JP2001267865A - High frequency power amplifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an undesired phenomenon such as oscillation by a feedback signal and to realize a stable operation in a high frequency power amplifier where output power is controlled by switching a high frequency amplification means connected in parallel. SOLUTION: A prescribed high frequency amplification means in N-pieces of high frequency amplification means is constituted in such a way that three or more amplification elements are connected in multiple stages. A control means controls at least one high frequency amplification means controlled to an off state among the prescribed high frequency amplification means in such a way that at least one amplification element except for the amplification elements of an initial stage and a final stage is set to be an on state. A high signal inputted from a common signal input terminal is amplified by the high frequency amplification means in an on state. The rate of signals which run back the high frequency amplification means in an off state from a common signal output terminal and feeds back to the common signal input terminal is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high frequency power amplifier for amplifying a high frequency signal. In particular, the present invention relates to a communication high-frequency high-output power amplifier for amplifying a high-frequency signal of a microwave band or higher.

[0002]

2. Description of the Related Art A high-frequency high-output power amplifier for communication (hereinafter referred to as "HPA") has a higher output power than the maximum output power for the purpose of reducing interference of output waves to other stations and reducing power consumption of the HPA itself. In some cases, a function of controlling the output power to be low is required. As an HPA that meets such a requirement, a method of controlling the output power by controlling the gain of a preamplifier and controlling the input power to the HPA is generally used.

Here, in a relatively low frequency band below the UHF band, if the HPA is constituted by, for example, a class B push-pull circuit, the power consumption of the HPA depends on the output power. Can also be reduced.

On the other hand, in a high frequency band equal to or higher than the microwave band, a class B operation in which an amplifying element is pinched off by a bias when there is no signal is not suitable for amplification due to the performance of a semiconductor element used for amplification. Therefore, it is necessary to configure a circuit to perform class A operation or class AB operation.

[0005] The amplification element used for HPA is a class A operation or an AB
In the class operation, the power load efficiency of the HPA has a maximum value near the saturation output. Then, when the input power is reduced from a state where a saturated output is obtained, the output power is reduced almost in proportion thereto. However, since the power consumption is almost constant, the power load efficiency is remarkably reduced as the output power is reduced. Therefore, an HPA that amplifies a high-frequency signal above the microwave band
In order to reduce the power consumption, the method of controlling the gain of the preamplifier to reduce the input power is not suitable.

(First Conventional Example) FIG. 7 shows a first configuration example of a conventional high frequency power amplifier capable of reducing power consumption and controlling output power.

In the figure, the present high-frequency power amplifier comprises a plurality of N high-frequency amplifiers 1-1 to 1-1 having different saturation outputs.
1-N are arranged in parallel, and a common signal input terminal 4 and high-frequency amplifiers 1-1 to 1-N are connected by an input-side high-frequency switch 2.
And the common signal output terminal 5 is connected to any one of the output terminals of the high frequency amplification means 1-1 to 1-N by the high frequency switch 3 on the output side. The bias control means 6a responds to a control signal input from the control signal input terminal 7 to control the high frequency amplification means 1-1 to 1-1.
1-N (in this case, 1-N) is turned on and the other is turned off, and the high-frequency amplifying means that is turned on is connected to the common signal input terminal 4.
And the high frequency switches 2 and 3 are controlled so as to be connected to the common signal output terminal 5.

In this high-frequency power amplifier, since the high-frequency amplifiers 1-1 to 1-N have different saturation outputs, the high-frequency amplifier having the highest power load efficiency at the required output power may be selected. That is, by controlling the high-frequency switches 2 and 3 to turn on the selected high-frequency amplification means and to turn off the other high-frequency amplification means, it is possible to reduce power consumption in accordance with the required output power.

Here, as the high frequency switches 2 and 3,
Generally, a switch using a semiconductor (semiconductor switch) is used. Among the performances required for this high-frequency switch, particularly, the on-state passage loss (insertion loss) and the ratio of the on-state passage loss to the off-state passage loss (on-off ratio) are important, and the insertion loss is low. The higher the on / off ratio, the higher the performance.

In a one-to-N switch that selectively connects one terminal and one of N selection terminals, such as the high-frequency switches 2 and 3 shown in FIG. The amount of power leakage suppression (inter-terminal isolation) indicating the leakage of a signal input to a terminal that has not been selected is also important, and the higher the inter-terminal isolation, the higher the performance.

However, it is difficult for a semiconductor switch used in a high frequency band equal to or higher than the microwave band to simultaneously satisfy a low insertion loss, a high on / off ratio, and a high isolation between terminals. Therefore, if a semiconductor switch having an excellent on / off ratio and terminal-to-terminal isolation is employed in the above-described conventional configuration, the insertion loss of the semiconductor switch becomes high, and it is necessary to amplify an extra signal to compensate for the loss. And power consumption increases. On the other hand, when a semiconductor switch having excellent insertion loss is employed, the on / off ratio and the isolation between terminals are reduced, so that components other than the selected signal path appear, making it difficult to obtain expected performance. .

Generally, a signal is input from the signal output terminal of the high-frequency amplifier, and the amount of the signal flowing back to the signal input terminal is zero.
However, the isolation between the terminals of the high-frequency switch is also a finite value. Therefore, the common signal input terminal 4
When the high-frequency signal input from is amplified by the on-state high-frequency amplifier and input to the high-frequency switch 3 on the output side, the signal leaks between the terminals and the signal is output from the signal output terminal of the off-state high-frequency amplifier. The signal flows back to the input terminal, and the backflow output is input to the high-frequency switch 2 on the input side, and a signal may leak between the terminals and return. In particular, when the inter-terminal isolation is not sufficient and the gain of the high frequency amplifying means that is turned on is high, phenomena such as oscillation due to a feedback signal may occur.

(Second Conventional Example) FIG. 8 shows a second configuration example of a conventional high-frequency power amplifier capable of reducing power consumption and controlling output power. Here, a configuration example that does not use a high-frequency switch is shown (references: Okazaki, Ohira, Araki, “Ku
Study on Efficient Transmission Power Control Method for Band Power Amplifier ",
IEICE Technical Report DSP99-156 (200
0-01)).

In the figure, the present high-frequency power amplifier comprises a plurality of N high-frequency amplifiers 1-1 to 1-1 having different saturated outputs.
1-N are arranged in parallel, and the common signal input terminal 4 and each signal input terminal of the high-frequency amplifiers 1-1 to 1-N are connected via the corresponding input-side transmission lines 8-1 to 8-N. And
An output-side transmission line 9 corresponding to each signal output terminal of the high-frequency amplifiers 1-1 to 1-N and the common signal output terminal 5 respectively.
Connect via -1 to 9-N. Bias control means 6b
Is a configuration in which, in accordance with a control signal input from the control signal input terminal 7, one of the high-frequency amplifiers 1-1 to 1-N is turned on and the other is turned off. .

The input-side transmission line 8-1 has a characteristic impedance equal to the value defined as the input impedance of the connected high-frequency amplifier 1-1, and when the high-frequency amplifier 1-1 is off, The electrical length is determined so that the input impedance from the common signal input terminal 4 to the high-frequency amplifier 1-1 becomes maximum at the signal frequency.
The input-side transmission lines 8-2 to 8-N also have the same characteristic impedance and electric length with respect to the connected high-frequency amplifiers 1-2 to 1-N.

The output-side transmission line 9-1 has a characteristic impedance equal to the value defined as the output impedance of the connected high-frequency amplifier 1-1, and when the high-frequency amplifier 1-1 is off, The electrical length is determined so that the output impedance from the common signal output terminal 5 to the high-frequency amplifier 1-1 becomes maximum at the signal frequency.
The output-side transmission lines 9-2 to 9-N also have the same characteristic impedance and electric length with respect to the connected high-frequency amplifiers 1-2 to 1-N.

In this high-frequency power amplifier, since the high-frequency amplifiers 1-1 to 1-N have different saturation outputs, the high-frequency amplifier having the highest power load efficiency at the required output power is selected and turned on. By turning off the other components, power consumption can be reduced in accordance with the required output power.

Here, the output side transmission lines 9-1 to 9-N
Is ideally infinite if the connected high-frequency amplifiers 1-1 to 1-N are in an off state, so that a signal flows into the off-state high-frequency amplifier without using a high-frequency switch. Never. However, since the impedance is actually finite, a signal flows into the high-frequency amplifier in an off state at a small rate. In particular, if the impedance seen from the common signal output terminal 5 to the high-frequency transmission line connected to the high-frequency amplifying means in the off state is only several times the output impedance of the high-frequency power amplifier, the first conventional example will be described. In this case, the same problem as in the case where the isolation between the terminals of the high frequency switch is not sufficient occurs. That is, the high-frequency signal input from the common signal input terminal 4 is amplified by the on-state high-frequency amplifying means, and is passed from the signal input terminal of the off-state high-frequency amplifying means to the signal input terminal via the high-frequency transmission line on the output side. And the amount of feedback through the high frequency transmission line on the input side cannot be ignored, and phenomena such as oscillation may occur.

[0019]

When the high frequency switch used in the first conventional example is used in a high frequency band, the insertion loss, the on / off ratio and the isolation between terminals have a trade-off relationship. That is, when priority is given to the on / off ratio and the isolation between terminals, power consumption increases to compensate for the increased insertion loss. On the other hand, if the insertion loss is prioritized, the on / off ratio and the inter-terminal isolation are reduced. In particular, when the gain of the high-frequency amplifying means that is turned on is high, there is a problem that the feedback signal causes oscillation or the like.

In the second prior art, a transmission line of a specific length is inserted so that the input impedance or the output impedance of the high-frequency amplifying means when viewed from the common signal input terminal or the common signal output terminal is not less than a predetermined value. Thereby, sufficient isolation can be obtained without a high-frequency switch. Thereby, the problem relating to the high-frequency switch is temporarily solved. However, since the input impedance or the output impedance cannot actually be made infinite, there is a problem that a small amount of signal flows into the high-frequency amplifying means in the off state, and the feedback signal causes oscillation or the like.

According to the present invention, there is provided a high-frequency power amplifier for controlling output power by switching high-frequency amplifiers connected in parallel, thereby preventing unwanted phenomena such as oscillation due to a feedback signal and enabling stable operation. It is an object to provide a power amplifier.

[0022]

According to a first aspect of the present invention, there is provided a high-frequency power amplifier according to the first aspect, wherein a high-frequency power input from a common signal input terminal to a predetermined one of N high-frequency amplifiers having different saturation outputs. Means are provided for reducing the ratio of a signal in which a signal is amplified by the on-state high-frequency amplifying means and flows back from the common signal output terminal to the off-state high-frequency amplifying means and returns to the common signal input terminal. Thus, it is possible to prevent an oscillation phenomenon or the like caused by the positive feedback signal.

The high-frequency power amplifier according to any one of claims 2 to 4 has a configuration in which predetermined high-frequency amplifying means among N high-frequency amplifying means having different saturation outputs are connected in multiple stages of three or more amplifying elements, The control means controls at least one of the predetermined high-frequency amplifying means, which is controlled to be in the off-state, to turn on at least one amplifying element other than the first and last-stage amplifying elements.

According to a fifth aspect of the present invention, in the configuration, the signal input terminals of the N high frequency amplifying means having different saturation outputs are connected to the common signal input terminal via the input high frequency switch. At least one of the N high-frequency amplifying units has a configuration in which two or more amplifying elements are connected in multiple stages, and the control unit controls at least one of the predetermined high-frequency amplifying units to be turned off. , Control is performed to turn on at least one amplifying element other than the last-stage amplifying element.

The high frequency power amplifier according to any one of claims 8 to 10, wherein the signal output terminals of the N high frequency amplifying means having different saturation outputs are connected to the common signal output terminal via the output high frequency switch. At least one of the N high-frequency amplifying units has a configuration in which two or more amplifying elements are connected in multiple stages, and the control unit controls at least one of the predetermined high-frequency amplifying units to be turned off. , Control is performed to turn on at least one amplifying element other than the first-stage amplifying element.

In the high frequency power amplifier according to the present invention, the signal input terminals of the N high frequency amplifying means having different saturated outputs are connected to the common signal input terminal via the input high frequency switch, and the N high frequency power amplifiers are connected to the common signal input terminal. In a configuration in which the signal output terminal of the high-frequency amplifier is connected to the common signal output terminal via the output-side high-frequency switch, a predetermined high-frequency amplifier of the N high-frequency amplifiers is a single amplifying element or two or more amplifiers. Amplifying elements are connected in multiple stages, and at least one high-frequency amplifying means, which is controlled by a control means to be in an off state among predetermined high-frequency amplifying means, has at least one
Control is performed to turn on the two amplifying elements.

With the above arrangement, when the predetermined high-frequency amplifying means, in which the feedback signal is relatively easy to flow backward, is controlled to be in the off state, some of the multi-stage connected amplifying elements are not turned off and some of them are turned on. State. This is because the power consumption is slightly increased as compared with the case where all the amplifying elements are turned off, but the amount of the feedback signal flowing backward when the predetermined high frequency amplifying means is turned off can be reduced. , An oscillation phenomenon caused by the feedback signal can be prevented.

In particular, when the input impedance or output impedance of the high-frequency amplifying means when turned off from the viewpoint of the common signal input terminal or the common signal output terminal is not sufficient (claims 2 to 10), or the isolation between the terminals of the high-frequency switch is sufficient. If not (claims 5 to 13), the effect of reducing the ratio of the feedback signal by the predetermined high-frequency amplifier is large. Even in a configuration in which a high-frequency switch is not used on the input side or the output side (claims 2 to 6, 8 to 9), since the first or last stage amplifying element of the high-frequency amplifying means is controlled to be off, the transmission line It does not affect the switch function using the impedance characteristic.

The high frequency power amplifier according to claim 14 is
A high-frequency signal input from a common signal input terminal is amplified by a high-frequency amplifier in an on state to a predetermined high-frequency amplifier among N high-frequency amplifiers having different saturated outputs from each other. Phase adjusting means is provided for adjusting the phase so that a signal flowing backward through the high frequency amplifying means and returning to the common signal input terminal becomes a negative feedback signal. As a result, the feedback signal passing through the predetermined high-frequency amplifier in the off state has a phase opposite to that of the original input signal, and is canceled. At this time, although the gain of the high frequency amplifying means which is turned on is slightly reduced, an oscillation phenomenon or the like caused by the feedback signal is prevented, and the stable operation of the high frequency power amplifier is realized.

The functions described in claims 2 to 13 and the functions described in claim 14 can be used in combination (claim 15). As a result, the ratio of the feedback signal can be reduced, and further, the phase can be adjusted so that the phase is opposite to that of the original input signal, and the feedback can be performed.

The configurations according to the first to fifteenth aspects may include a configuration in which, among the N high-frequency amplifiers having different saturated outputs, one having the same saturated output is provided as a standby system. In this case, as the high frequency power amplifier, for example, when i (i is an integer of 1 or more and N / 2 or less) high frequency amplifying units each include one standby system, substantially N-
The output power control is performed by switching the i high-frequency amplifiers.

[0032]

(First Embodiment) FIG. 1 shows a high-frequency power amplifier according to a first embodiment of the present invention. This embodiment corresponds to claim 2.

The high-frequency power amplifier according to the present embodiment comprises a plurality of N high-frequency amplifiers 1-1 to 1-1 having different saturation outputs.
−N are arranged in parallel, and the common signal input terminal 4 and each signal input terminal of the high-frequency amplifiers 1-1 to 1-N are connected via the corresponding input-side transmission lines 8-1 to 8-N. , The signal output terminals of the high-frequency amplifiers 1-1 to 1-N and the common signal output terminal 5 are respectively connected to the corresponding output-side transmission lines 9-.
Connect via 1-9-N. Bias control means 6c
Sets one of the high-frequency amplifiers 1-1 to 1-N (here, 1-N) to an on state and sets the other to an off state in response to a control signal input from a control signal input terminal 7. This is a configuration for performing such control.

The input-side transmission line 8-1 has a characteristic impedance equal to the value defined as the input impedance of the connected high-frequency amplifier 1-1, and when the high-frequency amplifier 1-1 is off, The electrical length is determined so that the input impedance from the common signal input terminal 4 to the high-frequency amplifier 1-1 becomes maximum at the signal frequency.
The input-side transmission lines 8-2 to 8-N also have the same characteristic impedance and electric length with respect to the connected high-frequency amplifiers 1-2 to 1-N.

The output side transmission line 9-1 has a characteristic impedance equal to the value defined as the output impedance of the connected high frequency amplifying means 1-1, and when the high frequency amplifying means 1-1 is off, The electrical length is determined so that the output impedance from the common signal output terminal 5 to the high-frequency amplifier 1-1 becomes maximum at the signal frequency.
The output-side transmission lines 9-2 to 9-N also have the same characteristic impedance and electric length with respect to the connected high-frequency amplifiers 1-2 to 1-N.

In this embodiment, the high frequency amplifying means 1-1 to 1-1
1-N have different saturated outputs, the required output power is selected by selecting the high-frequency amplifying means having the highest power load efficiency at the required output power, turning it on, and turning off the other high-frequency amplification means. In accordance with the power consumption.

Here, the feature of this embodiment is that the predetermined high frequency amplifying means 1-1 is constituted by three or more stages of amplifying elements (including input / output matching circuits), and the bias control means 6c is provided by the high frequency amplifying means 1-1. When 1 is turned off, control is performed to turn on at least one amplifying element other than the first and last stage amplifying elements. In FIG. 1, a broken line indicates a bias signal for off-control, and a solid line indicates a bias signal for on-control.

A simulation result when the amplifying element of the high frequency amplifying means 1-1 has a three-stage configuration will be described below. GaAsME with gate length 0.5μm as amplifying element
The following shows the characteristics when a high frequency signal of 14.2 GHz is input to the high frequency amplification means designed with the SFET as the source ground and the gate width of 200 μm, 400 μm and 3200 μm in the first, middle and last stages, respectively.

When the high-frequency amplifier is turned on, a drain bias voltage (hereinafter, referred to as "Vds") of 10 V is applied to all the amplifying elements, and a drain current is applied as a gate bias voltage (hereinafter, referred to as "Vgs"). When a voltage of -0.65 V, which is 0.6 times the saturated drain current value, is applied, the passing gain (hereinafter referred to as "S21") becomes 21.1 dB. The reverse pass gain (hereinafter, referred to as "S12") output from the output terminal to the high frequency signal input to the input terminal is -59.2 dB. On the other hand, when the high frequency amplifying means is turned off, applying 10 V as Vds to all the amplifying elements and applying -2.0 V as Vgs which causes the amplifying elements to pinch off, S21 becomes -25.8 dB.
And S12 is -25.9 dB.

In the high frequency amplification means 1-1 of the present embodiment,
The Vds of the first and last stage amplifiers are set to 10 V, Vgs are set to -2.0 V, and the Vds of the middle stage amplifier are set to 10 V so that the first and last stage amplifiers are turned off and the middle stage amplifier is turned on. , Vgs is -0.65V, S21 is -10.3
dB and S12 are -36.8 dB. Therefore, in the high frequency amplifying means 1-1, it is understood that S12 is improved by 10 dB or more as compared with the case where all the amplifying elements are turned off.

As described above, by bias-controlling the high frequency amplifying means 1-1 which is turned off, S12 is reduced to 10 dB.
Since the above is also improved, the power of the feedback signal flowing back through the high frequency amplifying means is significantly reduced. Thereby, phenomena such as oscillation can be prevented, and the operation of the high-frequency power amplifier can be stabilized.

It should be noted that among the high-frequency amplifiers controlled to be in the OFF state, the number of high-frequency amplifiers such as the high-frequency amplifier 1-1 of the present embodiment is not limited to one, and a plurality of high-frequency amplifiers may be provided. When the high frequency amplifying means having three or more stages of amplifying elements is controlled to be in the off state, the amplifying element to be turned on is arbitrary as long as it is an amplifying element other than the first and last stages. Further, when there is one high-frequency amplifying means having three or more stages of amplifying elements, and when it is controlled to be on, all other high-frequency amplifying means are uniformly controlled to be off. .

Further, the configuration shown in FIG. 1 includes an input-side high-frequency switch 2 for connecting the common signal input terminal 4 to any one of the N input-side transmission lines 8-1 to 8-N. (Claim 3). In this case, the bias control circuit 6c controls the high-frequency switch 2 on the input side so as to connect the signal input terminal of the high-frequency amplification means 1-N, which has been turned on, to the common signal input terminal 4.

Further, in the configuration of FIG. 1, the output side high-frequency switch 3 for connecting any one of the N output side transmission lines 9-1 to 9-N and the common signal output terminal 5 is provided. (Claim 4). In this case, the bias control circuit 6c controls the high-frequency switch 3 on the output side so as to connect the signal output terminal of the high-frequency amplification means 1-N, which has been turned on, to the common signal output terminal 5.

The input high-frequency switch 2 for connecting the common signal input terminal 4 to one of the N input-side transmission lines 8-1 to 8-N in the configuration of FIG.
And any one of the N output-side transmission lines 9-1 to 9-N
It may be configured to include an output-side high-frequency switch 3 that connects the common signal output terminal 5 and the common signal output terminal 5.

(Second Embodiment) FIG. 2 shows a high-frequency power amplifier according to a second embodiment of the present invention. In this embodiment,
This corresponds to claim 5.

The high-frequency power amplifier according to the present embodiment comprises a plurality of N high-frequency amplifiers 1-1 to 1-1 having different saturation outputs.
-N are arranged in parallel, and the common signal input terminal 4 and any one of the signal input terminals of the high-frequency amplifiers 1-1 to 1-N are connected by the high-frequency switch 2 on the input side. 1-N signal output terminals and common signal output terminal 5
Are connected via the corresponding output-side transmission lines 9-1 to 9-N, respectively. The bias control unit 6d is responsive to a control signal input from the control signal input terminal 7 to any one of the high-frequency amplification units 1-1 to 1-N (here, 1-N).
Is turned on, and the other is turned off, and the high-frequency switch 2 is connected to the common signal input terminal 4 to connect the high-frequency amplifier 1-N controlled to the on-state.
Is controlled.

The output-side transmission line 9-1 has a characteristic impedance equal to the value defined as the output impedance of the connected high-frequency amplifier 1-1, and when the high-frequency amplifier 1-1 is off, The electrical length is determined so that the output impedance from the common signal output terminal 5 to the high-frequency amplifier 1-1 becomes maximum at the signal frequency.
The output-side transmission lines 9-2 to 9-N also have the same characteristic impedance and electric length with respect to the connected high-frequency amplifiers 1-2 to 1-N.

In this embodiment, the high frequency amplifying means 1-1 to 1-1
1-N have different saturated outputs, the required output power is selected by selecting the high-frequency amplifying means having the highest power load efficiency at the required output power, turning it on, and turning off the other high-frequency amplification means. In accordance with the power consumption.

Here, the feature of this embodiment is that the predetermined high frequency amplifying means 1-1 is constituted by two or more stages of amplifying elements (including input / output matching circuits), and the bias control means 6d is provided by the high frequency amplifying means 1-1. When 1 is turned off, control is performed to turn on at least one amplifying element other than the last-stage amplifying element. In FIG. 2, a broken line indicates a bias signal for off-control, and a solid line indicates a bias signal for on-control.

A simulation result in the case where the amplifying element of the high frequency amplifying means 1-1 has a two-stage configuration will be described below. GaAsME with gate length 0.5μm as amplifying element
The graph shows the characteristics when a high frequency signal of 14.2 GHz is input to the high frequency amplifying means which is designed such that the SFET is grounded at the source and the gate width is 200 μm and 400 μm at the first and last stages, respectively.

When the high frequency amplifying means is turned on, 10 V is applied as Vds to all the amplifying elements, and a voltage -0.65 V at which the drain current becomes 0.6 times the saturated drain current value is applied as Vgs. Then, S21 is 13.7
dB. S12 is -37.3 dB. On the other hand, when turning off the high frequency amplifying means, applying 10 V as Vds to all the amplifying elements and applying -2.0 V as Vgs at which the amplifying elements are pinched off, S21 becomes -16.5 dB. And S12 becomes -16.5 dB.

In the high frequency amplifying means 1-1 of the present embodiment,
Vds of the last-stage amplifying element is set to 10 V and Vgs so that the last-stage amplifying element is turned off and the first-stage amplifying element is turned on.
Is −2.0 V, Vds of the first stage amplifying element is 10 V, and Vgs is −0.65 V, S21 is −3.80 dB, S12 is −28.4 d
B. Therefore, in the high frequency amplification means 1-1, S
12 is 10 times smaller than when all amplifiers are turned off.
It can be seen that dB or more is improved.

As described above, by bias-controlling the high frequency amplifying means 1-1 which is turned off, S12 is reduced to 10 dB.
Since the above is also improved, the power of the feedback signal flowing back through the high frequency amplifying means is significantly reduced. Thereby, phenomena such as oscillation can be prevented, and the operation of the high-frequency power amplifier can be stabilized.

It should be noted that among the high-frequency amplifiers controlled to be in the OFF state, the number of high-frequency amplifiers such as the high-frequency amplifier 1-1 of the present embodiment is not limited to one, and a plurality of high-frequency amplifiers may be provided. When the high frequency amplifying means having two or more stages of amplifying elements is controlled to be in the off state, the amplifying element to be turned on is arbitrary as long as it is an amplifying element other than the last stage. Further, when there is one high-frequency amplifying means having two or more stages of amplifying elements, and when it is controlled to be on, all other high-frequency amplifying means are uniformly controlled to be off. .

In the configuration shown in FIG. 2, the input-side transmission lines 8-1 to 8- are connected between the common signal input terminal 4 and the signal input terminals of the N high-frequency amplifiers 1-1 to 1-N. N may be inserted respectively (claim 6). However, the input-side transmission line 8-1 has a characteristic impedance equal to the value defined as the input impedance of the connected high-frequency amplifier 1-1, and is common when the high-frequency amplifier 1-1 is off. From the signal input terminal 4 to the high frequency amplification means 1-1
The electrical length is determined so that the input impedance obtained from the above becomes maximum at the signal frequency. Input side transmission line 8-2
8 to N have similar characteristic impedances and electrical lengths with respect to the connected high-frequency amplifiers 1-2 to 1-N, respectively.

Further, in the configuration shown in FIG. 2, an output-side high-frequency switch 3 for connecting any one of the N output-side transmission lines 9-1 to 9-N and the common signal output terminal 5 is provided. (Claim 7). In this case, the bias control circuit 6d controls the high-frequency switch 3 on the output side so as to connect the signal output terminal of the high-frequency amplification means 1-N, which has been further turned on, to the common signal output terminal 5.

In the configuration of FIG. 2, between the common signal input terminal 4 and the signal input terminals of the N high-frequency amplifiers 1-1 to 1-N, the input-side transmission lines 8-1 to 8- are connected. N respectively, and N output-side transmission lines 9-1 to 9-
A configuration may be adopted in which an output-side high-frequency switch 3 that connects any one of the N and the common signal output terminal 5 is provided.

(Third Embodiment) FIG. 3 shows a high-frequency power amplifier according to a third embodiment of the present invention. In this embodiment,
This corresponds to claim 8.

The high-frequency power amplifier of this embodiment has a plurality of N high-frequency amplifiers 1-1 to 1-1 having different saturation outputs.
−N are arranged in parallel, and the common signal input terminal 4 and each signal input terminal of the high-frequency amplifiers 1-1 to 1-N are connected via the corresponding input-side transmission lines 8-1 to 8-N. The high-frequency switch 3 on the output side controls the high-frequency amplification means 1-1 to 1-1.
1-N and the common signal output terminal 5 are connected. The bias control unit 6e is responsive to a control signal input from the control signal input terminal 7 to one of the high-frequency amplification units 1-1 to 1-N (here, 1-N).
Is turned on and the other is turned off, and the high-frequency switch 3 is connected to the common signal output terminal 5 with the high-frequency amplifier 1-N controlled to be on.
Is controlled.

The input-side transmission line 8-1 has a characteristic impedance equal to the value defined as the input impedance of the connected high-frequency amplifier 1-1, and when the high-frequency amplifier 1-1 is off, The electrical length is determined so that the input impedance from the common signal input terminal 4 to the high-frequency amplifier 1-1 becomes maximum at the signal frequency.
The input-side transmission lines 8-2 to 8-N also have the same characteristic impedance and electric length with respect to the connected high-frequency amplifiers 1-2 to 1-N.

In this embodiment, the high frequency amplifying means 1-1 to 1-1
1-N have different saturated outputs, the required output power is selected by selecting the high-frequency amplifying means having the highest power load efficiency at the required output power, turning it on, and turning off the other high-frequency amplification means. In accordance with the power consumption.

Here, the feature of the present embodiment is that the predetermined high frequency amplifying means 1-1 is constituted by two or more stages of amplifying elements (including input / output matching circuits), and the bias control means 6e is provided by the high frequency amplifying means 1-1. When 1 is turned off, control is performed to turn on at least one amplifying element other than the first-stage amplifying element. In FIG. 3, a broken line indicates a bias signal for off-control, and a solid line indicates a bias signal for on-control.

The simulation result when the amplifying elements of the high-frequency amplifying means 1-1 have a two-stage configuration is the same as in the second embodiment. In the high-frequency amplifying means 1-1, S12 turns off all the amplifying elements. It is improved by 10 dB or more as compared with the case of the state.

It should be noted that among the high-frequency amplifiers controlled to be in the OFF state, the number of high-frequency amplifiers such as the high-frequency amplifier 1-1 of the present embodiment is not limited to one, and a plurality of high-frequency amplifiers may be provided. When the high-frequency amplifier having two or more stages of amplifying elements is controlled to be in the off state, the amplifying element to be turned on is arbitrary as long as it is an amplifying element other than the first stage. Further, when there is one high-frequency amplifying means having two or more stages of amplifying elements, and when it is controlled to be on, all other high-frequency amplifying means are uniformly controlled to be off. .

In the configuration shown in FIG. 3, between the signal output terminals of the N high-frequency amplifiers 1-1 to 1-N and the common signal output terminal 5, output-side transmission lines 9-1 to 9- are connected. N may be inserted respectively (claim 9). However, the output-side transmission line 9-1 has a characteristic impedance equal to the value defined as the output impedance of the connected high-frequency amplifier 1-1, and is common when the high-frequency amplifier 1-1 is off. From the signal output terminal 5 to the high frequency amplifying means 1-1
The electrical length is determined so that the output impedance obtained from the above becomes maximum at the signal frequency. Output side transmission line 9-2
9-N have similar characteristic impedances and electrical lengths to the connected high-frequency amplifiers 1-2 to 1-N, respectively.

Further, the configuration shown in FIG. 3 includes an input-side high-frequency switch 2 for connecting the common signal input terminal 4 and any one of the N input-side transmission lines 8-1 to 8-N. (Claim 10). In this case, the bias control circuit 6e controls the input-side high-frequency switch 2 so as to connect the signal input terminal of the high-frequency amplifier 1-N and the common signal input terminal 4 that have been further turned on.

In the configuration shown in FIG. 3, between the signal output terminals of the N high-frequency amplifiers 1-1 to 1-N and the common signal output terminal 5, output-side transmission lines 9-1 to 9- are provided. N may be inserted, and the input high-frequency switch 2 may be provided to connect the common signal input terminal 4 and any one of the N input-side transmission lines 8-1 to 8-N.

(Fourth Embodiment) FIG. 4 shows a high-frequency power amplifier according to a fourth embodiment of the present invention. In this embodiment,
This corresponds to claim 11.

The high-frequency power amplifier of this embodiment has a plurality of N high-frequency amplifiers 1-1 to 1-1 having different saturation outputs.
−N are arranged in parallel, the common signal input terminal 4 is connected to any one of the signal input terminals of the high frequency amplifying means 1-1 to 1-N by the high frequency switch 2 on the input side, and the high frequency switch 3 on the output side The signal output terminal of any one of the high-frequency amplifiers 1-1 to 1-N is connected to the common signal output terminal 5. The bias control means 6f responds to the control signal input from the control signal input terminal 7 by using the high-frequency amplification means 1-1 to 1-1.
1-N (in this case, 1-N) is turned on and the other is turned off, and the high-frequency amplifier 1-N, which is turned on, is connected to the common signal input terminal 4 and In this configuration, the high-frequency switches 2 and 3 are controlled so as to be connected to the common signal output terminal 5.

In this embodiment, the high-frequency amplifiers 1-1 to 1-1
1-N have different saturated outputs, the required output power is selected by selecting the high-frequency amplifying means having the highest power load efficiency at the required output power, turning it on, and turning off the other high-frequency amplification means. In accordance with the power consumption.

Here, the feature of the present embodiment is that the predetermined high frequency amplifying means 1-1 is constituted by one amplifying element or two or more stages of amplifying elements (including an input / output matching circuit), and the bias control means 6f is provided by the bias controlling means 6f. When the high frequency amplifying means 1-1 is turned off, control is performed to turn on at least one amplifying element. In FIG. 4, a broken line indicates a bias signal for off-control, and a solid line indicates a bias signal for on-control.

A simulation result when the amplifying element of the high frequency amplifying means 1-1 has a single-stage configuration will be described below. GaAsME with gate length 0.5μm as amplifying element
The characteristics when a high frequency signal of 14.2 GHz is input to the high frequency amplifying means designed with the SFET as the source ground and the gate width as 400 μm are shown.

When the high frequency amplifying means is turned on, 10 V is applied as Vds to all the amplifying elements, and a voltage -0.65 V at which the drain current becomes 0.6 times the saturated drain current value is applied as Vgs. Then, S21 is 6.40
dB. S12 is -20.1 dB. On the other hand, when turning off the high frequency amplifying means, applying 10 V as Vds to all the amplifying elements and applying -2.0 V as Vgs at which the amplifying elements are pinched off, S21 becomes -10.9 dB. And S12 becomes -11.0 dB.

In the high-frequency amplifier 1-1 of the present embodiment,
When bias control is performed so that the amplification element is turned on,
S21 is -6.40 dB, and S12 is -20.1 dB. Therefore, in the high frequency amplification means 1-1, it is understood that S12 is improved by about 9 dB as compared with the case where the amplification element is turned off. As described above, by controlling the bias of the high-frequency amplifier 1-1, S12 is improved by about 9 dB, so that the power of the feedback signal flowing backward through the high-frequency amplifier is significantly reduced. Thereby, phenomena such as oscillation can be prevented, and the operation of the high-frequency power amplifier can be stabilized.

It should be noted that, of the high frequency amplifying means controlled to be in the off state, the number of high frequency amplifying means for turning on at least one amplifying element is not limited to one, and a plurality of high frequency amplifying means may be provided. When the high frequency amplifying means having two or more stages of amplifying elements is controlled to be in the off state, the amplifying element that is turned on is arbitrary.

In the configuration shown in FIG. 4, input-side transmission lines 8-1 to 8- are connected between the common signal input terminal 4 and the signal input terminals of the N high-frequency amplifiers 1-1 to 1-N. N may be inserted respectively (claim 12). However, the input-side transmission line 8-1 has a characteristic impedance equal to the value defined as the input impedance of the connected high-frequency amplifier 1-1, and is common when the high-frequency amplifier 1-1 is off. From the signal input terminal 4 to the high frequency amplification means 1-
The electrical length is determined so that the input impedance looking at 1 becomes maximum at the signal frequency. Input side transmission line 8-
2-8-N have similar characteristic impedances and electrical lengths with respect to the connected high-frequency amplifiers 1-2-1-N, respectively.

In the configuration shown in FIG. 4, between the signal output terminals of the N high-frequency amplifiers 1-1 to 1-N and the common signal output terminal 5, output-side transmission lines 9-1 to 9- are connected. N may be inserted respectively (claim 13). However, the output-side transmission line 9-1 has a characteristic impedance equal to the value defined as the output impedance of the connected high-frequency amplifier 1-1, and is common when the high-frequency amplifier 1-1 is off. From the signal output terminal 5 to the high-frequency amplification means 1-
The electrical length is determined so that the output impedance with a value of 1 becomes maximum at the signal frequency. Output side transmission line 9-
2 to 9-N also have the same characteristic impedance and electric length with respect to the connected high-frequency amplifiers 1-2 to 1-N, respectively.

In the configuration of FIG. 4, between the common signal input terminal 4 and the signal input terminals of the N high-frequency amplifiers 1-1 to 1-N, the input-side transmission lines 8-1 to 8-N are connected. N respectively, and N high-frequency amplifiers 1-1 to 1--1
The output-side transmission lines 9-1 to 9-N may be inserted between the N signal output terminals and the common signal output terminal 5, respectively.

(Fifth Embodiment) FIG. 5 shows a high-frequency power amplifier according to a fifth embodiment of the present invention. In this embodiment,
This corresponds to claim 14.

The high-frequency power amplifier of this embodiment has two high-frequency amplifiers 1-1 to 1-2 having different saturation outputs.
Are arranged in parallel, and the common signal input terminal 4 and each signal input terminal of the high frequency amplifying means 1-1 to 1-2 are connected via the corresponding input side transmission lines 8-1 to 8-2, respectively. Each signal output terminal of the amplifying means 1-1 to 1-2 and the common signal output terminal 5 are connected to the corresponding output side transmission line 9-1 to 9-1.
Connect via 9-2. The bias control unit 6a turns on one of the high-frequency amplification units 1-1 to 1-2 (here, 1-2) in accordance with the control signal input from the control signal input terminal 7, and sets the other high-frequency amplification units 1-1 to 1-2. This is a configuration for performing control to turn off the power supply.

The input-side transmission line 8-1 has a characteristic impedance equal to the value defined as the input impedance of the connected high-frequency amplifier 1-1, and when the high-frequency amplifier 1-1 is off, The electrical length is determined so that the input impedance from the common signal input terminal 4 to the high-frequency amplifier 1-1 becomes maximum at the signal frequency.
The input-side transmission line 8-2 also has the same characteristic impedance and electric length as the connected high-frequency amplifier 1-2.

The output-side transmission line 9-1 has a characteristic impedance equal to the value defined as the output impedance of the connected high-frequency amplifier 1-1, and when the high-frequency amplifier 1-1 is off, The electrical length is determined so that the output impedance from the common signal output terminal 5 to the high-frequency amplifier 1-1 becomes maximum at the signal frequency.
The output-side transmission line 9-2 also has the same characteristic impedance and electric length as the connected high-frequency amplifier 1-2.

In this embodiment, the high frequency amplifying means 1-1 to 1-1
1-2 each have a different saturation output, the high-frequency amplification means having the highest power load efficiency at the required output power is selected and turned on, and the remaining elements are turned off to obtain the required output power. In accordance with the power consumption.

Here, the feature of this embodiment is that a predetermined high frequency amplifying means 1-1 is composed of two-stage amplifying elements (including input / output matching circuits) 11 and 12 and a phase adjusting means 13 inserted therebetween. It is where it is composed. However, when the phase adjustment unit 13 is, for example, a transmission line, its electrical length is a signal frequency, and a high-frequency signal input from the common signal input terminal 4 is amplified by the on-state high-frequency amplification unit 1-2. The signal is set so that the signal which flows backward from the signal output terminal 5 through the high-frequency amplifier 1-1 in the OFF state and returns to the common signal input terminal 4 becomes a negative feedback signal. The electrical length of the transmission line that becomes a negative feedback signal at the common signal input terminal 4 is set so that the phase difference between the input signal and the feedback signal is an odd multiple of 180 °.

As a result, the high-frequency amplification means 1 in the off state
Since the phase of the feedback signal passing through -1 is opposite to the phase of the original input signal, an oscillation phenomenon caused by the feedback signal is prevented, and the operation of the high-frequency power amplifier is stabilized.

(Sixth Embodiment) FIG. 6 shows a high-frequency power amplifier according to a sixth embodiment of the present invention. In this embodiment,
This corresponds to claim 15, in which the configuration of claim 14 (fifth embodiment) is applied to the configuration of claim 5 (second embodiment). Note that the present invention can be similarly applied to other embodiments.

The high-frequency power amplifier of this embodiment has a plurality of N high-frequency amplifiers 1-1 to 1-1 having different saturation outputs.
-N are arranged in parallel, and the common signal input terminal 4 and any one of the signal input terminals of the high-frequency amplifiers 1-1 to 1-N are connected by the high-frequency switch 2 on the input side. 1-N signal output terminals and common signal output terminal 5
Are connected via the corresponding output-side transmission lines 9-1 to 9-N, respectively. The bias control unit 6d is responsive to a control signal input from the control signal input terminal 7 to any one of the high-frequency amplification units 1-1 to 1-N (here, 1-N).
Is turned on, and the other is turned off, and the high-frequency switch 2 is connected to the common signal input terminal 4 to connect the high-frequency amplifier 1-N controlled to the on-state.
Is controlled.

The output-side transmission line 9-1 has a characteristic impedance equal to the value defined as the output impedance of the connected high-frequency amplifier 1-1, and when the high-frequency amplifier 1-1 is off, The electrical length is determined so that the output impedance from the common signal output terminal 5 to the high-frequency amplifier 1-1 becomes maximum at the signal frequency.
The output-side transmission lines 9-2 to 9-N also have the same characteristic impedance and electric length with respect to the connected high-frequency amplifiers 1-2 to 1-N.

In this embodiment, the high frequency amplifying means 1-1 to 1-1
1-N have different saturated outputs, the required output power is selected by selecting the high-frequency amplifying means having the highest power load efficiency at the required output power, turning it on, and turning off the other high-frequency amplification means. In accordance with the power consumption.

Here, the feature of this embodiment is that the predetermined high-frequency amplification means 1-1 is constituted by two-stage amplification elements (including input / output matching circuits), and the phase adjustment means 13 is inserted between them. is there. However, when the phase adjustment unit 13 is, for example, a transmission line, the electrical length of the transmission line is the signal frequency, and the high-frequency signal input from the common signal input terminal 4 is amplified by the on-state high-frequency amplification unit 1-N. The signal is set so that the signal which flows backward from the signal output terminal 5 through the high-frequency amplifier 1-1 in the OFF state and returns to the common signal input terminal 4 becomes a negative feedback signal. The bias control means 6d
Is to perform control to turn off the last-stage amplifying element and turn on the first-stage amplifying element when the high-frequency amplifying unit 1-1 is turned off, as in the second embodiment. . In FIG. 6, a dashed line indicates a bias signal to be turned off,
A solid line indicates a bias signal to be turned on.

Thus, the high-frequency amplification means 1 in the off state
Since the S12 of -1 is improved, the feedback signal flowing backward becomes very small, and its phase becomes opposite to that of the original input signal, so that the oscillation phenomenon caused by the feedback signal is prevented.
The operation of the high-frequency power amplifier is stabilized.

When the high frequency amplifying means 1-1 is composed of three or more stages of amplifying elements, the phase adjusting means 13 is inserted between the stages of each amplifying element or between any stages of the amplifying elements. What is necessary is just to set the phase adjustment so that the whole becomes a negative feedback signal. In this case, as in the second embodiment, when the high frequency amplifying unit 1-1 is controlled to the off state, the amplifying element to be turned on is arbitrary as long as it is an amplifying element other than the last stage.

[0094]

As described above, the high-frequency power amplifier of the present invention is connected in multiple stages when a predetermined high-frequency amplifier among the N high-frequency amplifiers connected in parallel is turned off. By not turning off all of the amplifying elements but turning on some of them, the amount of the feedback signal flowing backward can be reduced. That is, when the input impedance or the output impedance of the high-frequency amplifying unit is off when viewed from the common signal input terminal or the common signal output terminal is not sufficient (claims 2 to 10), or when the isolation between the terminals of the high-frequency switch is not sufficient ( In the fifth to thirteenth aspects, the ratio of the feedback signal can be reduced by the predetermined high frequency amplifying means, so that the oscillation phenomenon caused by the feedback signal can be prevented. Thus, a stable operation can be realized in a high-frequency power amplifier that reduces power consumption according to the required output power while performing output power control.

The high-frequency power amplifier according to the present invention is configured such that when a predetermined one of the N high-frequency amplifiers connected in parallel is controlled to be in an off state, the high-frequency amplifier is reverse-flowed to the common high-frequency amplifier. By adjusting the phase so that the signal fed back to the signal input terminal becomes a negative feedback signal, it is possible to prevent an oscillation phenomenon or the like due to the feedback signal. Thus, a stable operation can be realized in a high-frequency power amplifier that reduces power consumption according to the required output power while performing output power control.

Further, by combining the above-described structures, the ratio of the feedback signal can be reduced and adjusted so as to be a negative feedback signal in the predetermined high-frequency amplifier controlled to be in the off state. Stable operation can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a high-frequency power amplifier according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a high-frequency power amplifier according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a high-frequency power amplifier according to a third embodiment of the present invention.

FIG. 4 is a diagram illustrating a high-frequency power amplifier according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing a high-frequency power amplifier according to a fifth embodiment of the present invention.

FIG. 6 is a diagram illustrating a high-frequency power amplifier according to a sixth embodiment of the present invention.

FIG. 7 is a diagram showing a first configuration example of a conventional high-frequency power amplifier.

FIG. 8 is a diagram showing a second configuration example of a conventional high-frequency power amplifier.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 High frequency amplification means 2, 3 High frequency switch 4 Common signal input terminal 5 Common signal output terminal 6a, 6b, 6c, 6d, 6e, 6f Bias control means 7 Control signal input terminal 8 Input side transmission line 9 Output side transmission line 11, 12 Amplifying element (including input / output matching circuit) 13 Phase adjusting means

Continued on the front page F-term (reference) 5J067 AA04 AA21 AA41 AA51 AA62 AA63 CA36 CA54 CA76 FA04 FA10 FA18 FA19 HA38 KA16 KA29 KA49 KA68 KS01 KS11 LS01 MA08 SA14 TA01 5J069 AA04 AA21 AA41 CAA18 FA18 FA18 KA29 KA49 KA68 KC06 KC07 MA08 SA14 TA01 5J091 AA04 AA21 AA41 AA51 AA62 AA63 CA36 CA54 CA76 FA04 FA10 FA18 FA19 HA38 KA16 KA29 KA49 KA68 MA08 SA14 TA01 5J092 AA04 AA21 AA41 FAA18CA18 FA18A18 MA08 SA14 TA01

Claims (15)

[Claims] 1. One of N (N is an integer of 2 or more) high-frequency amplifying means having different saturation outputs connected in parallel between a common signal input terminal and a common signal output terminal is turned on. In an off state, and amplifies a high-frequency signal input from the common signal input terminal and outputs the amplified signal to the common signal output terminal. A high-frequency signal input from the common signal input terminal is amplified by an on-state high-frequency amplifier, and a signal that returns from the common signal output terminal to the off-state high-frequency amplifier and returns to the common signal input terminal. A high-frequency power amplifier comprising means for reducing the ratio. 2. A high-frequency amplifier having N (N is an integer of 2 or more) different in saturation output connected in parallel between a common signal input terminal and a common signal output terminal; Each of the N high frequency amplifying means is disposed between each signal input terminal and each of the N high frequency amplifying means such that the input impedance of the off-state high frequency amplifying means from the common signal input terminal is equal to or higher than a predetermined value at the signal frequency to be amplified. N input-side transmission lines that define the electrical length of each of the N high-frequency amplifiers are disposed between each signal output terminal of the N high-frequency amplifiers and the common signal output terminal, and are in an off state from the common signal output terminal. N output-side transmission lines having respective electrical lengths determined so that the output impedance of the high-frequency amplifier means is equal to or greater than a predetermined value at the frequency of the signal to be amplified; Control means for selectively turning on any one of the N high-frequency amplifying means in accordance with a control signal, and controlling the other high-frequency amplifying means to an off-state. A high-frequency power amplifier that amplifies a high-frequency signal input from the common signal input terminal via the common signal input terminal and outputs the amplified high-frequency signal to the common signal output terminal; The above-mentioned amplification elements are connected in multiple stages, and the control means sets the first-stage and last-stage amplification elements to the off-state with respect to at least one of the predetermined high-frequency amplification means that is controlled to the off-state. And a control for turning on at least one other amplifying element. 3. The high-frequency power amplifier according to claim 2, further comprising: an input-side high-frequency switch that connects the common signal input terminal to any one of the N input-side transmission lines. A high-frequency power amplifier, wherein the input-side high-frequency switch is controlled so as to connect a signal input terminal of the high-frequency amplification means controlled to an on state and the common signal input terminal. 4. The high-frequency power amplifier according to claim 2, further comprising: an output-side high-frequency switch that connects any one of the N output-side transmission lines to the common signal output terminal. A high-frequency power amplifier, wherein the output-side high-frequency switch is controlled so as to connect the signal output terminal of the high-frequency amplification means controlled to the on state and the common signal output terminal. 5. A high-frequency amplifier having N (N is an integer of 2 or more) different in saturation output connected in parallel between a common signal input terminal and a common signal output terminal; An input-side high-frequency switch for connecting to any one of the signal input terminals of the N high-frequency amplifiers; and an input-side high-frequency switch disposed between each signal output terminal of the N high-frequency amplifiers and the common signal output terminal. N output-side transmission lines each having an electrical length determined so that the output impedance of the off-state high-frequency amplifier means from the common signal output terminal is equal to or greater than a predetermined value at the amplified signal frequency. One of the N high frequency amplifying means is selectively turned on in accordance with the control signal to be supplied, and the other high frequency amplifying means is controlled to be in an off state and controlled to be in an on state. Control means for controlling the input-side high-frequency switch so as to connect the signal input terminal of the high-frequency amplifying means to the common signal input terminal, and the common signal input terminal via the high-frequency amplifying means controlled to an on state. In the high-frequency power amplifier for amplifying the high-frequency signal input from and outputting the signal to the common signal output terminal, the predetermined high-frequency amplifier among the N high-frequency amplifiers has two or more amplifying elements connected in multiple stages. The control means, for at least one of the predetermined high-frequency amplifying means, which is controlled to an off-state, turns off a last-stage amplifying element and at least one other amplifying element A high-frequency power amplifier having a configuration for performing control for turning on a power supply. 6. The high-frequency power amplifier according to claim 5, wherein said common terminal is disposed between N selection terminals of said input high-frequency switch and each signal input terminal of said N high-frequency amplification means. N number of electric lengths are determined so that the input impedance from the signal input terminal (N selection terminals of the input side high-frequency switch) to the off-state high-frequency amplification means becomes a predetermined value or more at the amplified signal frequency. A high-frequency power amplifier comprising an input-side transmission line. 7. The high-frequency power amplifier according to claim 6, further comprising: an output-side high-frequency switch that connects any one of the N output-side transmission lines to the common signal output terminal. A high-frequency power amplifier, wherein the output-side high-frequency switch is controlled so as to connect the signal output terminal of the high-frequency amplification means controlled to the on state and the common signal output terminal. 8. A high-frequency amplifier having N (N is an integer of 2 or more) different in saturation output connected in parallel between a common signal input terminal and a common signal output terminal; Each of the N high frequency amplifying means is disposed between each signal input terminal and each of the N high frequency amplifying means such that the input impedance of the off-state high frequency amplifying means from the common signal input terminal is equal to or higher than a predetermined value at the signal frequency to be amplified. N input-side transmission lines that define the electrical lengths of: an output-side high-frequency switch that connects any one of the signal output terminals of the N high-frequency amplifiers to the common signal output terminal; One of the N high frequency amplifying means is selectively turned on in accordance with the control signal to be supplied, and the other high frequency amplifying means is controlled to be in an off state and controlled to be in an on state. Control means for controlling the output-side high-frequency switch so as to connect the signal output terminal of the high-frequency amplification means to the common signal output terminal, and the common signal input terminal via the high-frequency amplification means controlled to be on. In the high-frequency power amplifier for amplifying the high-frequency signal input from and outputting the signal to the common signal output terminal, the predetermined high-frequency amplifier among the N high-frequency amplifiers has two or more amplifying elements connected in multiple stages. The control means, for at least one of the predetermined high-frequency amplifying means, which is controlled to an off-state, the first stage amplifying element is turned off, and at least one other amplifying element is A high-frequency power amplifier having a configuration for performing control for turning it on. 9. The high-frequency power amplifier according to claim 8, wherein the common terminals are respectively disposed between the signal output terminals of the N high-frequency amplifiers and the N selection terminals of the output-side high-frequency switch. N number of electric lengths determined so that the output impedance from the signal output terminal (N selection terminals of the output side high frequency switch) to the off-state high frequency amplifying means is equal to or more than a predetermined value at the frequency of the signal to be amplified. A high frequency power amplifier comprising an output side transmission line. 10. The high-frequency power amplifier according to claim 8, further comprising: an input-side high-frequency switch that connects the common signal input terminal to any one of the N input-side transmission lines. A high-frequency power amplifier, wherein the input-side high-frequency switch is controlled so as to connect a signal input terminal of the high-frequency amplification means controlled to an on state and the common signal input terminal. 11. N (N is an integer of 2 or more) high frequency amplifying means having different saturated outputs and connected in parallel between a common signal input terminal and a common signal output terminal; An input-side high-frequency switch for connecting any one of the signal input terminals of the N high-frequency amplifiers; and one of the signal output terminals of the N high-frequency amplifiers and the common signal output terminal. An output-side high-frequency switch to be connected, and selectively control one of the N high-frequency amplifiers to an on state and control the other high-frequency amplifiers to an off state according to a control signal input from the outside; The signal input terminal of the high-frequency amplifier controlled to the on state is connected to the common signal input terminal, and the signal output terminal of the high-frequency amplifier controlled to the on state and the common signal output terminal are connected to each other. Control means for controlling the input-side high-frequency switch and the output-side high-frequency switch so as to be connected, and amplifies a high-frequency signal input from the common signal input terminal via high-frequency amplifying means controlled to an ON state; In the high-frequency power amplifier that outputs to the common signal output terminal, a predetermined high-frequency amplifier among the N high-frequency amplifiers has a configuration in which one amplification element or two or more amplification elements are connected in multiple stages; The high-frequency power is characterized in that the control means controls at least one of the predetermined high-frequency amplifying means, which controls an off state, to at least one amplifying element. amplifier. 12. The high-frequency power amplifier according to claim 11, wherein the common-side power switch is disposed between N selection terminals of the input-side high-frequency switch and signal input terminals of the N high-frequency amplifiers, respectively. N number of electric lengths are determined so that the input impedance from the signal input terminal (N selection terminals of the input side high-frequency switch) to the off-state high-frequency amplification means becomes a predetermined value or more at the amplified signal frequency. A high-frequency power amplifier comprising an input-side transmission line. 13. The high-frequency power amplifier according to claim 11, wherein each of said N high-frequency amplifiers is arranged between each signal output terminal of said N high-frequency amplifiers and N selection terminals of said output high-frequency switch, and N number of electric lengths determined so that the output impedance from the signal output terminal (N selection terminals of the output side high frequency switch) to the off-state high frequency amplifying means is equal to or more than a predetermined value at the frequency of the signal to be amplified. A high frequency power amplifier comprising an output side transmission line. 14. A high-frequency amplifier having N (N is an integer of 2 or more) different in saturation output connected in parallel between a common signal input terminal and a common signal output terminal; Each of the N high frequency amplifying means is disposed between each signal input terminal and each of the N high frequency amplifying means such that the input impedance of the off-state high frequency amplifying means from the common signal input terminal is equal to or higher than a predetermined value at the signal frequency to be amplified. N input-side transmission lines that define the electrical length of each of the N high-frequency amplifiers are disposed between each signal output terminal of the N high-frequency amplifiers and the common signal output terminal, and are in an off state from the common signal output terminal. N output-side transmission lines having respective electrical lengths determined so that the output impedance of the high-frequency amplification means is equal to or greater than a predetermined value at the frequency of the signal to be amplified. Control means for selectively turning on one of the N high-frequency amplifying means in accordance with a control signal to be provided and controlling the other high-frequency amplifying means to be in an off-state. A high-frequency power amplifier that amplifies a high-frequency signal input from the common signal input terminal via the common signal input terminal and outputs the amplified signal to the common signal output terminal; The high-frequency signal input from the signal input terminal is amplified by the on-state high-frequency amplifier, and the signal that flows back from the common signal output terminal to the off-state high-frequency amplifier and returns to the common signal input terminal becomes a negative feedback signal. A high-frequency power amplifier comprising a phase adjusting means for adjusting a phase of the high-frequency power. 15. The high-frequency power amplifier according to claim 2, wherein a high-frequency signal input from the common signal input terminal is input to a predetermined high-frequency amplifier of the N high-frequency amplifiers. A phase adjusting unit that is amplified by the high-frequency amplifying unit in an on state, and adjusts the phase so that a signal that flows back from the common signal output terminal to the high-frequency amplifying unit in an off state and returns to the common signal input terminal is a negative feedback signal. A high frequency power amplifier, comprising: