JPS58206212A - Output power synthesization control system - Google Patents

Abstract

PURPOSE:To keep the output power at a constant level without producing a hit of a circuit for the transmission system of a communication circuit which needs the stable output power, by using a voltage controller which controls the output power of each high frequency transistor amplifier in response to the change of the power supply voltage and a directional coupler which detects each output power. CONSTITUTION:In case the output is lowered or discontinued by some reason for the output of either one of two amplifiers, e.g., a high frequency transistor amplifier 4 and the control function of a DC amplifying circuit 15 is inactive, the circuit 15 cuts the voltage supplied to the amplifier 4 of a voltage controller 9 to stop forcibly the operation of the amplifier 4. At the same time, the controller 9 is actuated to start another DC amplifying circuit 16 and to raise the output power of another high frequency transistor amplifier 5 up to the final output power from 1/2 value. The output power supplied from an RF output terminal 8 can be kept at a constant level owing to a series of above-mentioned operations.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an output power synthesis control system for a power amplifier device that operates to constantly synthesize the outputs of several high-frequency transistor amplifiers to obtain a final output.

In particular, when the output of at least one of the constituent high-frequency transistor amplifiers decreases or stops for some reason, the output power synthesis of the power amplifier allows the operation to continue without reducing the final output power of the power amplifier. Regarding control methods, there is a tendency for the final output stage of communication line transmission systems to use power amplifiers that use high-frequency transistors to obtain large outputs instead of conventional electron tubes. The larger the power, the more lofty.

A method is used in which wave transistor amplifiers are operated in parallel and their output powers are matched in phase and combined to produce the final output (44).

FIG. 1 shows an example of a power amplifying device using nine conventional combination methods, and for ease of explanation, shows a case in which two high-frequency transistor amplifiers are used.

The high frequency human input signal is supplied to the l'jF input terminal 1, and the
After being branched into two by the f-node 2 and amplified by the high-frequency toso/nostar amplifiers 4 and 5, they are supplied to the electric power combiner 7, where they are combined and output from the RF output end to the power source end to a fixed voltage. is added. Mata No-1 Grid 2
The branch output signals of have a phase difference of 90° from each other,
A phase adjuster 3 is provided to maintain a phase difference of 90° when these signals are amplified and then input to the power combiner 7 for recombination.

FIG. 2 shows the relationship between the output power P and the power supply voltage V of a transistor used in a high-frequency transistor amplifier. As is clear from the curve in this figure, the output power can be easily changed by changing the power supply voltage.

However, in the conventional example, if the output power of one high-frequency transistor amplifier drops or stops for some reason, unbalanced power is generated in the power combiner 7, and the M final output power is not normally operated. It is known that the output power decreases to about 1/4 of the output power if the For this reason, there is a drawback that not only the quality of the communication line is degraded due to a decrease in transmission power, but also the efficiency of the overall power amplifier device is significantly reduced.

In view of two or more drawbacks, the present invention aims to provide a power amplifier device that can maintain stable output power without substantially reducing overall efficiency even if a high frequency transistor amplifier fails.

The present invention provides a power amplifier device that operates a plurality of high-frequency transistor amplifiers in parallel and synthesizes their output powers to obtain final output power. A controller and a directional coupler that detects and detects the respective output power.

It is equipped with a detector that detects the combined output, converts it into a DC voltage, and a DC amplifier circuit that amplifies the detected voltage and controls the voltage controller.2 Usually, each high-frequency transistor amplifier In order to make the output power an appropriate power so that the final output power after 9 combinations becomes the required value,
If the output power of one or more high-frequency transnostar amplifiers decreases or stops for some reason, the high-frequency transformer that caused the failure will・The electric power controller operates to cut off the power to the Lannostar amplifier, and also increases the output power of the other normal high frequency Tunnostar amplifiers to maintain the final output power after 9 combinations constant. .

For the sake of clarity, this embodiment will be described with reference to the drawings in the case of a power amplifier in which two high-frequency transnostar amplifiers are operated in parallel and their outputs are combined to obtain the final output power.

FIG. 3 is a block diagram showing one embodiment of the present invention. A high frequency input signal is supplied to RF input terminal 1,
)・Branched into 2 by Ibrid 2.

- After the power output is amplified by the high frequency transistor amplifier 4, it is applied to the power combiner 70 input terminal through the directional coupler 11. / The other output of the hybrid 2 passes through the phase adjuster 3 which is used to correct the phase error during power combination by negative 1j, is amplified by the high frequency transistor amplifier 5, and then is sent to the directional coupler 12. The current is applied to another input terminal of the power combiner 7. The two signals applied to the power combiner 7 are combined here and sent out through the RF output terminal 8 as the final output power.

The combined output taken out by the directional coupler 11 is:

The signal is detected by a wave detector 13 and converted into a DC voltage, which is then applied to a DC amplifier circuit 15. The combined output of the other directional coupler 12 is detected by a wave detector 14 and converted into a DC voltage, which is then applied to a DC amplification JrIH path 16. The DC amplifier circuit 15 controls the power supply voltage so that the output power of the high-frequency transistor amplifier 4 reaches the pre-distributed required output power, that is, the final output power that is outputted from the RF output terminal 8. It operates to control the voltage controller 9 of. Similarly, for the other DC amplifier circuit 16, the output power of the high-frequency transistor amplifier 5 is higher than that of the RF output terminal 8, resulting in the final output power being too high. control through f
a++ L,, -C. Due to these control operations, the high frequency input power of the RF input terminal 11-3 fluctuates due to some external factor, or the power input to the power supply terminal 6 fluctuates. The fluctuation in usage of is automatically corrected, and the power combiner 7-\
Since the power of the two people's Kai-i is always maintained constant,
The output terminal A8 force and the output terminal In force are also stabilized.

Now, for some reason, either one of the amplifiers, for example, a high frequency transistor amplification? +"44 output goes down-
or stop, and the above-mentioned 1tjl by the DC amplifier circuit 15
l, iil When the operation becomes impossible, this DC amplifier circuit 15 cuts off the voltage supplied to the high frequency transistor amplifier 4 of the voltage controller 9, and the high frequency transistor amplification;
Force the operation of ri 4 to stop F. At the same time, the voltage controller I6 is operated to act on the other DC amplifier 1111 path 16 and increase the output power of the other high frequency transistor amplifier 5 from noise to final output power -. This series of operations is the same even when there are three or more high-frequency transistor amplifiers, in which case the output of each DC amplifier circuit is connected in parallel to the remaining DC amplifier circuits. It goes without saying that you should. And each high-frequency transnostar amplifier has one or more failures (1 to 9) in normal times, 7191 width: '+'rl -'
Of course, they can be operated in parallel in an output state that can cover 61 minutes (1.+1'K).

From the above, in the transmission system of a communication line where output power stability is required, the output power can be maintained constant without causing a momentary interruption of the line. Moreover, since the power supply to the high-frequency transistor amplifier in which the abnormality has occurred is cut off, even if the power consumption of the power supply increases by increasing the output power of the remaining high-frequency transistor amplifier, the total power consumption of the power amplifier device will almost never increase. Therefore, the overall efficiency of the device is not lowered, and the power supply equipment can be installed economically. Furthermore, since the two individual high-frequency transistor amplifiers are normally operated with low electric power, less heat is generated and the life of the high-frequency transistors can be expected to be extended.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a power amplifier using a conventional output power combining method. Figure 2 is a characteristic diagram of a high-frequency amplification transistor. FIG. 3 is a block diagram showing one embodiment of the present invention. 1...RF input terminal, 2...Hybrid, 3...
- Phase adjuster, 4 and 5...high frequency transistor amplifier. 6...Power terminal, 7...Power combiner, 8...RF
Output terminal. ! 9 and 10...voltage controller, 11 and 12...directional coupler, 13 and 14...detector, 15 and 16...
・Curved flow amplification circuit・

Claims (1)

[Claims] l High frequency human chi 1. - A hybrid for branching the signal into multiple units with even power, multiple high frequency trunk transistors, and an l1 for controlling the transistor amplifier.
Lll control, mate and said!・A directional coupler and a detector that detect the output power of the transistor amplifier and convert it into a DC voltage, a DC amplifier circuit that amplifies the output voltage of the detector and controls the voltage controller, and a plurality of and a power combiner for combining the output powers of the transistor amplifiers into one output. The output power of the power combiner is always maintained constant by detecting a decrease or stoppage of the output power of at least one of the transistor amplifiers and then increasing the output power of the transistor amplifier. An output power synthesis control method characterized by: Margin below