JPS5836862B2 - satellite relay equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in communications satellites that provide interconnection between earth stations by beam sweeping.

As satellite antennas become larger, spot beam antennas become more advantageous in terms of directivity and effective use of frequencies.

When using a spot beam antenna, it is necessary to interconnect each beam within the satellite.
The beam sweeping force method is known to be effective as one method.

Phased array antennas are common as conventional beam-sweeping power type antennas, and the use of multi-beam antennas was thought to be difficult due to the need for switching at a high output stage.

Additionally, phased array antennas are difficult to share on the receiving and transmitting sides, requiring mutually synchronized beam sweeping on the uplink and downlink, or leakage of power outside the service area due to grating globes. Technical problems remained, such as the suppression of

Therefore, the present invention is intended to improve the above-mentioned drawbacks of the prior art, and its purpose is to provide a satellite relay device that has a simpler configuration than the prior art, and which performs ground-to-ground interconnection by switching spot beams. be.

The characteristics of the present invention to achieve this objective are that a multi-beam antenna is used, the received signals from each ground are simply combined without switching, and the beam sweeping on the transmitting side is performed in the low power section. It consists in what is done by switching.

Examples will be described below with reference to the drawings.

FIG. 1 shows a block diagram of one embodiment of a satellite relay device according to the present invention.

In the figure, reference numbers 1-1 to l-N are spot beam receiving antennas, 2-1 to 2-N are spot beam transmitting antennas, 3 is a low noise receiver, 4 is a frequency converter and amplifier, and 5 is a transfer antenna. 6 is a power amplifier for transmission, 7 is a power combiner, 8 is a power divider, 9 is a 2N terminal directional coupler,
10 indicates a switching control device.

Note that the antennas 1-1 to 1-N and 2-1 to 2-N are
In reality, a single reflecting mirror may be provided with a plurality of antenna elements, and an antenna duplexer (not shown) may be used to share the transmitting antenna and the receiving antenna.

FIG. 2 shows the signal structure of the uplink and the signal structure (downlink) within each burst of the uplink signal.

Although FIG. 2 shows the downlink only for (froml-1), the same applies to (froml-2) and the following.

Note that uplink refers to the link from the earth station to the satellite, and downlink refers to the link from the satellite to the earth station.

The operating principle of FIG. 1 will be explained using FIG. 2.

The burst-like uplink signals shown in FIG. 2 are transmitted from each earth station so that they do not overlap with each other.

After receiving uplink signals from antennas 1-1 to 1-N, the satellite amplifies them with a low-noise receiver 3, combines them with a power combiner 7, and combines the signals from each station on the time axis as shown in A in Figure 2. Arrange in.

The output of the power combiner 7 is converted to a downlink frequency by a frequency converter/amplifier 4, amplified, and then converted to N by a power divider 8.
Divided equally.

Each output of the power divider 8 is connected to a phase shifter 5 and a transmission power amplifier 6.
After that, the signals are combined by a 2N terminal directional coupler 9 and transmitted from antennas 2-1 to 2-N to each earth station.

A switching control device 10 is connected to all the phase shifters 5 so that the input of the power divider 8 is rapidly scanned (swept) to the N output terminals of the 2N terminal directional coupler 9 by destination within each burst. The amount of phase shift of the phase shifter 5 is controlled.

A 2N terminal directional coupler is a passive device having N input terminals and Ng output terminals, and input power from each input terminal is divided into N equal parts and outputted to N output terminals.

Therefore, an output obtained by combining the input powers from each input terminal according to the phase is obtained at each output terminal.

In other words, the combined output of N transmission power amplifiers 6 is always obtained as the output of the 2N terminal directional coupler 9.

Here, the power divider 8, phase shifter 5, transmission power amplifier 6, and 2N terminal directional coupler 9 substantially constitute a switching amplifier circuit.

The principle of this switching amplifier circuit will be explained for the case where N=4.

FIG. 9 shows the configuration of the switching amplifier circuit when N=4.

8 is a power divider, 5-1 to 5-4 are phase shifters, 6-1 to 6
-4 is a transmission power amplifier, and 9 is a 2N terminal directional coupler.

Reference numeral 12 indicates a hybrid coupler, the power divider 8 is composed of three hybrid couplers, and the 2N terminal directional coupler 9 is composed of four hybrid couplers.

Here, the signal power input to the power divider 8 is P.

Then, at the output terminal of the power divider 8, four outputs with the power equal to 2 and the relative phase `tOj)π are obtained.

Here, the phase shift amounts l1θ2, θ3 of the phase shifters 5-1 to 5-4 are
, θ4, and the power amplification factors of the transmission power amplifiers 6-1 to 6-4 are A, the 4 outputs T of the 2N terminal directional coupler 9
1 to T4 are as follows.

Then, T4=APo, T1=T2=T3-0 toner,
The combined output of the transmission power amplifiers 6-1 to 6-4 is transferred to the phase shifter 5.
By controlling the phase shifters -1 to 5-4, it is possible to output to any output terminal of the 2N terminal directional coupler 9.

Similarly, switching amplifier circuits are configured for other Ns as well.

Therefore, if the uplink signal is synchronized with the switching operation of the switching amplifier circuit, the downlink signal shown in FIG. 2 will be connected to each earth station for each destination.

In the embodiment shown in FIG. 1, the switching of the transmission signal is substantially performed by the phase shifter 5 (that is, the input side of the transmission power amplifier 6), and it is natural to perform switching in the low power section in this way. This is one of the characteristics of the invention.

FIG. 3 shows another embodiment according to the present invention, 11-1-
N, 2-1 to 2-N, 3, 4, 5, 6, 7, 8, 9, 1
0 indicates the same as in FIG.

Further, 11 indicates a polarization multiplexer.

FIG. 4 shows the uplink signal configuration and the signal configuration (downlink) within each burst of the uplink signal.

The operating principle of FIG. 3 will be explained using FIG. 4.

The N service areas that antennas 1-1 to 1-N face are divided into two groups: L ground and N-L (L〈N) ground, and the uplink signal is sent to one group. One group has vertical polarization, and the other group has horizontal polarization.

Burst uplink signals from each earth station are received by the antennas 1-1 to 1-N, amplified by the low-noise receiver 3, and then combined by the power combiner 7 for each group to form A in FIG. They are arranged on the time axis as shown in .

The output of the power combiner 7 is converted and amplified to a downlink frequency by a frequency converter/amplifier 4, and then sent to a power divider 8 and a phase shifter 5.
, the output of the r-side 2N-terminal directional coupler 9A, which is switched and outputted for each destination by a switching amplifier circuit composed of a transmission power amplifier 6 and a 2N-terminal directional coupler 9, is a vertically polarized wave, and the output of the other 2N-terminal directional coupler 9A is a vertically polarized wave. The output of the terminal directional coupler 9B is combined as a horizontally polarized wave with low loss in the polarization multiplexer 11, and is transmitted to each earth station from the antennas 2-1 to 2-N.

A switching controller 10 is connected to all the phase shifters 5 such that the input of the power divider 8 is fast swept within each burst to the N output terminal of the 2N terminal directional coupler 9. control the amount of phase shift.

At this time, the outputs of the two 2N terminal directional couplers 9 are controlled so that they are not connected to the same antenna terminal at the same time.

If the uplink signal is synchronized with the switching operation of the switching amplifier circuit, the downlink signal shown in FIG. 4 will be switched for each destination and connected to the earth station.

FIG. 5 is a block diagram of another embodiment of the present invention, 1-1 to 1-N, 2-1 to 2-N, 3, 4, 5
, 6, 7, 8, 9, and 10 are the same as in FIG.

1-1' to 1-N' are spot beam receiving antennas that irradiate the same areas as 1-1 to 1-N, respectively, and 2-1' to
2-N' are spot beam transmitting antennas that irradiate the same areas as 2-1 to 2-N, respectively.

FIG. 6 shows the uplink signal configuration and the signal configuration within each burst of the uplink signal (downlink).

The operating principle of FIG. 5 will be explained using FIG. 6.

Receiving antennas 1-1 to 1-N and 1-1' to 1-N'
N service areas facing each other are divided into L and N-L 2 service areas.
The uplink signal is vertically polarized for one group and horizontally polarized for the other group.

Burst uplink signals from each earth station are received by antennas 1-1 to 1-N and 1-1' to 1N/, amplified by low noise amplifier 3, and then combined by power combiner 7 for each group. and are arranged on the time axis as shown in FIG.

At this time, if spot beams in the same irradiation area are combined with the same phase, the gain will be doubled.

In addition, even if one of the low-noise receivers 3 for spot beams in the same irradiation area fails, the same area is irradiated by two spot beams, which prevents line disconnections and improves system reliability. ing.

The output of the power combiner 7 is converted and amplified to a downlink frequency by a frequency converter/amplifier 4, and then sent to a power divider 8 and a phase shifter 5.
, are output for each destination by a switching amplifier circuit composed of a transmission power amplifier 6 and a 2N terminal directional coupler 9.
(Sent from to each earth station.

A switching controller 10 is connected to all the phase shifters 5 such that the input of the power divider 8 is fast swept within each burst to the N output terminal of the 2N terminal directional coupler 9. control the amount of phase shift.

At this time, the outputs of the two 2N terminal directional couplers 9 are controlled so as not to be connected to antenna terminals that illuminate the same area.

If the uplink signal is synchronized with the switching operation of the switching amplifier circuit, the downlink signal shown in FIG. 5 will be connected to the earth station for each destination.

FIG. 7 shows another embodiment of the present invention, 1-1 to 1-N
．． 1-1'~1-N', 2-1~2-N, 2-cho~2-
N', 3, 4, 5, 6, 7, 8, 9, 10, 11 is the third
The same thing as that used in FIG. 5 is shown.

FIG. 8 shows the signal structure of the uplink and the signal structure within each burst of the uplink signal (downlink).

The operating principle of FIG. 7 will now be explained using FIG. 8.

The N service areas that antennas 1-1 to 1-N and 1-1' to 1-N' face are L1, L2-L1, L3-L2, and N-L3 (where N>L3> L2〉
L1), and the uplink signal is vertically polarized for two groups and horizontally polarized for the other two groups so that the polarization differs between adjacent areas.

Burst uplink signals from each earth station are received by antennas 1-1 to 1-N, 1-1' to 1-N',
After being amplified by the low noise receiver 3, the signals are combined by the power combiner 7 for each group and arranged on the time axis as shown in FIG.

At this time, spot beams in the same irradiation area are combined with the same phase, and also serves as a redundant system.

The output of the power combiner 7 is converted and amplified into a downlink frequency by a frequency converter/amplifier 4, and then is comprised of a power divider 8, a phase shifter 5, a transmission power amplifier 6, and a 2N terminal directional coupler 9. A switching amplifier circuit outputs each destination.

Out of the four 2N terminal directional couplers 9, two outputs are vertically polarized waves and the other two outputs are horizontally polarized waves, which are multiplexed two by two in a polarization multiplexer 11, and then sent to antennas 2-1 to 2-2. -N and 2-2' to 2-N' power) are transmitted to each earth station.

A switching controller 10 is connected to all the phase shifters 5 such that the input of the power divider 8 is fast swept within each burst to the N output terminal of the 2N terminal directional coupler 9. control the amount of phase shift.

At this time, the outputs of the four 2N terminal directional couplers 9 are all controlled to be connected to different antenna terminals.

If the uplink signal is synchronized with the switching operation of the switching amplifier circuit, the downlink signal shown in FIG. 8 will be connected to the earth station for each destination.

In the above description, only the case where there are two sets of N spot beams irradiating the same ground is dealt with, but it goes without saying that the case can be extended to any number of M sets.

Further, by using an antenna sharing device (not shown), antennas on the receiving side and the transmitting side can be shared.

As explained above, the present invention uses a multi-beam antenna to perform power combining for uplink signals and beam sweeping for downlink signals, making it possible to interconnect each earth station. There is.

Therefore, it is possible to use a high-gain spot beam antenna, and furthermore, the transmitting side can perform high-output transmission by combining power.

Furthermore, by variably controlling the time allocated to each station, it has the advantage of being able to flexibly deal with traffic fluctuations.

Furthermore, by sweeping multiple beams, it has the advantage of being able to cope with an increase in transmission capacity.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a signal configuration diagram for explaining FIG. 1, FIG. 3 is a block diagram of another embodiment of the present invention, and FIG. FIG. 5 is a block diagram of yet another embodiment of the present invention; FIG. 6 is a signal configuration diagram for explaining FIG. 5;
The figure is a block diagram of yet another embodiment of the present invention, FIG. 8 is a signal configuration diagram for explaining FIG. 7, and FIG. 9 is a block diagram for explaining the operating principle of FIG. 1. . 1-1 to 1-N, 1-1' to 1-N'...Spot beam receiving antenna input terminal, 2-1 to 2-N, 2-
1'~2-N'...Spot beam transmitting antenna output terminal, 3...Low noise receiver, 4...
・Frequency converter and amplifier, 5, 5-1 to 5-4...
... Phase shifter, 6, 6-1 to 6-4 ... Transmission power amplifier, 7 ... Power amplifier, 8 ...
...Power divider, 9...2N terminal directional coupler, 10...Switching control device, 11...Polarization multiplexer, 12... Hybrid combiner.

Claims (1)

[Claims] 1. In a satellite relay device that uses a multi-beam antenna that forms a number of spot beams equal to the number of targets to be irradiated, N uplink signals from each target base are amplified for each target base. a power combiner that combines the outputs of the low-noise amplifiers, a circuit that amplifies the output of the power combiner and performs frequency conversion, and a power divider that divides the output of the circuit into N parts. a plurality of variable phase shifters connected to each output of the power divider, a plurality of transmission power amplifiers connected to the output of each phase shifter, and an output of each transmission power amplifier and a transmission antenna. and a switching limiting device connected to the phase shifter and controlling the amount of phase shift of each phase shifter depending on the destination of the signal. . Satellite relay equipment. 2. A satellite relay device according to claim 1, in which N signals are composed of vertically polarized waves and horizontally polarized waves, and are combined so that both polarized waves do not simultaneously illuminate the same ground. .