in FIG. Will be installed near the.

Next, the operation will be described. In FIG. 10, the maximum transmission power of the amplification device 4 is P1max, the maximum transmission power of the amplification device 5 is P2max, the maximum transmission power of the amplification device 8 is P3max, and the maximum transmission power of the amplification device 9 is P4m.
The maximum transmission power of the ax and the amplification device 10 is P5max. Further, the transmission signal from the amplification device 4 is S1, the transmission signal from the amplification device 5 is S2, the transmission signal from the amplification device 8 is S3, the transmission signal from the amplification device 9 is S4, and the amplification device 10 is
The signal transmitted by is S5. In addition, the synthetic loss with respect to the outputs of the amplifiers 4, 5, 8, 9, 10 of the synthesizer 7 is L
1, L2, L3, L4, L5, and the loss of the connection waveguide 6 is LD. The antenna 1 has a gain Ga and a transmission signal S1,
Suppose S2, S3, S4 and S5 are transmitted. The losses of the connection waveguides 61 to 65 and the connection waveguide 6b are ignored.

Here, in order to simplify the explanation, P1max
= P2max = P3max = P4max = P5max
(= PNmax), S1 = S2 = S3 = S4 = S5
(= SN). Also, L1 = L2 = L3 = L4 = L
5 = (LN). For example, if the diameter of the antenna 1 is 13
m and the frequency of the transmission signal SN is in the 30 GHz band, P
Nmax = 350 [W], LN = 8 [dB], LD = 8
[DB] and Ga = 70 [dB]. In general, the operating point of the amplifier is operated at a place (back-off) lower than the maximum transmission power by 3 to 8 [dB]. This backoff is 8 [d
EIRP (effective radiated power) in the case of B] is 71.4 [d
BW], and it does not reach the target 80 [dBW].

FIG. 12 is a block diagram showing a structure of a conventional multi-frequency transmission system in which one amplifying device 17 is added to the structure of the multi-frequency transmission system shown in FIG. FIG. 13 is a block diagram of a satellite communication ground station provided with the multi-frequency transmission system shown in FIG. 12 and 13
In FIG. 10, components corresponding to those shown in FIGS. 10 and 11 are designated by the same reference numerals, and their description will be omitted. Here, in order to compare with the attenuation amount in the second embodiment described later, only the attenuation amount of this conventional example will be described. In order to simplify the explanation, it is assumed that the synthetic loss of the synthesizer is 4 [dB]. The connection waveguide 6 is 0.54 [dB / m] per unit length at a frequency of 30 [GHz]. Therefore, for example, the attenuation amount of the output signal of the amplification device 4 to the power feeding device 2 is, as shown in FIG. 12, attenuation amount = 4 + 3 + 4 = 11.
It becomes [dB]. However, the amplification devices 4, 5, 8, 9, 1
The amount of attenuation between 0 and 17 and the synthesizers 3 and 7 is ignored.

FIG. 14 is a block diagram showing the configuration of another conventional multi-frequency transmission system, and FIG. 15 is a configuration diagram of a satellite communication ground station provided with this multi-frequency transmission system.
14 and 15, components corresponding to those shown in FIGS. 10 and 11 are designated by the same reference numerals, and description thereof will be omitted. 14 and 15, in this multi-frequency transmission system, the connection between the synthesizer 7 and the antenna 1 is
Instead of a waveguide with a large loss, a beam transmission system with four mirrors or the like is used by a beam waveguide 16 with a small loss. The synthesizer 7 is installed in the lower communication room 12 of the satellite communication ground station. Beam waveguide 16
Is about 0 [dB], the EIRP described in FIGS. 10 and 11 is 71.4 [dBW], whereas the EIRP of this conventional example is 79.4 [dBW]. If changed (all signals are 80 [dB
W] is rarely needed) EIRP is 80 [dB
W] Obtained.

[0008]

In the conventional multi-frequency transmission system as described with reference to FIGS. 10 and 12, since the amplifying device is generally large, the plurality of amplifying devices are all on the ground surface (lower communication room). ) Has been installed. Therefore, the distance between the amplifying device and the antenna becomes long, and the loss due to the connection of the waveguide or the like from the combining device in the latter stage of the amplifying device to the antenna increases, and the EIRP cannot satisfy the required value. It is necessary to increase the maximum transmission power of.
Therefore, a high output amplifier must be used,
Also, the power consumption increases, and as a result, the desired E
There is a problem that the cost is high to realize the IRP. It should be noted that there is a problem that the desired EIRP cannot be realized if there is no amplifier capable of outputting the target maximum transmission power. Further, in the conventional multi-frequency transmission system as described with reference to FIGS. 14 and 15, instead of the waveguide,
EI using beam waveguide with almost no loss
Although the RP is increased, there is a problem that an antenna using such a beam waveguide becomes expensive.

In short, in the conventional multi-frequency transmission system as described above, since a plurality of amplifiers are all installed on the ground regardless of the type of output signal, it is necessary to lengthen the connecting waveguide. Therefore, there are problems that the loss of the connection waveguide becomes large, it is difficult to obtain a desired EIRP, and a high EIRP cannot be realized with an inexpensive connection waveguide.

The present invention has been made to solve the above problems, and uses an inexpensive connection waveguide,
High E while keeping the maximum transmission power of the amplifier relatively low
It is an object to provide a multi-frequency transmission system that makes it possible to obtain a high EIRP for a signal that requires an IRP.

[0011]

According to a first aspect of the present invention, a plurality of amplifying devices for amplifying a plurality of signals in one frequency band,
In a multi-frequency transmission system including a synthesizer for synthesizing signals amplified by these amplifiers and an antenna for transmitting the signals synthesized by this synthesizer, the amplifier is installed at two places, According to the above, the above-mentioned synthesizing device is divided into two, and an amplifying device and a synthesizing device that output a signal that requires a relatively low effective radiation power are installed on the ground, and an amplifying device and a synthesizing device that output a signal that requires a relatively high effective radiation power. It is characterized in that the device is installed near the antenna.

A second aspect of the present invention is a multi-frequency device including a plurality of amplifying devices for amplifying a plurality of signals in a plurality of frequency bands, and an antenna for synthesizing and transmitting the signals amplified by these amplifying devices. In the transmission system, the installation location of the amplification device is divided into two, and an amplification device that outputs a signal in a frequency band with relatively small loss such as a connection waveguide connecting the amplification device and the antenna is installed on the ground. It is characterized in that an amplifying device that is installed and outputs a signal in a frequency band with a relatively large loss such as a connecting waveguide is installed near the antenna 1.

A third aspect of the invention is characterized in that the synthesizing device makes the synthesizing ratio of synthesizing the signals from the plurality of amplifying devices variable according to operating conditions.

[0014]

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1. Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a multi-frequency transmission system according to the first embodiment, and FIG. 2 is a configuration diagram of a satellite communication ground station provided with this multi-frequency transmission system. 1 and 2, the multi-frequency transmission system includes a plurality of amplification devices 4, 5, 8, 9, 10 for amplifying a plurality of signals in one frequency band (for example, 30 GHz).
A synthesizing device 7 for synthesizing the signals amplified by the amplifying devices 8, 9 and 10, and a signal synthesized by the synthesizing device 7, a signal amplified by the amplifying device 4 and a signal amplified by the amplifying device 5. A power feeding device 2 for inputting the signal synthesized by the power synthesizing device 3, and an antenna for transmitting the signal output from the power feeding device 2. The synthesizer 3 and the synthesizer 7 are connected by a connection waveguide 6.
Connection waveguides 61, 62 are provided between the amplifiers 4, 5 and the synthesizer 3.
Are connected respectively. The amplifying devices 8, 9, 10 and the synthesizing device 7 are connected by connection waveguides 63, 64, 65, respectively. Further, the synthesis device 3 and the power feeding device 2 are connected by a connection waveguide 6a, and the power feeding device 2 and the antenna 1 are connected by a connection waveguide 6b.

Here, the amplifying device for outputting a signal that requires a relatively low EIRP (effective radiated power) is amplified by the amplifying devices 8, 9,
10 and the amplifying devices 4 and 5 that output signals requiring a relatively high EIRP, the amplifying devices 8, 9, 10 and the synthesizing device 7 are located under the satellite communication ground station as shown in FIG. It is installed in the communication room 12 (ground), and the amplifiers 4, 5 and the synthesizer 3 are installed in the upper communication room 11 (near the antenna 1) of the satellite communication ground station.

Next, the operation will be described. The connecting waveguides 61 and 62 for connecting the amplifiers 4 and 5 and the synthesizer 3 installed in the upper communication room 11 connect the synthesizer 7 installed in the lower communication room 12 and the synthesizer 3 to each other. Since it can be made shorter than the connecting waveguide 6 to be connected, that is, the connecting waveguides connecting the amplifying devices 4 and 5 and the antenna 1 are amplifying devices 8 and 9,
Since it can be made considerably shorter than the connecting waveguide connecting the antenna 10 and the antenna 1, the connection loss can be reduced. For example, consider the EIRP of the antenna 1 for the transmission signal S1 of the amplification device 4 installed in the upper communication room 11. Since the connection waveguide 61 can be shortened, the description will be made assuming that the attenuation amount by the connection waveguide 61 is zero. When the diameter of the antenna 1 is 13 m and the frequency of the transmission signal S1 of the amplification device 4 is in the 30 GHz band, the maximum transmission power P1max of the amplification device 4 is 350 [W], and the combined loss of the combination device 3 with respect to the amplification device 4 is 4 [W]. [D
B], the gain Ga of the antenna 1 is 70 [dB]. Generally, the operating point of the amplifier is 3 to 8 [d] of the maximum transmission power.
B] Operate in a low place (back-off). When this backoff is 8 [dB], the EIRP is 83.4 [dB].
W], and the target 80 [dBW] can be reached.

According to the first embodiment, the EI is relatively low.
A relatively high EIRP is required because an amplifier and synthesizer that outputs signals that require RP are installed on the ground, and an amplifier and synthesizer that outputs signals that require a relatively high EIRP are installed near the antenna. It is possible to shorten the connecting waveguide between the amplification device that outputs the signal and the antenna, and thereby reduce the maximum transmission power of the amplification device that outputs the signal that requires a relatively high EIRP, and thus the amplification device as a whole. High E while keeping the maximum transmission power of
It is possible to inexpensively provide a multi-frequency transmission system that makes it possible to obtain a high EIRP for a signal that requires an IRP.

Embodiment 2. FIG. 3 is a block diagram showing the configuration of the multi-frequency transmission system of the second embodiment in which one amplifying device 17 is further added to the configuration of the multi-frequency transmission system shown in FIG. FIG. 4 is a block diagram of a satellite communication ground station provided with the multi-frequency transmission system shown in FIG.
3 and 4, the components corresponding to those shown in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted. Here, only the amount of attenuation of the second embodiment will be described in order to compare with the amount of attenuation in the conventional example of FIGS. 9 and 10 described above. In order to simplify the explanation, it is assumed that the combined loss of the combining devices 3 and 7 is 4 [dB]. Since the loss (attenuation amount) of the connecting waveguide is almost determined by the frequency of the signal used (and is also determined by the waveguide size, that is, the cross-sectional shape, and the waveguide inner surface work finish), the example shown in FIG. In this case, the connection waveguide 6 has an attenuation of 0.54 [dB / m] per unit length at a frequency of 30 [GHz]. Therefore, for example, the attenuation amount of the output signal of the amplifying device 4 to the power feeding device 2 is, as shown in FIG. 3, attenuation amount = 4 + 4 = 8 [d
B]. However, since the connecting waveguide 61 connecting between the amplifying device 4 and the synthesizing device 3 is short, its attenuation amount is ignored.

In the conventional example shown in FIG. 12, the attenuation amount is 11
Although it is [dB], the attenuation amount is 8 in the second embodiment.
[DB], which is about 3 [dB] less than the conventional example. Here, for convenience of calculation, the difference in the attenuation amount is 4 [d
B]. When the difference 4 [dB] in the attenuation amount is converted into the aperture diameter (diameter) of the antenna 1, the efficiency conversion of 63% (37
%), It looks as if the antenna 1 according to the second embodiment had a diameter of 13 m, but it looked like an antenna of 8.2 m in spite of the diameter of the conventional antenna 1 of FIG. 9 being 13 m. . Considering that the cost of the antenna is proportional to the cube of the diameter, the same EIRP as in the second embodiment.
In the case of the conventional example, in order to obtain (1) at the antenna output point, an antenna with a 4 times higher cost and a large diameter of 20.6 m is required.
Alternatively, when the maximum saturation output of the amplifying apparatus is 350 W in the second embodiment without changing the antenna, it is expensive to obtain the same EIRP as in the second embodiment at the antenna output point in the conventional example. Therefore, a large amplification device with a maximum saturation power of 880 W is required. In the case of a 30 GHz band amplifying device, the cost is also a problem, but since only an amplifying device with a maximum saturation power of about 400 W is currently developed and marketed, the conventional example cannot deal with it, but the second embodiment is expensive. Therefore, it is possible to cope with the situation without using an amplifier having a large maximum saturation power.

Embodiment 3. 5 is a block diagram showing a configuration of a multi-frequency transmission system according to a third embodiment of the present invention, and FIG. 6 is a configuration diagram of a satellite communication ground station provided with this multi-frequency transmission system. 5 and 6,
The multi-frequency transmission system includes a plurality of amplifying devices 13, 14, 15 for respectively amplifying a plurality of signals in a plurality of frequency bands.
And a power feeding device 2 for inputting signals amplified by these amplifying devices 13, 14, 15 and an antenna 1 for synthesizing and transmitting signals from the power feeding device 2. The amplification device 13 and the power feeding device 2 are connected by a connection waveguide 67, and the amplification device 14 and the power feeding device 2 are connected by a connection waveguide 68. Further, the amplification device 15 and the power feeding device 2 are connected by a connection waveguide 69.

Here, for example, the frequency band of the output signal of the amplifier 13 is 30 GHz, the frequency band of the output signal of the amplifier 14 is 14 GHz, and the frequency band of the output signal of the amplifier 15 is 1.6 GHz. The loss (attenuation) of the connecting waveguide increases as the frequency band increases. In this example, since the frequency band of the output signal of the amplification device 13 is the highest, the loss per unit length of the connection waveguide 67 is the highest. Therefore, as shown in FIG. 6, the amplification device 13 is installed in the upper communication device room 11 in the vicinity of the antenna 1, and the power feeding device 2 is also installed in the upper communication device room 11.
The length of the connecting waveguide 67 between them is made as short as possible to reduce the loss. The frequency band of the output signals of the amplifying devices 14 and 15 is considerably lower than the frequency band of the output signals of the amplifying device 13, and the loss is small even if the connecting waveguides 68 and 69 are long. Therefore, as shown in FIG. The devices 14 and 15 are installed in the lower communication room 12 (ground).

According to the third embodiment, an amplifying device for outputting a signal in a frequency band in which the connection waveguide has a relatively small loss is installed on the ground, and a frequency band in which the connection waveguide has a relatively large loss is provided. Since the amplification device that outputs the signal is installed near the antenna, the connection waveguide between the amplification device that outputs the high frequency signal and the antenna can be shortened, which allows the maximum transmission of the amplification device that outputs the high frequency signal. Higher EIRP for signals that require higher EIRP while lowering the power and thus relatively lowering the maximum transmit power of the overall amplifier.
It is possible to provide a multi-frequency transmission system that makes it possible to inexpensively obtain.

Fourth Embodiment FIG. 7 is a block diagram showing the basic configuration of a combination ratio variable combination device in which the combination devices 3 and 7 shown in FIG. 1 are variable combination ratio combination devices. In FIG. 7, an input signal IN1 and an input signal IN2 from an amplifier (not shown) are input to a circuit 71 which is a high frequency circuit, and a signal line 74 of this circuit 71 outputs [IN1 + IN2 (reverse phase)] / 2 = (IN1- IN
The signal of 2) / 2, which is the inverse phase combination, is output. Also,
From the signal line 75 of the circuit 71, (IN1 + IN2) /
An in-phase combined signal of 2 is output. If there is no variable phase shifter 72 in the other circuit 73, [(IN1 + I
N2) / 2] + [(IN1-IN2) / 2] = IN1 and the same output signal as the input signal IN1 is output from the output terminal OUT.
It is output from 1. However, if the variable phase shifter 72 is provided between the signal line 75 and the signal line 76, the signal line 7
If there is no phase shift change in the signals of 5 and 76, only the input signal IN1 is output from the output terminal OUT1 at the operating point of point A in FIG. 8, and the operation of the variable phase shifter 72 causes the phase shift of the signal on the signal line 76. When the amount increases, for example, the amount of phase shift increases by 90 degrees, signals of the same level of two waves (passage loss is 3 dB, for example) corresponding to point B in FIG. 8 are output to the output end OUT1 and the output end OUT2, respectively. . Since the output terminal OUT2 is terminated and not used, only the output terminal OUT1 is used.

FIG. 9 is a block diagram for explaining an example of the configuration of a combination ratio variable combination device which combines a plurality of combination ratio variable combination devices shown in FIG. 7 to combine a plurality of input signals and outputs as one output signal. . In FIG. 9, reference numeral 91 is a variable synthesis ratio synthesizer corresponding to the variable synthesis ratio synthesizer shown in FIG. 91a, 91b and 91c are composition ratio variable composition devices 9
1 corresponds to each of the four input signals IN1,
IN2, IN3, IN4 are combined to output 1 from output terminal OUT
It is configured to output an output signal. By combining such configurations, it is possible to synthesize 2 N input signals and output 1 output signal.

According to the fourth embodiment, by varying the synthesis ratio, when transmission with high power is required for a communication signal with a high bit rate, the synthesis loss of the communication signal is reduced, and the reverse. In this case, the synthetic loss can be increased. In addition, it is possible to maximize the combined loss of communication signals that are not used and increase the maximum transmission power of other signals, thus improving versatility and flexibility of operation.

[0026]

As described above, according to the first aspect of the present invention, an amplifier for outputting a signal with a relatively low EIRP and a synthesizer corresponding thereto are installed on the ground, and a relatively high EI is set.
Since the amplification device that outputs a signal that requires RP and the corresponding synthesis device are installed near the antenna, the connection between the amplification device that outputs a signal that requires a relatively high EIRP and the antenna The length of the waveguide can be shortened, whereby the maximum transmission power of the amplifying device that outputs a signal that requires a relatively high EIRP can be reduced, and thus, the maximum transmission power of the amplifying device can be relatively low while the high E
For a signal that requires an IRP, there is an effect that a multi-frequency transmission system that makes it possible to obtain a high EIRP can be provided at low cost.

According to the second aspect of the invention, an amplifying device for outputting a signal in a frequency band in which the connection waveguide has a relatively small loss is installed on the ground, and a frequency band in which the connection waveguide has a relatively large loss. Since the amplifier that outputs the signal is installed near the antenna, the connection waveguide between the amplifier that outputs the high frequency signal and the antenna can be shortened, and the amplifier that outputs the high frequency signal can be amplified. A low-cost multi-frequency transmission system that makes it possible to obtain a high EIRP for a signal that requires a high EIRP, while making it possible to reduce the maximum transmission power of the device and thus relatively lower the maximum transmission power of the amplifying device as a whole. There is an effect that it can be provided.

According to the third aspect of the invention, since the synthesizing device is configured to vary the synthesizing ratio for synthesizing the signals from the plurality of amplifying devices according to the operating conditions, the synthesizing ratio can be changed according to the operating conditions. As a result, the synthetic loss can be reduced or increased, and the versatility and flexibility of operation can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a multi-frequency transmission system according to Embodiment 1 of the present invention.

FIG. 2 is a configuration diagram of a satellite communication ground station provided with the multi-frequency transmission system according to the first embodiment.

FIG. 3 is a block diagram showing a configuration of a multi-frequency transmission system according to Embodiment 2 of the present invention.

FIG. 4 is a configuration diagram of a satellite communication ground station provided with the multi-frequency transmission system according to the second embodiment.

FIG. 5 is a block diagram showing a configuration of a multi-frequency transmission system according to Embodiment 3 of the present invention.

FIG. 6 is a configuration diagram of a satellite communication ground station provided with the multi-frequency transmission system according to the third embodiment.

FIG. 7 is a block diagram showing a basic configuration of a combination ratio variable device provided in a multi-frequency transmission system according to Embodiment 4 of the present invention.

FIG. 8 is a graph showing a relationship between a phase shifter and a passage loss of the variable phase shifter according to the fourth embodiment.

9 is a block diagram for explaining a configuration in which a plurality of synthesis ratio variable synthesis devices shown in FIG. 7 are combined.

FIG. 10 is a block diagram showing a configuration of a conventional multi-frequency transmission system.

11 is a configuration diagram of a satellite communication ground station provided with the conventional multi-frequency transmission system shown in FIG.

FIG. 12 is a block diagram showing a configuration of a conventional multi-frequency transmission system.

13 is a configuration diagram of a satellite communication ground station provided with the conventional multi-frequency transmission system shown in FIG.

FIG. 14 is a block diagram showing the configuration of another conventional multi-frequency transmission system.

FIG. 15 is a configuration diagram of a satellite communication ground station provided with the conventional multi-frequency transmission system shown in FIG.

[Explanation of symbols]

1 antenna, 2 feeding device, 3,7 combining device, 4,
5,8,9,10,13,14,15,17 Amplification device, 6,6a, 6b, 61-69 Connection waveguide, 11
Upper communication room, 12 lower communication room, 16 beam guide, S1 to S6 transmission signals, 71, 73 circuit, 72 variable phase shifter, 91, 91a, 91b, 91c
Synthesizer with variable composition ratio.

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01Q 23/00 H01Q 1/00-3/46 H04B 7/155

Claims (3)

(57) [Claims] 1. A plurality of amplifiers for amplifying a plurality of signals in one frequency band, a combiner for combining the signals amplified by these amplifiers, and a signal combined by the combiner In a multi-frequency transmission system including an antenna, an amplification device that divides the installation location of the amplification device, divides the synthesis device accordingly, and outputs a signal with a relatively low effective radiation power, and a corresponding device A multi-purpose synthesizing device is installed on the ground, and an amplifying device that outputs a signal that requires relatively high effective radiation power and a synthesizing device corresponding to this are installed near the antenna. Frequency transmission system. 2. A multi-frequency transmission system comprising: a plurality of amplifying devices for respectively amplifying a plurality of signals in a plurality of frequency bands; and an antenna for synthesizing and transmitting the signals amplified by these amplifying devices. The installation location of the amplification device is divided, and an amplification device that outputs a signal in a frequency band with relatively small loss such as a connection waveguide connecting the amplification device and the antenna is installed on the ground, and A multi-frequency transmission system characterized in that an amplifying device for outputting a signal in a frequency band with a relatively large loss such as a connecting waveguide is installed near the antenna. 3. The multi-frequency transmission system according to claim 1, wherein the synthesizing device is configured to vary a synthesizing ratio for synthesizing signals from the plurality of amplifying devices in accordance with operating conditions.