JPS6333336B2 - - Google Patents

Description

[Detailed description of the invention]

[Description of Technical Field] The present invention relates to a switching system for a redundant system of high-output amplifiers in a communication device. In particular, it relates to a switching system suitable for satellite communication systems. [Prior Art] Conventionally, high-output amplification sections of communication devices that require high reliability, such as those used onboard satellites, have often configured redundant systems as shown in FIG. That is, the first
In the figure, numerals 1 and 2 are high-output amplifiers, one of which is normally used and the other is a standby, numeral 3 is a hybrid that distributes input signals, and numeral 4 is a high-output amplifier.
indicate a switch for selecting the output of amplifier 1 or 2, respectively. In addition, starting (ON) amplifiers 1 and 2,
Stop (OFF) and switch 4 switch (S ₀ −S ₁
connection (or S ₀ -S ₂ connection) is effected by command signals not shown in FIG. In Fig. 1, for example, when amplifier 1 is in current use and amplifier 2 is switched to current use, amplifier 1 is stopped, switch 4 is switched from S ₀ - _{S 1} connection to S ₀ - S ₂ connection, and amplifier 2 activation operation is required. In order to avoid the complexity of these operations and avoid erroneous operations, these operations are normally performed using one command signal. In the case of satellite-mounted equipment, the number of commands may be limited, so each device in Figure 1 is operated using three commands C ₁ , C ₂ , and C ₃ . This command signal is shown in the table below.

[Explanation of purpose]

The present invention improves this point by providing a time difference in the application of command signals to these amplifiers and switching devices when switching the high-output amplifier redundant system, and switching the switching devices when the output power of the amplifier is not applied. The purpose is to provide a switching method that allows stable switching. [Summary of the Invention] The present invention provides a delay circuit in the path of the command signal, so that when the command signal arrives, the signal is first applied to the stop command input of the current amplifier, and is delayed by the time that this transient operation ends. Then, a signal is applied to the switching command input of the switching device, and after a further delay corresponding to the operation delay time of this switching device and the time when transient operations such as chattering are completed, a signal is applied to the startup command input of the amplifier that was used as a backup. Characterized by being given. This generally avoids opening the output of a high power amplifier or causing a chattering of a switch in a high power signal path. [Example] An example of the present invention will be described based on the drawings. 1 and 4 are block diagrams of essential parts of an apparatus according to an embodiment of the present invention. FIG. 1 shows connections for communication signals, and FIG. 4 shows connections for command signals. In FIG. 1, two high output amplifiers 1 and 2 having almost the same characteristics are provided.
An input signal is branched by the hybrid 3 and applied to each input. The amplified outputs of amplifiers 1 and 2 are respectively connected to terminals S ₁ and S ₂ of a switch 4, which switches either terminal S ₁ or S ₂ according to a command signal applied to the switching command input of the switch 4. It is configured to be connected to terminal _S0 .
The amplifier on the side selected by this switch 4 is set as the working unit, and the amplifier on the other side is set as the standby unit. FIG. 4 is a system diagram showing the connection of command signals for controlling the above switching. Each terminal 5 and 6 of amplifiers 1 and 2 is a start command input terminal for starting amplifiers 1 and 2, respectively. Terminals 7 and 8 of amplifiers 1 and 2 are stop command input terminals for stopping amplifiers 1 and 2, respectively. Terminal 9 of the switch 4 is a switching command input terminal for selecting the output signal of the amplifier 1, and terminal 10 is a switching command input terminal for selecting the output signal of the amplifier 2. Command signal C ₁ activates amplifier 1 and activates amplifier 2
The command signal _C2 is a command signal that stops the output of amplifier 1 and selects the output of amplifier 1.
This is a command signal to start amplifier 1, stop amplifier 1, and select the output of amplifier 2, and command signal C ₃
is a command signal to stop both amplifiers 1 and 2. This is as shown in the table above. Command signal C ₁ is connected to terminal 8 through diode 11, command signal C ₂ is connected to terminal 7 through diode 14, and command signal C ₃ is connected to terminal 8 and 7 through diode 12 and 13, respectively. connected to. The diodes 11 to 14 are used to prevent backflow, and the directions shown in FIG. 4 indicate connections when the command signals are of positive polarity. Here, in this example circuit, the command signal
The feature is that delay circuits 25 and 27 are provided in the path of _C1 , and delay circuits 20 and 22 are provided in the path of command signal _C2 . In Figure 4, each delay circuit 2
Pulse generating circuits 26 are connected to the outputs of signals 1, 22, 25, and 27, respectively, and this is for shaping the waveform of the command signal that has passed through each delay circuit to clarify its rise. Command signal C ₁ is applied to amplifier 1 as described above.
This command signal starts the amplifier 2, stops the amplifier 2, and selects the output of the amplifier 1. This command signal _C1 is input directly to the stop command input terminal 8 of the amplifier 2, and is input to the switching command input terminal of the switching circuit 4. It is input to terminal 9 via delay circuit 25, and amplifier 1
A delay circuit 2 is further connected to the startup command input terminal 5 of the
Input via 7. i.e. command signal
C ₁ is the stop command input for amplifier 2, switch 4
The configuration is such that the signals are input with a delay in the order of the input of the switching command and the input of the activation command of the amplifier 1. On the other hand, the command signal C ₂ is a command signal that starts amplifier 2, stops amplifier 1, and selects the output of amplifier 2, but this command signal C ₂ is directly input to the stop command input terminal 7 of amplifier 1. The signal is inputted to the switching command input terminal 10 of the switching circuit 4 via a delay circuit 20, and further inputted to the startup command input terminal 6 of the amplifier 2 via a delay circuit 22. That is, the command signal _C2 is configured such that the signals are input with a delay in the following order: a stop command input to the amplifier 1, a switching command input to the switch 4, and a start command input to the amplifier 2. FIG. 5 is an operation time chart showing the signal waveforms of each part when switching from the active amplifier 1 to the backup amplifier 2 is performed by the command signal C ₂ in the circuit shown in FIG. 4. It is. That is, FIG. 5a shows the waveform of the command signal _C2 . FIG. 5b shows the pulse generation circuit 21
represents the output waveform of FIG. 5c shows the output waveform of the pulse generating circuit 23. Here, in Figure 5
T ₅ indicates the delay time of the delay circuit 20, and T ₆ indicates the delay time of the delay circuit 22. FIG. 5d shows the output power waveform of the high-output amplifier 1, and _T1 represents the fall time of the output power similarly to FIG. 3b. FIG. 5e shows the output power waveform of the high-power amplifier 2,
T ₂ represents the rise time of the output power as in FIG. 3c. FIG. 5f shows the connection state between S ₀ and S ₁ of the switch 4. FIG. 5g shows S ₀ − of the switch 4.
Indicates the connection status between S ₂ . Also, in Figure 5
T ₃ and T ₄ represent the operation delay time and chattering time of the switching device 4, respectively, similarly to FIGS. 3d and 3e. With such a circuit configuration, when the command signal C ₂ is input, the amplifier 1 is stopped by directly inputting the command signal C ₂ to the stop command input 7, and the switch 4 outputs the output pulse of the pulse generation circuit 21. The amplifier 2 is switched by the pulse generating circuit 2.
It is activated by the output pulse of 3. Therefore, the delay time T ₅ of the delay circuit 20 is equal to the operation delay time T ₃ of the switch 4 between the fall time T 1 when the amplifier 1 is stopped _.
If it is set longer than the difference T ₁ −T ₃ , the switch 4 will be disconnected between S ₀ and S ₁ after the output power of the high-output amplifier 1 becomes 0. Therefore, total reflection of output power and switching of contacts when applying large power can be avoided, and stress will not be applied to the equipment. In addition, the delay time T ₆ of the delay circuit 22 is set by the switch 4
If the setting is longer than the sum of the operation delay time T ₃ and the chattering time T ₄ (T ₃ + T ₄₎ , the amplifier 2 will be activated after the switch 4 between S ₀ and S ₂ is completely connected, and the device will be connected. No added stress. Similarly, by appropriately setting the delay times of the delay circuits 25 and 27, it is possible to switch from amplifier 2 to amplifier 1 without adding stress to the equipment when the command signal _C1 is input. In addition, the switching system according to the present invention is not limited to the case where the high-output amplifier redundant system configures a 1/2 system (1 working, 1 standby) as shown in Fig. 1. It can also be applied when the amplifier redundant system constitutes an m/n system (current m, standby nm, where n>m). In FIG. 6, reference numeral 30 is an input signal distribution circuit, 31 is a switching circuit constituted by a switch or a combination of a plurality of switches, and 32
₁ to 32 _o represent high output amplifiers, respectively. [Description of Effects] As described above, according to the present invention, when switching the high-output amplifiers constituting the high-output amplifier redundant system, the switching device is switched in a state where the output power of the high-output amplifier is not applied. In addition, we decided to provide a time difference in the application of command signals to the high-output amplifier and switch. Therefore, it is possible to prevent deterioration of the high-output amplifier due to total reflection of output power and other causes, and it is possible to prevent deterioration of the switch contacts due to switching when large power is applied, thereby improving the reliability of the equipment. It has great effects. The present invention is particularly effective when implemented in satellite communication power amplifiers that require high reliability.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the flow of communication signals in a redundant high-output amplifier system. FIG. 2 is a circuit diagram showing the connection of command signals. FIG. 3 is an operation time chart showing the signal waveforms of FIG. 2. FIG. 4 is a main circuit configuration diagram showing the connection of command signals in one embodiment of the present invention.
FIG. 5 is an operation time chart showing the signal waveform of FIG. 4. FIG. 6 is a block diagram of main parts showing an m/n redundant system. 1, 2...High output amplifier, 3...Hybrid, 4...Switcher, 5-10...Command input terminal, 20, 22, 25, 27...Delay circuit, 2
1, 23, 26, 28...Pulse generation circuit.

Claims (1)

[Claims] 1. A plurality of high-output amplifiers 1 and 2 with substantially the same characteristics.
and a switching circuit 4 for selecting one of the outputs of this amplifier, and a command signal for switching control is provided as a switching command input of the switching circuit, a startup command input of the amplifier to be started from among the amplifiers, and others. in a switching system connected respectively to the stop command inputs of the amplifiers, each of which has a delay time in the path of the command signal that is at least a time corresponding to the transient operation controlled by the command inputs; A high-output amplifier redundant switching system, characterized in that a delay circuit is provided to provide a signal in the order of the switching command input and the startup command input. 2 The delay time _T5 from the above stop command input to the above switching command input is the fall time of the amplifier.
It is set to be larger than the difference between _T1 and the switching circuit operation delay time _T3 , and the delay time _T6 from the above switching command input to the above startup command input is the switching circuit operation delay time.
The method according to claim 1, wherein the value is set to be greater than the sum of T ₃ and the chattering time T ₄ of the switching circuit.