JPH0473810B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a receiving device suitable for being mounted on an artificial satellite or the like, and particularly to a receiving device using a balanced amplifier as a low-noise preamplifier.

(Prior Art) In order to communicate with a moving object (ship, aircraft) through a satellite, there is a method in which the target area of the moving object is divided into a plurality of areas, and an antenna is set in each area to perform communication. This system uses satellite-mounted communications equipment that receives signals from moving objects and transmits them to base stations on Earth. FIG. 2 shows a conventional configuration of a receiving device in this satellite-borne communication equipment.

In the figure, 1 and 2 are antennas that receive signals from moving objects in different regions, 5 and 6 are low-noise preamplifiers connected to the antennas, and 11 and 1 are low-noise preamplifiers connected to the antennas.
2 is the RF signal output terminal of the low-noise preamplifier.
As the low-noise preamplifiers 5 and 6, balanced amplifiers are used in order to minimize input circuit loss and improve the noise figure at the L-band frequency currently allocated for mobile object communication. There are many. The details of the configuration of the balanced amplifier as the low-noise preamplifier 5 are shown below: 51 is an input hybrid, 52 and 53 are amplifiers, and 54 is an output hybrid. The RF signal applied to the input terminal 55 of the input hybrid 51 is transmitted to 58 of the two output terminals 57 and 58 of the output hybrid 54.
It is sent to 57, but it does not appear in 57. Similarly, the RF signal applied to the input terminal 56 is sent to the output terminal 57 of the output hybrid 54;
It is said that it does not appear in

(Problems to be Solved by the Invention) However, in the conventional receiving apparatus shown in FIG. 2, if the balanced amplifier 5 or 6 fails, no signal is output to the output terminal 11 or 12. Therefore, in the past, the RF signal from the antenna was received at one end by a switching device, and two low-noise preamplifiers were installed after the switching device, one for working and one for backup, and a redundant system was created by switching between these two low-noise preamplifiers. It consists of
However, in such a redundant system configuration, the number of low-noise preamplifiers is doubled, so there is a drawback that the weight of the receiving device is doubled. Weight reduction is one of the important factors for satellites with limited weight.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a receiving apparatus that eliminates the above-mentioned drawbacks, that is, a receiving apparatus that does not require a dedicated low-noise preamplifier and can also constitute a redundant system.

(Means for Solving the Problems) Means provided by the present invention for solving the above-mentioned problems includes first and second antennas, and first and second antennas that amplify the received signals of these antennas. A balanced amplifier is provided, the balanced amplifier has first and second input terminals and first and second output terminals, respectively, and the signal input to the first input terminal is amplified. the receiving device, wherein the signal is output from the second output terminal, and the signal input from the second input terminal is amplified and output from the first output terminal, the receiving device comprising first and second switching devices; and first and second output combining circuits, wherein both the switching devices have first and second input terminals and first and second output terminals, respectively, and the first and second switching circuits have first and second input terminals and first and second output terminals, respectively. The first input terminal of the switch is connected to the first and second antennas, respectively, and the second input terminal of the first and second switch is connected to the first and second terminating resistors. the first output terminals of the first and second switching devices are respectively connected to the first input terminals of the first and second balanced amplifiers; the second of the first and second switching devices;
output terminals are connected to the second input terminals of the second and first balanced amplifiers, respectively, and both output combining circuits have first and second input terminals and an output terminal, respectively. , the first input terminals of the first and second output combining circuits are connected to the second output terminals of the second and first balanced amplifiers, respectively; The second input terminal of the output combining circuit is connected to the first output terminal of the first and second balanced amplifiers, respectively, and the both switching devices connect the first input terminal to the first output terminal of the first and second balanced amplifiers. When connected to the output terminal of , the second input terminal is connected to the second output terminal, and when the first input terminal is connected to the second output terminal, the second input terminal is connected to It is characterized in that it is connected to the first output terminal.

(Example) Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. In the figure, the same parts as in FIG. 2 are designated by the same reference numerals. In the figure, 3 and 4 are switchers, 7
and 8 are output synthesis circuits, and 9 and 10 are output side terminals.

The RF signal from the antenna 1 is amplified through the terminals 31, 32 of the switch 3, through the input terminal 55 of the low-noise preamplifier 5, and is sent only to the output terminal 58, as explained earlier, to the output synthesis circuit. 8 and is sent to the output terminal 10. In that case, the input terminal 56 of the low-noise preamplifier 5 is connected to the terminal 4 of the switch 4.
It is connected to a terminator 45 via terminals 3 and 44.

Similarly, another RF signal from the antenna 2 passes through terminals 41 and 42 of the switch 4 to the low noise preamplifier 6.
is amplified by the output terminal 9 via the output synthesis circuit 7.
sent to. Similarly, the other input terminal of the low-noise preamplifier 6 is connected to a terminator 35 via terminals 33 and 34 of the switch 3.

If the low-noise preamplifier 6 were to fail, the connection would be changed so that the terminal 41 is connected to the terminal 43 in the switch 4 by a command from the ground base or by an automatic switching device within the satellite. It will be done. By switching the connection of the switch 4, the RF signal from the antenna 2 is transferred to the terminals 41, 43 of the switch 4.
The signal is input to the input terminal 56 of the low-noise preamplifier 5 through the filter, is amplified, reaches the output terminal 57, and is sent to the output side terminal 9 via the output synthesis circuit 7. That is, when the low noise preamplifier 6 fails, the separate RF signals from the antennas 1 and 2 are amplified by the low noise preamplifier 5 and separated and sent out to separate output terminals 9 and 10.

Similarly, if the low noise preamplifier 5 fails, the RF signal from the antenna 1 will be transferred to the terminal 31 of the switch 3,
33, is amplified by a low-noise preamplifier 6, and is sent to an output side terminal 10 via an output synthesis circuit 8.

(Effects of the Invention) As explained above, the present invention uses a balanced amplifier as a low-noise preamplifier, and by taking advantage of the characteristics of the balanced amplifier, two switchers and two output combiners can be combined. By simply adding a circuit, a redundant system can be constructed without requiring a dedicated low-noise preamplifier. Since two switchers and two output combining circuits are lighter than one low-noise preamplifier, a redundant system can be constructed without significantly increasing the weight, which is an important element of the satellite. It improves the reliability of communication equipment and is very effective.

Note that although the above explanation is based on a receiving device with two systems, a receiving device with an even number of systems has two systems.
It goes without saying that similar configurations can be obtained by combining systems.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional receiving apparatus. 1, 2... Antenna, 3, 4... Switcher, 3
1, 32, 33, 34, 41, 42, 43, 44
...Switcher terminal, 5,6...Balanced amplifier, 51...Input hybrid, 52,53...
Amplifier, 54... Output hybrid, 55, 56
... Input terminal, 57, 58 ... Output terminal, 7, 8
... Output synthesis circuit, 9, 10, 11, 12 ... Output side terminal, 35, 45 ... Termination device.

Claims (1)

[Claims] 1 includes first and second antennas and first and second balanced amplifiers that amplify reception signals of these antennas, the balanced amplifiers having first and second input terminals and first and second input terminals. each has a second output terminal, a signal input to the first input terminal is amplified and output from the second output terminal, and a signal input from the second input terminal is amplified and output from the second output terminal. The receiving device outputs the output from the first output terminal, and includes first and second switching devices and first and second output combining circuits, and both the switching devices connect the first and second input terminals. and the first
and a second output terminal, and the first input terminal of the first and second switch
and a second said antenna, respectively, said second input terminals of said first and second switching devices are connected to said first and second terminating resistors, respectively, said first and second said antennas. the first switch of the second switch;
output terminals are connected to the first input terminals of the first and second balanced amplifiers, respectively, and the second output terminals of the first and second switchers are connected to the first input terminals of the first and second balanced amplifiers, respectively. are connected to the second input terminals of the first balanced amplifier, and the two output combining circuits have first and second input terminals and output terminals, respectively, and the first and second The first input terminal of the output combining circuit is connected to the second output terminal of the second and first balanced amplifiers, respectively, and the first input terminal of the output combining circuit is connected to the second output terminal of the second and first balanced amplifiers, respectively. The input terminals are respectively connected to the first output terminals of the first and second balanced amplifiers, and when the first input terminal is connected to the first output terminal of the two switchers, When the second input terminal is connected to the second output terminal and the first input terminal is connected to the second output terminal, the second input terminal is connected to the first output terminal. A receiving device characterized by: