JP2017143342A - Power amplifier and control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow for reduction of the margin of an envelope signal for the amplitude of a transmission signal, by adjusting the phase shift of the transmission signal and envelope signal at at least the transmission start time.SOLUTION: A power amplifier 10 of envelope tracking system includes an envelope signal generation unit 2 for generating an envelope signal by making an envelope signal, generated based on the transmission signal of baseband, have a predetermined margin, an input envelope signal processing unit 4 for generating a control power supply voltage from the envelope signal, a transmission signal processing unit 5 for generating a RF signal from the transmission signal, and generating an output transmission signal from the RF signal, with the control power supply voltage as the power supply voltage, and a phase adjustment unit 3 for adjusting the phase of any one of the input envelope signal and input envelope signal, so that the phase of the RF signal the phase of the control power supply voltage. After completion of phase adjustment, envelope signal generation unit 2 generates an envelope signal where the predetermined margin was reduced.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an envelope tracking power amplifier and a control method thereof.

  An envelope tracking method (ET method) is used for a high-frequency amplifier in a power amplifier (PA) of a transmitter in order to increase its power efficiency. In this method, an envelope (envelope: a line connecting the peaks of the waveform of the modulation signal) is generated from the baseband input transmission signal, and the power supply voltage supplied to the high-frequency amplifier based on the envelope signal is RF (Radio). By controlling according to the envelope of the frequency (frequency) signal, the power consumption is suppressed, and the power added efficiency (PAE: power added efficiency) of the high frequency amplifier is consumed by the high frequency amplifier. This represents the ratio of DC power, and the same output power, the higher the power added efficiency, the lower the power consumption).

In this envelope tracking type power amplifier, the phase of the transmission signal (RF signal) to be amplified input to the high frequency amplifier and the phase of the control power supply voltage generated based on the envelope signal and applied to the high frequency amplifier If there is a shift, the power supply voltage corresponding to the amplitude of the transmission signal (RF signal) is not supplied, and the transmission signal output from the high frequency amplifier is distorted. Therefore, it is important that the respective phases do not shift.
This phase shift is caused by the electrical length of the electrical circuit (the length of the wiring expressed with reference to the wavelength of the electrical signal in the wiring) until the input transmission signal is input to the high-frequency amplifier, the characteristics of the electronic component, and the input Due to the difference between the electrical length of the electric circuit and the characteristics of the electronic components from the generation of the envelope signal from the transmission signal to the generation of the control power supply voltage for the high frequency amplifier based on the envelope signal and the supply to the high frequency amplifier It is. For this reason, a circuit design is performed so as not to cause a phase shift, and a certain margin is given to the value of the control power supply voltage in anticipation of a certain phase shift.

  Actually, a phase shift occurs between the input transmission signal input to the high-frequency amplifier and the applied control power supply voltage due to variations in individual circuits including electronic components, changes in operating temperature, aging, etc. A technique for automatically adjusting the phase between a transmission signal and a control power supply voltage using a test signal periodically has been proposed (for example, see Patent Document 1).

International Publication No. 2011/125261

However, in this prior art, when phase adjustment is performed, the phase between the transmission signal and the control power supply voltage is adjusted using the test signal, so that phase adjustment cannot be performed during transmission. Therefore, if a phase shift occurs during transmission, it cannot be corrected. Therefore, considering the phase shift during transmission, the margin of the control power supply voltage cannot be reduced, and the power added efficiency (PAE) of the high-frequency amplifier can be reduced. There was a problem that sufficient power efficiency could not be improved.
Therefore, the present invention has been made paying attention to the problems of the prior art, and allows the phase of the transmission signal and the control power supply voltage to be adjusted during transmission without using the test signal, so that the margin of the control power supply voltage can be adjusted. It is an object of the present invention to provide a power amplifying apparatus capable of improving power added efficiency (PAE) by reducing the power and a control method thereof.

  A power amplifying device according to an aspect of the present invention is an envelope tracking power amplifying device, an input envelope signal generating unit that generates an input envelope signal from a baseband input transmission signal, an input transmission signal, and an input envelope signal A phase adjustment unit that adjusts one of the phases and outputs a transmission signal and an envelope signal, an envelope signal processing unit that amplifies the amplitude of the envelope signal to generate a control power supply voltage, and an RF signal from the transmission signal And a transmission signal processing unit that amplifies the signal level of the RF signal using the control power supply voltage as the power supply voltage and generates an output transmission signal. The phase adjustment unit adjusts the phase of either the input transmission signal or the input envelope signal so that the phase of the RF signal and the control power supply voltage matches, and when the phase of the RF signal and the control power supply voltage matches The adjustment completion notification is output to the input envelope signal generation unit. The input envelope signal generation unit generates an input envelope signal in which a predetermined margin is given to the input envelope signal generated based on the input transmission signal until the adjustment completion notification is received, and after receiving the adjustment completion notification, An envelope signal with a reduced margin is generated.

  According to one aspect of the present invention, the phase of the RF signal input to the high-frequency amplifier during transmission and the phase of the control power supply voltage are adjusted so that the margin of the control power supply voltage can be reduced and the power is amplified. The power added efficiency (PAE) of the apparatus can be improved.

It is a block diagram which shows the structural example of the power amplification apparatus which concerns on 1st Embodiment of this invention. It is a flowchart which shows the flow of a process of the phase adjustment and envelope signal generation by the power amplifier which concerns on 1st Embodiment of this invention. It is a figure which shows an example of the waveform of the envelope signal in a prior art. It is a figure which shows an example of the waveform of the envelope signal in 1st Embodiment of this invention. It is a block diagram which shows the structural example of the power amplification apparatus which concerns on 2nd Embodiment of this invention. It is a flowchart which shows an example of the distortion suppression process procedure performed with the phase adjustment part in the power amplification apparatus which concerns on 2nd Embodiment of this invention.

Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and different from the actual ones. Therefore, specific components should be determined in consideration of the following description.
Further, the embodiments described below exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention includes the shape, structure, arrangement, etc. of components. It is not specified to the following. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of one embodiment of the present invention. However, it will be apparent that one or more embodiments may be practiced without such specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.

<First Embodiment>
The power amplifying device according to the first embodiment of the present invention will be described below.
(System configuration)
As shown in FIG. 1, the power amplifying apparatus 10 according to the first embodiment includes a transmission signal generation unit 1, an input envelope signal generation unit 2, a phase adjustment unit 3, an envelope signal processing unit 4, and a transmission signal processing. Unit 5, correlation detection processing unit 6, and distortion detection processing unit 7.
The transmission signal generation unit 1 generates an input transmission signal SIT that is a baseband digital signal, and outputs the generated input transmission signal SIT to the input envelope signal generation unit 2 and the phase adjustment unit 3. The transmission signal generation unit 1 may be provided outside the power amplification device 10 according to the first embodiment. That is, the transmission signal may be an input signal from the outside of the power amplification device 10 according to the first embodiment. In this case, the power amplifying apparatus 10 according to the first embodiment may have an input unit for connecting to the external transmission signal generating unit 1.

The input envelope signal generation unit 2 generates an input envelope signal SIE based on the input transmission signal SIT from the transmission signal generation unit 1.
At this time, the input envelope signal generation unit 2 adds a predetermined margin to the amplitude of the envelope signal generated based on the input transmission signal SIT until receiving an adjustment completion notification SAC from a phase adjustment unit 3 described later at the start of transmission. The added input envelope signal SIE is generated and is used as the second input envelope signal SIE2.
The predetermined margin includes the phase of the RF signal SRF based on the input transmission signal SIT to be amplified input to the high frequency amplifier and the phase of the control power supply voltage VCP generated based on the envelope signal and applied to the high frequency amplifier. The voltage margin is taken into consideration so that the phase of the control power supply voltage does not become insufficient when the phase is adjusted by the phase adjusting unit 3 to be described later.

Further, after receiving the adjustment completion notification SAC from the phase adjustment unit 3, the input envelope signal generation unit 2 reduces the minimum margin (a later-described distortion including zero worsens) by reducing a predetermined margin added to the amplitude of the envelope signal. An input envelope signal is added to the previous value, and this is used as the first input envelope signal SIE1.
For example, after receiving the adjustment completion notification SAC from the phase adjustment unit 3, the input envelope signal generation unit 2 requests a required adjacent channel leakage power ratio based on a distortion detection signal from a distortion detection processing unit 7 described later. A first input envelope signal SIE1 is generated so that power added efficiency (PAE) is improved while ensuring (ACPR: Adjacent Channel Leakage Power Ratio). Then, the input envelope signal generation unit 2 outputs the generated first input envelope signal SIE1 or second input envelope signal SIE2 to the phase adjustment unit 3.

The phase adjustment unit 3 adjusts the phase of the input transmission signal input from the transmission signal generation unit 1 and outputs the transmission signal to the transmission signal processing unit 5, and the first input from the input envelope signal generation unit 2. A process of adjusting the phase of the input envelope signal SIE1 or the second input envelope signal SIE2 and outputting the first envelope signal SE1 or the second envelope signal SE2 to the envelope signal processing unit 4 is executed.
The phase adjustment unit 3 correlates the phase of the RF signal SRF input to the high frequency amplifier 5d described later and the control power supply voltage VCP so as to eliminate the phase shift, and the correlation value CV notified from the correlation detection processing unit 6 described later. Is adjusted to the phase of the input transmission signal SIT and the first input envelope signal SIE1 or the second input envelope signal SIE2 so that becomes the maximum value.

Then, when the correlation value CV notified from the correlation detection processing unit 6 reaches the maximum value, the phase adjustment unit 3 completes the phase adjustment assuming that the phases of the RF signal SRF and the control power supply voltage VCP match, and notifies the adjustment completion. The SAC is output to the input envelope signal generator 2.
The envelope signal processing unit 4 amplifies the first envelope signal SE1 or the second envelope signal SE2 from the phase adjustment unit 3 to generate the control power supply voltage VCP, and the control power supply voltage VCP is transmitted to the transmission signal processing unit 5 and Output to the correlation detection processing unit 6. The control power supply voltage based on the first envelope signal SE1 is distinguished as the first control power supply voltage VCP1, and the control power supply voltage based on the second envelope signal SE2 is distinguished as the second control power supply voltage VCP2.

Here, as an example, the envelope signal processing unit 4 includes a D / A converter (hereinafter referred to as DAC) 4a, a low-pass filter (hereinafter referred to as LPF) 4b, an amplifier 4c, and a DC power source 4d.
The DAC 4a converts the first envelope signal SE1 or the second envelope signal SE2 from the phase adjustment unit 3 from a digital signal to an analog signal, and outputs the analog signal to the subsequent LPF 4b. The LPF 4b attenuates a component having a frequency higher than the cut-off frequency with respect to the envelope signal from the DAC 4a and outputs the attenuated component to the subsequent amplifier 4c.

The amplifier 4c operates by receiving the DC voltage supplied from the DC power supply 4d, and amplifies the first envelope signal SE1 or the second envelope signal SE2 from the LPF 4b to generate the first or second control power supply voltage. Then, the first control power supply voltage VCP1 or the second control power supply voltage VCP2 is output to the transmission signal processing unit 5 and the correlation detection processing unit 6.
The DC power source 4d is a DC power source such as a battery. Note that the DC power supply 4d may be provided outside the power amplifying apparatus 10 according to the first embodiment. In this case, the power amplifying apparatus 10 according to the first embodiment may have a power input unit for connecting to the external DC power supply 4d.

The transmission signal processing unit 5 receives an oscillation signal from an oscillator 8 to be described later, converts the input transmission signal from the phase adjustment unit 3 into an RF (Radio Frequency) signal SRF, and performs envelope signal processing on the RF signal SRF. An output transmission signal is generated by amplification by a high frequency amplifier to which the first control power supply voltage VCP1 or the second control power supply voltage VCP2 from the unit 4 is applied, and the output transmission signal is sent to the distortion detection processing unit 7 and the antenna 9 Output.
Here, as an example, the transmission signal processing unit 5 includes a DAC 5a, an LPF 5b, a mixer 5c, and a high-frequency amplifier 5d.

  The DAC 5a converts the transmission signal ST from the phase adjustment unit 3 from a digital signal to an analog signal and outputs the analog signal to the subsequent LPF 5b. The LPF 5b attenuates the frequency component higher than the cut-off frequency with respect to the analog transmission signal from the DAC 5a and outputs the attenuated component to the subsequent mixer 5c. The mixer 5c receives the analog transmission signal from the LPF 5b and the oscillation signal from the oscillator 8, and upconverts the frequency of the analog transmission signal to a high frequency in the RF band (for example, 260 MHz to 270 MHz band) to generate the RF signal SRF. Then, the RF signal SRF is output to the subsequent high-frequency amplifier 5d.

  The high frequency amplifier 5d includes, for example, an N-channel field effect transistor (FET), and applies the first control power supply voltage VCP1 or the second control power supply voltage VCP2 output from the envelope signal processing unit 4 to the drain electrode. To do. In particular, when the first control power supply voltage VCP1 with a predetermined margin reduced is applied, the RF signal SRF output from the mixer 5c is amplified with high efficiency by operating near the saturation power point of the high-frequency amplifier 5d. Thus, an output transmission signal SOT is generated. Then, the high frequency amplifier 5d outputs the output transmission signal SOT to the distortion detection processing unit 7 and the antenna 9.

The correlation detection processing unit 6 detects the correlation value of the signal waveform between the waveform of the second control power supply voltage VCP2 from the envelope signal processing unit 4 and the RF signal SRF from the transmission signal processing unit 5, and the signal waveform The correlation value CV is notified to the phase adjustment unit 3.
Here, as an example, the correlation detection processing unit 6 includes an envelope detection unit 6a, an A / D converter (hereinafter referred to as ADC) 6b, an ADC 6c, and a correlation detection unit 6d.
The envelope detector 6a receives the RF signal SRF output from the mixer 5c of the transmission signal processor 5, detects the RF signal SRF, and generates an envelope signal SED. Then, the envelope detector 6a outputs the generated envelope signal SED to the subsequent ADC 6b. That is, the envelope detector 6a detects the high frequency RF signal SRF from the mixer 5c and outputs the envelope signal SED.

The ADC 6b converts the envelope signal SED from the envelope detector 6a from an analog signal to a digital signal and outputs the converted signal to the subsequent correlation detector 6d. The ADC 6c converts the second control power supply voltage VCP2 from the amplifier 4c of the envelope signal processing unit 4 from an analog signal to a digital signal, and outputs it to the subsequent correlation detection unit 6d.
The correlation detection unit 6d detects the correlation between the envelope signal SED from the ADC 6b and the signal waveform of the second control power supply voltage VCP2 from the ADC 6c, and outputs the correlation value CV of the signal waveform to the phase adjustment unit 3. For example, the correlation detection unit 6d takes in the signal waveform of the envelope signal SED from the ADC 6b and the signal waveform of the second control power supply voltage VCP2 from the ADC 6c, and correlates, for example, the peak values of these two signal waveforms. Thus, a correlation value CV indicating the degree of coincidence between the envelope signal SED and the peak value of the second control power supply voltage VCP2 is output to the phase adjustment unit 3.

The distortion detection processing unit 7 receives an oscillation signal from an oscillator 8 described later, converts the output transmission signal SOT from the transmission signal processing unit 5 into a baseband signal, and detects distortion of the signal waveform of the baseband signal. The detected distortion value is output to the input envelope signal generation unit 2.
Here, as an example, the distortion detection processing unit 7 includes a mixer 7a, an LPF 7b, an ADC 7c, and a distortion detection unit 7d.
The mixer 7a receives the oscillation signal from the oscillator 8 and the output transmission signal SOT from the high-frequency amplifier 5d, down-converts the frequency of the output transmission signal SOT, generates a baseband signal, and converts the baseband signal to the subsequent stage. Output to the LPF 7b. The LPF 7b attenuates a component having a frequency higher than the cutoff frequency with respect to the baseband signal from the mixer 7a and outputs the attenuated component to the ADC 7c at the subsequent stage. The ADC 7c converts the baseband signal from the LPF 7b from an analog signal to a digital signal and outputs the converted signal to the subsequent distortion detection unit 7d.
The distortion detection unit 7d performs fast Fourier transform (FFT) on the baseband signal from the ADC 7c, and near the frequency of an adjacent channel in the baseband signal (for example, 6.25 kHz when the channel interval is 6.25 kHz). The adjacent channel leakage power ratio (ACPR) indicating the distortion of the appearing waveform is detected as a distortion detection value, and the distortion detection value (ACPR) is output to the input envelope signal generation unit 2.

The oscillator 8 generates an oscillation signal having a constant frequency, and outputs the generated oscillation signal to the transmission signal processing unit 5 and the distortion detection processing unit 7. The oscillator 8 may be provided outside the power amplification device 10 according to the first embodiment. In this case, the power amplifying device 10 according to the first embodiment may have an input unit for connecting to the external oscillator 8.
The antenna 9 is a device for transmitting the output transmission signal SOT to the outside of the power amplification device 10 according to the first embodiment by radiating the output transmission signal SOT from the transmission signal processing unit 5 as a radio wave (electromagnetic wave) to the space. It is. The antenna 9 may be provided outside the power amplification device 10 according to the first embodiment. In this case, the power amplifying apparatus 10 according to the first embodiment may have an output unit for connecting to the external antenna 9.

(Phase adjustment and envelope signal generation processing)
Next, phase adjustment and envelope signal generation for matching the phases of the RF signal SRF and the second control power supply voltage VCP2 input to the high-frequency amplifier 5d at the start of transmission by the power amplifying apparatus 10 according to the first embodiment are performed. The processing flow will be described with reference to FIG.
The transmission signal generation unit 1 generates a baseband input transmission signal SIT, and outputs the generated input transmission signal SIT to the input envelope signal generation unit 2 and the phase adjustment unit 3 (step S101).

  Since the input envelope signal generation unit 2 has not received the adjustment completion notification SAC from the phase adjustment unit 3 at the start of transmission (No in step S102), the control power supply of the high-frequency amplifier 5d is used for the transmission signal during phase adjustment. To prevent the voltage from becoming insufficient, the control power supply voltage of the high frequency amplifier 5d needs to have a voltage margin with respect to the transmission signal as shown in FIG. 3, and the input transmission signal SIT is also provided to have this voltage margin. The second input envelope signal SIE2 obtained by adding a predetermined margin to the amplitude of the generated envelope signal is output to the phase adjustment unit 3 (step S103).

The phase adjustment unit 3 outputs the transmission signal ST to the transmission signal processing unit 5 without adjusting the phase because it has not received the notification of the correlation value CV from the correlation detection processing unit 6 at the start of transmission, and the second envelope signal SE2 is output to the envelope signal processing unit 4 (step S104).
The envelope signal processing unit 4 generates the second control power supply voltage VCP2 based on the second envelope signal SE2 from the phase adjustment unit 3 (step S105).
The transmission signal processing unit 5 generates an RF signal SRF from the transmission signal ST from the phase adjustment unit 3 (step S106).

The correlation detection processing unit 6 detects the correlation value CV between the waveform of the second control power supply voltage VCP2 from the envelope signal processing unit 4 and the waveform of the RF signal SRF from the transmission signal processing unit 5, and calculates the correlation value CV. It outputs to the phase adjustment part 3 (step S107).
When receiving the notification of the correlation value CV from the correlation detection processing unit 6, the phase adjustment unit 3 determines whether or not the correlation value CV is the maximum value (step S108). In order to determine whether or not the correlation value CV is the maximum value, the previous correlation value CVn-1 is compared with the current correlation value CVn, and the current correlation value CVn is greater than the previous correlation value CVn-1. When (CVn> CVn-1), the phase adjustment is performed again without determining the maximum value, and when the current correlation value is smaller than the previous correlation value CVn-1 (CVn <CVn-1), the previous time Is determined as the maximum value of the correlation value CV, and the envelope signal SE and the transmission signal ST at the previous phase adjustment are output.

If it is determined that the correlation value is not the maximum value (No in step S108), the phase of either the input transmission signal SIT or the second input envelope signal SIE2 is adjusted so that the correlation value becomes the maximum value. (Step S109). Here, the phase adjustment unit 3 sets the phase of the input transmission signal SIT and the second input envelope signal SIE2 so that the correlation value CV between the signal waveforms of the input transmission signal SIT and the second input envelope signal SIE2 is maximized. Adjust the phase on the lead side by delaying it.
Then, the phase adjustment unit 3 outputs the transmission signal ST to the transmission signal processing unit 5, outputs the second envelope signal SE2 to the envelope signal processing unit 4, and proceeds to step S105, and then correlates again in step S108. A determination is made whether the value CV is the maximum value. In order to determine the phase advance side of the input transmission signal SIT and the second input envelope signal SIE2, the phase is adjusted when the second correlation value (current correlation value) is smaller than the first correlation value. Becomes the delay side, and when it is larger, it can be determined as the advance side.

When the correlation adjustment unit 3 receives the notification of the correlation value CV from the correlation detection processing unit 6 and determines that the correlation value CV is the maximum value (Yes in step S108), the phase adjustment unit 3 outputs the phase having the maximum value. At the same time, an adjustment completion notification SAC is output to the input envelope signal generator 2 (step S110).
After receiving the phase completion notification SAC from the phase adjustment unit 3 (Yes in step S102), the input envelope signal generation unit 2 performs the second control power supply of the high-frequency amplifier 5d with respect to the RF signal SRF as shown in FIG. In order to provide the voltage VCP2 with a voltage margin, the predetermined margin in the second input envelope signal VCP2 set in step S103 is reduced and the first input envelope signal SIE2 is output (step S111). At the time of reduction, the voltage is reduced stepwise while observing a distortion detection result (distortion detection value) described later to obtain a voltage margin for the RF signal as shown in FIG.

The input envelope signal generation unit 2 receives a notification of the distortion detection value ACPR after reducing the predetermined margin from the distortion detection processing unit 7 (step S112).
The input envelope signal generation unit 2 determines whether or not the distortion value satisfying the required performance of the distortion detection value ACPR from the distortion detection processing unit 7 is equal to or less than a predetermined setting value (step S113), and is larger than the setting value (step S113). If the required performance is not satisfied (No in step S113), the margin of the first input envelope signal SIE1 is returned to the margin before the previous reduction (step S115), and the series of processing ends.

In addition, when the distortion detection value ACPR from the distortion detection processing unit 7 is equal to or less than the set value (satisfies the required performance) (Yes in step S113), the input envelope signal generation unit 2 performs the first input envelope. It is determined whether or not a margin that can be reduced still remains in the signal SIE1 (step S114). The determination method is based on whether or not the margin added by the second input envelope signal SIE2 remains. If there is a margin that can be reduced (Yes in step S114), the process returns to step S111 to further reduce the margin of the first input envelope signal SIE1.
On the contrary, if there is no remaining margin that can be reduced (No in step S114), the above series of processing ends.

(Effect by 1st Embodiment)
Below, the effect by 1st Embodiment is demonstrated.
In the conventional method, the control power supply voltage supplied to the high frequency amplifier based on the envelope signal generated by the input envelope generation unit needs to have a voltage margin with respect to the RF signal as shown in FIG.
In the first embodiment, the phase is adjusted so that the phase of the RF signal SRF and the second control power supply voltage VCP2 coincide with each other in a state where the second control power supply voltage VCP2 has a voltage margin as shown in FIG. When the phase is matched and the adjustment is completed, the first control power supply voltage VCP1 with a reduced margin can be obtained as shown in FIG. 4, and therefore a power amplifying device with higher power added efficiency (PAE) is provided. Can do. Therefore, power consumption of a DC power source such as a battery can be suppressed.

  In the above embodiment, the phase of the input transmission signal to be amplified input to the high frequency amplifier at the start of transmission is matched with the phase of the control power supply voltage generated based on the envelope signal and applied to the high frequency amplifier. However, the present invention is not limited to the above embodiment, and the phase adjustment unit 3 is adjusted by operating the correlation detection processing unit 6 every predetermined time. May be. In this case, when the transmission time is long, a deviation between the RF signal and the control power supply voltage can be compensated during transmission, and power amplification with higher power added efficiency (PAE) can be performed.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to FIGS.
In the second embodiment, the distortion of the output transmission signal being transmitted is monitored, and the phase of the RF signal to be amplified that is input to the high frequency amplifier when the distortion detection value is equal to or higher than a preset setting value. The phase adjustment is performed to match the phase of the control power supply voltage generated based on the envelope signal and applied to the high frequency amplifier.
That is, in the second embodiment, as shown in FIG. 5, in the configuration of FIG. 1 of the first embodiment described above, an adjustment start signal for starting phase adjustment is provided from the input envelope signal generation unit 2 to the phase adjustment unit 3. ing.

In the second embodiment, the phase adjustment unit 3 adjusts the phase of the second input envelope signal SIE2 or the input transmission signal SIT at the start of transmission, as in the first embodiment described above, and also detects the distortion detection value during transmission. The ACPR is monitored, and the phase of the second input envelope signal SIE2 or the input transmission signal SIT is adjusted based on the distortion detection value ACPR.
Since other configurations have the same configurations as those of the first embodiment described above, the same reference numerals are given to corresponding portions to those in FIG. 1, and detailed descriptions thereof will be omitted.
The input envelope signal generation unit 2 executes the distortion suppression process shown in FIG. 6 every predetermined time.

In this distortion suppression process, first, the distortion detection value ACPR output from the distortion detection unit 7d of the distortion detection processing unit 7 is read (step S201), and then the distortion detection value is equal to or greater than a predetermined set value (for example, −55 dB). It is determined whether or not (step S202). The distortion detection value output from the distortion detector 7d is the adjacent channel leakage power ratio (ACPR), and the predetermined set value is set to a value that satisfies the required performance.
When the distortion detection value ACPR is less than the set value in the determination result in step S202 (No in step S202), the phase of the input transmission signal SIT and the first input envelope signal SIE1 is appropriate, and the output transmission signal It is determined that SOT distortion is suppressed, and the process ends.

  When the distortion detection value ACPR is equal to or larger than the set value in the determination result in step S202 (Yes in step S202), the input envelope signal generation unit 2 notifies the phase adjustment unit 3 of the adjustment start signal SAS for starting phase adjustment. 2 (step S203), the process proceeds to step 103 in the flowchart of FIG. 2 to generate the second input envelope signal SIE2 having a predetermined margin (step S103), and as described in the flowchart of FIG. Then, the phase of the second input envelope signal SIE2 or the input transmission signal SIT is adjusted, and the phase of the RF signal to be amplified input to the high frequency amplifier 5d and the envelope signal are generated and supplied to the high frequency amplifier 5d. The phase of the applied second control power supply voltage VCP2 is matched to eliminate distortion degradation.

(Effect by 2nd Embodiment)
According to the second embodiment, during the transmission, the distortion of the output transmission signal SOT becomes larger than a predetermined set value by monitoring the distortion detection value of the output transmission signal SOT by the input envelope signal generation unit 2. In this case, the phase adjustment is performed to suppress the distortion of the output transmission signal, so that the adjacent channel leakage power ratio (ACPR) can be surely kept below the set value, and the power added efficiency (PAE) of the power amplification device Can always be in an efficient state.
While the present invention has been described with reference to specific embodiments, it is not intended that the invention be limited by these descriptions. From the description of the invention, other embodiments of the invention will be apparent to persons skilled in the art, along with various variations of the disclosed embodiments. Therefore, it is to be understood that the claims encompass these modifications and embodiments that fall within the scope and spirit of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Transmission signal generation part, 2 ... Input envelope signal generation part, 3 ... Phase adjustment part, 4 ... Envelope signal processing part, 4a ... DAC, 4b ... LPF, 4c ... Amplifier, 4d ... DC power supply, 5 ... Transmission signal processing 5a ... DAC 5b ... LPF 5c ... mixer 5d ... high frequency amplifier 6 ... correlation detection processing unit 6a ... envelope detection unit 6b, 6c ... ADC 6d ... correlation detection unit 7 ... distortion detection processing 7a, mixer, 7b, LPF, 7c, ADC, 7d, distortion detection unit, 8 oscillator, 9 antenna, 10 power amplifier

Claims (6)

An envelope tracking type power amplification device,
An input envelope signal generator for generating an input envelope signal from a baseband input transmission signal;
A phase adjustment unit that adjusts the phase of either the input transmission signal or the input envelope signal and outputs the signal as a transmission signal and an envelope signal, and
An envelope signal processing unit for amplifying the envelope signal to generate a control power supply voltage;
A transmission signal processing unit that generates an RF signal from the transmission signal and amplifies the RF signal using the control power supply voltage as a power supply voltage to generate an output transmission signal;
With
The phase adjustment unit adjusts the phase of the input transmission signal or the input envelope signal so that the phase of the RF signal and the control power supply voltage match, and when the phase of the RF signal and the control power supply voltage match Then, an adjustment completion notification is output to the input envelope signal generation unit,
The input envelope signal generation unit generates an input envelope signal in which a predetermined margin is given to the input envelope signal generated based on the transmission signal until receiving the adjustment completion notification, and receives the adjustment completion notification Thereafter, the input envelope signal in which the predetermined margin is reduced is generated. An envelope detector for detecting an envelope from the RF signal;
A correlation detection processing unit comprising a correlation detection unit for detecting a correlation value between the envelope and the waveform of the control power supply voltage;
2. The power according to claim 1, wherein the phase adjustment unit adjusts a phase of one of the input transmission signal and the input envelope signal based on a correlation value from the correlation detection processing unit. Amplification equipment.   The phase adjustment unit delays the phase of the signal on the phase advance side of the input transmission signal and the input envelope signal so that the correlation value from the correlation detection processing unit is maximized. 3. The power amplifying device according to 2. A distortion detection processing unit that detects distortion of the signal waveform of the output transmission signal output from the transmission signal processing unit and outputs a distortion detection value;
After receiving the adjustment completion notification from the phase adjustment unit, the input envelope signal generation unit secures the adjacent channel leakage power ratio based on the distortion detection value from the distortion detection processing unit and The power amplifying apparatus according to claim 1, wherein the input envelope signal for reducing a margin is generated.   The input envelope signal generation unit receives the distortion detection value from the distortion detection processing unit, and when the distortion detection value is greater than or equal to a predetermined set value, the input is performed so that the distortion detection value is less than the set value. The power amplification device according to claim 4, wherein the phase of the transmission signal or the input envelope signal is adjusted. A phase control method for an envelope tracking type power amplification device,
Generate an input envelope signal with a predetermined margin to the input envelope signal generated based on the baseband input transmission signal,
Amplifying the amplitude of the envelope signal to generate a control power supply voltage;
Generating an RF signal from the input transmission signal;
Amplifying a signal level of the RF signal using the control power supply voltage as a power supply voltage to generate an output transmission signal;
Adjusting the phase of the input transmission signal or the input envelope signal so that the phase of the RF signal and the control power supply voltage match,
A control method for a power amplifying apparatus, comprising: generating the envelope signal in which the margin is reduced after the phase is matched and adjustment is completed.

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