JPS60260216A - Combined amplifier - Google Patents

Abstract

PURPOSE:To reduce an unnecessary higher mode generated assymmetrically by interrupting the supply of power in pairs including a faulty amplifier if one of amplifiers forming a pair is failed. CONSTITUTION:Amplifiers 31 and 35, 32 and 36, and 33 and 37 placed at a symmetrical position with respect to a combiner 4 are paired respectively. Power is applied to the amplifiers 31, 35 in the said pairs from a power supply circuit 8 and power is supplied respectively to the other amplifier pairs from other power supply circuit. When a detection circuit 9 provided to the output side of the amplifiers 31, 35 detects that e.g., the amplifier 31 is faulty, the power supply circuit 8 is interrupted via the control circuit 7 so as to interrupt the operation of the amplifier pair. Since the symmetricity of the entire amplifier is not lost in this way, the generation of the spurious higher mode caused by asymmetricity is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high-power solid-state amplifier used in microwave radio equipment.

In recent years, vacuum tubes have become more and more solid-state, and most of them are now solid-state. However, the development of solid-state microwave high-output amplification tubes has not yet progressed sufficiently.

For example, a ground station transmission amplifier for satellite communication is 6 GHz,
An output of several 10 W to several KW is required in the 14 GHz2 and 30 GHz bands. For this reason, traveling wave tubes have been widely used for some time, but because they are electron tubes, they have a short lifespan.

Therefore, there is a demand for a high-output amplifier using semiconductor elements that have a longer lifespan than electron tubes.

[Conventional technology]

Although an amplification semiconductor device that completely satisfies the above conditions has not yet been commercialized, the performance of gallium arsenide field effect transistors (hereinafter abbreviated as GaAs-FETs) has improved year by year, and the There are products on the market that can provide microwave output.

Therefore, research into solid-state microwave high-output amplifiers using such transistors is being actively conducted.

FIG. 2 fat shows a block diagram of a conventional example.

In the same figure, the input microwave applied to terminal 1 is divided into n by divider 2, and each is divided into n by GaAs4ET amplifier 3.
After being amplified by 1.32..., the signals are combined by a synthesizer 4 and output from a terminal 5.

Note that power is supplied to these GaAs-FET amplifiers from one power supply circuit 6, and the same divider as the combiner is used.

In a synthetic amplifier having such a configuration, if, for example, the amplifier 31 fails, the synthetic output will be reduced by that amount, but ripples will occur in the overall flat frequency characteristics and the characteristics will deteriorate.

When the amplifiers are operating normally, they excite the combiner 4 in the same phase, but if one of the amplifiers fails, one excitation source is lost. The impedance when looking at the amplifier side 32... is different.

Therefore, since the impedance of the amplifiers 31, 32, etc. becomes asymmetrical, the electromagnetic field distribution inside the combiner 4 changes, causing a higher-order unnecessary mode and causing ripples in the frequency characteristics. .

Figure 2 (in Figure 2) is an example of the layout of Figure 2 (al).
1 is a sectional view for explaining the structure of the synthesizer.

In FIG. 2 fbl and (C1, the combiner 4 uses a resonator type combiner consisting of a TM mode cavity resonator, and the amplifiers 31, 32...・ are arranged, and the output terminals 31L 321 ・ of each amplifier are arranged.
... is magnetically coupled to the synthesizer 4 via the line and conductor 41,
The combined output is taken out from the output terminal 42 with a circular plate antenna.

Note that this resonator type combiner is generally used because it has low loss, but when the amplifier fails, the isolation is not very good, so the effect of asymmetry becomes noticeable.

[Problem that the invention seeks to solve]

2nd fI! As explained above, the conventional synthesis circuit shown in J(al) has a problem in that a high-order unnecessary mode occurs in the synthesizer due to a failure of the amplifier, and ripples occur in the frequency characteristics.

Means for Solving Problem C] The above problem consists of a power supply circuit that independently supplies power to multiple groups of amplifiers located at symmetrical positions with respect to the combiner, and The problem is solved by the composite amplifier of the present invention, which comprises detection and control means that detects when at least one amplifier fails and shuts off the operation of the power supply circuit supplying power to the group including the failed amplifier. I can do that.

[Effect]

The present invention divides amplifiers at symmetrical positions with respect to the combiner into groups and supplies power from independent power supplies, and detects when at least one amplifier in the group fails, The power supply to the group was cut off.

That is, instead of a single power supply that powers all the amplifiers, and if one amplifier fails, it continues to power all the other amplifiers, it is made up of symmetrically located amplifiers. Power is supplied to a plurality of groups from independent power sources, so that, for example, when an amplifier fails, the power supplied to the group including the failed amplifier is cut off.

By doing this, the symmetry is not impaired, so higher-order unnecessary modes are reduced, ripples in the frequency characteristics are also reduced, and performance is improved.

〔Example〕

, ” Figure 1+a) is a block diagram showing the configuration of the present invention, in which the number of amplifiers is, for example, eight.

FIG. 1 (bl shows the layout of FIG. 1 tal).

Note that the same reference numerals indicate the same objects throughout.

In FIG. 1 (bl), amplifiers 31 and 35, 32 and 36, and 33 and 37 located at symmetrical positions with respect to the combiner 4 are paired, respectively.

Among these pairs, amplifiers 31 and 35 are supplied with power from a power supply circuit 8, as shown in FIG. The configuration is the same as in the case of 35 and 35, so it is not shown.

Here, a detection circuit 9 provided on the output side of the amplifiers 31 and 35 monitors the state of the output, and if the detection circuit 9 detects, for example, that the amplifier 31 has failed, the power supply circuit 8 to turn off the operation of this amplifier pair.

Therefore, since the overall symmetry is not impaired, the generation of unnecessary higher-order modes caused by asymmetry can be reduced, and the amplitude frequency characteristics can be improved.

Next, the above-described symmetry may be realized by further combining the above-described amplifier pairs to form a symmetrical block, to which independent power supply circuits are connected.

For example, amplifiers 31 and 35 and amplifiers 33 and 37 may be grouped. At this time, for example, if amplifier 31 fails, symmetry can be maintained by turning off three amplifiers 33, 35 and 37.

Although the above explanation has been made regarding a resonator type combiner, other types of combiners may be used, or a 3 dB hybrid chain may be used.

〔Effect of the invention〕

As explained above, in the present invention, if one of the amplifiers constituting one pair fails, by cutting off the power supply to the pair including the failed amplifier, unnecessary high-order Since the generation of modes can be reduced, the frequency characteristics can be improved.

In addition, since the power supply circuit is divided, even if one power supply circuit fails, the other power supply circuit will supply power to the remaining amplifiers, so there is less chance that the output will go to O, which increases the reliability of the power supply circuit. At the same time, the cost is reduced because a small-capacity power supply circuit can be used.

[Brief explanation of drawings]

Figure 1 (al is a block diagram of an embodiment of the present invention, Figure 1 (
BL is the layout diagram of FIG. 1 (al layout diagram, FIG. 2 (a) is the conventional block diagram, In the figure, 1 and 5 are terminals, 2 is a distributor, 4 is a combiner, 7 is a control circuit, 8 is a power supply circuit, ) 9 is a detection circuit, 31, 35, 32... are amplifiers .寥 1 寥（久） （し）

Claims (1)

[Claims] 1. A power supply circuit that independently supplies power to a plurality of groups of amplifiers located at symmetrical positions with respect to a combiner, and when at least one amplifier in the group fails. A composite amplifier characterized in that it comprises detection and control means that detects this and cuts off the operation of the power supply circuit that supplies power to the group including the failed amplifier. 2. The composite amplifier according to claim 1, wherein the group is composed of a pair of amplifiers. 3. The composite amplifier according to claim 1, wherein the group is composed of a combination of amplifier pairs.