JP2003008365A - Circuit for power amplification, control method of circuit for power amplification and portable terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit for power amplification which realize superior characteristic over a wide load impedance range, with small circuit scale as compared with the conventional case. SOLUTION: The circuit for power amplification is provided with a DC/DC converter 2108, a directional coupler 2101, detectors 2102, 2103, etc. The DC/DC converter 2108 supplies a power source voltage supplied from a battery 2111 to a power amplifier 1302, in accordance with a control command from a control circuit 2109. When an output signal to be outputted to an antenna 1306 is inputted from a second matching circuit 105, the directional coupler 2101 outputs a signal corresponding to the inputted signal, from one terminal 2101a. When a reflected wave is inputted from the antenna 1306, the directional coupler 2101 outputs a signal corresponding to the reflected wave, from the other terminal 2101b, and detectors 2102, → 2103, and the like are equipped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power amplification circuit having a wide dynamic range and high efficiency, a control method of the power amplification circuit, and a portable terminal device.

[0002]

2. Description of the Related Art For example, in a CDMA mobile terminal, the probability of maximum output is low, and the output is often 10 to 20 dB lower. Therefore, in order to extend the battery life of the terminal, it is important to reduce the power consumption at such low output.

FIG. 11 shows a conventional power amplifier capable of reducing the power consumption at such a low output.

In FIG. 11, the power amplifier includes an input terminal 1101, an output terminal 1102, a matching circuit 1103, a transistor 1104, a matching circuit 1105, and a bias circuit 1.
106, a bias circuit 1107, a step-down DC / DC converter 1108, and a control means 1109.

This conventional power amplifier has an input terminal 110.
The matching circuit 1103 matches the impedance of the input signal input from 1, the transistor 1104 amplifies the impedance, the matching circuit 1105 matches the impedance, and the output signal is output to the outside from the output terminal 1102.

The step-down DC / DC converter 1108 is
The power supply voltage supplied from the power supply terminal 1111 is adjusted by reducing the output voltage output to the bias circuit 1107 according to the control of the control means 1109.

That is, the step-down DC / DC converter 1
108, when the output power from the output terminal 1102 is large, the collector or drain voltage of the transistor 1104 is set to the same value as or slightly lower than the power supply voltage of the power supply connected to the power supply terminal 1111.
When the output power is low, the collector or drain voltage of the transistor 1104 is set to a value lower than the power supply voltage of the power supply connected to the power supply terminal 1111 to realize a highly efficient power amplification device with a wide dynamic range. That is, conventionally, the collector or drain voltage of the transistor has not been used higher than the power supply voltage.

Next, in a power amplifier used in a mobile terminal such as a CDMA system, an isolator is inserted between the power amplifier and the antenna in order to suppress fluctuations in the load of the power amplifier.

FIG. 13 shows a conventional power amplifier 1 as described above.
302 is shown.

At the time of reception, the antenna switch (or duplexer) 1304 outputs the signal received by the antenna 1306 to the reception signal output terminal 1305.

During transmission, the transmission signal input terminal 13
The transmission signal input from 01 is amplified by the power amplifier 1302 and output to the isolator 1303. The isolator 1303 outputs the output of the power amplifier 1302 to the antenna switch (or duplexer) 1304. Then, the antenna switch (or duplexer) 1304 outputs the output power from the isolator 1303 to the antenna 1306.

When a human body approaches the antenna 1306 during transmission, the load on the antenna 1306 changes. However, even if the load on the antenna fluctuates in this way, the isolator 1303 is inserted between the power amplifier 1302 and the antenna switch (or duplexer) 1304, so that the load on the output side of the power amplifier 1302 is substantially reduced. It can be kept constant.

[0013]

The problem to be solved by the invention is shown in FIG.
The characteristic of the step-down DC / DC converter 1108 used in the first power amplifier is shown. That is, FIG. 12 (A)
Is a step-down DC / DC converter 1108,
n is an input voltage supplied to the step-down DC / DC converter 1108 from the power supply connected to the power supply terminal 1111;
Vout is an output voltage output from the step-down DC / DC converter 1108.

That is, in FIG. 12B, the input voltage V
Under the condition that in is constant, the horizontal axis is the output voltage Vout, and the vertical axis is the efficiency (%) of the step-down DC / DC converter 1108. The efficiency is the output power Pou when the output voltage Vout is output with respect to the input power Pin when the input voltage Vin is applied to the power supply terminal 1111.
The ratio of t corresponds to 100. That is, this efficiency is 100 × Pout / Pin
It is represented by.

As is apparent from FIG. 12B, it is understood that the efficiency decreases as the output voltage Vout of the step-down DC / DC converter 1108 decreases.

In the power amplifier of FIG. 11, the frequency of actual use is higher when the output power from the output terminal 1102 is low. In case of low output, the step-down DC / D
The output voltage of the C converter 1108 becomes low. Therefore,
As is clear from FIG. 12B, the voltage conversion ratio of the step-down DC / DC converter 1108 is large when the power amplifier has a low output. In such a case, the conversion efficiency of the step-down DC / DC converter 1108 decreases. Therefore, the step-down DC / DC converter 110 is used at a low output which is frequently used.
Since the conversion efficiency of No. 8 is reduced, the effect of reducing power consumption is reduced as a result.

That is, in the conventional power amplifier, there is a problem that the power consumption of the power amplifier cannot be reduced because the conversion efficiency of the step-down DC / DC converter is lowered.

On the other hand, as described with reference to FIG. 13, the power amplifier 1302 and the antenna switch (or duplexer) 130.
An isolator 1303 is provided between the four lines, which causes a problem that the circuit scale increases.

The isolator 1303 causes a power loss of, for example, about 0.2 to 0.8 db. Therefore, although the load fluctuation of the power amplifier 1302 can be suppressed, it is necessary to increase the output power of the power amplifier 1302 in order to compensate for the power loss by the isolator 1303, and as a result, the power consumption increases.

That is, in the conventional power amplifier, since power loss occurs in the isolator, there is a problem that the power consumption of the power amplifier increases when the loss is compensated.

In consideration of the above problems of the conventional power amplifier, the present invention can realize good characteristics over a wide load impedance range with a circuit scale smaller than the conventional power amplifier circuit and power amplifier. It is an object of the present invention to provide a method for controlling a power supply circuit and a mobile terminal device using the power amplification circuit. It is another object of the present invention to provide a power amplification circuit having a wide dynamic range and high efficiency, a method for controlling the power amplification circuit, and a mobile terminal device using the power amplification circuit.

[0022]

[Means for Solving the Problems] The first invention (Claim 1)
(Corresponding to the present invention described) is a first matching circuit for matching and outputting an input signal input thereto, a first bias circuit connected to the output of the first matching circuit, A second bias circuit, one of which is connected to the output of the transistor, a second bias circuit of which one is connected to the output of the transistor, and a second bias circuit which is connected to the output of the transistor and outputs an output signal of the transistor by matching. Power amplifier including a matching circuit, a voltage converting means having its output connected to the other side of the second bias circuit, and a power source connected to its input, and a control means for controlling the operation of the voltage converting means. Circuit, further comprising load impedance detection means for detecting a load impedance on the output side of the power amplification circuit, wherein the control means includes at least the load impedance. On the basis of the detection result of the detecting means, wherein changing the output voltage of the voltage converting means, wherein the output voltage is a power amplifier circuit to be applied as a power supply voltage to the transistor.

A second aspect of the present invention (corresponding to the present invention according to claim 2) is the power amplification according to the first aspect of the present invention, which includes an isolator arranged between the load impedance detecting means and the antenna. Circuit.

According to a third aspect of the present invention (corresponding to the present invention according to claim 3), the load impedance detecting means is
(1) When an output signal output to the load side from the second matching circuit is input, a signal corresponding to the input signal is output from one terminal, and a reflected wave is output from the load side. A directional coupler that outputs a signal corresponding to the reflected wave from the other terminal when input, and (2) data relating to the amplitude and phase of the signal using the signal output from the one terminal The first detector including: a first detector that outputs the signal; and (3) a second detector that outputs data regarding the amplitude and phase of the signal using the signal output from the other terminal. 2 or the power amplification circuit of the present invention.

According to a fourth aspect of the present invention (corresponding to the present invention according to claim 4), the control means sets the transistor of the transistor according to the value of the load impedance which is the detection result of the load impedance detection means. The power amplification circuit according to any one of the first to third aspects of the present invention, which controls the value of the power supply voltage.

Further, in a fifth aspect of the present invention (corresponding to the present invention according to claim 5), the control means is used for the control, which indicates a correspondence relationship between the value of the load impedance and the value of the power supply voltage. It is a power amplification circuit according to the fourth aspect of the present invention, which is provided with a storage means for storing data as a table.

A sixth aspect of the present invention (corresponding to the present invention according to claim 6) is a first matching circuit for matching and outputting an input signal input thereto, and an output of the first matching circuit. Connected to the first bias circuit, a transistor connected to the output of the first matching circuit, a second bias circuit one of which is connected to the output of the transistor, and connected to the output of the transistor A second matching circuit for matching and outputting the output signal of the transistor, and a voltage converting means having its output connected to the other of the second bias circuit and a power supply connected to its input, and the voltage converting circuit. And a control means for controlling the operation of the means, wherein the voltage conversion means outputs an output voltage according to the control of the control means, and the control means is the power amplification circuit. Output power of In response, with respect to the voltage conversion means,
The power amplification circuit determines whether to perform a boosting operation for increasing the output voltage higher than a predetermined power supply voltage or a step-down operation for decreasing the output voltage lower than the power supply voltage.

Further, in a seventh aspect of the present invention (corresponding to the present invention according to claim 7), the control means includes a load impedance value which is the detection result of the load impedance detection means, and the power amplification circuit. Controlling the value of the power supply voltage of the transistor according to the value of the output power of the first transistor.
Is a circuit for power amplification of the present invention.

Further, in an eighth aspect of the present invention (corresponding to the present invention according to claim 8), the control means is used for the control, which indicates a correspondence relationship between the value of the load impedance and the value of the power supply voltage. The power amplification circuit according to the seventh aspect of the present invention, further comprising storage means for storing data as a table according to the output power.

Further, in a ninth aspect of the present invention (corresponding to the present invention according to claim 9), the power conversion means is a DC / DC converter according to the first or sixth aspect of the present invention. is there.

A tenth aspect of the present invention (corresponding to the present invention according to claim 10) is the power amplifying circuit according to the ninth aspect of the present invention, wherein the DC / DC converter is a step-up / down type.

An eleventh aspect of the present invention (corresponding to the present invention according to claim 11) is (1) a first matching circuit for matching and outputting input signals, and (2) the first matching circuit. A first bias circuit connected to the output of the one matching circuit,
(3) a transistor connected to the output of the first matching circuit, (4) a second bias circuit having one connected to the output of the transistor, and (5) connected to the output of the transistor, A second matching circuit for matching and outputting the output signals of the transistors; and (6) voltage conversion means having its output connected to the other of the second bias circuits and a power supply connected to its input, ) A control method of a power amplification circuit, comprising: a control means for controlling the operation of the voltage conversion means, wherein the load impedance on the output side of the power amplification circuit is detected, and the control means is at least the detection means. Based on the applied load impedance, the output voltage of the voltage conversion means is changed, and the output voltage is applied to the transistor as a power supply voltage. .

A twelfth aspect of the present invention (corresponding to the present invention according to claim 12) is an antenna used for transmission and reception, and a power according to claim 1 or 6 for outputting a transmission signal from the antenna. Transmission circuit means including an amplification circuit, reception circuit means for processing a reception signal from the antenna, transmission / reception separation circuit means provided between the antenna and the transmission circuit means and the reception circuit means. And a mobile terminal device.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below mainly in Embodiments 4, 5, and 6.
Further, the first to third embodiments mainly describe the embodiments relating to the technology related to the present invention. (Embodiment 1) Here, Embodiment 1 of the technique related to the present invention will be described with reference to FIG.

In FIG. 1, the transistor 104 is matched on the input side and the output side by a matching circuit 103 and a matching circuit 105, respectively. The collector voltage is the power supply terminal 11
1, the voltage is converted by the step-up / down type DC / DC converter 108 and then supplied to the transistor 104 via the bias circuit 107. On the other hand, the base voltage is supplied from the power supply terminal 110 to the transistor 104 via the bias circuit 106.

FIG. 8 shows the relationship between the output voltage of the step-up / down type DC / DC converter 108 of the power amplifier of this embodiment and the output power from the output terminal 102.

The voltage supplied to the power supply terminal 111 is Vcc
Then, when the output from the output terminal 102 is maximum, the output voltage from the buck-boost DC / DC converter 108 is Vm.
ax (> Vcc), and the output voltage from the step-up / down type DC / DC converter 108 is reduced as the output from the output terminal 102 decreases.

Further, as shown in FIG.
The voltage Vcc supplied to is set between the above Vmax and the voltage Vmin at which the output voltage of the step-up / step-down DC / DC converter 108 becomes minimum.

Therefore, when the output power is larger than a certain value Po, the step-up / down type DC / DC converter operates in a step-up manner.
When it is smaller than Po, the step-up / down type DC / DC converter operates to step down.

Therefore, the minimum output voltage and the maximum output voltage output when the step-down DC / DC converter 1108 used in the conventional power amplifier is used in the power amplifier are assumed to be the values of the present embodiment. Buck-boost DC / D
If it is the same as the C converter 108, that is, if the dynamic range is the same, the buck-boost DC / DC converter 108 of the present embodiment has a voltage conversion ratio higher than that of the step-down DC / DC converter 1108. Becomes smaller, the conversion efficiency of the step-up / down DC / DC converter 108 is improved accordingly.

With such a configuration, it is possible to improve the efficiency of the DC / DC converter at low output, which is frequently used, and reduce the power consumption of the power amplifier.

As described above, when the step-up / step-down DC / DC converter 108 has the same dynamic range,
The power amplifier of the present embodiment can reduce power consumption more than the conventional power amplifier described in FIG.

Further, comparing the conventional step-down DC / DC converter 1108 with the step-up / step-down DC / DC converter 108 of the present embodiment, the output voltage of which the characteristic of the power amplifier is equal to or higher than the allowable minimum value is obtained. The difference between the maximum value and the minimum value is larger in the buck-boost DC / DC converter 108. That is, the buck-boost DC / DC converter 10
8 has a wider dynamic range of the output voltage having a conversion efficiency equal to or higher than the allowable value. Even if this is utilized, the reduction of power consumption can be realized. This will be described while comparing the conventional power amplifier described in FIG. 11 and the power amplifier of the present embodiment.

First, the conventional power amplifier of FIG. 11 will be described in more detail.

That is, FIG. 9 (A) shows the relationship between the output power of the conventional power amplifier described in FIG. 11 and the output voltage of the step-down DC / DC converter 1108, and FIG. 9 (B).
Similarly, the relationship between the output power and efficiency of the conventional power amplifier is shown.

The conventional power amplifier shown in FIG. 11 uses the step-down DC / DC converter 1108 which outputs the voltage obtained by stepping down the power supply voltage as the output voltage as described above. In FIG. 9A, when the power supply voltage applied to the power supply terminal 1111 is Vbat and the minimum voltage required for the transistor 1104 to operate normally is Vmin, the variable range of the collector voltage changes from Vbat to Vmin.
The minimum voltage Vmin at which the transistor 1104 operates normally is determined as follows.

That is, when a normal transistor is used for the purpose of amplifying electric power, it is necessary to make the emitter voltage lower than the base voltage and the collector voltage higher than the base voltage. Therefore, when the collector voltage is higher than the base voltage, it is possible to amplify the power, but when the collector voltage becomes close to the base voltage, problems such as a decrease in gain occur. Therefore, the minimum collector voltage is set within a range in which the amplified signal can be used without any practical problems.

For example, the power supply voltage of a lithium ion battery currently used in a mobile phone or the like is 3.7 V, and when a GaAs-HBT is used as a transistor, for example, when the base voltage is about 1.2 V, The minimum collector voltage Vmin is about 1.5V.

In this case, the output terminal 1102 of the power amplifier
At the maximum output of the output from, the voltage of Vbat is supplied to the transistor 1104. For example, when the power source is a lithium-ion battery, Vbat is 3.7V. And
As the output from the output terminal 1102 of the power amplifier decreases, the step-down DC / DC converter 1108 decreases the power supply voltage to maintain high efficiency.

However, when the output of the output terminal 1102 of the power amplifier becomes a certain output P1, the collector voltage becomes Vmin.
To reach. Note that Vmin is about 1.5 V when the transistor is a GaAs-HBT as described above. Then, when the output of the output terminal 1102 of the power amplifier becomes P1 or less, the efficiency of the power amplifier decreases as shown in FIG. 9B. The efficiency of the power amplifier is defined as the ratio of the output power of the power amplifier to the power consumption of the power amplifier expressed as a percentage.

However, in the CDMA system and the like, the power control of the output power of the power amplifier is performed according to the distance from the base station. That is, when the mobile phone terminal is closer to the base station, the power of the output power of the power amplifier is controlled to be smaller, and the mobile phone terminal moves away from the base station, and the area where communication with the base station and the area where communication with the base station are impossible The power of the output power of the power amplifier is controlled to be maximum in the vicinity of the boundary between and, but the probability that the power of the output power of the power amplifier is maximum is thus small. Therefore, the output from the output terminal 1102 of the power amplifier has a high probability of being used at low output, and it is important to improve the efficiency at low output. However, in the conventional power amplifier, the conversion efficiency of the step-down DC / DC converter 1108 decreases when the output from the output terminal 1102 of the power amplifier is low, as shown in FIG. It becomes inefficient and power consumption cannot be reduced.

Next, the power amplifier of this embodiment will be described. FIG. 10A shows the relationship between the output power of the output terminal 102 of the power amplifier of this embodiment and the output voltage of the step-up / down type DC / DC converter 108.
(B) shows the output terminal 102 of the power amplifier of the present embodiment.
2 shows the relationship between the output power of the power amplifier and the efficiency of the power amplifier.

First, when the maximum output power is the same, the transistor size used in the power amplifier of this embodiment is smaller than that of the conventional power amplifier.

In FIG. 10A, the power supply voltage applied to the power supply terminal 111 of FIG.
4 is the minimum voltage required for normal operation of Vmin
Then, the variable range of the collector voltage is from Vmin to Vb.
It is up to Vmax larger than at.

At the maximum output from the output terminal 102 of the power amplifier, the voltage supplied to the transistor 104 is boosted to Vmax by the step-up / down DC / DC converter 108. For example, if the power supply is a lithium-ion battery, the voltage of 3.7V input to the power supply terminal 111 is set to 5V or 6 by the step-up / down DC / DC converter 108.
The voltage is raised to a value such as V. Therefore, even a transistor smaller than the transistor of the conventional power amplifier can output the maximum output equivalent to that of the conventional power amplifier.

Further, the output voltage of the step-up / down DC / DC converter 108 is gradually lowered as the output from the output terminal 102 of the power amplifier is lowered.

Lowest Buck-Boost DC / DC Converter 108
Output is Vmin, the output power P2 from the output terminal 102 of the power amplifier at this time is P1> P2 because the transistor size is smaller in this embodiment than P1 in FIG. .

Further, as described above, the step-up / down type DC /
The DC converter 108 has a wider output voltage dynamic range than the conventional step-down DC / DC converter 1108. Therefore, as shown in FIG. 10 (B), when the output power from the output terminal 102 is P2, the efficiency of the power amplifier is less reduced than in the conventional configuration.

In this way, high efficiency can be maintained up to a lower output power. As a result, the power consumed by the power amplifier can be reduced and the battery life is extended.

Next, the buck-boost DC / DC converter 10
The control method of No. 8 will be described. There are three possible methods.

As a first method, the information regarding the output power of the power amplifier is received from the baseband section, and the control means 109 controls the step-up / down type DC / DC converter 10.
8 control the output voltage. That is, the baseband unit outputs a baseband signal. The baseband signal includes a plurality of types of signals and information such as data of a signal to be transmitted and information regarding output power that indicates how many watts the output power should be. Further, this information regarding the output power is used to control the gain of the variable gain amplifier that is provided before the power amplifier. The control means 109 is
The information on the output power is received, and as described above, the output voltage of the step-up / down type DC / DC converter 108 is controlled based on this information. That is, the control means 10
Reference numeral 9 detects the input power to the transistor of the power amplifier based on the baseband signal output from the baseband unit, and outputs the output voltage of the step-up / down DC / DC converter 108 according to the detected input power. To control.

The second method will be described with reference to FIG. In addition to the configuration of FIG. 1, in FIG. 2, a part of the input signal of the input signal is detected by the distribution circuit 212.
It is input to 13 and detects the magnitude of the input signal. The control means 209 controls the output voltage of the step-up / down type DC / DC converter 208 according to the magnitude of the input signal. That is, the control unit 209 increases the output voltage of the step-up / down type DC / DC converter 208 as the magnitude of the input signal increases.

The third method will be described with reference to FIG. In FIG. 3, in addition to the configuration of FIG. 1, a part of the output signal of the output signal is detected by the distribution circuit 312.
It is input to 13 and the magnitude of the output signal is detected. The control means 309 controls the output voltage of the step-up / down type DC / DC converter 308 according to the magnitude of the output signal. That is, the control unit 309 increases the output voltage of the step-up / down type DC / DC converter 308 as the magnitude of the output signal increases.

Further, here, the step-up / down type DC / DC converters 108, 208, 3 are selected depending on the magnitude of the output signal.
Although the method of controlling the output voltage of 08 has been described, it may be controlled depending on the type of modulation. For example, GMS
In the case of a constant envelope modulation signal such as K, the output voltage of the step-up / down type DC / DC converters 108, 208, 308 is controlled so that it is used near the saturated output of the power amplifier, and the ED
In the case of a modulation signal requiring linearity such as GE, the buck-boost DC / DC converters 108 and 20 are operated so as to operate at an output lower than the saturation output so as to obtain desired linearity.
The output voltage of 8, 308 is controlled.

Further, here, the matching circuits 103, 10
Although it has been assumed that 5, 203, 205, 303, and 305 are fixed circuits, the buck-boost DC / DC converter 10
Changing the output voltage of 8, 208, 308 changes the optimum load conditions. Therefore, when the output voltage of the step-up / down type DC / DC converters 108, 208, 308 changes, the maximum value can be obtained by controlling one or both of the input sides 103, 203, 303 and the output sides 105, 205, 305 of the matching circuit. The efficiency of is obtained.

Note that similar control may be performed when the frequency of the carrier wave changes.

FIG. 4 shows a power amplifier as shown in FIG.
It is a configuration in which two are connected in series. The signal input from the input terminal 401 is amplified by the power amplifier 403, further amplified by the power amplifier 404, and output from the output terminal 402. The power amplifier 403 is supplied with power from a power supply terminal 407 via a buck-boost DC / DC converter 405, and the power amplifier 404 is a buck-boost DC / DC converter 4.
Power is supplied from the power supply terminal 408 via 06. In this way, by independently controlling the two step-up / down type DC / DC converters, highly efficient operation is achieved as a whole.

In the power amplification shown in FIG.
Although three power amplifiers are connected in series, three or more power amplifiers may be connected in series.

(Embodiment 2) Embodiment 2 will be described with reference to FIG. In FIG. 5, the transistor 504 is
The matching circuit 503 and the matching circuit 505 match the input side and the output side, respectively. One of the collector voltages is input from the power supply terminal 514 to the switch 508 after being voltage-converted by the step-up / step-down DC / DC converter 509, and the other is input from the power supply terminal 515 to the step-up / step-down DC / DC converter.
The voltage is converted by the DC converter 511 and then input to the other of the switches 508. The switch 508 outputs the output of either the buck-boost DC / DC converter 509 or the buck-boost DC / DC converter 511 to the bias circuit 507.
Supply to. On the other hand, the base voltage is from the power supply terminal 513,
It is supplied to the transistor 504 through the bias circuit 506.

Next, the operation will be described. When amplifying the first modulated signal, the bias circuit 50 is switched by the switch 508.
7 is connected to the step-up / down type DC / DC converter 511, power is supplied from the power supply terminal 515, and the output voltage of the step-up / down type DC / DC converter 511 is controlled by the control circuit 512 according to the output power of the power amplifier. Further, when amplifying the second modulated signal, the switch 508 connects the bias circuit 507 and the step-up / down type DC / DC converter 509, supplies power from the power supply terminal 514, and raises / lowers according to the output power of the power amplifier. The output voltage of the pressure type DC / DC converter 509 is controlled by the control circuit 510. That is, when the voltage variable range varies depending on the modulation signal, as shown in FIG. 6, two power supply voltages having different output voltages are prepared, and the output voltage of each buck-boost DC / DC converter is switched by switching with a low loss switch. Control and operate the power amplifier.

By operating in this way, it is possible to reduce the total power consumption.

Although the switch is switched by the modulation signal here, the switch may be switched by the output power or the frequency of the transmission signal.

Further, as will be described later, the switches may be switched by changing the load on the output side of the power amplifier.

(Third Embodiment) Regarding the third embodiment,
This will be described with reference to FIGS.

The operation of FIG. 1 is as described in the first embodiment. Here, the setting of the power supply voltage will be described in more detail.

FIG. 7 shows the probability frequency of the output power and the output voltage of the step-up / down DC / DC converter at that time.
In this figure, the output power with the highest probability frequency is Pave, and the output voltage of the step-up / down DC / DC converter at this time is Vave. The maximum output power is Pmax, and the output voltage of the step-up / down DC / DC converter at this time is Vmax. In addition to improving the conversion efficiency of the buck-boost DC / DC converter in Pave, the power consumption is high at the time of high output, so that the buck-boost DC / DC of Pmax is increased.
It is required to improve the conversion efficiency of the DC converter. Therefore, by setting the power supply voltage to a voltage between Vave and Vmax, a power amplifier having the maximum total efficiency can be realized.

In short, although the efficiency may be slightly lower than that in the case where the power supply voltage is set as in the third embodiment, the power supply voltage corresponds to the step-up / down type when the output power of the transistor becomes maximum. It only has to be set to a voltage between the output voltage of the DC / DC converter and the output voltage of the step-up / down DC / DC converter corresponding to the case where the output power of the transistor becomes the minimum.

(Embodiment 4) Next, the point that the efficiency of the power amplifier can be improved by removing the isolator from the power amplification circuit of the present embodiment will be described in detail.

In the conventional power amplification circuit described with reference to FIG. 13, an isolator 1303 is inserted in order to suppress the fluctuation of the load on the output side of the power amplifier 1302. As a result, the load impedance when viewed from the output side of the power amplifier 1302 is always adjusted to 50Ω. However, the power loss occurs in the isolator 1303, and as a result, the efficiency of the power amplifier 1302 decreases. This point has been described in the related art.

Therefore, it is assumed that the isolator 1303 is removed in order to reduce the loss on the output side of the power amplifier 1302 or to reduce the number of parts. Then, the output side load of the power amplifier 1302 fluctuates, so that VSWR (power standing wave ratio, voltage stage) is generated.
nending-Wave Ratio) increases. Then, the fluctuation of the load on the output side is unchanged as it is in the power amplifier 1302.
Therefore, the distortion characteristic of the power amplifier 1302 is deteriorated.

That is, the transistor has the characteristic that the output signal from the transistor becomes a signal containing a large amount of distortion when the load on the output side changes.

In addition, a transistor such as the transistor 104 in FIG. 1 generally has a characteristic that the larger the voltage applied to the collector or the drain, the smaller the distortion included in the output signal of the transistor. That is, the strain characteristic improves as the voltage applied to the collector or drain increases.

Therefore, considering another configuration example using the power amplifier of FIG. 1, for example, the following configuration may be adopted. That is, the configuration example is a configuration in which the value of the load on the output side is detected and the output voltage of the buck-boost DC / DC converter 108 is increased according to the value of the load.

That is, the control means 109 in FIG. 1 detects the value of the load on the output terminal 102, and the greater the fluctuation of the load, that is, the greater the deviation of the load impedance from 50Ω, the more the buck-boost DC. The / DC converter 108 controls to increase the output voltage. In this way, the distortion characteristic does not deteriorate even if the load of the power amplifier changes, even though the isolator is not used.

That is, even when the value of VSWR is large, the output voltage of the step-up / down DC / DC converter 108 becomes high, so that the distortion component included in the output power output from the output terminal 102 of the power amplifier is small. So
It is possible to suppress the deterioration of the distortion characteristic of the power amplifier.

FIG. 14 is a diagram showing a conventional power amplification circuit of the type that does not use an isolator. The power amplification circuit in FIG. 14 has an impedance adjuster 1403 inserted in order to absorb the load fluctuation when the isolator 1303 is removed from the power amplification circuit in FIG.
The impedance is changed according to the value of the load. That is, the impedance adjuster 1403 absorbs the variation of the load by changing the impedance of the antenna 1306 according to the value of the load of the antenna 1306.

However, in this case, the impedance adjuster 1403 causes a loss of output power. When the impedance adjuster 1403 causes a loss, it is necessary to increase the output power from the transistor in order to compensate for the loss, resulting in an increase in power consumption. Further, it is difficult for the impedance adjuster 1403 to adjust the entire impedance range.

Therefore, in the present embodiment, the collector or drain voltage of the transistor used in the power amplifier 1302 is also increased in the power amplification circuit of FIG. 14 in accordance with the load value of the antenna 1306. As a result, the distortion characteristic of the power amplifier 1302 does not deteriorate even if the load of the antenna 1306 changes.

The above-described configuration applied to the power amplifier shown in FIG. 14 can be similarly applied to the power amplifiers shown in FIGS. That is, the step-up / down type DC is similarly applied to the load fluctuation on the output side of the power amplifier in the first and second embodiments.
/ DC converters 108, 208, 308 output voltage is changed, and the matching circuit input side 103, 203,
Controlling the impedance of one or both of 303 and the output side 105, 205, 305 alleviates the efficiency drop of the power amplifier.

Here, the matching circuit has the same function as the impedance adjuster 1403.

In general, there is a trade-off relationship between the variable range of the impedance and the loss caused by the impedance adjusting function. That is, the loss becomes large when the variable range of the impedance is sufficiently set. Therefore, here, a configuration is used in which the loss is small but the variable range is small. And, the lack of performance that the variable range of the impedance is small,
The above-mentioned step-up / down type DC / DC converter is used to make up for this. As a result, the deterioration of the distortion characteristic is alleviated as described above in the entire power amplification circuit.

By doing so, the isolator can be removed from the power amplification circuit, and the efficiency of the power amplifier is further improved.

(Fifth Embodiment) In the fourth embodiment,
Detecting the load fluctuation of the output terminal 102 (see FIG. 1),
Based on the detection result, the DC / DC converter 10
The configuration for controlling the output voltage value of 8 has been briefly described.

In the present embodiment, the configuration and operation of one embodiment of the power amplification circuit of the present invention will be described with reference to the more detailed configuration diagram. FIG. 15 is a block diagram showing the configuration of the power amplification circuit according to the present embodiment.
The same components as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted.

Here, at the same time as the description of the operation of this embodiment, an embodiment of the operation method of the power amplification circuit of the present invention will also be described.

In FIG. 15, the DC / DC converter 2
Reference numeral 108 denotes a power supply voltage supplied from the battery 2111 according to a control command from the control circuit 2109.
It is a means for supplying to 302. The power amplifier 1302
Is a configuration including the first matching circuit 103, the second matching circuit 105, the first bias circuit 106, and the second bias circuit 107 shown in FIG.

When the output signal wave output from the second matching circuit 105 to the antenna 1306 is input, the directional coupler 2101 outputs a signal corresponding to the input wave from one terminal 2101a. Also, when a reflected wave is input from the antenna 1306, it is means for outputting a signal corresponding to the reflected wave from the other terminal 2101b. Detector 2
Reference numeral 102 denotes a first detector of the present invention which utilizes a signal output from one terminal 2101a and outputs data regarding the amplitude and phase of the signal. The detector 2103 is
Using the signal output from the other terminal 2101b,
It is the second detector of the present invention that outputs data regarding the amplitude and phase of the signal.

Further, the control circuit 2109 has a detector 210.
This is means for calculating the value of the load impedance on the antenna 1306 side by comparing the amplitude and the phase between the input wave and the reflected wave based on the output data from 2, 2103. Further, the control circuit 2109 is
According to the value of the load impedance as the calculation result and the value of the output power of the power amplifier 1302, the power amplifier 1
DC / DC converter 2108 which is the power supply voltage of 302
Is a means for controlling the value of the output voltage. Furthermore, the control circuit 2109 shows a table according to the output power of the data used for the control, which indicates the correspondence between the value of the load impedance and the value of the power supply voltage (also referred to as a power supply voltage map here). Memory means (not shown) for storing as.

FIGS. 16 (A) and 16 (B) are conceptual diagrams for explaining the above table, which are represented by using a Smith chart. If the reflectance of the load impedance is Γ (gamma), the position on the Smith chart is determined for each value of Γ (real part, imaginary part). On the other hand, preset application areas of a plurality of types of power supply voltages are assigned to the power amplifier 1302 on the Smith chart. As shown in FIG. 16 (A), it can be seen that the value of the power supply voltage to be supplied tends to increase with distance from the position of 50Ω (the center point of the circle) in the same figure. In FIG. 16A, the output power is P
16 is a power supply voltage map for when the output power is 1, and FIG. 16B is a power supply voltage map for when the output power is P2. However,
P1> P2. That is, such a power supply voltage map is
A plurality is prepared according to the output power.

If the power supply voltage is controlled only on the basis of the load impedance, one such table may be prepared.

Next, a method of determining the power supply voltage in the control circuit 2109 will be described with reference to FIGS. 16 (A) and 16 (B).

For example, it is assumed that the load impedance in a certain situation is calculated by the control circuit 2109 from the data from the detectors 2102 and 2103. The reflectance of the load impedance is Q, and the output power at that time is P1.

In this case, the table corresponding to the power supply voltage map shown in FIG. 16 (A) is used. Then, since the position of point Q is uniquely determined on the Smith chart of the same figure,
From the position where this Q point exists, it is determined that the power supply voltage should be 3.5V. However, if the output power is P2, the power supply voltage will be 3.0 V from FIG. 16B even if the reflectance is Q.

As described above, since the isolator is not used, the circuit scale is smaller than the conventional one.
The effect is that good characteristics can be realized over a wide range of load impedance.

(Sixth Embodiment) Next, an embodiment of the power amplifying circuit of the present invention will be described with reference to the drawings.

FIG. 17 is a block diagram of the power amplification circuit of this embodiment. The same components as those in FIG. 15 are designated by the same reference numerals, and the description thereof will be omitted.

Here, the main difference in structure is that an isolator 2303 is further provided in the structure of the fifth embodiment.

That is, the isolator 230 shown in FIG.
No. 3 does not have an excellent isolation function in order to reduce the power loss of the isolator itself, and intentionally uses an insufficient isolation function. Then, the deficiency of the directional coupler 21 is described above.
01, detectors 2102, 2103, and control circuit 210
It is configured to be supplemented with 9 or the like.

As a result, the power supply voltage to be applied to the power amplifier 1302 can be suppressed smaller than that of the configuration of FIG. 15 (see FIG. 18). For Figure 18,
It will be described later. Whether or not the power consumption of the power amplification circuit as a whole is reduced depends on the performance of the isolator.

FIG. 18 is a power supply voltage map in the present embodiment, and shows an output voltage for P1.

As described above, due to the effect of the isolator 2303, the power supply voltage region 3101 to be applied is located within a small concentric circle centered on the origin (0, 0). Thereby, for example, even if the load conditions around the antenna 1306 are the same, in the case of the configuration of FIG.
While it may be necessary to apply a voltage around V, in the configuration of FIG. 18, 3 V or less is sufficient.

In the above embodiment, the case where the memory means (corresponding to the storage means of the present invention) is provided in the control circuit 2109 has been described, but the present invention is not limited to this.
It may be provided anywhere.

Further, it is desirable to use a step-up / down DC / DC converter in order to change the collector or drain voltage of the transistor of the power amplifier according to the load fluctuation on the output side. Type DC / DC converter may be used.

Further, the voltage supplied to the transistor can be changed as described in this embodiment according to the instantaneous power of the power amplifier. That is, when the instantaneous power of the power amplifier is large, the voltage supplied to the transistor can be increased by the step-up operation of the step-up / down DC / DC converter. Therefore, the effect of distortion compensation of the output power of the power amplifier can also be expected. Can be done.

At present, various functions are added to the mobile phone terminal to make it highly functional, and the power consumption tends to increase from the initial mobile phone terminal. Lithium-ion batteries are often used in mobile phone terminals, but for such highly functionalized mobile phone terminals, lithium-ion batteries using current materials are not suitable for use as a power source. The capacity is becoming insufficient. Therefore, it is expected that a battery made of a new material such as a battery in which the materials of the positive electrode and the negative electrode are changed is used as a power source. However, the output voltage of the battery made of such a new material is lower than 3.7 V of the lithium ion battery. Using such a new material battery as a power source
It can be expected that the power amplifier described in the present embodiment plays a very important role in applying it to a system such as side band CDMA.

Here, the portable telephone terminal, for example, as shown in FIG. 19, includes (a) an antenna 1306 used for transmission and reception, and (b) a transmission / reception separation circuit 4106.
A transmission amplifier 4103 (corresponding to the power amplification circuit of the present invention) for outputting a transmission signal from the antenna 1306,
(C) a transmission circuit means including a modulator 4102, a reception amplifier 4105 for amplifying a reception signal from the antenna 1306 via a transmission / reception separation circuit 4106, and a demodulator 4
Receiving circuit means including 104, and (d) baseband unit 4
And 101.

The functions of all or some of the means (or devices, elements, circuits, sections, etc.) including at least the load impedance detection means and the control means of the power amplification circuit of the present invention described above are executed by a computer. A program for operating a computer, which operates in cooperation with a computer, and is operated by using hardware such as a CPU (computer) incorporated in a mobile phone device, for example, and is similar to the above. It is also possible to exert the effect of.

In addition, all or some of the steps (or steps, operations, or steps) of the control method for the power amplification circuit of the present invention described above.
A program for causing a computer to execute the operations (operations, etc.), which operates in cooperation with the computer, and uses, for example, hardware such as a CPU (computer) built in the mobile phone device. It is also possible to exert the same effect as described above by operating in this manner.

Also, the same effect as above can be obtained when a medium that carries the above-mentioned program and is readable by a computer, and the read program constitutes a medium that cooperates with the computer to execute the function. Exert.

The above-mentioned part of the means (or device, element, circuit, part, etc.) of the present invention and part of the step (or process, operation, action, etc.) of the present invention means a plurality of them. It means several means or steps among the means or steps, or means some functions or some operations within one means or steps.

[0121] Further, one usage form of a program as a technique related to the present invention may be a mode in which the program is recorded in a computer-readable recording medium and operates in cooperation with the computer.

Further, one usage form of the program may be a mode in which the program is transmitted through a transmission medium, read by a computer, and operates in cooperation with the computer.

Further, the recording medium includes a ROM and the like, and the transmission medium includes a transmission medium such as the Internet and light, radio waves and sound waves.

Further, the computer of the present invention described above is C
The hardware is not limited to pure hardware such as PU, but may include firmware, OS, and peripheral devices.

As described above, the structure of the present invention is
It may be realized by software or hardware.

The mutual relations of the inventions disclosed in the present specification are as follows.

According to a first aspect of the present invention, there is provided a first matching circuit for matching and outputting input signals, a first bias circuit connected to the output of the first matching circuit, and the first matching circuit. A second bias circuit, one of which is connected to the output of the transistor, a second bias circuit of which one is connected to the output of the transistor, and a second bias circuit which is connected to the output of the transistor and outputs an output signal of the transistor by matching. Of the second bias circuit, and its output is connected to the other of the matching circuit and the power supply is connected to its input.
A step-up / down type DC / D converter, and a control means for controlling the operation of the step-up / down type DC / DC converter.
The C converter outputs an output voltage according to the control of the control means, and the step-up / down type DC / DC converter performs a boosting operation for increasing the output voltage higher than the power supply voltage and lowers the output voltage lower than the power supply voltage. It is a circuit for power amplification which performs the voltage step-down operation.

A second aspect of the present invention is the step-up / down type DC / D.
The step-up / down type DC / DC is provided with switch means for outputting the output of the C converter to the other of the second bias circuits.
There are a plurality of converters, and a plurality of the step-up / down type DC / Ds.
A power source different from that of the other step-up / step-down DC / DC converters is connected to the input of all or part of the C converter, and the control means also controls the operation of the switch means. Is a plurality of the step-up / down type D
The power amplification circuit according to the first aspect of the present invention, which outputs the output of the step-up / down type DC / DC converter instructed by the control of the control means among the C / DC converters to the other of the second bias circuits.

In the third invention, the voltage of the power source is the output voltage of the step-up / down DC / DC converter corresponding to the case where the output power from the transistor is maximum, and the output power from the transistor. The power amplification circuit according to the first or second aspect of the invention is set to a voltage between the output voltage of the step-up / down DC / DC converter and the output voltage of the step-up / down DC / DC converter.

In the fourth invention, the voltage of the power source is the output voltage of the step-up / down type DC / DC converter corresponding to the output power from the transistor that has the highest output frequency, and the maximum output from the transistor. The power amplification circuit according to the third aspect of the present invention is set between the output voltage of the step-up / down DC / DC converter corresponding to electric power.

Further, in the fifth invention, the voltage of the power source corresponds to the output voltage of the step-up DC / DC converter corresponding to the minimum output power from the transistor and the maximum output power from the transistor. Vertical DC / DC
The power amplification circuit according to the third aspect of the invention is set to a voltage lower than the center of the output voltage of the converter.

In a sixth aspect of the present invention, the control means changes the output voltage of the step-up / down type DC / DC converter according to the magnitude of output power from the transistor. It is a circuit for power amplification of the invention.

According to a seventh aspect of the invention, in the control means, the step-up / down type DC voltage is higher when the output power from the transistor is higher than when the output power from the transistor is low. The power amplification circuit according to the sixth aspect of the present invention, which controls the output voltage of the / DC converter to be larger.

In the eighth invention, the control means changes the output voltage of the step-up / down type DC / DC converter according to the magnitude of the input power to the transistor. It is a circuit for power amplification of the invention.

According to a ninth aspect of the present invention, in the control means, the step-up / down type is more effective when the input power to the transistor is higher than when the input power to the transistor is low. It is a circuit for power amplification according to the eighth aspect of the present invention, which controls the output voltage of the DC / DC converter to be larger.

According to a tenth aspect of the invention, the control means is connected to a baseband section which outputs a baseband signal, and detects the input power to the transistor by the output baseband signal, The power amplification circuit according to any one of the first to fifth inventions, which controls the step-up / down type DC / DC converter according to the detected input power.

According to an eleventh aspect of the present invention, the control means uses the step-up / down type DC when the detected input power is larger than when the detected input power is small.
The power amplification circuit according to the tenth aspect of the invention, which controls to increase the output voltage of the / DC converter.

The twelfth aspect of the present invention is that the output of the second matching circuit is connected to the first output, and the output of one of the distribution circuits is connected to its input to input the signal. A detection means for detecting the magnitude, the output of the detection means is connected to the control means, and the output power from the transistor is the output power from the detection means. Alternatively, it is a circuit for power amplification of the invention of 7.

A thirteenth aspect of the present invention is that the input of the first matching circuit is connected to one of the outputs of the distribution circuit, and the other output of the distribution circuit is connected to the input of the distribution circuit. A detection unit for detecting the output of the detection unit, the output of the detection unit is connected to the control unit, and the input power to the transistor is the output power from the detection unit. It is a circuit for power amplification of the invention.

According to a fourteenth aspect of the invention, the control means is characterized in that in accordance with the type of modulation of the input signal, the frequency of the carrier wave of the input signal, or the variation of the load of the transistor. The power amplification circuit according to any one of the first to fifth inventions, which changes the output voltage of the step-up / down DC / DC converter.

In the fifteenth aspect of the invention, the control means is responsive to the output power from the transistor, or is responsive to the input power to the transistor, or is responsive to the type of modulation of the input signal, or The switch means changes the step-up / down DC / DC converter whose output is connected to the other of the second bias circuits according to the frequency of the carrier wave of the input signal or according to the variation of the load of the transistor. It is a power amplification circuit of the second invention.

In a sixteenth aspect of the invention, the impedance of either or both of the first and second matching circuits is variable, and the control means is responsive to the output power from the transistor, or According to the input power to the transistor, or according to the type of modulation of the input signal, or according to the frequency of the carrier of the input signal, or according to the variation of the load of the transistor, the first, second The power amplification circuit according to any one of the first to fifteenth inventions, which controls either one or both of the matching circuits.

In the seventeenth aspect of the invention, the power amplification circuit according to any one of the first to sixteenth aspects of the invention is connected in multiple stages, and the control means of the power amplification circuit of each of the stages has each of the stages. Is a circuit for power amplification that independently controls the output voltage of the step-up / down type DC / DC converter.

The eighteenth aspect of the invention is to provide a first matching circuit for matching and outputting an input signal inputted thereto, and a first bias circuit connected to the output of the first matching circuit,
A transistor connected to the output of the first matching circuit, a second bias circuit having one connected to the output of the transistor, and connected to the output of the transistor,
A second matching circuit for matching and outputting the output signal of the transistor; a voltage converting means having its output connected to the other of the second bias circuit and a power supply connected to its input; and the voltage converting means. And a control means for controlling the operation of the power amplification circuit, wherein the voltage conversion means,
An output voltage according to the control of the control means is output, and the control means is a power amplification circuit that changes the output voltage of the voltage conversion means according to the output side load of the power amplification circuit.

A nineteenth aspect of the present invention is provided with a switch means for outputting the output of the voltage conversion means to the other of the second bias circuits, and the voltage conversion means has a plurality of voltage conversion means. A power source different from the other voltage conversion means is connected to all or some of the inputs, the control means also controls the operation of the switch means, and the switch means controls the operation of the control means. The power amplification circuit according to the eighteenth aspect of the present invention, which outputs the output of the voltage conversion unit instructed by the control of the control unit among the plurality of voltage conversion units to the other of the second bias circuits according to the control. Is.

According to a twentieth aspect of the invention, the control means is characterized in that, when the fluctuation of the output side load of the power amplification circuit is large, the voltage conversion is more efficient than when the fluctuation of the output side load of the power amplification circuit is small. It is a circuit for power amplification according to the eighteenth or nineteenth aspect of the invention, which controls to increase the output voltage of the means.

In a twenty-first aspect of the invention, the impedance of one or both of the first and second matching circuits is variable, and the control means controls the matching by the output side load of the power amplification circuit. The power amplification circuit according to any one of the eighteenth to twentieth aspects of the present invention, which controls one or both of the circuits.

In the twenty-second aspect of the present invention, the voltage conversion means performs a step-up / down type DC / voltage boosting operation for increasing its output voltage above the power supply voltage and a step-down operation for decreasing its output voltage below the power supply voltage. A DC converter, a step-up DC / DC converter that performs a step-up operation that raises its output voltage above the power supply voltage, or a step-down DC / DC converter that performs a step-down operation that lowers its output voltage below the power supply voltage. 18 is a circuit for power amplification according to any one of inventions 18 to 21.

As described above, according to the above structure, highly efficient characteristics can be obtained even when the operating state of the power amplifier is changed.

Further, according to the above construction, highly efficient characteristics can be obtained in a wide output dynamic range.

Further, according to the above configuration, the input power and output power of the power amplifier can be detected, and the buck-boost DC / DC converter can be appropriately controlled.

Further, according to the above configuration, the power amplifier can be operated with high efficiency even if the modulation method or the carrier frequency changes.

Further, according to the above configuration, the power amplifier (power amplification circuit) can be operated with high efficiency even if the output power changes.

Further, according to the above configuration, the power amplifier (power amplification circuit) can be operated with high efficiency even if the type of modulation or the frequency of the carrier changes.

Further, according to the above configuration, a highly efficient power amplifier (power amplification circuit) can be realized even when a large gain is required.

Further, according to the above configuration, even when there is no isolator at the output of the power amplifier and there is a load fluctuation,
Efficiency deterioration can be reduced.

Further, according to the above construction, it is possible to realize high efficiency as a whole when the dynamic range is large.

Further, according to the above configuration, a power amplifier (power amplification circuit) having a high efficiency as a whole can be realized by selecting the power supply voltage.

[0159]

As is apparent from the above description, the present invention has an advantage that good characteristics can be realized over a wide load impedance range with a circuit scale smaller than the conventional one.

Further, the present invention has an advantage that it is possible to provide a power amplification circuit having a wide dynamic range and higher efficiency, a control method of the power amplification circuit, and a portable terminal device using the power amplification circuit.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a power amplifier (power amplification circuit) according to a first embodiment of a technique related to the present invention.

FIG. 2 is a configuration diagram of a power amplifier according to the first embodiment.

FIG. 3 is a configuration diagram of a power amplifier according to the first embodiment.

FIG. 4 is a configuration diagram of a power amplifier according to the first embodiment.

FIG. 5 is a configuration diagram of a power amplifier according to the first embodiment.

FIG. 6 is a diagram illustrating a variable range of voltage in the second embodiment of the technology related to the present invention.

FIG. 7 is a diagram illustrating how to determine a power supply voltage according to the third embodiment of the technology related to the present invention.

FIG. 8 is a diagram illustrating how to determine a power supply voltage in Embodiment 1.

9A is a diagram showing the relationship between the output power and the power supply voltage of a conventional power amplifier compared with the power amplifier according to the first embodiment. FIG. 9B is compared with the power amplifier according to the first embodiment. The figure which shows the output power of the conventional power amplifier, and the relationship of efficiency.

10A is a diagram showing the relationship between the power amplifier output power and the power supply voltage in the first embodiment, and FIG. 10B is a diagram showing the relationship between the output power and the efficiency of the power amplifier in the first embodiment.

FIG. 11 is a diagram showing a configuration of a conventional power amplifier.

FIG. 12A is a block diagram of a conventional step-down DC / DC converter, and FIG. 12B is a diagram showing a relationship between output voltage and efficiency of a conventional step-down DC / DC converter.

FIG. 13 is a diagram showing a power amplifier capable of suppressing load fluctuation using a conventional isolator.

FIG. 14 is a conventional power amplification circuit shown for comparison in order to explain a power amplification circuit according to a fourth embodiment of the present invention, in which an impedance adjuster is used instead of the conventional isolator. Diagram showing a power amplification circuit that suppresses load fluctuations

FIG. 15 is a configuration diagram of a power amplification circuit according to a fifth embodiment of the present invention.

FIG. 16A is a power supply voltage map for when the output power is P1 in the fifth embodiment. FIG. 16B is a power supply voltage when the output power is P2 for the fifth embodiment. Illustration showing map

FIG. 17 is a configuration diagram of a power amplification circuit according to a sixth embodiment of the present invention.

FIG. 18 is a diagram showing a power supply voltage map when the output power is P1 in the sixth embodiment.

FIG. 19 is a configuration diagram of a mobile phone terminal device using the power amplification circuit of the present invention.

[Explanation of symbols]

101 input terminal 102 output terminals 103, 105 matching circuit 104 transistor 106, 107 bias circuit 108 Buck-boost DC / DC converter 109 control means 110,111 Power terminal 201 input terminal 202 output terminal 203, 205 Matching circuit 204 transistor 206, 207 bias circuit 208 Step-up / down type DC / DC converter 209 control means 210, 211 Power supply terminal 212 distribution circuit 213 Detection circuit 301 input terminal 302 output terminal 303, 305 Matching circuit 304 transistor 306, 307 Bias circuit 308 Buck-boost DC / DC converter 309 Control means 310, 311 power supply terminal 312 distribution circuit 313 Detection circuit 401 input terminal 402 output terminal 403, 404 Power amplifier 405, 406 Buck-boost DC / DC converter 407, 408 Power supply terminal 409 control circuit 501 input terminal 502 output terminal 503, 505 Matching circuit 504 transistor 506 and 507 bias circuit 508 switch 509,511 Buck-boost DC / DC converter 510, 512 control means 513, 514, 515 Power supply terminal 1101 input terminal 1102 output terminal 1103, 1105 Matching circuit 1104 Transistor Bias circuits 1106 and 1107 1108 Step-down DC / DC converter 1109 control means 1110 and 1111 power supply terminals

Continued front page    (72) Inventor Makoto Sakakura             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Hiroyuki Handa             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Toshio Ohara             3-1, Tsunashima-Higashi 4-chome, Kohoku-ku, Yokohama-shi, Kanagawa             Matsushita Communication Industry Co., Ltd. F term (reference) 5J091 AA01 AA41 CA32 CA36 CA92                       FA01 HA02 HA38 KA00 KA05                       KA12 KA29 KA47 KA53 KA55                       KA68 TA01 TA02 UW08                 5K060 DD04 HH06 HH09 JJ08 LL11                       MM00

Claims (12)

[Claims] 1. A first matching circuit that matches and outputs an input signal that is input, a first bias circuit connected to an output of the first matching circuit, and a first matching circuit of the first matching circuit. A transistor connected to the output, a second bias circuit one of which is connected to the output of the transistor, a second matching circuit connected to the output of the transistor and matching and outputting the output signal of the transistor, , The output of which is connected to the other of the second bias circuit,
A power amplification circuit comprising a voltage conversion means having a power supply connected to its input and a control means for controlling the operation of the voltage conversion means, wherein a load impedance on the output side of the power amplification circuit is detected. Further comprising load impedance detection means for controlling the output voltage of the voltage conversion means based on the detection result of at least the load impedance detection means, the output voltage being the power supply voltage to the transistor. For power amplification applied as. 2. An isolator disposed between the load impedance detecting means and the antenna.
The circuit for power amplification described. 3. The load impedance detection means,
(1) When an output signal output to the load side from the second matching circuit is input, a signal corresponding to the input signal is output from one terminal, and a reflected wave is output from the load side. A directional coupler that outputs a signal corresponding to the reflected wave from the other terminal when input, and (2) data relating to the amplitude and phase of the signal using the signal output from the one terminal And a second detector that outputs (3) data relating to the amplitude and phase of the signal by using the signal output from the other terminal. Or the circuit for power amplification according to 2. 4. The control means controls the value of the power supply voltage of the transistor according to the value of the load impedance which is the detection result of the load impedance detection means. The circuit for power amplification according to. 5. The control means comprises a storage means for storing, as a table, data used for the control, which indicates a correspondence relationship between a value of the load impedance and a value of the power supply voltage. The circuit for power amplification described. 6. A first matching circuit for matching and outputting an input signal input thereto, a first bias circuit connected to an output of the first matching circuit, and a first matching circuit of the first matching circuit. A transistor connected to the output, a second bias circuit one of which is connected to the output of the transistor, a second matching circuit connected to the output of the transistor and matching and outputting the output signal of the transistor, , The output of which is connected to the other of the second bias circuit,
A power amplification circuit comprising: a voltage conversion unit having a power supply connected to its input; and a control unit controlling the operation of the voltage conversion unit, wherein the voltage conversion unit responds to the control of the control unit. Outputting an output voltage, the control means, according to the output power of the power amplification circuit, the voltage conversion means, to perform a boosting operation to make the output voltage higher than a predetermined power supply voltage, Alternatively, a power amplification circuit that determines whether to perform a step-down operation that lowers the output voltage below the power supply voltage. 7. The control means is responsive to a value of load impedance which is the detection result of the load impedance detection means and a value of output power of the power amplification circuit,
The power amplification circuit according to claim 1, wherein a value of the power supply voltage of the transistor is controlled. 8. The storage means for storing, as a table according to the output power, data used for the control, which indicates a correspondence relationship between the value of the load impedance and the value of the power supply voltage. The power amplification circuit according to claim 7, which is provided. 9. The power amplification circuit according to claim 1, wherein the power conversion means is a DC / DC converter. 10. The power amplification circuit according to claim 9, wherein the DC / DC converter is a step-up / down type. 11. (1) A first matching circuit for matching and outputting an input signal that is input, and (2) a first bias circuit connected to an output of the first matching circuit.
(3) a transistor connected to the output of the first matching circuit, (4) a second bias circuit having one connected to the output of the transistor, and (5) connected to the output of the transistor, A second matching circuit for matching and outputting the output signals of the transistors; and (6) voltage conversion means having its output connected to the other of the second bias circuits and a power supply connected to its input, ) A control method for a power amplification circuit, comprising: a control means for controlling the operation of the voltage conversion means, wherein a load impedance on the output side of the power amplification circuit is detected, and the control means is at least the detection means. A method for controlling a power amplification circuit, which changes the output voltage of the voltage converting means based on the applied load impedance and applies the output voltage to the transistor as a power supply voltage. 12. An antenna used for transmission and reception, and a transmission signal for outputting a transmission signal from the antenna.
Or transmission circuit means including the power amplification circuit according to claim 6, reception circuit means for processing a reception signal from the antenna, the antenna, the transmission circuit means and the reception circuit means. And a transmitting / receiving separation circuit means.