WO2012111100A1

WO2012111100A1 - Amplification device

Info

Publication number: WO2012111100A1
Application number: PCT/JP2011/053194
Authority: WO
Inventors: 廣信本郷; 勝利石堂
Original assignee: 富士通株式会社
Priority date: 2011-02-16
Filing date: 2011-02-16
Publication date: 2012-08-23

Abstract

The present invention increases power efficiency. An amplifier (1) amplifies an input signal using power fed to a power node (N1). A generator (2) generates an envelope signal based on the envelope of the input signal amplified by the amplifier (1). A power source unit (3) feeds power at a fixed voltage to the power node (N1). A power source unit (4) feeds, to the power node (N1), power at a variable voltage in accordance with the envelope signal generated by the generator (2). A power source power feed unit (5) feeds power at a different voltages to the power source unit (4), on the basis of the size of the envelope signal generated by the generator (2).

Description

Amplifier

This case relates to the power supply of the amplification device that amplifies the signal.

In recent years, electronic devices are required to have low power consumption coupled with international environmental measures. For example, an amplification device for amplifying a transmission signal is provided at the final stage of the transmission unit of the base station of the mobile phone system, and the power consumption of the amplification device is required to be reduced.

Envelope tracking is a method for improving the power efficiency of amplifiers. Envelope tracking is a technique for reducing power loss by supplying a power supply voltage corresponding to the amplitude of a signal amplified by an amplifier of an amplification device to the amplifier.

For example, in envelope tracking, when the envelope of a signal to be amplified is below a predetermined threshold, only a fixed voltage power from a high efficiency power supply is supplied to the amplifier (fixed voltage power mode). In addition, when the envelope of the signal to be amplified exceeds a predetermined threshold value, envelope tracking is performed by supplying the power of the variable voltage corresponding to the envelope of the signal to be amplified to the amplifier from the low-efficiency power supply in addition to the power supply of the fixed voltage. Supply (variable voltage power mode). As described above, in the envelope tracking, the power efficiency is improved by switching the power source based on the envelope size of the signal to be amplified.

Conventionally, there has been proposed a power control apparatus that achieves lower power consumption than the conventional one while controlling the output power of the transmission power amplifying apparatus to match the set value (see, for example, Patent Document 1). .

In addition, an amplifier capable of controlling transmission power using a drain bias adjustment circuit has been proposed that improves efficiency and distortion characteristics even at low output power and facilitates integration on the same substrate (for example, Patent Document 2). reference).

Furthermore, an amplifier power supply voltage switching circuit that realizes a high-speed response to an output voltage and a low power loss in a semiconductor switch that switches the power supply has been proposed (for example, see Patent Document 3).

JP-A-6-85580 JP 2000-196387 A Japanese Utility Model Publication No. 5-53318

However, in the conventional amplifying apparatus, when the amplitude of the signal to be amplified in the variable voltage power mode is small, there is a problem that power is wasted as heat and efficiency is low.
The present invention has been made in view of such a point, and an object thereof is to provide an amplifying apparatus that improves power efficiency.

In order to solve the above problems, an amplifying apparatus for amplifying a signal is provided. The amplifying device amplifies an input signal by power supplied to a power node, a generation unit that generates an envelope signal based on an envelope of the input signal, and a first voltage that supplies fixed voltage power to the power node. A first power supply unit, a second power supply unit that supplies power of a variable voltage according to the envelope signal to the power node, and a voltage of a different voltage applied to the second power supply unit based on the magnitude of the envelope signal. And a power supply unit for supplying power.

According to the disclosed amplification device, the power efficiency can be increased.
These and other objects, features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings which illustrate preferred embodiments by way of example of the present invention.

It is the figure which showed an example of the amplifier which concerns on 1st Embodiment. It is a figure explaining operation | movement of the amplifier of FIG. It is the figure which showed an example of the circuit block of the amplifier which concerns on 2nd Embodiment. It is the figure which added the signal waveform to an example of the circuit block of FIG. It is the figure which showed an example of the block of a digital signal processing part. It is a figure explaining operation | movement of the block of FIG. It is the figure which showed a part of amplification apparatus in case the power supply which supplies electric power to a variable voltage power supply is one. It is a figure explaining the loss of the variable voltage power supply of FIG. It is the figure which showed an example of the block of the digital signal processing part which concerns on 3rd Embodiment. It is a figure explaining operation | movement of a voltage switching signal production | generation part. It is the figure which showed an example of the block of the digital signal processing part which concerns on 4th Embodiment. It is a figure explaining operation | movement of a voltage switching signal production | generation part. It is the figure which showed an example of the circuit block of the amplifier which concerns on 5th Embodiment. It is a figure explaining operation | movement of a voltage switching signal production | generation part. It is the figure which showed an example of the circuit block of the amplifier which concerns on 6th Embodiment. It is the figure which showed an example at the time of applying an amplifier to a radio | wireless apparatus.

Hereinafter, embodiments will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 1 is a diagram illustrating an example of an amplifying apparatus according to the first embodiment. As illustrated in FIG. 1, the amplifying apparatus includes an amplifying unit 1, a generating unit 2,

power supply units

3 and 4, and a power supply unit 5.

The input signal to be amplified is input to the amplification unit 1. The input signal is, for example, a modulated signal. The amplifying unit 1 amplifies the input signal with the power supplied to the power node N1 and outputs it.

The generation unit 2 generates an envelope signal based on the envelope of the input signal amplified by the amplification unit 1. For example, the generation unit 2 generates an envelope of an input signal that is larger than a predetermined threshold (hereinafter referred to as th) as an envelope signal.

The power supply unit 3 supplies power of a fixed voltage (hereinafter referred to as Vd) to the power node N1.
The power supply unit 4 supplies variable power according to the envelope signal generated by the generation unit 2 to the power node N1.

Here, the power supply unit 3 supplies a fixed voltage Vd to the power node N1. When the envelope of the input signal exceeds the threshold th, the power supply unit 4 supplies power of a voltage corresponding to the envelope of the input signal to the amplifier unit 1. That is, when the envelope of the input signal is less than or equal to the threshold th, the amplifying device supplies only the power of the power supply unit 3 to the amplifier 1 (fixed voltage power mode), and when the envelope of the input signal exceeds the threshold th, The power of the voltage according to the envelope of the input signal is supplied from the power supply unit 4 to the amplification unit 1 (variable voltage power mode).

The power supply unit 5 supplies power of a different voltage to the power supply unit 4 based on the magnitude of the envelope signal generated by the generation unit 2. For example, the power supply unit 5 supplies power of the voltage V1 to the power supply unit 4 if the envelope signal is equal to or less than a predetermined threshold (hereinafter referred to as env), and if the envelope signal is greater than the threshold env, the power supply unit 4 is supplied with electric power having a voltage V2 higher than the voltage V1.

FIG. 2 is a diagram for explaining the operation of the amplifying apparatus of FIG. FIG. 2A shows an envelope of an input signal amplified by the amplification unit 1. FIG. 2B shows an envelope signal generated by the generation unit 2. FIG. 2C shows the voltage waveform at the power node N11.

The envelope signal is, for example, a signal larger than the threshold value th of the envelope of the input signal shown in FIG. Therefore, the envelope signal generated by the generation unit 2 is a signal obtained by slicing the envelope of the input signal with the threshold th as shown in FIG.

The power supply unit 3 supplies power of a fixed voltage Vd to the power node N1, and the power supply unit 4 supplies power of variable voltage corresponding to the envelope signal shown in FIG. 2B to the power node N1. Therefore, the voltage waveform at the power node N1 is as shown in FIG.

The power source power supply unit 5 supplies power of the voltage V1 to the power source unit 4 if the envelope signal is equal to or less than the predetermined threshold value env. If the envelope signal is greater than the threshold value env, the power source unit 4 supplies the power source unit 4 with a voltage V2 greater than the voltage V1. Supply power.

Therefore, the power consumed wastefully as heat in the power supply unit 4 is as indicated by the hatched portion in FIG. Thereby, for example, the power supply unit 4 can suppress the power consumption of the portion indicated by the arrow A1 compared to the case where only the power of the voltage V2 is supplied.

As described above, the amplifying apparatus includes the power supply unit 3 that supplies power of a fixed voltage and the power supply unit 4 that supplies power of variable voltage, and the magnitude of the envelope signal based on the envelope of the input signal amplified by the amplification unit 1. Based on this, power of different voltages V1 and V2 is supplied to the power supply unit 4. Thereby, the electric power of the voltage according to the magnitude | size of the envelope of an input signal is supplied to the power supply part 4, and power efficiency can be made highly efficient.

[Second Embodiment]
Next, a second embodiment will be described in detail with reference to the drawings.
FIG. 3 is a diagram illustrating an example of a circuit block of the amplifying apparatus according to the second embodiment. As shown in FIG. 3, the amplifying apparatus includes a digital signal processing unit 11, DACs (Digital to Analog Converters) 12 and 16, an oscillator 13, a multiplier 14, an amplifier 15, a bias power supply 17, an AS (Active Short) circuit 18, Transistors M11 to M13, capacitors C11 to C15, an inductor L11, and a diode D11 are included. The amplification device shown in FIG. 3 is applied to a base station of a mobile phone system, for example.

FIG. 4 is a diagram in which signal waveforms are added to the example of the circuit block of FIG. 4, the same components as those in FIG. 3 are denoted by the same reference numerals.
For example, a transmission signal as indicated by a waveform W11 is input to the digital signal processing unit 11. The transmission signal is, for example, a signal to be transmitted wirelessly to a mobile phone. The transmission signal is input to the digital signal processing unit 11 as a digital value, but is shown in an analog form in the waveform W11. The digital signal processing unit 11 is formed by, for example, a DSP (Digital Signal Processor) or a CPU (Central Processing Unit).

The DAC 12 performs digital-analog conversion on the transmission signal output from the digital signal processing unit 11. A waveform W12 represents a transmission signal that has been digital-analog converted by the DAC 12.

The oscillator 13 outputs an oscillation signal for modulating the transmission signal into a radio signal having a radio frequency. The multiplier 14 multiplies the transmission signal output from the DAC 12 by the oscillation signal output from the oscillator 13 and outputs a radio signal. A waveform W13 indicates a radio signal output from the multiplier 14.

The amplifier 15 is supplied with power via the power node N11. The amplifier 15 amplifies the radio signal output from the multiplier 14 with the power supplied to the power node N11. The amplified wireless signal is wirelessly transmitted to a mobile phone via an antenna, for example. A waveform W14 shows the radio signal amplified by the amplifier 15.

The digital signal processing unit 11 outputs an envelope signal based on the envelope of the radio signal amplified by the amplifier 15 to the DAC 16. Here, the radio signal amplified by the amplifier 15 is obtained by modulating the transmission signal input to the digital signal processing unit 11. Therefore, the digital signal processing unit 11 outputs a signal larger than a predetermined threshold (Vth shown in the waveform W11) of the input transmission signal as an envelope signal. A waveform W15 indicates an envelope signal exceeding the transmission signal threshold value Vth shown in the waveform W11.

Also, the digital signal processing unit 11 outputs a voltage switching signal for turning on / off the transistor M12. As will be described later, the digital signal processor 11 outputs a voltage switching signal based on the magnitude of the envelope signal.

The DAC 16 digital-analog converts the envelope signal output from the digital signal processing unit 11. A waveform W16 represents an envelope signal digital-analog converted by the DAC 16.

The power source of the voltage Vdc is connected to the power node N11 via the inductor L11. The power source of the voltage Vdc is connected to the ground via the capacitor C11. The power supply of the voltage Vdc is lower than the power supplies of the voltages Vds1 and Vds2, and the fixed voltage including the voltages Vds1 and Vds2 is a highly efficient power supply. The power supply of the voltage Vdc supplies the power of the fixed voltage (Vdc) to the power node N11.

The transistor M11 is, for example, an NMOS transistor. An envelope signal is input to the gate of the transistor M11 via the capacitor C12. A bias voltage of the voltage Vg is supplied from the bias power supply 17 to the gate of the transistor M11.

The drain of the transistor M11 is connected to the cathode of the diode D11 and the drain of the transistor M12. The source of the transistor M11 is connected to the power node N11. The transistor M11 supplies the power node N11 with power of a voltage corresponding to the change in the envelope signal based on the voltage of the envelope signal input to the gate and the source voltage (power node N11).

The power source of the voltage Vds1 is connected to the drain of the transistor M11 via the diode D11. The power source of the voltage Vds1 is connected to the ground through the capacitor C13. The power source of the voltage Vds1 supplies power of a fixed voltage (Vds1) to the drain of the transistor M11.

The transistor M12 is, for example, a PMOS (Positive-channel Metal-Oxide Semiconductor) transistor. The voltage switching signal output from the digital signal processing unit 11 is input to the gate of the transistor M12.

The source of the transistor M12 is connected to the ground via the capacitor C14. The source of the transistor M12 is connected to the power supply of the voltage Vds2. The power supply of the voltage Vds2 is larger in voltage than the power supply of the voltage Vds1, and the power supply of the voltage Vds1 is larger in voltage than the power supply of the voltage Vdc. That is, the voltages Vdc, Vds1, and Vds2 have a relationship of Vdc <Vds1 <Vds2.

The drain of the transistor M12 is connected to the drain of the transistor M11. The transistor M12 supplies the power of the power source of the voltage Vds2 to the transistor M11 according to the voltage switching signal input to the gate. The diode D11 prevents the current flowing from the transistor M12 to the transistor M11 from flowing to the power supply of the voltage Vds1.

Here, it can be said that the transistor M11 is a linear amplifier that supplies power of a variable voltage to the power node N11 based on the envelope signal and the voltage of the power node N11. Hereinafter, the power supply by the transistor M11 may be referred to as a variable voltage power supply. The power supply of voltage Vdc supplies fixed voltage power to power node N11. Hereinafter, the power source of the voltage Vdc may be referred to as a fixed voltage power source.

The inductor L11 couples the output voltage of the fixed voltage power supply and the output voltage of the variable voltage power supply. A waveform W17 represents a voltage waveform obtained by combining the output voltage of the fixed voltage power supply and the output voltage of the variable voltage power supply.

The variable voltage power supply is supplied with the power of the power supply of voltage Vds1 and the power of the power supply by the transistor M12. The power of the power source by the transistor M12 is supplied to the variable voltage power source when the transistor M12 is turned on by the voltage switching signal output from the digital signal processing unit 11.

It can be said that the power supply of the voltage Vds1 and the power supply by the transistor M12 supply power of different voltages to the variable voltage power supply. Hereinafter, the power supply of the voltage Vds1 and the power supply by the transistor M12 may be referred to as a power supply power supply power supply.

The digital signal processing unit 11 outputs a voltage switching signal based on the magnitude of the envelope signal. For example, the digital signal processing unit 11 outputs a voltage switching signal for turning on the transistor M12 when the envelope signal is larger than a predetermined threshold (hereinafter, this threshold is referred to as Venv). The digital signal processing unit 11 outputs a voltage switching signal for turning off the transistor M12 when the envelope signal is equal to or lower than a predetermined threshold value Venv.

That is, the amplifying apparatus supplies the power of the fixed voltage power source to the amplifier when a non-signal envelope signal (for example, the horizontal portion of the waveform W16) is input to the gate of the variable voltage power source. In addition, the amplification device superimposes the power of the variable voltage power supply on the power of the fixed voltage power supply when a signal envelope signal (for example, an upward peak indicated by the waveform W16) is input to the gate of the variable voltage power supply. This is supplied to the amplifier 15.

That is, the amplifying apparatus supplies the power of the high-efficiency power source with a fixed voltage to the amplifier 15 when the envelope of the radio signal input to the amplifier 15 is small. Then, when the envelope of the radio signal is large, the amplifying device supplies electric power of a power source that can output a high voltage with low efficiency according to the envelope.

When the variable voltage power supply is operating and the envelope signal is equal to or lower than the predetermined threshold value Venv, the amplifying device supplies the power of the power supply of the voltage Vds1 to the variable voltage power supply, and the envelope signal is set to the predetermined threshold value Venv. If it is larger, the power of the voltage Vds2 higher than the voltage Vds1 is supplied to the variable voltage power supply.

As described above, the amplifying apparatus controls the power supply to the amplifier 15 by the fixed voltage power source and the variable voltage power source, and also controls the power supply to the variable voltage power source when the variable voltage power source operates, thereby reducing the power efficiency. To improve efficiency.

The AS circuit 18 includes a transistor M13 and a capacitor C15. Capacitor C15 has one end connected to power node N11 and the other end connected to the drain of transistor M13.

The transistor M13 is, for example, an NMOS transistor. The gate of the transistor M13 is connected to the digital signal processing unit 11. The source of the transistor M13 is connected to the ground.

The power node N11 is grounded via the capacitor C15 by turning on / off the transistor M13. In the fixed voltage power mode in which only the fixed voltage power supply supplies power to the power node N11, the digital signal processing unit 11 outputs an AS signal so that the power node N11 is grounded via the capacitor C15.

That is, the AS circuit 18 is a circuit that actively controls the bypass capacitor (capacitor C15), and reduces the impedance of the power node N11 in the fixed voltage power mode. That is, the AS circuit 18 suppresses the voltage change of the power node N11 at the fixed voltage power node. Hereinafter, grounding the power node N11 to the ground via the capacitor C15 may be referred to as AS. The time when the fixed voltage power source and the variable voltage power source supply power to the power node N11 may be referred to as a variable voltage power mode.

In the fixed voltage power mode, the envelope signal input to the transistor M11 is in a no-signal state as indicated by the waveform W16. The gate of the transistor M11 is supplied with, for example, a bias of the voltage Vg for class B operation from the bias power supply 17, and the transistor M11 is turned off when an envelope signal in a non-signal state is input. .

FIG. 5 is a diagram showing an example of a block of the digital signal processing unit. As described above, the digital signal processing unit 11 has a function as shown in FIG. 5 by executing a program formed by, for example, a DSP or CPU and stored in the memory. As shown in FIG. 5, the digital signal processing unit 11 includes an envelope signal generation unit 21, an AS signal generation unit 22, and a voltage switching signal generation unit 23.

The envelope signal generation unit 21 receives a transmission signal. The envelope signal generation unit 21 generates a transmission signal larger than a predetermined threshold as an envelope signal.
For example, the envelope signal generating unit 21 generates an envelope signal by extracting a transmission signal that is larger than the threshold Vth described with reference to FIG. That is, the envelope signal generation unit 21 generates a signal obtained by slicing the transmission signal with the threshold value Vth as an envelope signal, as shown by the waveforms W11 and W15 in FIG.

Note that the radio signal input to the amplifier 15 is a signal obtained by modulating the transmission signal. Therefore, the transmission signal input to the envelope signal generation unit 21 can be said to be an envelope of a radio signal amplified by the amplifier 15.

In addition, when a non-signal envelope signal is output, the transistor M11 is turned off, and only the fixed voltage power supply supplies power to the amplifier 15. Therefore, when a no-envelope envelope signal is output, the amplifying device is in the fixed voltage power mode. Further, when a signal envelope signal is output, the transistor M11 supplies power to the amplifier 15 with a voltage corresponding to a change in the signal envelope signal. Therefore, when an envelope signal with a signal is output, the amplification device is in the variable voltage power mode.

The AS signal generation unit 22 outputs an AS signal for AS of the power node N11 when the amplification device is in the fixed voltage power mode. Further, the AS signal generation unit 22 outputs an AS signal for opening the AS of the power node N11 in the variable voltage power mode.

For example, a transmission signal is input to the AS signal generation unit 22. The AS signal generation unit 22 outputs an AS signal for AS for the power node N11 when the envelope of the transmission signal is equal to or lower than the threshold value Vth, that is, in the fixed voltage power mode. For example, the AS signal generation unit 22 outputs an AS signal in the H state for turning on the transistor M13 of the AS circuit 18.

Also, the AS signal generation unit 22 outputs an AS signal for releasing the AS of the power node N11 when the envelope of the transmission signal is larger than the threshold value Vth, that is, in the variable voltage power mode. For example, the AS signal generation unit 22 outputs an AS signal in an L state for turning off the transistor M13 of the AS circuit 18.

The voltage switching signal generator 23 receives a transmission signal, an envelope signal, and an AS signal. The voltage switching signal generator 23 is in the variable voltage power mode, and the maximum value of the envelope signal in the section in which the transistor M11 continuously operates (the section in which power is continuously supplied to the power node N11), the threshold Venv, Compare Then, the voltage switching signal generator 23 turns on the transistor M12 so that the power of the power source of the voltage Vds2 is supplied to the transistor M11 if the maximum value of the envelope signal is larger than the threshold value Venv in the continuously operating period. Outputs a voltage switching signal. For example, the voltage switching signal generator 23 outputs an L state voltage switching signal.

Further, the voltage switching signal generation unit 23 is configured so that only the power of the power source of the voltage Vds1 is supplied to the transistor M11 if the maximum value of the envelope signal is equal to or lower than the threshold value Venv in the section in which the transistor M11 operates continuously. A voltage switching signal for turning off the transistor M12 is output. For example, the voltage switching signal generator 23 outputs an H state voltage switching signal.

Note that the voltage switching signal generation unit 23 can recognize a section in which the transistor M11 continuously operates based on the AS signal. For example, the voltage switching signal generator 23 can recognize that the transistor M11 is operating continuously when the AS signal is in the L state.

5 includes an envelope signal output from the envelope signal generation unit 21, an AS signal output from the AS signal generation unit 22, a voltage switching signal output from the voltage switching signal generation unit 23, and the DAC 12. Processing is performed so that the timings of the output transmission signals match.

FIG. 6 is a diagram for explaining the operation of the block of FIG. 6A shows transmission signals input to the envelope signal generation unit 21, the AS signal generation unit 22, and the voltage switching signal generation unit 23. FIG. FIG. 6B shows an envelope signal generated by the envelope signal generation unit 21. FIG. 6C shows a voltage waveform at the power node N11. FIG. 6D shows an AS signal generated by the AS signal generation unit 22. FIG. 6E shows a voltage switching signal generated by the voltage switching signal generator 23.

The envelope signal generation unit 21 compares the transmission signal with the threshold value Vth, as shown in FIG. When the transmission signal is larger than the threshold value Vth, the envelope signal generation unit 21 extracts the transmission signal and generates an envelope signal as shown in FIG.

The generated envelope signal is output to the transistor M11. The transistor M11 is turned off when a non-envelope envelope signal is input, and the power node N11 is supplied with the power supply voltage of the voltage Vdc. Further, the transistor M11 is turned on when a signal envelope signal is input, and the power node N11 is supplied with the voltage of the power supply power supply corresponding to the signal envelope. Thereby, the voltage waveform of the power node N11 becomes as shown in FIG.

As shown in FIG. 6D, the AS signal generation unit 22 outputs an AS signal in the L state when the transmission signal is larger than the threshold value Vth. Further, as shown in FIG. 6D, the AS signal generation unit 22 generates an H-state signal when the transmission signal is equal to or lower than the threshold value Vth.

That is, when in the fixed voltage power mode, the AS signal generation unit 22 outputs an AS signal for turning on the transistor M13 so that the power node N11 is AS. The AS signal generation unit 22 outputs an AS signal for turning off the transistor M13 so as to open the AS of the power node N11 in the variable voltage power mode.

The transistor M11 is turned on when the AS signal is in the L state, and continuously supplies the power of the power supply power supply to the power node N11. That is, when the AS signal is in the L state, the transistor M11 continuously operates.

As shown in FIGS. 6D and 6B, the voltage switching signal generator 23 compares the envelope signal when the AS signal is in the L state with the threshold value Venv. That is, the voltage switching signal generation unit 23 compares the envelope signal and the threshold value Venv in the section in which the transistor M11 operates continuously. When the envelope signal in the section in which the transistor M11 continuously operates is larger than the threshold value Venv, the voltage switching signal generation unit 23 turns on the voltage switching signal in the L state so as to turn on the transistor M12 as shown in FIG. Is output.

Thereby, in the variable voltage power mode (when the AS signal is in the L state), when the envelope signal is larger than the threshold value Venv, the power of the power source of the voltage Vds2 is supplied to the drain of the transistor M11. In the variable voltage power mode, when the envelope signal is equal to or lower than the threshold value Venv, the power of the power source of the voltage Vds1 is supplied to the drain of the transistor M11.

Therefore, when the envelope signal is larger than the threshold value Venv, the power consumed wastefully by the transistor M11 (power consumed as heat) is the shaded portion shown on the leftmost side in FIG. When the envelope signal is equal to or lower than the threshold value Venv, the power consumed in the transistor M11 is the second to fourth shaded portion from the left in FIG. 6C.

FIG. 7 is a diagram showing a part of the amplifying apparatus when there is one power source for supplying power to the variable voltage power source. 7 that are the same as those in FIG. 3 are given the same reference numerals, and descriptions thereof are omitted.
In the amplifying device of FIG. 7, a power source having a voltage Vds2 is connected to the drain of the transistor M11. That is, in the amplifying apparatus of FIG. 7, the power source that supplies power to the variable voltage power source is one power source of the voltage Vds2.

FIG. 8 is a diagram for explaining the loss of the variable voltage power supply of FIG. FIG. 8 shows a voltage waveform at the power node N11 in FIG.
As described above, in the amplifying apparatus of FIG. 7, the power source that supplies power to the variable voltage power source is one power source of the voltage Vds2. Therefore, the power consumed wastefully by the transistor M11 is the hatched portion in FIG. That is, in the amplifying apparatus of FIG. 7, when the amplitude of the envelope signal is small in the variable voltage power mode, power is wasted as heat and power efficiency is low.

On the other hand, in the amplifying apparatus of FIG. 3, power of different voltages Vds1 and Vds2 is supplied to the variable voltage power supply based on the magnitude of the envelope signal. Therefore, in the amplifying apparatus in FIG. 3, as shown by an arrow A11 in FIG. 6C, it is possible to suppress power that is wasted as heat.

As described above, the amplifying apparatus supplies power of different voltages to the variable voltage power source based on the magnitude of the envelope signal. Thereby, the amplifying apparatus can increase the power efficiency.

[Third Embodiment]
Next, a third embodiment will be described in detail with reference to the drawings. In the third embodiment, the switching timing of the voltage switching signal will be described.

FIG. 9 is a diagram illustrating an example of a block of the digital signal processing unit according to the third embodiment. 9, the same components as those in FIG. 5 are denoted by the same reference numerals, and the description thereof is omitted. Note that the circuit block of the amplification device according to the third embodiment is the same as the circuit block of the amplification device of FIG.

As shown in FIG. 9, the digital signal processing unit 11 has a voltage switching signal generation unit 31. The voltage switching signal generator 31 transitions the state of the voltage switching signal after a predetermined time has elapsed since the variable voltage power supply entered the power supply stop period. Other functions of the voltage switching signal generator 31 are the same as those of the voltage switching signal generator 23 described with reference to FIG.

FIG. 10 is a diagram for explaining the operation of the voltage switching signal generator. FIG. 10A shows an envelope signal generated by the envelope signal generation unit 21. The sections S11 to S14 shown in FIG. 10A indicate the power supply stop period of the variable voltage power supply (transistor M11). FIG. 10B shows a voltage switching signal generated by the voltage switching signal generator 31. FIG. 10C shows an AS signal generated by the AS signal generation unit 22.

As shown in FIGS. 10A to 10C, the voltage switching signal generation unit 31 switches the voltage in the L state to turn on the transistor M12 when the AS signal is in the L state and the envelope signal is larger than the threshold value Venv. Generate a signal. At this time, the voltage switching signal generation unit 31 generates a voltage switching signal that transitions from the H state to the L state after a predetermined time since the variable voltage power supply enters the power supply stop period. For example, as shown in FIG. 10B, the voltage switching signal generation unit 31 changes the voltage switching signal from the H state to the L state after a predetermined time (T1) has elapsed after entering the sections S11 and S13.

Further, as shown in FIGS. 10A to 10C, the voltage switching signal generator 31 is in the H state so as to turn off the transistor M12 when the AS signal is in the L state and the envelope signal is equal to or lower than the threshold value Venv. A voltage switching signal is generated. At this time, the voltage switching signal generation unit 31 generates a voltage switching signal that transitions from the L state to the H state after a predetermined time from the start of the power supply stop period. For example, as shown in FIG. 10B, the voltage switching signal generation unit 31 changes the voltage switching signal from the L state to the H state after a predetermined time (T2) has elapsed after entering the sections S12 and S14.

The voltage switching signal generator 31 can recognize the power supply stop period based on the AS signal. For example, the voltage switching signal generator 31 can recognize that the variable voltage power supply is in the power supply stop period when the AS signal is in the H state.

As described above, the amplifying apparatus changes the state of the voltage switching signal after a predetermined time has elapsed since the variable voltage power supply enters the power supply stop period. Thereby, the amplifying apparatus can prevent a sudden current from flowing through the power node N11 when the power mode is switched.

For example, when the variable voltage power supply supplies power to the power node N11 or when the variable voltage power supply stops supplying power to the power node N11, the voltage of the power supplied from the power supply power supply power to the variable voltage power supply is When changed, a rapid current flows through power node N11. However, since the amplifying apparatus changes the state of the voltage switching signal after a lapse of a predetermined time after the variable voltage power supply enters the power supply stop period, it is possible to suppress the rapid generation of current.

[Fourth Embodiment]
Next, a fourth embodiment will be described in detail with reference to the drawings. The power supply power supply that supplies different voltage power to the variable voltage power supply in accordance with the voltage switching signal requires time to switch the voltage. Therefore, for example, when the time between the first interval in which the variable voltage power supply continuously operates and the second interval in which the variable voltage power supply continuously operates is shorter than the voltage switching time of the power supply power supply, There is a case where the voltage switching of the power supply power supply is not in time. Therefore, in the fourth embodiment, even when the time between the first section in which the variable voltage power supply continuously operates and the next second section is shorter than the voltage switching time of the power supply power supply, Make sure that the power supply is properly switched.

FIG. 11 is a diagram illustrating an example of a block of the digital signal processing unit according to the fourth embodiment. 11 that are the same as those in FIG. 5 are given the same reference numerals, and descriptions thereof are omitted. Note that the circuit block of the amplifier according to the fourth embodiment is the same as the circuit block of the amplifier of FIG.

As shown in FIG. 11, the digital signal processing unit 11 has a voltage switching signal generation unit 41. When the section in which the variable voltage power supply continuously operates occurs in a time shorter than the voltage switching time of the power supply power supply, the voltage switching signal generator 41 sets these sections as one continuously operating section. . The voltage switching signal generation unit 41 compares the maximum value of the envelope signal in one section that is continuously operated with the threshold value Venv. Other functions of the voltage switching signal generator 41 are the same as those of the voltage switching signal generator 23 described with reference to FIG.

FIG. 12 is a diagram for explaining the operation of the voltage switching signal generator. FIG. 12A shows an envelope signal generated by the envelope signal generator 21. FIG. 12B shows an AS signal generated by the AS signal generation unit 22. In FIG. 12C, even if the section in which the variable voltage power supply (transistor M11) operates continuously occurs in a time shorter than the voltage switching time of the power supply power supply (transistor M12 and the power supply of the voltage Vdc), A voltage switching signal that has not been corrected is shown. FIG. 12D shows changes in the drain voltage of the transistor M12 in response to the voltage switching signal shown in FIG. FIG. 12E shows a switching impossibility signal generated by the voltage switching signal generator 41. FIG. 12F shows a voltage switching signal generated by the voltage switching signal generation unit 41. FIG. 12G shows a change in drain voltage of the transistor M12 in response to the voltage switching signal shown in FIG.

First, the case where the voltage switching signal is not corrected will be described. As shown in FIGS. 12A and 12C, when the envelope signal is larger than the threshold value Venv, the voltage switching signal is in the L state so that the transistor M12 is turned on and the power of the voltage Vds2 is supplied to the transistor M11. Become.

Here, the transistor M12 requires time for voltage switching. For example, as shown in FIGS. 12C and 12D, even if the voltage switching signal changes from the H state to the L state, the drain voltage change of the transistor M12 has a slope. Some PMOS transistors require, for example, 100 nsec for voltage switching.

Therefore, when the section in which the transistor M11 continuously operates occurs in a time shorter than the voltage switching time of the transistor M12, the voltage switching of the transistor M12 may not be in time for the voltage to be supplied to the transistor M11.

For example, a section in which the transistor M11 continuously operates at time t1-t2 in FIG. 12A and a section in which the transistor M11 continuously operates at time t3-t4 in FIG. Assume that the time between them (that is, the time between time t2 and t3) is shorter than the voltage switching time of the transistor M12. In this case, as shown at times t3-t4 in FIGS. 12A and 12D, the transistor M11 is supplied with electric power whose voltage changes from the transistor M12. For this reason, the amplifier 15 may change the gain and cannot amplify the radio signal appropriately.

Further, for example, a section in which the transistor M11 continuously operates at time t5-t6 in FIG. 12A and a section in which the transistor M11 continuously operates at time t7-t8 in FIG. (Ie, the time between times t6 and t7) is shorter than the voltage switching time of the transistor M12. In this case, as shown at times t7 to t8 in FIGS. 12A and 12D, the transistor M11 is supplied with electric power whose voltage changes from the transistor M12. For this reason, the amplifier 15 may change the gain and cannot amplify the radio signal appropriately.

Next, when the voltage switching signal is corrected, that is, the operation of the voltage switching signal generator 41 will be described. Based on the AS signal, the voltage switching signal generation unit 41 detects that the section in which the variable voltage power supply continuously operates occurs in a time shorter than the voltage switching time of the power supply power supply.

For example, as shown in FIG. 12B, the L state of the AS signal indicates a section in which the transistor M11 operates continuously. Accordingly, the voltage switching signal generation unit 41 compares the time of the AS signal in the H state with the voltage switching time of the transistor M12, so that the section in which the variable voltage power supply continuously operates is the voltage of the power supply power supply. It is possible to detect that it occurred in a time shorter than the switching time. For example, the voltage switching signal generation unit 41 detects that the time of the H state between the times t2 and t3 of the AS signal shown in FIG. 12B is shorter than the voltage switching time of the power supply source. .

When the voltage switching signal generation unit 41 detects that the section in which the variable voltage power supply continuously operates is generated in a time shorter than the voltage switching time of the power supply power supply by the AS signal, the voltage switching signal generation unit 41 in FIG. As shown, a switch disable signal is generated. For example, the voltage switching signal generation unit 41 generates the AS signal as a non-switchable signal when it is detected that the section in which the variable voltage power supply continuously operates occurs in a time shorter than the voltage switching time of the power supply power supply. To do.

When the voltage switching signal generation unit 41 generates the switching impossibility signal, the section in which the transistor M11 before and after the switching impossibility signal continuously operates is defined as one continuously operating section.
For example, as shown in section S21 of FIG. 12E, the voltage switching signal generation unit 41 includes a continuous section at time t1-t2 before and after the H state switching disable signal, and a continuous section at time t3-t4. Is one continuous section. Further, as shown in the section S22 in FIG. 12E, the voltage switching signal generation unit 41 includes a continuous section at time t5-t6 before and after the H state switching disable signal, and a continuous section at time t7-t8. Is one continuous section.

As a result, as shown at time t3-t4 in FIG. 12G, the transistor M11 is supplied with power having a constant voltage from the transistor M12. Therefore, the amplifier 15 can appropriately amplify the radio signal without changing the gain. Further, as shown at time t7-t8 in FIG. 12G, the transistor M11 is supplied with power having a constant voltage from the transistor M12. Therefore, the amplifier 15 can appropriately amplify the radio signal without changing the gain.

As described above, when the section in which the variable voltage power supply continuously operates occurs in a time shorter than the voltage switching time of the power supply power supply, the amplifier apparatus sets these sections as one continuously operating section. . Then, the amplifying device compares the maximum value of the envelope signal in this section with the threshold value Venv to generate a voltage switching signal. Thereby, the amplification device can appropriately amplify the radio signal.

For example, when the amplification device is applied to a mobile phone system, the amplifier 15 is required to have gain linearity. When the gain of the amplifier 15 changes due to a change in supplied power, an AM (Amplitude Modulation) component is added as noise to the radio signal to be amplified, resulting in distortion. However, in the amplifying apparatus described above, the gain change of the amplifier 15 can be suppressed, and the distortion of the radio signal can be suppressed.

In addition, when the section in which the variable voltage power supply continuously operates occurs in a time shorter than the voltage switching time of the power supply power supply, the amplifying apparatus sets the sections as one continuously operating section. Therefore, it is not necessary to use a high-speed NMOS transistor for the transistor M12. That is, a low-cost PMOS transistor such as 2SJ or 2SA can be used as the transistor M12.

Note that the second embodiment and the third embodiment can be combined with the fourth embodiment.
[Fifth Embodiment]
Next, a fifth embodiment will be described in detail with reference to the drawings. In the second embodiment, the power supply for supplying power supplies two types of voltage power to the variable voltage power supply. In the fifth embodiment, an example in which power of three types of voltages is supplied to a variable voltage power source will be described.

FIG. 13 is a diagram illustrating an example of a circuit block of the amplifying apparatus according to the fifth embodiment. 13 that are the same as those in FIG. 3 are given the same reference numerals, and descriptions thereof are omitted.
In FIG. 13, the amplifying device includes a PMOS transistor M21, a capacitor C21, and a diode D21. In FIG. 13, as described with reference to FIG. 4, it is assumed that the power source of the voltage Vdc is connected to the inductor L <b> 11, and the power source of the voltage Vds <b> 1 is connected to the anode of the diode D <b> 11. In FIG. 13, it is assumed that the power source of the voltage Vds2 is connected to the source of the transistor M21, and the power source of the voltage Vds3 is connected to the source of the transistor M12. There is a relationship of Vdc <Vds1 <Vds2 <Vds3 among the voltages Vdc and Vds1 to Vds3.

One end of a capacitor C21 is connected to the source of the transistor M21. The other end of the capacitor C21 is connected to the ground. The drain of the transistor M21 is connected to the anode of the diode D21, and the cathode of the diode D21 is connected to the drain of the transistor M11. The diode D21 prevents the current output from the transistor M12 from flowing into the transistor M21.

The digital signal processing unit 11 has the same blocks as the blocks described in FIG. 5 generates a voltage switching signal by comparing one threshold Venv and an envelope signal, but the voltage switching signal generator 23 of the digital signal processing unit 11 of FIG. The threshold value and the envelope signal are compared to generate a voltage switching signal. Hereinafter, the two threshold values are referred to as threshold values Venv1 and Venv2. The thresholds Venv1 and Venv2 have a relationship of Venv1 <Venv2. The voltage switching signal generator 23 outputs the generated voltage switching signal to the transistors M21 and M12.

FIG. 14 is a diagram for explaining the operation of the voltage switching signal generator. FIG. 14A shows a transmission signal. FIG. 14B shows an envelope signal. FIG. 14C shows a voltage waveform at the power node N11. FIG. 14D shows the state of the voltage switching signal generated by the voltage switching signal generator 23.

A voltage switching signal Vsw1 shown in FIG. 14 indicates a voltage switching signal output from the voltage switching signal generator 23 to the gate of the transistor M21, and is expressed by whether the transistor M21 is “ON” or “OFF”. . The voltage switching signal Vsw2 indicates a voltage switching signal output from the voltage switching signal generation unit 23 to the gate of the transistor M12. Similar to the transistor M21, the voltage switching signal Vsw2 is expressed by whether the transistor M12 is “ON” or “OFF”. ing. Further, ENVmax shown in FIG. 14 indicates the maximum value of the envelope signal in the section in which the variable voltage power supply continuously operates. Further, Venv1 and Venv2 shown in FIG. 14 indicate threshold values that the voltage switching signal generator 23 compares with the maximum value ENVmax of the envelope signal.

The voltage switching signal generation unit 23 compares the maximum value ENVmax of the envelope signal and the threshold values Venv1 and Venv2 in the section in which the variable voltage power supply continuously operates. As shown in Table 1 in FIG. 14, the voltage switching signal generation unit 23 causes the transistor M21 to supply the power of the power source of the voltage Vds1 to the variable voltage power source if the maximum value ENVmax of the envelope signal is smaller than the threshold value Venv1. , M12 are generated to generate voltage switching signals Vsw1 and Vsw2.

Further, as shown in Table 2 of FIG. 14, the voltage switching signal generator 23 converts the power of the power source of the voltage Vds2 to the variable voltage power source if the maximum value ENVmax of the envelope signal is not less than the threshold value Venv1 and not more than the threshold value Venv2. In order to be supplied, voltage switching signals Vsw1 and Vsw2 are generated which turn off the transistor M21 and turn on the transistor M12.

Further, as shown in Table 3 in FIG. 14, the voltage switching signal generator 23 is configured such that if the maximum value ENVmax of the envelope signal is larger than the threshold value Venv2, the power of the power source of the voltage Vds3 is supplied to the variable voltage power source. Voltage switching signals Vsw1 and Vsw2 are generated to turn off the transistor M21 and turn on the transistor M12.

That is, the voltage switching signal generation unit 23 sets the power supply power supply power so as to supply the variable voltage power supply with a finer voltage power corresponding to the magnitude of the envelope signal in the section where the variable voltage power supply continuously operates. Control.

Thus, the amplifying apparatus compares the envelope signal with a plurality of threshold values so that the power supply power supply supplies a plurality of voltages of power to the variable voltage power supply. Accordingly, it is possible to finely suppress power consumed in the variable voltage power source, and to further increase power efficiency.

In the above description, the case where the power supply power supply outputs power of three types of voltages has been described. However, power of four or more types of voltages can be output in the same manner. For example, by increasing the threshold value to be compared with the envelope signal and increasing the number of transistors of the power supply power supply, it is possible to output power of four or more types of voltages.

Further, the fourth embodiment and the third embodiment can be combined with the fifth embodiment.
[Sixth Embodiment]
Next, a sixth embodiment will be described in detail with reference to the drawings. In the sixth embodiment, a case where the power supply power supply is a voltage conversion module will be described.

FIG. 15 is a diagram illustrating an example of a circuit block of the amplifying device according to the sixth embodiment. 15, the same components as those in FIG. 3 are denoted by the same reference numerals, and the description thereof is omitted. In FIG. 15, the amplification device has a DC / DC converter 51.

The digital signal processing unit 11 has the same blocks as the blocks described in FIG. The voltage switching signal generated by the voltage switching signal generation unit 23 included in the digital signal processing unit 11 is output to the DC / DC converter 51.

The DC / DC converter 51 outputs voltages Vds1 and Vds2 according to the voltage switching signal output from the voltage switching signal generator 23. The voltages Vds1 and Vds2 are output to the drain of the transistor M11.

For example, the DC / DC converter 51 outputs the voltage Vds1 when the voltage switching signal generator 23 determines that the maximum value of the envelope signal is equal to or less than the threshold value Venv and outputs an H state voltage switching signal. Further, when the voltage switching signal generator 23 determines that the maximum value of the envelope signal is larger than the threshold value Venv and outputs the voltage switching signal in the L state, the DC / DC converter 51 outputs the voltage Vds2.

As described above, the amplifying apparatus can increase the power efficiency even when the power supply power supply is formed by the voltage conversion module of the DC / DC converter 51, for example.
If the DC / DC converter 51 is a DC / DC converter that can output three or more types of voltages, as described in the fifth embodiment, a finer voltage power is supplied to the variable voltage power supply. Can do.

Hereinafter, an example in which the amplification device is applied to a wireless device will be described.
FIG. 16 is a diagram illustrating an example in which the amplification device is applied to a wireless device. The amplification device shown in FIG. 3 is applied to, for example, a transmission unit of a base station of a mobile phone system.

As shown in FIG. 16, the transmission unit 60 includes a baseband processing unit 61, a digital processing unit 62, a DVC (DVC: Dynamic Voltage Control) power supply unit 63, and an RF (Radio Frequency) unit 64. The digital processing unit 62 includes a DVC signal processing unit 62a,

DACs

62b and 62d, a distortion compensation processing unit 62c, a modulation unit 62e, a frequency conversion unit 62f, and an ADC (Analog to Digital Converter) 62g. The DVC power supply unit 63 has a power supply 63a. The RF unit 64 has an amplifier 64a.

A transmission signal is input to the baseband processing unit 61. The baseband processing unit 61 performs baseband processing of the transmission signal.
The DVC signal processing unit 62a and the distortion compensation processing unit 62c of the digital processing unit 62 correspond to, for example, the digital signal processing unit 11 in FIG. The DACs 62b and 62d correspond to, for example, the

DACs

16 and 12 in FIG. The modulation unit 62e corresponds to, for example, the oscillator 13 and the multiplier 14 in FIG.

The ADC 62g and the frequency converter 62f are not shown in FIG. The frequency converter 62f down-converts the frequency of the radio signal amplified by the amplifier 64a, and the ADC 62a performs digital-analog change of the down-converted radio signal. The distortion compensation processing unit 62c performs distortion compensation processing on the transmission signal output to the DAC 62d based on the transmission signal output from the baseband processing unit 61 and the feedback signal output from the ADC 62g.

The power source 63a corresponds to, for example, the transistors M11 to M13, the capacitors C11 to C15, the inductor L11, the diode D11, the bias power source 17, and the AS circuit 18 in FIG. The amplifier 64a corresponds to, for example, the amplifier 15 in FIG.

In the present invention, signal processing is performed after the maximum value of the input envelope signal is detected in advance. This is realized by providing a delay in the main signal system. For example, it is possible to perform the DVC processing earlier by the delay time by providing the delay before the distortion compensation processing unit 62c of FIG.

The above merely shows the principle of the present invention. In addition, many modifications and changes can be made by those skilled in the art, and the present invention is not limited to the precise configuration and application shown and described above, and all corresponding modifications and equivalents may be And the equivalents thereof are considered to be within the scope of the invention.

DESCRIPTION OF SYMBOLS 1 Amplification part 2 Generation | occurrence |

production part

3, 4 Power supply part 5 Power supply power supply part N1 Power node

Claims

In an amplification device for amplifying a signal,
An amplifying unit for amplifying an input signal by power supplied to the power node;
A generator for generating an envelope signal based on an envelope of the input signal;
A first power supply for supplying a fixed voltage power to the power node;
A second power supply unit for supplying power of a variable voltage according to the envelope signal to the power node;
A power supply unit that supplies power of a different voltage to the second power supply unit based on the magnitude of the envelope signal;
An amplifying device comprising:
The power supply unit is
A switching signal generator for generating a voltage switching signal based on the magnitude of the envelope signal;
A variable power supply unit that supplies power of a different voltage to the second power supply unit in response to the voltage switching signal;
The amplifying apparatus according to claim 1, further comprising:
The switching signal generation unit generates the voltage switching signal based on a comparison result between a maximum value of the envelope signal and a predetermined threshold value in a section in which the second power supply unit continuously operates. The amplification device according to claim 2.
4. The range according to claim 2 or 3, wherein the switching signal generation unit transitions the state of the voltage switching signal after a predetermined time has elapsed since the second power supply unit entered the power supply stop period. An amplifying device according to 1.
The switching signal generation unit operates continuously when one of the sections in which the second power supply unit operates continuously is shorter than the voltage switching time of the variable power supply unit. 4. The amplifying device according to claim 3, wherein the amplifying device is a section.
The amplification device according to claim 2, wherein the variable power supply unit is a voltage conversion module.
The amplification device according to claim 1, wherein the generation unit generates an envelope of the input signal that is larger than a predetermined threshold as the envelope signal.