WO2009151097A1 - Power amplifier and amplification method thereof, and radio wave transmitter using same - Google Patents

Power amplifier and amplification method thereof, and radio wave transmitter using same Download PDF

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Publication number
WO2009151097A1
WO2009151097A1 PCT/JP2009/060695 JP2009060695W WO2009151097A1 WO 2009151097 A1 WO2009151097 A1 WO 2009151097A1 JP 2009060695 W JP2009060695 W JP 2009060695W WO 2009151097 A1 WO2009151097 A1 WO 2009151097A1
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Prior art keywords
power
frequency
signal
modulation signal
output
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PCT/JP2009/060695
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French (fr)
Japanese (ja)
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清彦 高橋
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日本電気株式会社
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Priority to JP2010516880A priority Critical patent/JP5440498B2/en
Publication of WO2009151097A1 publication Critical patent/WO2009151097A1/en

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/02—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
    • H03F1/0205—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers
    • H03F1/0277—Selecting one or more amplifiers from a plurality of amplifiers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/26—Modifications of amplifiers to reduce influence of noise generated by amplifying elements
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/20—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers
    • H03F3/21—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers with semiconductor devices only
    • H03F3/211—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers with semiconductor devices only using a combination of several amplifiers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/20—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers
    • H03F3/24—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers of transmitter output stages
    • H03F3/245—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers of transmitter output stages with semiconductor devices only
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/72—Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/451—Indexing scheme relating to amplifiers the amplifier being a radio frequency amplifier
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/541—Transformer coupled at the output of an amplifier
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2203/00—Indexing scheme relating to amplifiers with only discharge tubes or only semiconductor devices as amplifying elements covered by H03F3/00
    • H03F2203/72—Indexing scheme relating to gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal
    • H03F2203/7221—Indexing scheme relating to gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal the gated amplifier being switched on or off by a switch at the output of the amplifier
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2203/00—Indexing scheme relating to amplifiers with only discharge tubes or only semiconductor devices as amplifying elements covered by H03F3/00
    • H03F2203/72—Indexing scheme relating to gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal
    • H03F2203/7236—Indexing scheme relating to gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal the gated amplifier being switched on or off by putting into parallel or not, by choosing between amplifiers by (a ) switch(es)

Definitions

  • the present invention relates to a power amplifier, an amplification method thereof, and a radio wave transmitter using the power amplifier, and more particularly to a highly efficient polar modulation type power amplifier in which linearity does not change even when the average power of input / output signals is changed. .
  • PAPR peak power to average power ratio
  • backoff is required at least as much as PAPR.
  • the efficiency of the class AB amplifier is maximized when the output is saturated, and decreases as the back-off increases. For this reason, it is difficult to increase the power efficiency of the power amplifier as the high frequency modulation signal has a large PAPR.
  • FIG. 1 shows an example of background art of a transmitter including a power amplifier that amplifies a high-frequency modulated signal with a large PAPR with high efficiency.
  • the transmitter shown in FIG. 1 includes a polar modulation type power amplifier 221 having the same configuration as that of the power amplifier disclosed in Patent Document 1.
  • 1 includes a digital baseband unit 201, an analog baseband unit 205, and a power amplification unit 214.
  • the digital baseband unit 201 receives three types of signals, that is, a power control signal, an I signal (InphaseQSignal), and a Q signal (Quadrature Signal) from a power control signal output terminal 202, an I signal output terminal 203, and a Q signal output terminal 204, respectively. Output.
  • the I signal output from the I signal output terminal 203 is input to a digital-to-analog converter (DAC) 206 and converted into an analog signal.
  • DAC digital-to-analog converter
  • the Q signal output from the Q signal output terminal 204 is input to a digital-analog converter (DAC) 210 and converted into an analog signal.
  • the I signal and the Q signal converted into analog signals are multiplied by the output of the local transmitter 208 supplied via the phase shifter 209 and the mixer 207 and the mixer 211, respectively.
  • the signal supplied from the phase shifter 209 to the mixer 211 has a phase delay of 90 ° with respect to the signal supplied from the phase shifter 209 to the mixer 207.
  • the output signals of the mixer 207 and the mixer 211 are added together by an adder 212 to become a high frequency modulation signal.
  • the high frequency modulation signal output from the adder 212 is amplified by the variable gain amplifier 213 and supplied to the power amplifier 214. At this time, the gain of the variable gain amplifier 213 changes according to the signal from the power control signal output terminal 202.
  • the power amplifying unit 214 switches the number of high-frequency power amplifiers to be in an operating state (on state) among n high-frequency power amplifiers 218-1 to 218-n (n represents a natural number of 2 or more). Perform amplitude modulation.
  • the high frequency modulation signal input to the power amplifier 214 is input to the limiter 217 and the envelope detector 215.
  • the limiter 217 extracts a high-frequency phase modulation signal having a constant amplitude from the input signal, and outputs it to the high-frequency power amplifiers 218-1 to 218-n.
  • Envelope detector 215 extracts an amplitude modulation signal from the input signal.
  • the amplitude modulation signal output from the envelope detector 215 is AD converted in the amplitude control circuit 216 and then converted into control signals for the high frequency power amplifiers 218-1 to 218-n.
  • Each of the high frequency power amplifiers 218-1 to 218-n arranged in parallel is determined by the control signal from the amplitude control circuit 216 to be in an operating state or a sleep state (off state).
  • the high frequency phase modulation signal amplified by the active high frequency power amplifier is added by the power combining circuit 219 and output from the output terminal 220. Accordingly, an output signal having a larger amplitude can be obtained as the number of high-frequency power amplifiers that are turned on among the high-frequency power amplifiers 218-1 to 218-n is increased.
  • the reason why the power efficiency can be increased by using the power amplifying unit 214 is that the high-frequency power amplifiers 218-1 to 218-n can take only the operating state or the sleeping state. For this reason, the high-frequency power amplifier in the operating state can always be used in the saturation operation.
  • a general high-frequency power amplifier has a characteristic of operating at the highest efficiency when the output is saturated. Therefore, the output efficiency of the transmitter shown in FIG. 1 is ideally always the maximum efficiency of the high-frequency power amplifiers 218-1 to 218-n.
  • the SNR (Signal-to-NoiseNRatio) of the output signal deteriorates as the output power decreases from the maximum power. This is due to AD conversion performed by the amplitude control circuit 216. Since the amplitude control circuit 216 converts the amplitude-modulated signal into a time-discrete signal quantized by analog-digital conversion (AD conversion), quantization noise is generated. In the power amplifying unit 214 of the transmitter shown in FIG. 1, the intensity of quantization noise is substantially constant regardless of the output power. For this reason, the SNR of the output signal deteriorates as the output power decreases from the maximum power.
  • FIG. 2 shows the relationship between the input power and the SNR of the output signal in an ideal AD converter.
  • the SNR (dB) of the output signal can be expressed by a linear function of the input power (dBm) in the range up to the output saturation. This is shown, for example, in Non-Patent Document 1, Non-Patent Document 2, and the like.
  • FIG. 3 shows an example of the polar modulation type power amplifier 221 of FIG.
  • the power amplifier of FIG. 3 is shown in Non-Patent Document 3.
  • the power amplifier of FIG. 3 includes an amplitude modulation signal input 401, high frequency phase modulation signal inputs 402 and 403, and an output power control signal input 404. Also, amplitude modulation transistors 405-1 to 405-21, two-terminal current limit switches 406-1 to 406-21, phase modulation transistors 407-1 to 407-6, a power control device 408, and 1
  • a transformer 409 having a three-sided tap on the secondary side and a two-terminal on the secondary side, and an output antenna 410 are provided.
  • the gates of the amplitude modulation transistors 405-1 to 405-21 are connected to the amplitude modulation signal input 401, and the sources are all grounded.
  • the drains of the amplitude modulation transistors 405-1 to 405-21 are connected to one terminals of two-terminal current limit switches 406-1 to 406-21, respectively.
  • the other terminals of the current limit switches 406-1 to 406-7 are connected to the sources of the phase modulation transistors 407-1 and 407-4.
  • each of the current limit switches 406-8 to 406-14 is connected to the sources of the phase modulation transistors 407-2 and 407-5, and one terminal of each of the current limit switches 406-15 to 406-21 is The phase modulation transistors 407-3 and 407-6 are connected to the sources.
  • the gates of the phase modulation transistors 407-1 to 407-3 are connected to the high frequency phase modulation signal input 402, and the gates of the phase modulation transistors 407-4 to 407-6 are connected to the high frequency phase modulation signal input 403.
  • the drains of the phase modulation transistors 407-1 to 407-3 are connected together to one of the two terminals other than the midpoint on the primary side of the transformer 409.
  • the drains of the phase modulation transistors 407-4 to 407-6 are connected together to the remaining one terminal other than the midpoint of the primary side of the transformer 409.
  • the middle point of the transformer 409 is connected to the output of the power control device 408, and the signal input of the power control device 408 is connected to the output power control signal input 404.
  • One of the secondary terminals of the transformer 409 is grounded, and the other is connected to the output antenna 410.
  • the amplitude modulation signal is input from the amplitude modulation signal input 401 and controls the gate bias of the amplitude modulation transistors 405-1 to 405-21.
  • the high-frequency phase modulation signal is input as a differential signal from two high-frequency phase modulation signal inputs 402 and 403, and drives the gates of the phase modulation transistors 407-1 to 407-3 and the phase modulation transistors 407-4 to 407-6, respectively. To do.
  • a combination circuit of the amplitude modulation transistors 405-1 to 405-21 and the phase modulation transistors 407-1 to 407-6 is a circuit serving as a mixer. Therefore, the signal output from the drains of the phase modulation transistors 407-1 to 407-6 is a high frequency modulation signal obtained by multiplying the amplitude modulation signal and the high frequency phase modulation signal.
  • the output power control signal is a 7-bit digital signal that controls on / off of the current limit switches 406-1 to 406-7, each having two terminals, one bit at a time. Similarly, the 7-bit signal controls ON / OFF of the current limit switches 406-8 to 406-14 and ON / OFF of the current limit switches 406-15 to 406-21 one bit at a time. At the same time, the 7-bit output power control signal is sent from the output power control signal input 404 to the power control device 408 to control the output power to the transformer 409.
  • the average power of the output signal is controlled by turning on / off the current limit switches 406-1 to 406-21.
  • the current value of the signal output to the primary side of the transformer 409 varies depending on the number of current limit switches that are turned on, and the signal output from the output antenna 410 Average power is controlled.
  • the power control device 408 is used to adjust the bias voltage to the phase modulation transistors 407-1 to 407-6 to the minimum, thereby suppressing the waste of power.
  • the power amplifier of FIG. 3 maintains high efficiency even when the average power of the output signal is reduced. Even if the amplitude modulation signal input from the amplitude modulation signal input 401 always has a constant average power, the average power of the signal output from the output antenna 410 can be changed. However, the amplitude modulation signal input to the amplitude modulation signal input 401 is an analog value. Therefore, the phase modulation transistors 407-1 to 407-6 must be operated with a back-off corresponding to the PAPR of the modulation signal to be output. This is the same problem as the class AB amplifier, and it is difficult to increase the efficiency when a signal having a large PAPR is amplified.
  • FIG. 1 Ovidiu Bajdechi and Johan H. Huijsing, ⁇ Systematic Design of Sigma-Delta Analog-to-digital Converters '', Kluwer Academic Publishers, p.16, Figure 2.6 Jurgen van Engelen and Rudy van de Plassche, ⁇ Bandpass Si gma Delta Modulators '', Kluwer Academic Publishers, p.47, Figure 4.7 Amin Shameli, et al. ⁇ A Two-Point Modulation Technique for CMOS Power Amplifier in Polar Transmitter Architecture''IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 56, NO. 1, JANUARY 2008- 38-Page
  • the SNR changes in the amplification path of the amplitude modulation signal, and as a result, the SNR of the output signal changes.
  • the SNR of the output signal tends to deteriorate. Therefore, in the power amplifier, it has been a problem to keep the SNR of the output signal substantially constant regardless of the average power of the output signal.
  • an exemplary object according to the present invention is to provide a power amplifier capable of keeping the SNR of the output signal substantially constant regardless of the average power of the output signal, an amplification method thereof, and a radio wave transmitter using the power amplifier. It is to provide.
  • An exemplary power amplifier includes a plurality of high-frequency power amplifiers that amplify a high-frequency phase modulation signal in which a phase modulation component of the high-frequency modulation signal included in the high-frequency modulation signal is up-converted to a carrier frequency band; An amplitude control circuit that quantizes an amplitude modulation signal including an amplitude modulation component included in the high frequency modulation signal and controls on / off of the plurality of high frequency power amplifiers based on the quantized amplitude modulation signal; A power control circuit for controlling saturation output power of the plurality of high-frequency power amplifiers based on an external power control signal; A power combining circuit for adding and outputting the output signals of the on-state high-frequency power amplifier among the plurality of high-frequency power amplifiers; Have The amplitude control circuit performs amplitude modulation of the high-frequency phase modulation signal by switching on and off the plurality of high-frequency power amplifiers, The power control circuit adjusts an average output power of the high-frequency phase modul
  • An exemplary power amplifier amplification method includes a plurality of amplifying high-frequency phase modulation signals obtained by up-converting a phase modulation component of the high-frequency modulation signal included in the high-frequency modulation signal to a carrier frequency band.
  • a high frequency power amplifier An amplitude control circuit that quantizes an amplitude modulation signal including an amplitude modulation component included in the high frequency modulation signal and controls on / off of the plurality of high frequency power amplifiers based on the quantized amplitude modulation signal;
  • a power control circuit for controlling saturation output power of the plurality of high-frequency power amplifiers based on an external power control signal;
  • a power combining circuit for adding and outputting the output signals of the on-state high-frequency power amplifier among the plurality of high-frequency power amplifiers;
  • a method for amplifying a power amplifier comprising: The amplitude control circuit performs amplitude modulation of the high-frequency phase modulation signal by switching on and off the plurality of high-frequency power amplifiers, Adjusting the average output power of the high-frequency phase modulation signal by controlling the saturation output power of the on-state high-frequency power amplifier by the power control circuit, The output signal of the on-state high-frequency power amplifier among the plurality of high-frequency power amplifiers is summed and
  • the SNR of the quantized amplitude modulation signal can be made substantially constant, and the SNR of the output signal of the power amplifier can be made substantially constant. Therefore, the SNR of the output signal of the power amplifier can be kept substantially constant regardless of the average power of the output signal.
  • 1 is a block diagram showing a first embodiment of a power amplifier according to the present invention. It is a figure which shows the distortion characteristic of the output signal of this invention. It is a block diagram which shows the 2nd Embodiment of this invention. It is a block diagram which shows the 3rd Embodiment of this invention. It is a flowchart which shows operation
  • the configuration of the power amplifier 10 according to the first embodiment of the present invention is shown in FIG.
  • the power amplifier 10 of this embodiment includes a power control circuit 11, an amplitude control circuit 12, a plurality of high-frequency power amplifiers 13-1 to 13-n (n is a natural number of 2 or more), and a power combining circuit 14. I have.
  • the power amplifier of this embodiment can be used as a part of the radio wave transmitter shown in FIG. 1, and a radio wave transmitter using the power amplifier of this embodiment can be configured.
  • the power amplifier 221 of the radio wave transmitter in FIG. 1 is replaced with the power amplifier 10, and the power control signal output from the power control signal output terminal 202 of the digital baseband unit 201 is input to the power control circuit 11.
  • the amplitude modulation signal output from the envelope detector 215 is input to the amplitude control circuit 12, and the high frequency phase modulation signal from the limiter 217 is input to the plurality of high frequency power amplifiers 13-1 to 13-n.
  • the power control circuit 11 controls the saturation output power of the plurality of high-frequency power amplifiers 13-1 to 13-n based on a power control signal input from the outside, thereby reducing the average power of the output signal of the power amplifier 10. adjust.
  • the amplitude control circuit 12 receives an amplitude modulation signal including the amplitude modulation component of the high frequency modulation signal used for wireless communication, and converts it into a signal for controlling on / off of the high frequency power amplifiers 13-1 to 13-n.
  • the amplitude control circuit 12 has a built-in device for quantizing the input amplitude modulation signal, and determines on / off operation states of the high-frequency power amplifiers 13-1 to 13-n according to the value of the quantized amplitude modulation signal. .
  • the high frequency power amplifiers 13-1 to 13-n controlled to be turned on by the amplitude control circuit 12 amplify the high frequency phase modulation signal including the phase modulation component of the high frequency modulation signal. At this time, among the high-frequency power amplifiers 13-1 to 13-n, the high-frequency power amplifier in the on state operates with the saturated output power controlled by the power control circuit 11.
  • the power combining circuit 14 adds up and outputs the high-frequency phase modulation signals output from the high-frequency power amplifiers 13-1 to 13-n in the on state among the high-frequency power amplifiers 13-1 to 13-n.
  • the signal output from the power combining circuit 14 is a high-frequency modulation signal having both phase modulation and amplitude modulation components.
  • the saturation output power of each of the high frequency power amplifiers 13-1 to 13-n is controlled by the power control circuit 11, and adjusted so that the average power of the output signal of the power amplifier 10 becomes a desired value. Yes.
  • the reason why the power efficiency can be improved by using the power amplifying unit 10 is that the high-frequency power amplifiers 13-1 to 13-n can take only the on state or the off state. For this reason, the high-frequency power amplifier in the operating state can always be used in the saturation operation.
  • the general high-frequency power amplifiers 13-1 to 13-n have a characteristic of operating at the highest efficiency when the output is saturated. Therefore, the output efficiency of the power amplifier shown in FIG. 4 can ideally obtain the maximum efficiency of the high-frequency power amplifiers 13-1 to 13-n.
  • the process of controlling the average power of the output signal does not enter the previous stage of the process of quantizing the amplitude modulation signal. Therefore, the power amplifier 10 can control the relationship between the average power of the output signal and the SNR of the output signal in an uncorrelated manner.
  • FIG. 5 shows the ACPR (Adjacent Channel Power Ratio) of the output signal when the power control circuit 11 and the amplitude control circuit 12 are ideally operated in the power amplifier 10 of the present embodiment.
  • FIG. 5 shows a comparison of changes in ACPR with respect to output power between the power amplifier of this embodiment and the background art circuit shown in FIG.
  • the dynamic range of the quantization device built in the amplitude control circuit 12 is always maximized by adjusting the average power of the amplitude modulation signal input to the amplitude control circuit 12 to be substantially constant.
  • the output power of the power amplifier 10 is adjusted by adjusting the saturation output of each of the high frequency power amplifiers 13-1 to 13-n by the power control circuit 11 regardless of the average power of the input signal to the amplitude control circuit 12. Therefore, as shown in FIG. 5, the ACPR of the output signal of the power amplifier becomes substantially constant regardless of the output power.
  • the amplitude modulation signal is amplified by the amplitude control circuit 12 and the plurality of high-frequency power amplifiers, and the average power of the output signal of the power amplifier 10 is adjusted by the power control circuit 11.
  • the amplitude control circuit 12 has a function of AD converting the amplitude modulation signal, and controls on / off of the high frequency power amplifier according to the quantized numerical value of the amplitude modulation signal.
  • the power control circuit 12 controls the saturated output power in the ON state of the plurality of high frequency power amplifiers according to the desired average power of the output signal.
  • the high frequency modulation signal output from the power amplifier is obtained by adding the outputs of the high frequency power amplifiers in the on state by the power combining circuit 14.
  • the average power of the output signal is not adjusted before the amplitude modulation signal is quantized by the amplitude control circuit 12.
  • the SNR of the quantized amplitude modulation signal becomes substantially constant, so that the SNR of the output signal of the power amplifier can be made substantially constant.
  • the SNR of the output signal of the power amplifier can be kept substantially constant regardless of the average power of the output signal.
  • the output power of the high-frequency power amplifiers 13-1 to 13-n may be weighted as 1: 2: 4,...: 2n, or may be the same without weighting. .
  • FIG. 6 is a block diagram showing a configuration of a radio wave transmitter using the power amplifier of the present invention.
  • the saturation output power of the high-frequency power amplifier is controlled by controlling the power supply voltage of a plurality of high-frequency power amplifiers using a voltage control circuit 111 serving as a power control circuit.
  • the other plurality of high-frequency power amplifiers, amplitude control circuits, and power combining circuits are the same as those in FIG.
  • the radio amplifier can be configured by replacing the power amplifier shown in FIG. 6 with the power amplifier shown in FIG.
  • the radio wave transmitter includes a digital baseband unit 101, a polar coordinate conversion circuit 105, and a power amplifier 110.
  • the polar coordinate conversion circuit 105 can be configured by the analog baseband unit 205, the envelope detector 215, and the limiter 217 of FIG. However, the configuration of the polar coordinate conversion circuit 105 is not limited to such a configuration, and other configurations can be adopted.
  • the power control signal output from the power control signal output terminal 202 of the digital baseband unit 201 is input to the variable gain amplifier 213, but is input to the voltage control circuit 111 in this embodiment.
  • the digital baseband unit 101 includes a power control signal output terminal 102, an I signal output terminal 103, and a Q signal output terminal 104.
  • the polar coordinate conversion circuit 105 includes an I signal input terminal 106, a Q signal input terminal 107, an amplitude modulation signal output terminal 108, and a high frequency phase modulation signal output terminal 109.
  • the power amplifier 110 includes a voltage control circuit 111, an amplitude control circuit 112, high frequency power amplifiers 113-1 to 113-n (n is a natural number of 2 or more), a power combining circuit 114, a modulation signal output terminal 115, It has.
  • the digital baseband unit 101 generates a power control signal, an I signal, and a Q signal.
  • the power control signal is output from the power control signal output terminal 102 to the power amplifier 110.
  • the I signal and the Q signal are output from the I signal output terminal 103 and the Q signal output terminal 104 to the polar coordinate conversion circuit 105, respectively.
  • the polar coordinate conversion circuit 105 receives an I signal and a Q signal from an I signal input terminal 106 and a Q signal input terminal 107, respectively.
  • the polar coordinate conversion circuit 105 generates an amplitude modulation signal and a high frequency phase modulation signal based on the input I / Q signal.
  • the high-frequency phase modulation signal is obtained by up-converting the phase modulation signal to the carrier frequency band, and the envelope is substantially constant.
  • the amplitude modulation signal and the phase modulation signal are output from the amplitude modulation signal output terminal 108 and the high frequency phase modulation signal output terminal 109 to the power amplifier 110, respectively.
  • the amplitude modulation signal input from the amplitude modulation signal output terminal 108 is input to the amplitude control circuit 112.
  • the high frequency phase modulation signal input from the high frequency phase modulation signal output terminal 109 is input to the high frequency power amplifiers 113-1 to 113-n.
  • the power control signal output from the power control signal output terminal 102 is input to the voltage control circuit 111.
  • the amplitude control circuit 112 quantizes the input amplitude modulation signal and generates a signal for controlling on / off of the high-frequency power amplifiers 113-1 to 113-n according to the value.
  • the high-frequency power amplifier in the on state amplifies the input high-frequency phase signal and outputs it to the power combining circuit 114.
  • the voltage control circuit 111 controls the power supply voltage of the high-frequency power amplifiers 113-1 to 113-n to increase or decrease the saturation output power of the individual high-frequency power amplifiers 113-1 to 113-n.
  • the power combining circuit 114 adds the high-frequency phase modulation signals output from the high-frequency power amplifiers in the on state among the high-frequency power amplifiers 113-1 to 113-n, and outputs the sum from the modulation signal output terminal 115.
  • the on / off of the high-frequency power amplifiers 113-1 to 113-n is controlled by a signal from the amplitude control circuit 112, and the sum of the output signals is adjusted so as to obtain a desired amplitude modulation. Therefore, the signal output from the modulation signal output terminal 115 is a high-frequency modulation signal having both phase modulation and amplitude modulation components.
  • the saturation output power of each of the high-frequency power amplifiers 113-1 to 113-n is controlled by the voltage control circuit 111, and the average output power of the power amplifier 110 is controlled to a desired value.
  • the processing for controlling the average power of the output signal by taking the above configuration does not enter the previous stage of the processing for quantizing the amplitude modulation signal. Therefore, the power amplifier 110 of this embodiment can control the relationship between the average power of the output signal and the SNR of the output signal in an uncorrelated manner.
  • the output power of the high-frequency power amplifiers 113-1 to 113-n may be weighted as 1: 2: 4 :,. ,both are fine.
  • FIG. 7 is a block diagram showing a radio wave transmitter using the power amplifier of the present invention.
  • the configuration of the power amplifier is different from that in FIG. That is, high-frequency current sources 313-1 to 313-n are used for amplification of the high-frequency phase modulation signal. Accordingly, a current control circuit 311 that controls the current of the high-frequency current source is used.
  • the current control circuit 311 is a power control circuit.
  • the radio wave transmitter of this embodiment includes a digital baseband unit 101 and a polar coordinate conversion circuit 105, as in FIG. A power amplifier 310 is also provided.
  • the polar coordinate conversion circuit 105 can be configured by the analog baseband unit 205, the envelope detector 215, and the limiter 217 of FIG.
  • the configuration of the polar coordinate conversion circuit 105 is not limited to such a configuration, and other configurations can be adopted.
  • the power control signal output from the power control signal output terminal 202 of the digital baseband unit 201 is input to the variable gain amplifier 213, but is input to the current control circuit 311 in this embodiment.
  • the digital baseband unit 101 includes a power control signal output terminal 102, an I signal output terminal 103, and a Q signal output terminal 104.
  • the polar coordinate conversion circuit 105 includes an I signal input terminal 106, a Q signal input terminal 107, an amplitude modulation signal output terminal 108, and a high frequency phase modulation signal output terminal 109.
  • the power amplifier 310 includes a current control circuit 311, an amplitude control circuit 312, high-frequency current sources 313-1 to 313-n (n is a natural number of 2 or more), and a modulation signal output terminal 314.
  • the digital baseband unit 101 generates a power control signal, an I signal, and a Q signal.
  • the power control signal is output from the power control signal output terminal 102 to the power amplifier 310.
  • the I signal and the Q signal are output from the I signal output terminal 103 and the Q signal output terminal 104 to the polar coordinate conversion circuit 105, respectively.
  • the polar coordinate conversion circuit 105 receives an I signal and a Q signal from an I signal input terminal 106 and a Q signal input terminal 107, respectively.
  • the polar coordinate conversion circuit 105 generates an amplitude modulation signal and a high frequency phase modulation signal based on the input I / Q signal.
  • the high-frequency phase modulation signal is obtained by up-converting the phase modulation signal to the carrier frequency band, and the envelope is substantially constant.
  • the amplitude modulation signal and the phase modulation signal are output from the amplitude modulation signal output terminal 108 and the high frequency phase modulation signal output terminal 109 to the power amplifier 310, respectively.
  • the amplitude modulation signal input from the amplitude modulation signal output terminal 108 is input to the amplitude control circuit 312.
  • the high frequency phase modulation signal input from the high frequency phase modulation signal output terminal 109 is input to the high frequency current sources 313-1 to 313-n.
  • the power control signal output from the power control signal output terminal 102 is input to the current control circuit 311.
  • the amplitude control circuit 312 quantizes the input amplitude modulation signal and generates a signal for controlling on / off of the high-frequency current sources 313-1 to 313-n according to the value.
  • the on-state high-frequency current sources 313-1 to 313-n amplify the input high-frequency phase signal and output it to the modulation signal output terminal 314.
  • the output terminals of the high-frequency current sources 313-1 to 313-n are combined into one node and then connected to the modulation signal output terminal 314.
  • the current control circuit 311 increases or decreases the saturation output current of each of the high-frequency current sources 313-1 to 313-n based on the signal from the power control signal output terminal 102.
  • the on / off of the high-frequency current sources 313-1 to 313-n is controlled by a signal from the amplitude control circuit 312, and the sum of the output signals is adjusted so as to obtain a desired amplitude modulation. Therefore, the signal output from the modulation signal output terminal 314 is a high-frequency modulation signal having both phase modulation and amplitude modulation components.
  • the saturation output currents of the individual high-frequency current sources 313-1 to 313-n are controlled by the current control circuit 311 and controlled so that the average output power of the power amplifier circuit 310 becomes a desired value. .
  • the process for controlling the average power of the output signal does not enter the previous stage of the process for quantizing the amplitude modulation signal, as in the case of FIGS. Therefore, also in this embodiment, the relationship between the average power of the output signal and the SNR of the output signal can be controlled without correlation.
  • the high-frequency current sources 313-1 to 313-n are used to amplify the high-frequency phase modulation signal. Since the current source has a high output impedance, the output synthesis can be performed only by combining the output nodes of the high-frequency current sources 313-1 to 313-n. Therefore, in the present embodiment, the power combining circuit can be configured with a wiring portion, and a portion corresponding to the power combining circuit of FIGS. 4 and 6 can be easily mounted.
  • the output power of the high-frequency power amplifiers 313-1 to 313-n can be weighted as 1: 2: 4 :,. both are fine.
  • Steps S13 to S15 show the operation of the power amplifier.
  • the digital baseband unit generates a power control signal, an I signal, and a Q signal (step S11).
  • the power control signal is input to the power control circuit 11, the voltage control circuit 111, or the current control circuit 311.
  • the polar coordinate conversion circuit 105 shown in FIGS. 6 and 7 or the polar coordinate conversion circuit constituted by the analog baseband unit 205, the envelope detector 215, and the limiter 217 shown in FIG. 1 has an amplitude based on the input I signal and Q signal.
  • a modulation signal and a high frequency phase modulation signal are generated.
  • the high frequency phase modulation signal is input to a plurality of high frequency power amplifiers (step S12).
  • the amplitude modulation signal is input to the amplitude control circuit 12, 112 or 312.
  • the amplitude control circuit 12, 112, or 312 quantizes the amplitude modulation signal and determines the on / off operation of the plurality of high-frequency power amplifiers (step S13).
  • the power control circuit 11, the voltage control circuit 111, or the current control circuit 311 controls the saturated output power of the plurality of high frequency power amplifiers based on the power control signal (step S14).
  • the power combining circuits 14 and 114 or the wiring unit serving as the power combining circuit of FIG. 7 adds up and outputs the output signals of the on-state high-frequency power amplifier (step S15).
  • step S13 and step S14 in the flowchart of FIG. 8 may be performed simultaneously, or the operation of step S13 may be performed after step S14.

Abstract

The amplifier is equipped with multiple high‑frequency power amplifiers that amplify high‑frequency phase modulated signals, an amplitude control circuit that quantizes amplitude-modulated signals from the high‑frequency-modulated signals and turns the multiple high‑frequency power amplifiers on and off based on the quantized amplitude-modulated signals, and a power control circuit that controls the saturated output power of the multiple high‑frequency power amplifiers. For example, an amplitude control circuit (12) modulates the amplitudes of high‑frequency phase modulated signals by turning the multiple high‑frequency power amplifiers on and off. A power control circuit (11) adjusts the average output power of the high‑frequency phase modulated signals by controlling the saturated output power of the high‑frequency power amplifiers in the on state.

Description

電力増幅器及びその増幅方法、それを用いた電波送信機Power amplifier, amplification method thereof, and radio wave transmitter using the same
　本発明は、電力増幅器及びその増幅方法、それを用いた電波送信機に関し、特に、入出力信号の平均電力を変化させても線形性が変化しない高効率なポーラ変調型電力増幅器に関するものである。 The present invention relates to a power amplifier, an amplification method thereof, and a radio wave transmitter using the power amplifier, and more particularly to a highly efficient polar modulation type power amplifier in which linearity does not change even when the average power of input / output signals is changed. .
　近年、携帯電話等の無線通信に採用されている変調方式は、高い周波数利用効率を有すると同時に大きなピーク電力対平均電力比(PAPR: Peak to Average Power Ratio)も有している。無線通信の分野で使用されているＡＢ級アンプを用いて振幅変調を行う信号を増幅するには、線形性を維持するために十分なバックオフをとる必要がある。 In recent years, modulation schemes adopted for wireless communication such as cellular phones have high frequency utilization efficiency and at the same time have a large peak power to average power ratio (PAPR). In order to amplify a signal subjected to amplitude modulation using a class AB amplifier used in the field of wireless communication, it is necessary to take a sufficient back-off in order to maintain linearity.
　一般的には、バックオフは少なくともＰＡＰＲと同程度必要となる。これに対して、ＡＢ級アンプの効率は出力飽和時に最大となり、バックオフが大きくなるほど低下する。このため、ＰＡＰＲの大きな高周波変調信号ほど電力増幅器の電力効率を上げることが難しくなる。 Generally, backoff is required at least as much as PAPR. On the other hand, the efficiency of the class AB amplifier is maximized when the output is saturated, and decreases as the back-off increases. For this reason, it is difficult to increase the power efficiency of the power amplifier as the high frequency modulation signal has a large PAPR.
　ＰＡＰＲの大きな高周波変調信号を高効率に増幅する電力増幅器を備えた送信機の背景技術となる例を図１に示す。図１の送信機は特許文献１に示されている電力増幅器と同じ構成のポーラ変調型電力増幅器２２１を備えている。図１の送信機はデジタルベースバンド部２０１、アナログベースバンド部２０５、電力増幅部２１４で構成されている。 FIG. 1 shows an example of background art of a transmitter including a power amplifier that amplifies a high-frequency modulated signal with a large PAPR with high efficiency. The transmitter shown in FIG. 1 includes a polar modulation type power amplifier 221 having the same configuration as that of the power amplifier disclosed in Patent Document 1. 1 includes a digital baseband unit 201, an analog baseband unit 205, and a power amplification unit 214.
　デジタルベースバンド部２０１は電力制御信号とＩ信号(Inphase Signal)とＱ信号(Quadrature Signal)の３種類の信号を、それぞれ電力制御信号出力端子２０２、I信号出力端子２０３、Ｑ信号出力端子２０４から出力する。Ｉ信号出力端子２０３から出力されたＩ信号はデジタル－アナログ（Digital-to-Analog）コンバータ（ＤＡＣ）２０６に入力され、アナログ信号に変換される。同様に、Ｑ信号出力端子２０４から出力されたＱ信号はデジタル－アナログコンバータ（ＤＡＣ）２１０に入力され、アナログ信号に変換される。 The digital baseband unit 201 receives three types of signals, that is, a power control signal, an I signal (InphaseＱSignal), and a Q signal (Quadrature Signal) from a power control signal output terminal 202, an I signal output terminal 203, and a Q signal output terminal 204, respectively. Output. The I signal output from the I signal output terminal 203 is input to a digital-to-analog converter (DAC) 206 and converted into an analog signal. Similarly, the Q signal output from the Q signal output terminal 204 is input to a digital-analog converter (DAC) 210 and converted into an analog signal.
　アナログ信号に変換されたＩ信号とＱ信号は、移相器２０９を介して供給される局部発信機２０８の出力と、それぞれミキサ２０７とミキサ２１１によって乗算される。この時、移相器２０９からミキサ２１１に供給される信号は、移相器２０９からミキサ２０７に供給される信号に対して９０°の位相遅延がある。ミキサ２０７とミキサ２１１の出力信号は加算器２１２で合算され、高周波変調信号となる。加算器２１２から出力された高周波変調信号は、可変利得増幅器２１３によって増幅され、電力増幅部２１４へ供給される。この時、可変利得増幅器２１３の利得は、電力制御信号出力端子２０２からの信号によって変化する。 The I signal and the Q signal converted into analog signals are multiplied by the output of the local transmitter 208 supplied via the phase shifter 209 and the mixer 207 and the mixer 211, respectively. At this time, the signal supplied from the phase shifter 209 to the mixer 211 has a phase delay of 90 ° with respect to the signal supplied from the phase shifter 209 to the mixer 207. The output signals of the mixer 207 and the mixer 211 are added together by an adder 212 to become a high frequency modulation signal. The high frequency modulation signal output from the adder 212 is amplified by the variable gain amplifier 213 and supplied to the power amplifier 214. At this time, the gain of the variable gain amplifier 213 changes according to the signal from the power control signal output terminal 202.
　電力増幅部２１４は、ｎ個存在する高周波電力増幅器２１８－１～２１８－ｎのうち（ｎは２以上の自然数を示す）、動作状態（オン状態）とする高周波電力増幅器の数を切り替えることで振幅変調を行う。電力増幅部２１４へ入力された高周波変調信号はリミッタ２１７と包絡線検波器２１５に入力される。リミッタ２１７は入力信号から振幅一定の高周波位相変調信号を抽出し、高周波電力増幅器２１８－１～２１８－ｎへと出力する。 The power amplifying unit 214 switches the number of high-frequency power amplifiers to be in an operating state (on state) among n high-frequency power amplifiers 218-1 to 218-n (n represents a natural number of 2 or more). Perform amplitude modulation. The high frequency modulation signal input to the power amplifier 214 is input to the limiter 217 and the envelope detector 215. The limiter 217 extracts a high-frequency phase modulation signal having a constant amplitude from the input signal, and outputs it to the high-frequency power amplifiers 218-1 to 218-n.
　包絡線検波器２１５は入力信号から振幅変調信号を抽出する。包絡線検波器２１５から出力された振幅変調信号は、振幅制御回路２１６内でＡＤ変換された後に高周波電力増幅器２１８－１～２１８－ｎの制御信号に変換される。並列に複数並べられた個々の高周波電力増幅器２１８－１～２１８－ｎは、振幅制御回路２１６からの制御信号によって動作状態になるか休眠状態（オフ状態）になるかが決められる。 Envelope detector 215 extracts an amplitude modulation signal from the input signal. The amplitude modulation signal output from the envelope detector 215 is AD converted in the amplitude control circuit 216 and then converted into control signals for the high frequency power amplifiers 218-1 to 218-n. Each of the high frequency power amplifiers 218-1 to 218-n arranged in parallel is determined by the control signal from the amplitude control circuit 216 to be in an operating state or a sleep state (off state).
　高周波電力増幅器２１８－１～２１８－ｎのうち、動作状態にある高周波電力増幅器によって増幅された高周波位相変調信号は、電力合成回路２１９によって加算処理され、出力端子２２０から出力される。従って、高周波電力増幅器２１８－１～２１８－ｎのうち、オン状態となる高周波電力増幅器が多いほど大きな振幅の出力信号が得られる。 Among the high frequency power amplifiers 218-1 to 218-n, the high frequency phase modulation signal amplified by the active high frequency power amplifier is added by the power combining circuit 219 and output from the output terminal 220. Accordingly, an output signal having a larger amplitude can be obtained as the number of high-frequency power amplifiers that are turned on among the high-frequency power amplifiers 218-1 to 218-n is increased.
　電力増幅部２１４を用いることで電力効率を上げられる理由は、高周波電力増幅器２１８－１～２１８－ｎが動作状態か休眠状態のどちらかの状態しか取らないことにある。このため、動作状態にある高周波電力増幅器を常に飽和動作で使用できる。一般的な高周波電力増幅器は出力飽和時に最高の効率で動作する特性を持つ。従って、図１に示す送信機の出力効率は、理想的には常に高周波電力増幅器２１８－１～２１８－ｎの最大効率が得られる。 The reason why the power efficiency can be increased by using the power amplifying unit 214 is that the high-frequency power amplifiers 218-1 to 218-n can take only the operating state or the sleeping state. For this reason, the high-frequency power amplifier in the operating state can always be used in the saturation operation. A general high-frequency power amplifier has a characteristic of operating at the highest efficiency when the output is saturated. Therefore, the output efficiency of the transmitter shown in FIG. 1 is ideally always the maximum efficiency of the high-frequency power amplifiers 218-1 to 218-n.
　しかしながら、図１に示す電力増幅部２１４では、出力電力が最大電力から低下するほど出力信号のＳＮＲ(Signal-to-Noise Ratio)が劣化する。これは、振幅制御回路２１６で行うＡＤ変換に起因している。振幅制御回路２１６は振幅変調信号をアナログ-デジタル変換（ＡＤ変換）によって量子化された時間離散信号に変換するため、量子化雑音が発生する。図1に示す送信機の電力増幅部２１４では、量子化雑音の強度は出力電力に依らず略一定となる。このため、出力電力が最大電力から低下するほど出力信号のＳＮＲが劣化する。 However, in the power amplifying unit 214 shown in FIG. 1, the SNR (Signal-to-NoiseNRatio) of the output signal deteriorates as the output power decreases from the maximum power. This is due to AD conversion performed by the amplitude control circuit 216. Since the amplitude control circuit 216 converts the amplitude-modulated signal into a time-discrete signal quantized by analog-digital conversion (AD conversion), quantization noise is generated. In the power amplifying unit 214 of the transmitter shown in FIG. 1, the intensity of quantization noise is substantially constant regardless of the output power. For this reason, the SNR of the output signal deteriorates as the output power decreases from the maximum power.
　図２は理想的なＡＤ変換器における入力電力と出力信号のＳＮＲの関係を示す。図２に示すように理想的なＡＤ変換器では、出力信号のＳＮＲ（ｄＢ）は、出力飽和までの範囲では入力電力（ｄＢｍ）の一次関数で表すことができる。このことは、例えば、非特許文献１や非特許文献２等に示されている。 FIG. 2 shows the relationship between the input power and the SNR of the output signal in an ideal AD converter. As shown in FIG. 2, in an ideal AD converter, the SNR (dB) of the output signal can be expressed by a linear function of the input power (dBm) in the range up to the output saturation. This is shown, for example, in Non-Patent Document 1, Non-Patent Document 2, and the like.
　以上の理由から、振幅制御回路２１６でＡＤ変換される振幅変調信号の平均電力が低くなれば、ＡＤ変換器から出力される振幅変調信号のＳＮＲは劣化してしまう。 For the above reasons, when the average power of the amplitude modulation signal AD-converted by the amplitude control circuit 216 is lowered, the SNR of the amplitude modulation signal output from the AD converter is deteriorated.
　図３は図１のポーラ変調型電力増幅器２２１の一例を示す。図３の電力増幅器は非特許文献３に示されている。図３の電力増幅器は、振幅変調信号入力４０１と、高周波位相変調信号入力４０２、４０３と、出力電力制御信号入力４０４とを備えている。また、振幅変調用トランジスタ４０５－１～４０５－２１と、２端子の電流制限スイッチ４０６－１～４０６－２１と、位相変調用トランジスタ４０７－１～４０７－６と、電力制御装置４０８と、１次側が中点タップの３端子で２次側が２端子のトランス４０９と、出力アンテナ４１０とを備えている。 FIG. 3 shows an example of the polar modulation type power amplifier 221 of FIG. The power amplifier of FIG. 3 is shown in Non-Patent Document 3. The power amplifier of FIG. 3 includes an amplitude modulation signal input 401, high frequency phase modulation signal inputs 402 and 403, and an output power control signal input 404. Also, amplitude modulation transistors 405-1 to 405-21, two-terminal current limit switches 406-1 to 406-21, phase modulation transistors 407-1 to 407-6, a power control device 408, and 1 A transformer 409 having a three-sided tap on the secondary side and a two-terminal on the secondary side, and an output antenna 410 are provided.
　振幅変調用トランジスタ４０５－１～４０５－２１のゲートは振幅変調信号入力４０１に接続され、ソースは全て接地されている。振幅変調用トランジスタ４０５－１～４０５－２１のドレインはそれぞれ２端子の電流制限スイッチ４０６－１～４０６－２１の一方の端子に接続されている。電流制限スイッチ４０６－１～４０６－７の他方の端子は位相変調用トランジスタ４０７－１及び４０７－４のソースに接続されている。 The gates of the amplitude modulation transistors 405-1 to 405-21 are connected to the amplitude modulation signal input 401, and the sources are all grounded. The drains of the amplitude modulation transistors 405-1 to 405-21 are connected to one terminals of two-terminal current limit switches 406-1 to 406-21, respectively. The other terminals of the current limit switches 406-1 to 406-7 are connected to the sources of the phase modulation transistors 407-1 and 407-4.
　同様に、電流制限スイッチ４０６－８～４０６－１４の一方の端子は位相変調用トランジスタ４０７－２及び４０７－５のソースに接続され、電流制限スイッチ４０６－１５～４０６－２１の一方の端子は位相変調用トランジスタ４０７－３及び４０７－６のソースに接続されている。位相変調用トランジスタ４０７－１～４０７－３のゲートは高周波位相変調信号入力４０２に接続され、位相変調用トランジスタ４０７－４～４０７－６のゲートは高周波位相変調信号入力４０３に接続されている。 Similarly, one terminal of each of the current limit switches 406-8 to 406-14 is connected to the sources of the phase modulation transistors 407-2 and 407-5, and one terminal of each of the current limit switches 406-15 to 406-21 is The phase modulation transistors 407-3 and 407-6 are connected to the sources. The gates of the phase modulation transistors 407-1 to 407-3 are connected to the high frequency phase modulation signal input 402, and the gates of the phase modulation transistors 407-4 to 407-6 are connected to the high frequency phase modulation signal input 403.
　位相変調用トランジスタ４０７－１～４０７－３のドレインは、トランス４０９の１次側の中点以外の２端子の片方にまとめて接続されている。位相変調用トランジスタ４０７－４～４０７－６のドレインは、トランス４０９の１次側の中点以外の残りの１端子にまとめて接続されている。トランス４０９の中点は電力制御装置４０８の出力に接続され、電力制御装置４０８の信号入力は出力電力制御信号入力４０４に接続されている。トランス４０９の2次側の２端子は片方が接地され、もう片方は出力アンテナ４１０に接続されている。 The drains of the phase modulation transistors 407-1 to 407-3 are connected together to one of the two terminals other than the midpoint on the primary side of the transformer 409. The drains of the phase modulation transistors 407-4 to 407-6 are connected together to the remaining one terminal other than the midpoint of the primary side of the transformer 409. The middle point of the transformer 409 is connected to the output of the power control device 408, and the signal input of the power control device 408 is connected to the output power control signal input 404. One of the secondary terminals of the transformer 409 is grounded, and the other is connected to the output antenna 410.
　図３の電力増幅器には振幅変調信号と高周波位相信号と出力電力制御信号の３つの信号が外部から入力される。振幅変調信号は振幅変調信号入力４０１から入力され、振幅変調用トランジスタ４０５－１～４０５－２１のゲートバイアスを制御する。高周波位相変調信号はディファレンシャル信号として２つの高周波位相変調信号入力４０２、４０３から入力され、それぞれ位相変調用トランジスタ４０７－１～４０７－３と位相変調用トランジスタ４０７－４～４０７－６のゲートを駆動する。 3 is input from the outside into the power amplifier of FIG. 3; an amplitude modulation signal, a high frequency phase signal, and an output power control signal. The amplitude modulation signal is input from the amplitude modulation signal input 401 and controls the gate bias of the amplitude modulation transistors 405-1 to 405-21. The high-frequency phase modulation signal is input as a differential signal from two high-frequency phase modulation signal inputs 402 and 403, and drives the gates of the phase modulation transistors 407-1 to 407-3 and the phase modulation transistors 407-4 to 407-6, respectively. To do.
　振幅変調用トランジスタ４０５－１～４０５－２１と位相変調用トランジスタ４０７－１～４０７－６の組み合わせの回路は、ミキサとなる回路である。従って、位相変調用トランジスタ４０７－１～４０７－６のドレインから出力される信号は、振幅変調信号と高周波位相変調信号を掛け算した高周波変調信号となる。 A combination circuit of the amplitude modulation transistors 405-1 to 405-21 and the phase modulation transistors 407-1 to 407-6 is a circuit serving as a mixer. Therefore, the signal output from the drains of the phase modulation transistors 407-1 to 407-6 is a high frequency modulation signal obtained by multiplying the amplitude modulation signal and the high frequency phase modulation signal.
　出力電力制御信号は７ビットのデジタル信号で、１ビットずつそれぞれ２端子の電流制限スイッチ４０６－１～４０６－７のオン・オフを制御する。同様に、７ビットの信号は１ビットずつそれぞれ電流制限スイッチ４０６－８～４０６－１４のオン・オフと、電流制限スイッチ４０６－１５～４０６－２１のオン・オフを制御する。同時に、７ビットの出力電力制御信号は、出力電力制御信号入力４０４から電力制御装置４０８に送られ、トランス４０９への出力電力を制御する。 The output power control signal is a 7-bit digital signal that controls on / off of the current limit switches 406-1 to 406-7, each having two terminals, one bit at a time. Similarly, the 7-bit signal controls ON / OFF of the current limit switches 406-8 to 406-14 and ON / OFF of the current limit switches 406-15 to 406-21 one bit at a time. At the same time, the 7-bit output power control signal is sent from the output power control signal input 404 to the power control device 408 to control the output power to the transformer 409.
　図３の電力増幅器では、出力信号の平均電力の制御は電流制限スイッチ４０６－１～４０６－２１のオン・オフで行う。電流制限スイッチ４０６－１～４０６－２１のうち、オン状態になる電流制限スイッチの数によってトランス４０９の１次側に出力される信号の電流値が変化し、出力アンテナ４１０から出力される信号の平均電力が制御される。 In the power amplifier of FIG. 3, the average power of the output signal is controlled by turning on / off the current limit switches 406-1 to 406-21. Of the current limit switches 406-1 to 406-21, the current value of the signal output to the primary side of the transformer 409 varies depending on the number of current limit switches that are turned on, and the signal output from the output antenna 410 Average power is controlled.
　同時に、トランス４０９の１次側に出力される信号の電流値が変化すると、トランス４０９の１次側にかかる電圧振幅の平均値が変化する。このことは、電圧振幅の平均値が小さい場合は、位相変調用トランジスタ４０７－１～４０７－６と振幅変調用トランジスタ４０５－１～４０５－２１で、大きな電力を浪費することを意味する。これに対処するため、電力制御装置４０８を使用して位相変調用トランジスタ４０７－１～４０７－６へのバイアス電圧を最小限に調整し、電力の浪費を抑えている。 At the same time, when the current value of the signal output to the primary side of the transformer 409 changes, the average value of the voltage amplitude applied to the primary side of the transformer 409 changes. This means that if the average value of the voltage amplitude is small, the phase modulation transistors 407-1 to 407-6 and the amplitude modulation transistors 405-1 to 405-21 waste a large amount of power. In order to cope with this, the power control device 408 is used to adjust the bias voltage to the phase modulation transistors 407-1 to 407-6 to the minimum, thereby suppressing the waste of power.
　上記方式を用いることにより、図３の電力増幅器では出力信号の平均電力が低下しても高い効率を維持している。また、振幅変調信号入力４０１から入力される振幅変調信号が常に一定の平均電力を持っていても、出力アンテナ４１０から出力される信号の平均電力を変えることができる。しかし、振幅変調信号入力４０１へ入力される振幅変調信号はアナログ値になっている。従って、位相変調用トランジスタ４０７－１～４０７－６は、出力する変調信号のＰＡＰＲ分のバックオフをとって動作させる必要がある。これは、ＡＢ級アンプと同じ問題であり、ＰＡＰＲの大きな信号を増幅する場合に効率を上げることは困難である。 By using the above method, the power amplifier of FIG. 3 maintains high efficiency even when the average power of the output signal is reduced. Even if the amplitude modulation signal input from the amplitude modulation signal input 401 always has a constant average power, the average power of the signal output from the output antenna 410 can be changed. However, the amplitude modulation signal input to the amplitude modulation signal input 401 is an analog value. Therefore, the phase modulation transistors 407-1 to 407-6 must be operated with a back-off corresponding to the PAPR of the modulation signal to be output. This is the same problem as the class AB amplifier, and it is difficult to increase the efficiency when a signal having a large PAPR is amplified.
特開２００５－８６６７３号公報（図１）Japanese Patent Laying-Open No. 2005-86673 (FIG. 1)
　以上のように電波送信機に用いられる電力増幅器では、出力信号の平均電力を変化させると、振幅変調信号の増幅経路においてＳＮＲが変化し、その結果、出力信号のＳＮＲが変化する。特に、電力増幅器の出力信号の平均電力が小さくなったときに出力信号のＳＮＲが劣化する傾向にある。このことから、電力増幅器においては、出力信号の平均電力に依らず出力信号のＳＮＲを略一定に保つことが課題であった。 As described above, in the power amplifier used in the radio wave transmitter, when the average power of the output signal is changed, the SNR changes in the amplification path of the amplitude modulation signal, and as a result, the SNR of the output signal changes. In particular, when the average power of the output signal of the power amplifier decreases, the SNR of the output signal tends to deteriorate. Therefore, in the power amplifier, it has been a problem to keep the SNR of the output signal substantially constant regardless of the average power of the output signal.
　そこで、本発明による典型的(exemplary)な目的は、出力信号の平均電力に依らず出力信号のＳＮＲを略一定に保つことが可能な電力増幅器及びその増幅方法、それを用いた電波送信機を提供することにある。 Therefore, an exemplary object according to the present invention is to provide a power amplifier capable of keeping the SNR of the output signal substantially constant regardless of the average power of the output signal, an amplification method thereof, and a radio wave transmitter using the power amplifier. It is to provide.
　本発明による典型的(exemplary)な電力増幅器は、高周波変調信号に含まれる当該高周波変調信号の位相変調成分が搬送波周波数帯にアップコンバートされた高周波位相変調信号を増幅する複数の高周波電力増幅器と、
　前記高周波変調信号に含まれる振幅変調成分を含む振幅変調信号を量子化し、量子化された振幅変調信号に基づいて前記複数の高周波電力増幅器のオン・オフを制御する振幅制御回路と、
　外部からの電力制御信号に基づいて前記複数の高周波電力増幅器の飽和出力電力を制御する電力制御回路と、
　前記複数の高周波電力増幅器のうちオン状態の高周波電力増幅器の出力信号を合算して出力する電力合成回路と、
を有し、
　前記振幅制御回路は、前記高周波位相変調信号の振幅変調を前記複数の高周波電力増幅器のオン・オフを切り替えることで行い、
　前記電力制御回路は、前記高周波位相変調信号の平均出力電力を前記オン状態の高周波電力増幅器の飽和出力電力を制御することで調整することを特徴とする。 An exemplary power amplifier according to the present invention includes a plurality of high-frequency power amplifiers that amplify a high-frequency phase modulation signal in which a phase modulation component of the high-frequency modulation signal included in the high-frequency modulation signal is up-converted to a carrier frequency band;
An amplitude control circuit that quantizes an amplitude modulation signal including an amplitude modulation component included in the high frequency modulation signal and controls on / off of the plurality of high frequency power amplifiers based on the quantized amplitude modulation signal;
A power control circuit for controlling saturation output power of the plurality of high-frequency power amplifiers based on an external power control signal;
A power combining circuit for adding and outputting the output signals of the on-state high-frequency power amplifier among the plurality of high-frequency power amplifiers;
Have
The amplitude control circuit performs amplitude modulation of the high-frequency phase modulation signal by switching on and off the plurality of high-frequency power amplifiers,
The power control circuit adjusts an average output power of the high-frequency phase modulation signal by controlling a saturated output power of the on-state high-frequency power amplifier.
　また、本発明による典型的(exemplary)な電力増幅器の増幅方法は、高周波変調信号に含まれる当該高周波変調信号の位相変調成分が搬送波周波数帯にアップコンバートされた高周波位相変調信号を増幅する複数の高周波電力増幅器と、
　前記高周波変調信号に含まれる振幅変調成分を含む振幅変調信号を量子化し、量子化された振幅変調信号に基づいて前記複数の高周波電力増幅器のオン・オフを制御する振幅制御回路と、
　外部からの電力制御信号に基づいて前記複数の高周波電力増幅器の飽和出力電力を制御する電力制御回路と、
　前記複数の高周波電力増幅器のうちオン状態の高周波電力増幅器の出力信号を合算して出力する電力合成回路と、
を有する電力増幅器の増幅方法であって、
　前記振幅制御回路により前記高周波位相変調信号の振幅変調を前記複数の高周波電力増幅器のオン・オフを切り替えることで行い、
前記電力制御回路により前記高周波位相変調信号の平均出力電力を前記オン状態の高周波電力増幅器の飽和出力電力を制御することで調整し、
　前記電力合成回路により前記複数の高周波電力増幅器のうちオン状態の高周波電力増幅器の出力信号を合算して出力する、
することを特徴とする。 An exemplary power amplifier amplification method according to the present invention includes a plurality of amplifying high-frequency phase modulation signals obtained by up-converting a phase modulation component of the high-frequency modulation signal included in the high-frequency modulation signal to a carrier frequency band. A high frequency power amplifier;
An amplitude control circuit that quantizes an amplitude modulation signal including an amplitude modulation component included in the high frequency modulation signal and controls on / off of the plurality of high frequency power amplifiers based on the quantized amplitude modulation signal;
A power control circuit for controlling saturation output power of the plurality of high-frequency power amplifiers based on an external power control signal;
A power combining circuit for adding and outputting the output signals of the on-state high-frequency power amplifier among the plurality of high-frequency power amplifiers;
A method for amplifying a power amplifier comprising:
The amplitude control circuit performs amplitude modulation of the high-frequency phase modulation signal by switching on and off the plurality of high-frequency power amplifiers,
Adjusting the average output power of the high-frequency phase modulation signal by controlling the saturation output power of the on-state high-frequency power amplifier by the power control circuit,
The output signal of the on-state high-frequency power amplifier among the plurality of high-frequency power amplifiers is summed and output by the power combining circuit.
It is characterized by doing.
　本発明によれば、量子化された振幅変調信号のＳＮＲを略一定にでき、電力増幅器の出力信号のＳＮＲを略一定にすることができる。そのため、電力増幅器の出力信号のＳＮＲを、出力信号の平均電力に依らず、略一定に保つことが可能となる。 According to the present invention, the SNR of the quantized amplitude modulation signal can be made substantially constant, and the SNR of the output signal of the power amplifier can be made substantially constant. Therefore, the SNR of the output signal of the power amplifier can be kept substantially constant regardless of the average power of the output signal.
背景技術のポーラ変調型高効率電力増幅器を用いた電波送信機を示すブロック図である。It is a block diagram which shows the radio wave transmitter using the polar modulation type | mold high efficiency power amplifier of background art. ＡＤ変換器のＳＮＲ特性を示す図である。It is a figure which shows the SNR characteristic of AD converter. ポーラ変調型高効率電力増幅器の背景技術となる例を示す回路図である。It is a circuit diagram which shows the example used as the background art of a polar modulation type | mold high efficiency power amplifier. 本発明に係る電力増幅器の第１の実施形態を示すブロック図である。1 is a block diagram showing a first embodiment of a power amplifier according to the present invention. 本発明の出力信号の歪特性を示す図である。It is a figure which shows the distortion characteristic of the output signal of this invention. 本発明の第２の実施形態を示すブロック図である。It is a block diagram which shows the 2nd Embodiment of this invention. 本発明の第３の実施形態を示すブロック図である。It is a block diagram which shows the 3rd Embodiment of this invention. 送信機の動作を示すフローチャートである。It is a flowchart which shows operation | movement of a transmitter.
　次に、発明を実施するための形態について図面を参照して詳細に説明する。 Next, embodiments for carrying out the invention will be described in detail with reference to the drawings.
　（第１の実施形態）
　本発明の第１の実施形態に係る電力増幅器１０の構成を図４に示す。本実施形態の電力増幅器１０は、電力制御回路１１と、振幅制御回路１２と、複数の高周波電力増幅器１３－１～１３－ｎ（ｎは２以上の自然数）と、電力合成回路１４と、を備えている。本実施形態の電力増幅器は、図１に示した電波送信機の一部として用いることができ、本実施形態の電力増幅器を用いた電波送信機を構成することができる。この場合、図１の電波送信機の電力増幅器２２１は電力増幅器１０に置き換えられ、デジタルベースバンド部２０１の電力制御信号出力端子２０２から出力される電力制御信号は電力制御回路１１へ入力される。また、包絡線検波器２１５から出力される振幅変調信号は振幅制御回路１２へ入力され、リミッタ２１７からの高周波位相変調信号は複数の高周波電力増幅器１３－１～１３－ｎへ入力される。 (First embodiment)
The configuration of the power amplifier 10 according to the first embodiment of the present invention is shown in FIG. The power amplifier 10 of this embodiment includes a power control circuit 11, an amplitude control circuit 12, a plurality of high-frequency power amplifiers 13-1 to 13-n (n is a natural number of 2 or more), and a power combining circuit 14. I have. The power amplifier of this embodiment can be used as a part of the radio wave transmitter shown in FIG. 1, and a radio wave transmitter using the power amplifier of this embodiment can be configured. In this case, the power amplifier 221 of the radio wave transmitter in FIG. 1 is replaced with the power amplifier 10, and the power control signal output from the power control signal output terminal 202 of the digital baseband unit 201 is input to the power control circuit 11. The amplitude modulation signal output from the envelope detector 215 is input to the amplitude control circuit 12, and the high frequency phase modulation signal from the limiter 217 is input to the plurality of high frequency power amplifiers 13-1 to 13-n.
　電力制御回路１１は、外部から入力される電力制御信号をもとに複数の高周波電力増幅器１３－１～１３－ｎの飽和出力電力を制御することで、電力増幅器１０の出力信号の平均電力を調整する。 The power control circuit 11 controls the saturation output power of the plurality of high-frequency power amplifiers 13-1 to 13-n based on a power control signal input from the outside, thereby reducing the average power of the output signal of the power amplifier 10. adjust.
　振幅制御回路１２は、無線通信に使用する高周波変調信号の振幅変調成分を含む振幅変調信号を入力し、高周波電力増幅器１３－１～１３－ｎのオン・オフを制御する信号に変換する。振幅制御回路１２は入力された振幅変調信号を量子化する装置を内蔵し、量子化された振幅変調信号の値によって高周波電力増幅器１３－１～１３－ｎのオン・オフの動作状態を決定する。 The amplitude control circuit 12 receives an amplitude modulation signal including the amplitude modulation component of the high frequency modulation signal used for wireless communication, and converts it into a signal for controlling on / off of the high frequency power amplifiers 13-1 to 13-n. The amplitude control circuit 12 has a built-in device for quantizing the input amplitude modulation signal, and determines on / off operation states of the high-frequency power amplifiers 13-1 to 13-n according to the value of the quantized amplitude modulation signal. .
　振幅制御回路１２によってオン状態に制御された高周波電力増幅器１３－１～１３－ｎは、高周波変調信号の位相変調成分を含む高周波位相変調信号を増幅する。この時、高周波電力増幅器１３－１～１３－ｎのうち、オン状態にある高周波電力増幅器は、電力制御回路１１によって制御された飽和出力電力で動作する。 The high frequency power amplifiers 13-1 to 13-n controlled to be turned on by the amplitude control circuit 12 amplify the high frequency phase modulation signal including the phase modulation component of the high frequency modulation signal. At this time, among the high-frequency power amplifiers 13-1 to 13-n, the high-frequency power amplifier in the on state operates with the saturated output power controlled by the power control circuit 11.
　電力合成回路１４は、高周波電力増幅器１３－１～１３－ｎのうち、オン状態にある高周波電力増幅器１３－１～１３－ｎから出力された高周波位相変調信号を合算して出力する。この時、高周波電力増幅器１３－１～１３－ｎのオン・オフは、振幅制御回路１２からの信号で制御されており、その出力信号の合計は所望の振幅変調が得られるように調整される。従って、電力合成回路１４から出力される信号は、位相変調と振幅変調の両方の成分を持つ高周波変調信号となる。同時に、個々の高周波電力増幅器１３－１～１３－ｎの飽和出力電力は、電力制御回路１１によって制御されており、電力増幅器１０の出力信号の平均電力が所望の値になるように調整されている。 The power combining circuit 14 adds up and outputs the high-frequency phase modulation signals output from the high-frequency power amplifiers 13-1 to 13-n in the on state among the high-frequency power amplifiers 13-1 to 13-n. At this time, on / off of the high-frequency power amplifiers 13-1 to 13-n is controlled by a signal from the amplitude control circuit 12, and the sum of the output signals is adjusted so as to obtain a desired amplitude modulation. . Therefore, the signal output from the power combining circuit 14 is a high-frequency modulation signal having both phase modulation and amplitude modulation components. At the same time, the saturation output power of each of the high frequency power amplifiers 13-1 to 13-n is controlled by the power control circuit 11, and adjusted so that the average power of the output signal of the power amplifier 10 becomes a desired value. Yes.
　上記電力増幅部１０を用いることで電力効率を上げられる理由は、高周波電力増幅器１３－１～１３－ｎがオン状態かオフ状態のどちらかの状態しか取らないことにある。このため、動作状態にある高周波電力増幅器を常に飽和動作で使用できる。一般的な高周波電力増幅器１３－１～１３－ｎは、出力飽和時に最高の効率で動作する特性を持つ。従って、図４に示す電力増幅器の出力効率は、理想的には高周波電力増幅器１３－１～１３－ｎの最大効率を得られる。 The reason why the power efficiency can be improved by using the power amplifying unit 10 is that the high-frequency power amplifiers 13-1 to 13-n can take only the on state or the off state. For this reason, the high-frequency power amplifier in the operating state can always be used in the saturation operation. The general high-frequency power amplifiers 13-1 to 13-n have a characteristic of operating at the highest efficiency when the output is saturated. Therefore, the output efficiency of the power amplifier shown in FIG. 4 can ideally obtain the maximum efficiency of the high-frequency power amplifiers 13-1 to 13-n.
　上記構成をとることによって、本実施形態の電力増幅器１０は、出力信号の平均電力を制御する処理が、振幅変調信号の量子化を行う処理の前段に入らない。従って、電力増幅器１０は出力信号の平均電力と出力信号のＳＮＲの関係を無相関に制御できる。 By adopting the above configuration, in the power amplifier 10 of the present embodiment, the process of controlling the average power of the output signal does not enter the previous stage of the process of quantizing the amplitude modulation signal. Therefore, the power amplifier 10 can control the relationship between the average power of the output signal and the SNR of the output signal in an uncorrelated manner.
　本実施形態の電力増幅器１０において、電力制御回路１１及び振幅制御回路１２を理想的に動作させた場合の、出力信号のＡＣＰＲ（Adjacent Channel Power Ratio）を図５に示す。図５は本実施形態の電力増幅器と図２に示した背景技術となる回路とで出力電力に対するＡＣＰＲの変化を比較して示す。 FIG. 5 shows the ACPR (Adjacent Channel Power Ratio) of the output signal when the power control circuit 11 and the amplitude control circuit 12 are ideally operated in the power amplifier 10 of the present embodiment. FIG. 5 shows a comparison of changes in ACPR with respect to output power between the power amplifier of this embodiment and the background art circuit shown in FIG.
　図２に示す背景技術の電力増幅器では、出力信号の平均電力を低下させると、出力信号のＡＣＰＲが増大していることが分かる。この原因は、出力信号の平均電力を下げようとすると、これに伴って振幅制御回路２１６への入力信号の平均電力を下げる必要が有り、結果として振幅制御回路２１６に内蔵される量子化装置（ＡＤ変換器）の出力信号のＳＮＲが低下するためである。 2 that the ACPR of the output signal increases when the average power of the output signal is reduced. This is because if the average power of the output signal is to be lowered, the average power of the input signal to the amplitude control circuit 216 needs to be lowered accordingly. As a result, the quantization device ( This is because the SNR of the output signal of the (AD converter) decreases.
　本実施形態の電力増幅器１０では、振幅制御回路１２に入力される振幅変調信号の平均電力を略一定に調整することで、振幅制御回路１２に内蔵される量子化装置のダイナミックレンジを常に最大限に利用する。電力増幅器１０の出力電力の調整は、振幅制御回路１２への入力信号の平均電力に関係なく、電力制御回路１１によって個々の高周波電力増幅器１３－１～１３－ｎの飽和出力を調整する。そのため、図５に示すように電力増幅器の出力信号のＡＣＰＲは、出力電力に関係なく略一定となる。 In the power amplifier 10 of the present embodiment, the dynamic range of the quantization device built in the amplitude control circuit 12 is always maximized by adjusting the average power of the amplitude modulation signal input to the amplitude control circuit 12 to be substantially constant. To use. The output power of the power amplifier 10 is adjusted by adjusting the saturation output of each of the high frequency power amplifiers 13-1 to 13-n by the power control circuit 11 regardless of the average power of the input signal to the amplitude control circuit 12. Therefore, as shown in FIG. 5, the ACPR of the output signal of the power amplifier becomes substantially constant regardless of the output power.
　以上のように本実施形態では、振幅変調信号の増幅は振幅制御回路１２と、複数の高周波電力増幅器とで行い、電力増幅器１０の出力信号の平均電力の調整は電力制御回路１１で行う。 As described above, in this embodiment, the amplitude modulation signal is amplified by the amplitude control circuit 12 and the plurality of high-frequency power amplifiers, and the average power of the output signal of the power amplifier 10 is adjusted by the power control circuit 11.
　振幅制御回路１２は振幅変調信号をＡＤ変換する機能を有しており、振幅変調信号の量子化された数値に応じて高周波電力増幅器のオン・オフを制御する。電力制御回路１２は出力信号の所望の平均電力に応じて複数の高周波電力増幅器のオン状態での飽和出力電力を制御する。電力増幅器から出力される高周波変調信号は、オン状態にある高周波電力増幅器の出力を電力合成回路１４で合算したものである。 The amplitude control circuit 12 has a function of AD converting the amplitude modulation signal, and controls on / off of the high frequency power amplifier according to the quantized numerical value of the amplitude modulation signal. The power control circuit 12 controls the saturated output power in the ON state of the plurality of high frequency power amplifiers according to the desired average power of the output signal. The high frequency modulation signal output from the power amplifier is obtained by adding the outputs of the high frequency power amplifiers in the on state by the power combining circuit 14.
　上記構成の電力増幅器では、振幅制御回路１２が行う振幅変調信号の量子化の前段において、出力信号の平均電力の調整は行われない。その結果、量子化された振幅変調信号のＳＮＲは略一定になるため、電力増幅器の出力信号のＳＮＲを略一定とすることができる。以上の理由により、電力増幅器の出力信号のＳＮＲを出力信号の平均電力に依らず、略一定に保つことが可能となる。 In the power amplifier having the above configuration, the average power of the output signal is not adjusted before the amplitude modulation signal is quantized by the amplitude control circuit 12. As a result, the SNR of the quantized amplitude modulation signal becomes substantially constant, so that the SNR of the output signal of the power amplifier can be made substantially constant. For the above reasons, the SNR of the output signal of the power amplifier can be kept substantially constant regardless of the average power of the output signal.
　なお、図４では、高周波電力増幅器１３－１～１３－ｎの出力電力を、１：２：４、…、：２ｎのように重み付けても、重み付けしないで全く同じにしても、どちらでも良い。 In FIG. 4, the output power of the high-frequency power amplifiers 13-1 to 13-n may be weighted as 1: 2: 4,...: 2n, or may be the same without weighting. .
　（第２の実施形態）
　図６は本発明の電力増幅器を用いた電波送信機の構成を示すブロック図である。図６では電力制御回路となる電圧制御回路１１１を用いて複数の高周波電力増幅器の電源電圧を制御することによって高周波電力増幅器の飽和出力電力を制御している。その他の複数の高周波電力増幅器、振幅制御回路、電力合成回路は図４のものと同じである。なお、図６に示す電力増幅器を図４の電力増幅器に置き換え、電波送信機を構成できることはもちろんである。 (Second Embodiment)
FIG. 6 is a block diagram showing a configuration of a radio wave transmitter using the power amplifier of the present invention. In FIG. 6, the saturation output power of the high-frequency power amplifier is controlled by controlling the power supply voltage of a plurality of high-frequency power amplifiers using a voltage control circuit 111 serving as a power control circuit. The other plurality of high-frequency power amplifiers, amplitude control circuits, and power combining circuits are the same as those in FIG. Of course, the radio amplifier can be configured by replacing the power amplifier shown in FIG. 6 with the power amplifier shown in FIG.
　電波送信機は、デジタルベースバンド部１０１と、極座標変換回路１０５と、電力増幅器１１０と、を備えている。極座標変換回路１０５は、図１のアナログベースバンド部２０５、包絡線検波器２１５、リミッタ２１７で構成することができる。しかし極座標変換回路１０５の構成はかかる構成に限定されず、他の構成をとることができる。なお、図１ではデジタルベースバンド部２０１の電力制御信号出力端子２０２から出力される電力制御信号は可変利得増幅器２１３に入力されているが、本実施形態では、電圧制御回路１１１へ入力される。 The radio wave transmitter includes a digital baseband unit 101, a polar coordinate conversion circuit 105, and a power amplifier 110. The polar coordinate conversion circuit 105 can be configured by the analog baseband unit 205, the envelope detector 215, and the limiter 217 of FIG. However, the configuration of the polar coordinate conversion circuit 105 is not limited to such a configuration, and other configurations can be adopted. In FIG. 1, the power control signal output from the power control signal output terminal 202 of the digital baseband unit 201 is input to the variable gain amplifier 213, but is input to the voltage control circuit 111 in this embodiment.
　デジタルベースバンド部１０１は、電力制御信号出力端子１０２と、Ｉ信号出力端子１０３と、Ｑ信号出力端子１０４と、を備えている。極座標変換回路１０５は、Ｉ信号入力端子１０６と、Ｑ信号入力端子１０７と、振幅変調信号出力端子１０８と、高周波位相変調信号出力端子１０９と、を備えている。電力増幅器１１０は、電圧制御回路１１１と、振幅制御回路１１２と、高周波電力増幅器１１３－１～１１３－ｎ（ｎは２以上の自然数）と、電力合成回路１１４と、変調信号出力端子１１５と、を備えている。 The digital baseband unit 101 includes a power control signal output terminal 102, an I signal output terminal 103, and a Q signal output terminal 104. The polar coordinate conversion circuit 105 includes an I signal input terminal 106, a Q signal input terminal 107, an amplitude modulation signal output terminal 108, and a high frequency phase modulation signal output terminal 109. The power amplifier 110 includes a voltage control circuit 111, an amplitude control circuit 112, high frequency power amplifiers 113-1 to 113-n (n is a natural number of 2 or more), a power combining circuit 114, a modulation signal output terminal 115, It has.
　デジタルベースバンド部１０１は、電力制御信号、Ｉ信号及びＱ信号を生成する。電力制御信号は、電力制御信号出力端子１０２から電力増幅器１１０へと出力される。Ｉ信号及びＱ信号はそれぞれＩ信号出力端子１０３及びＱ信号出力端子１０４から極座標変換回路１０５へと出力される。 The digital baseband unit 101 generates a power control signal, an I signal, and a Q signal. The power control signal is output from the power control signal output terminal 102 to the power amplifier 110. The I signal and the Q signal are output from the I signal output terminal 103 and the Q signal output terminal 104 to the polar coordinate conversion circuit 105, respectively.
　極座標変換回路１０５にはＩ信号入力端子１０６及びＱ信号入力端子１０７からそれぞれＩ信号及びＱ信号が入力される。極座標変換回路１０５は入力されたＩ／Ｑ信号を基に振幅変調信号と高周波位相変調信号を生成する。高周波位相変調信号は位相変調信号が搬送波周波数帯にアップコンバートされたものであり、包絡線が略一定となっている。振幅変調信号及び位相変調信号はそれぞれ振幅変調信号出力端子１０８及び高周波位相変調信号出力端子１０９から電力増幅器１１０へと出力される。 The polar coordinate conversion circuit 105 receives an I signal and a Q signal from an I signal input terminal 106 and a Q signal input terminal 107, respectively. The polar coordinate conversion circuit 105 generates an amplitude modulation signal and a high frequency phase modulation signal based on the input I / Q signal. The high-frequency phase modulation signal is obtained by up-converting the phase modulation signal to the carrier frequency band, and the envelope is substantially constant. The amplitude modulation signal and the phase modulation signal are output from the amplitude modulation signal output terminal 108 and the high frequency phase modulation signal output terminal 109 to the power amplifier 110, respectively.
　振幅変調信号出力端子１０８から入力された振幅変調信号は、振幅制御回路１１２へと入力される。高周波位相変調信号出力端子１０９から入力された高周波位相変調信号は、高周波電力増幅器１１３－１～１１３－ｎへと入力される。電力制御信号出力端子１０２から出力された電力制御信号は、電圧制御回路１１１へと入力される。 The amplitude modulation signal input from the amplitude modulation signal output terminal 108 is input to the amplitude control circuit 112. The high frequency phase modulation signal input from the high frequency phase modulation signal output terminal 109 is input to the high frequency power amplifiers 113-1 to 113-n. The power control signal output from the power control signal output terminal 102 is input to the voltage control circuit 111.
　振幅制御回路１１２は入力された振幅変調信号を量子化し、その値によって高周波電力増幅器１１３－１～１１３－ｎのオン・オフを制御する信号を生成する。高周波電力増幅器１１３－１～１１３－ｎのうち、オン状態の高周波電力増幅器は、入力された高周波位相信号を増幅し、電力合成回路１１４へ出力する。 The amplitude control circuit 112 quantizes the input amplitude modulation signal and generates a signal for controlling on / off of the high-frequency power amplifiers 113-1 to 113-n according to the value. Among the high-frequency power amplifiers 113-1 to 113-n, the high-frequency power amplifier in the on state amplifies the input high-frequency phase signal and outputs it to the power combining circuit 114.
　電圧制御回路１１１は高周波電力増幅器１１３－１～１１３－ｎの電源電圧を制御することで、個々の高周波電力増幅器１１３－１～１１３－ｎの飽和出力電力を増減させる。電力合成回路１１４は、高周波電力増幅器１１３－１～１１３－ｎのうち、オン状態にある高周波電力増幅器から出力された高周波位相変調信号を合算し、変調信号出力端子１１５から出力する。 The voltage control circuit 111 controls the power supply voltage of the high-frequency power amplifiers 113-1 to 113-n to increase or decrease the saturation output power of the individual high-frequency power amplifiers 113-1 to 113-n. The power combining circuit 114 adds the high-frequency phase modulation signals output from the high-frequency power amplifiers in the on state among the high-frequency power amplifiers 113-1 to 113-n, and outputs the sum from the modulation signal output terminal 115.
　高周波電力増幅器１１３－１～１１３－ｎのオン・オフは、振幅制御回路１１２からの信号で制御されており、その出力信号の合計は所望の振幅変調が得られるように調整される。従って、変調信号出力端子１１５から出力される信号は、位相変調と振幅変調の両方の成分を持つ高周波変調信号となる。同時に、個々の高周波電力増幅器１１３－１～１１３－ｎの飽和出力電力は、電圧制御回路１１１によって制御されており、電力増幅器１１０の平均出力電力が所望の値となるように制御されている。 The on / off of the high-frequency power amplifiers 113-1 to 113-n is controlled by a signal from the amplitude control circuit 112, and the sum of the output signals is adjusted so as to obtain a desired amplitude modulation. Therefore, the signal output from the modulation signal output terminal 115 is a high-frequency modulation signal having both phase modulation and amplitude modulation components. At the same time, the saturation output power of each of the high-frequency power amplifiers 113-1 to 113-n is controlled by the voltage control circuit 111, and the average output power of the power amplifier 110 is controlled to a desired value.
　本実施形態では、上記構成をとることによって出力信号の平均電力を制御する処理が振幅変調信号の量子化を行う処理の前段に入らない。従って、本実施形態の電力増幅器１１０は出力信号の平均電力と出力信号のＳＮＲの関係を無相関に制御できる。 In this embodiment, the processing for controlling the average power of the output signal by taking the above configuration does not enter the previous stage of the processing for quantizing the amplitude modulation signal. Therefore, the power amplifier 110 of this embodiment can control the relationship between the average power of the output signal and the SNR of the output signal in an uncorrelated manner.
　なお、本実施形態おいても、高周波電力増幅器１１３－１～１１３－ｎの出力電力を、１：２：４：、…、：２ｎのように重み付けても、重み付けしないで全く同じにしても、どちらでも良い。 Also in this embodiment, the output power of the high-frequency power amplifiers 113-1 to 113-n may be weighted as 1: 2: 4 :,. ,both are fine.
　（第３の実施形態）
　図７は本発明の電力増幅器を用いた電波送信機を示すブロック図である。図７では図６と同一部分には同一符号を付している。本実施形態では、電力増幅器の構成が図４と異なっている。即ち、高周波位相変調信号の増幅に高周波電流源３１３－１～３１３－ｎを使用している。それに伴い、高周波電流源の電流を制御する電流制御回路３１１を使用している。電流制御回路３１１は電力制御回路となる。 (Third embodiment)
FIG. 7 is a block diagram showing a radio wave transmitter using the power amplifier of the present invention. In FIG. 7, the same parts as those in FIG. In the present embodiment, the configuration of the power amplifier is different from that in FIG. That is, high-frequency current sources 313-1 to 313-n are used for amplification of the high-frequency phase modulation signal. Accordingly, a current control circuit 311 that controls the current of the high-frequency current source is used. The current control circuit 311 is a power control circuit.
　それ以外の構成及び動作は図４や図６と同様である。なお、電流源は出力インピーダンスが高いため、各高周波電流源３１３－１～３１３－ｎの出力ノードを１つにまとめるだけで出力合成をしている。 Other configurations and operations are the same as those in FIGS. Since the current source has a high output impedance, output synthesis is performed simply by combining the output nodes of the high-frequency current sources 313-1 to 313-n.
　図７に示すように本実施形態の電波送信機は、図６と同様にデジタルベースバンド部１０１と、極座標変換回路１０５とを備えている。また、電力増幅器３１０を備えている。極座標変換回路１０５は、図１のアナログベースバンド部２０５、包絡線検波器２１５、リミッタ２１７で構成することができる。しかし極座標変換回路１０５の構成はかかる構成に限定されず、他の構成をとることができる。なお、図１ではデジタルベースバンド部２０１の電力制御信号出力端子２０２から出力される電力制御信号は可変利得増幅器２１３に入力されているが、本実施形態では、電流制御回路３１１へ入力される。 As shown in FIG. 7, the radio wave transmitter of this embodiment includes a digital baseband unit 101 and a polar coordinate conversion circuit 105, as in FIG. A power amplifier 310 is also provided. The polar coordinate conversion circuit 105 can be configured by the analog baseband unit 205, the envelope detector 215, and the limiter 217 of FIG. However, the configuration of the polar coordinate conversion circuit 105 is not limited to such a configuration, and other configurations can be adopted. In FIG. 1, the power control signal output from the power control signal output terminal 202 of the digital baseband unit 201 is input to the variable gain amplifier 213, but is input to the current control circuit 311 in this embodiment.
　デジタルベースバンド部１０１は、電力制御信号出力端子１０２と、Ｉ信号出力端子１０３と、Ｑ信号出力端子１０４とを備えている。極座標変換回路１０５は、Ｉ信号入力端子１０６と、Ｑ信号入力端子１０７と、振幅変調信号出力端子１０８と、高周波位相変調信号出力端子１０９とを備えている。電力増幅器３１０は、電流制御回路３１１と、振幅制御回路３１２と、高周波電流源３１３－１～３１３－ｎ（ｎは２以上の自然数）と、変調信号出力端子３１４とを備えている。 The digital baseband unit 101 includes a power control signal output terminal 102, an I signal output terminal 103, and a Q signal output terminal 104. The polar coordinate conversion circuit 105 includes an I signal input terminal 106, a Q signal input terminal 107, an amplitude modulation signal output terminal 108, and a high frequency phase modulation signal output terminal 109. The power amplifier 310 includes a current control circuit 311, an amplitude control circuit 312, high-frequency current sources 313-1 to 313-n (n is a natural number of 2 or more), and a modulation signal output terminal 314.
　デジタルベースバンド部１０１は、電力制御信号、Ｉ信号及びＱ信号を生成する。電力制御信号は電力制御信号出力端子１０２から電力増幅器３１０へと出力される。Ｉ信号及びＱ信号はそれぞれＩ信号出力端子１０３及びＱ信号出力端子１０４から極座標変換回路１０５へと出力される。 The digital baseband unit 101 generates a power control signal, an I signal, and a Q signal. The power control signal is output from the power control signal output terminal 102 to the power amplifier 310. The I signal and the Q signal are output from the I signal output terminal 103 and the Q signal output terminal 104 to the polar coordinate conversion circuit 105, respectively.
　極座標変換回路１０５には、Ｉ信号入力端子１０６及びＱ信号入力端子１０７からそれぞれＩ信号及びＱ信号が入力される。極座標変換回路１０５は入力されたＩ／Ｑ信号を基に振幅変調信号と高周波位相変調信号を生成する。高周波位相変調信号は、位相変調信号が搬送波周波数帯にアップコンバートされたものであり、包絡線が略一定となっている。振幅変調信号及び位相変調信号はそれぞれ振幅変調信号出力端子１０８及び高周波位相変調信号出力端子１０９から電力増幅器３１０へと出力される。 The polar coordinate conversion circuit 105 receives an I signal and a Q signal from an I signal input terminal 106 and a Q signal input terminal 107, respectively. The polar coordinate conversion circuit 105 generates an amplitude modulation signal and a high frequency phase modulation signal based on the input I / Q signal. The high-frequency phase modulation signal is obtained by up-converting the phase modulation signal to the carrier frequency band, and the envelope is substantially constant. The amplitude modulation signal and the phase modulation signal are output from the amplitude modulation signal output terminal 108 and the high frequency phase modulation signal output terminal 109 to the power amplifier 310, respectively.
　振幅変調信号出力端子１０８から入力された振幅変調信号は、振幅制御回路３１２へと入力される。高周波位相変調信号出力端子１０９から入力された高周波位相変調信号は高周波電流源３１３－１～３１３－ｎへと入力される。電力制御信号出力端子１０２から出力された電力制御信号は、電流制御回路３１１へと入力される。 The amplitude modulation signal input from the amplitude modulation signal output terminal 108 is input to the amplitude control circuit 312. The high frequency phase modulation signal input from the high frequency phase modulation signal output terminal 109 is input to the high frequency current sources 313-1 to 313-n. The power control signal output from the power control signal output terminal 102 is input to the current control circuit 311.
　振幅制御回路３１２は、入力された振幅変調信号を量子化し、その値によって高周波電流源３１３－１～３１３－ｎのオン・オフを制御する信号を生成する。オン状態の高周波電流源３１３－１～３１３－ｎは、入力された高周波位相信号を増幅し、変調信号出力端子３１４へ出力する。 The amplitude control circuit 312 quantizes the input amplitude modulation signal and generates a signal for controlling on / off of the high-frequency current sources 313-1 to 313-n according to the value. The on-state high-frequency current sources 313-1 to 313-n amplify the input high-frequency phase signal and output it to the modulation signal output terminal 314.
　ここで、高周波電流源３１３－１～３１３－ｎの出力端子は、１つのノードにまとめてから変調信号出力端子３１４に繋げられている。電流制御回路３１１は、電力制御信号出力端子１０２からの信号をもとに個々の高周波電流源３１３－１～３１３－ｎの飽和出力電流を増減させる。 Here, the output terminals of the high-frequency current sources 313-1 to 313-n are combined into one node and then connected to the modulation signal output terminal 314. The current control circuit 311 increases or decreases the saturation output current of each of the high-frequency current sources 313-1 to 313-n based on the signal from the power control signal output terminal 102.
　高周波電流源３１３－１～３１３－ｎのオン・オフは、振幅制御回路３１２からの信号で制御されており、その出力信号の合計は所望の振幅変調が得られるように調整される。従って、変調信号出力端子３１４から出力される信号は、位相変調と振幅変調の両方の成分を持つ高周波変調信号となる。同時に、個々の高周波電流源３１３－１～３１３－ｎの飽和出力電流は、電流制御回路３１１によって制御されており、電力増幅回路３１０の平均出力電力が所望の値となるように制御されている。 The on / off of the high-frequency current sources 313-1 to 313-n is controlled by a signal from the amplitude control circuit 312, and the sum of the output signals is adjusted so as to obtain a desired amplitude modulation. Therefore, the signal output from the modulation signal output terminal 314 is a high-frequency modulation signal having both phase modulation and amplitude modulation components. At the same time, the saturation output currents of the individual high-frequency current sources 313-1 to 313-n are controlled by the current control circuit 311 and controlled so that the average output power of the power amplifier circuit 310 becomes a desired value. .
　上記構成をとることによって、図４、図６の場合と同様に出力信号の平均電力を制御する処理が振幅変調信号の量子化を行う処理の前段に入らない。従って、本実施形態においても出力信号の平均電力と出力信号のＳＮＲの関係を無相関に制御できる。 By adopting the above configuration, the process for controlling the average power of the output signal does not enter the previous stage of the process for quantizing the amplitude modulation signal, as in the case of FIGS. Therefore, also in this embodiment, the relationship between the average power of the output signal and the SNR of the output signal can be controlled without correlation.
　また、上述のように高周波位相変調信号の増幅に高周波電流源３１３－１～３１３－ｎを使用している。電流源は出力インピーダンスが高いため、各高周波電流源３１３－１～３１３－ｎ出力ノードを１つにまとめるだけで出力合成ができる。そのため、本実施形態では電力合成回路を配線部で構成でき、図４や図６の電力合成回路に相当する部分を容易に実装することができる。 Further, as described above, the high-frequency current sources 313-1 to 313-n are used to amplify the high-frequency phase modulation signal. Since the current source has a high output impedance, the output synthesis can be performed only by combining the output nodes of the high-frequency current sources 313-1 to 313-n. Therefore, in the present embodiment, the power combining circuit can be configured with a wiring portion, and a portion corresponding to the power combining circuit of FIGS. 4 and 6 can be easily mounted.
なお、本実施形態においても、高周波電力増幅器３１３－１～３１３－ｎの出力電力を、１：２：４：、…、：２ｎのように重み付けても、重み付けしないで全く同じにしても、どちらでも良い。 Also in this embodiment, the output power of the high-frequency power amplifiers 313-1 to 313-n can be weighted as 1: 2: 4 :,. both are fine.
次に、第１から第３の実施形態の送信機の動作を図８のフローチャートを用いて説明する。ステップＳ１３からステップＳ１５は電力増幅器の動作を示す。 Next, the operation of the transmitters of the first to third embodiments will be described using the flowchart of FIG. Steps S13 to S15 show the operation of the power amplifier.
図８に示すように、デジタルベースバンド部は電力制御信号、Ｉ信号、Ｑ信号を生成する（ステップＳ１１）。電力制御信号は電力制御回路１１、電圧制御回路１１１又は電流制御回路３１１に入力される。図６、図７の極座標変換回路１０５、又は図１のアナログベースバンド部２０５、包絡線検波器２１５、リミッタ２１７により構成される極座標変換回路は、入力されたＩ信号、Ｑ信号を基に振幅変調信号と高周波位相変調信号を生成する。高周波位相変調信号は複数の高周波電力増幅器に入力される（ステップＳ１２）。 As shown in FIG. 8, the digital baseband unit generates a power control signal, an I signal, and a Q signal (step S11). The power control signal is input to the power control circuit 11, the voltage control circuit 111, or the current control circuit 311. The polar coordinate conversion circuit 105 shown in FIGS. 6 and 7 or the polar coordinate conversion circuit constituted by the analog baseband unit 205, the envelope detector 215, and the limiter 217 shown in FIG. 1 has an amplitude based on the input I signal and Q signal. A modulation signal and a high frequency phase modulation signal are generated. The high frequency phase modulation signal is input to a plurality of high frequency power amplifiers (step S12).
振幅変調信号は振幅制御回路１２、１１２又は３１２に入力される。振幅制御回路１２、１１２又は３１２は、振幅変調信号を量子化し、複数の高周波電力増幅器のオン・オフの動作を決定する（ステップＳ１３）。電力制御回路１１、電圧制御回路１１１又は電流制御回路３１１は電力制御信号に基づき、複数の高周波電力増幅器の飽和出力電力を制御する（ステップＳ１４）。そして、電力合成回路１４、１１４又は図７の電力合成回路となる配線部はオン状態の高周波電力増幅器の出力信号を合算して出力する（ステップＳ１５）。 The amplitude modulation signal is input to the amplitude control circuit 12, 112 or 312. The amplitude control circuit 12, 112, or 312 quantizes the amplitude modulation signal and determines the on / off operation of the plurality of high-frequency power amplifiers (step S13). The power control circuit 11, the voltage control circuit 111, or the current control circuit 311 controls the saturated output power of the plurality of high frequency power amplifiers based on the power control signal (step S14). Then, the power combining circuits 14 and 114 or the wiring unit serving as the power combining circuit of FIG. 7 adds up and outputs the output signals of the on-state high-frequency power amplifier (step S15).
なお、図８のフローチャートのステップＳ１３とステップＳ１４の動作は同時に実行されてもよく、ステップＳ１４の後にステップＳ１３の動作が実行されてもよい。 Note that the operations of step S13 and step S14 in the flowchart of FIG. 8 may be performed simultaneously, or the operation of step S13 may be performed after step S14.
以上、本発明の代表的な実施形態について説明したが、本発明は、本願の請求の範囲によって規定される、その精神または主要な特徴から逸脱することなく、他の種々の形で実施することができる。そのため、前述した各実施形態は単なる例示にすぎず、限定的に解釈されるべきではない。本発明の範囲は特許請求の範囲によって示すものであって、明細書や要約書の記載には拘束されない。さらに、特許請求の範囲の均等範囲に属する変形や変更はすべて本発明の範囲内のものである。 While typical embodiments of the present invention have been described above, the present invention can be carried out in various other forms without departing from the spirit or main features defined by the claims of the present application. Can do. Therefore, each embodiment mentioned above is only an illustration, and should not be interpreted limitedly. The scope of the present invention is indicated by the claims, and is not restricted by the description or the abstract. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.
本願は、２００８年６月１３日に出願された特願２００８－１５５４０２号を基礎とする優先権を主張するものである。そして、特願２００８－１５５４０２号に開示された全ての内容は本願の内容に含まれる。 This application claims priority based on Japanese Patent Application No. 2008-155402 filed on Jun. 13, 2008. All contents disclosed in Japanese Patent Application No. 2008-155402 are included in the contents of the present application.
　　　　１０１　デジタルベースバンド部
　　　　１０２　電力制御信号出力端子
　　　　１０３　Ｉ信号出力端子
　　　　１０４　Ｑ信号出力端子
　　　　１０５　極座標変換回路
　　　　１０６　Ｉ信号入力端子
　　　　１０７　Ｑ信号入力端子
　　　　１０８　振幅変調信号出力端子
　　　　１０９　高周波位相変調信号出力端子
　　　　１０，１１０，３１０　電力増幅器
　　　　１１　電力制御回路
　　　　１１１　電圧制御回路
　　　　３１１　電流制御回路
　　　　１２，１１２，３１２　振幅制御回路
　　　　１３－１～１３－ｎ，１１３－１～１１３－ｎ　高周波電力増幅器
　　　　３１３－１～３１３－ｎ　高周波電流源
　　　　１４，１１４　電力合成回路
　　　　１１５、３１４　変調信号出力端子 DESCRIPTION OF SYMBOLS 101 Digital baseband part 102 Power control signal output terminal 103 I signal output terminal 104 Q signal output terminal 105 Polar coordinate transformation circuit 106 I signal input terminal 107 Q signal input terminal 108 Amplitude modulation signal output terminal 109 High frequency phase modulation signal output terminal 10, 110, 310 Power amplifier 11 Power control circuit 111 Voltage control circuit 311 Current control circuit 12, 112, 312 Amplitude control circuits 13-1 to 13-n, 113-1 to 113-n High-frequency power amplifiers 313-1 to 313-n High-frequency current source 14,114 Power combining circuit 115,314 Modulation signal output terminal

Claims (7)

  1. 高周波変調信号に含まれる当該高周波変調信号の位相変調成分が搬送波周波数帯にアップコンバートされた高周波位相変調信号を増幅する複数の高周波電力増幅器と、
    　前記高周波変調信号に含まれる振幅変調成分を含む振幅変調信号を量子化し、量子化された振幅変調信号に基づいて前記複数の高周波電力増幅器のオン・オフを制御する振幅制御回路と、
    　外部からの電力制御信号に基づいて前記複数の高周波電力増幅器の飽和出力電力を制御する電力制御回路と、
    　前記複数の高周波電力増幅器のうちオン状態の高周波電力増幅器の出力信号を合算して出力する電力合成回路と、
    を有し、
    　前記振幅制御回路は、前記高周波位相変調信号の振幅変調を前記複数の高周波電力増幅器のオン・オフを切り替えることで行い、
    　前記電力制御回路は、前記高周波位相変調信号の平均出力電力を前記オン状態の高周波電力増幅器の飽和出力電力を制御することで調整する電力増幅器。     A plurality of high-frequency power amplifiers that amplify the high-frequency phase modulation signal obtained by up-converting the phase modulation component of the high-frequency modulation signal included in the high-frequency modulation signal to a carrier frequency band;
    An amplitude control circuit that quantizes an amplitude modulation signal including an amplitude modulation component included in the high frequency modulation signal and controls on / off of the plurality of high frequency power amplifiers based on the quantized amplitude modulation signal;
    A power control circuit for controlling saturation output power of the plurality of high-frequency power amplifiers based on an external power control signal;
    A power combining circuit for adding and outputting the output signals of the on-state high-frequency power amplifier among the plurality of high-frequency power amplifiers;
    Have
    The amplitude control circuit performs amplitude modulation of the high-frequency phase modulation signal by switching on and off the plurality of high-frequency power amplifiers,
    The power control circuit adjusts an average output power of the high-frequency phase modulation signal by controlling a saturated output power of the on-state high-frequency power amplifier.
  2. 前記電力制御回路は、前記複数の高周波電力増幅器の電源電圧を制御することで前記飽和出力電力を制御することを特徴とする請求項１に記載の電力増幅器。 The power amplifier according to claim 1, wherein the power control circuit controls the saturation output power by controlling a power supply voltage of the plurality of high-frequency power amplifiers.
  3. 前記複数の高周波電力増幅器は複数の電流源で構成され、前記前記複数の電流源の飽和出力電流を制御し、前記電流源の出力ノードを１つにまとめて出力することで出力合成を行うことを特徴とする請求項１に記載の電力増幅器。 The plurality of high frequency power amplifiers are composed of a plurality of current sources, control saturation output currents of the plurality of current sources, and perform output synthesis by collectively outputting the output nodes of the current sources. The power amplifier according to claim 1.
  4. 前記複数の高周波電力増幅器の出力電力は、重み付けされていることを特徴とする請求項１乃至３のいずれか１項に記載の電力増幅器。 4. The power amplifier according to claim 1, wherein output power of the plurality of high-frequency power amplifiers is weighted. 5.
  5. 前記振幅制御回路へ入力される前記振幅変調信号の平均電力は略一定に制御されることを特徴とする請求項１乃至４のいずれか１項に記載の電力増幅器。 5. The power amplifier according to claim 1, wherein an average power of the amplitude modulation signal input to the amplitude control circuit is controlled to be substantially constant. 6.
  6. 高周波変調信号に含まれる当該高周波変調信号の位相変調成分が搬送波周波数帯にアップコンバートされた高周波位相変調信号を増幅する複数の高周波電力増幅器と、
    　前記高周波変調信号に含まれる振幅変調成分を含む振幅変調信号を量子化し、量子化された振幅変調信号に基づいて前記複数の高周波電力増幅器のオン・オフを制御する振幅制御回路と、
    　外部からの電力制御信号に基づいて前記複数の高周波電力増幅器の飽和出力電力を制御する電力制御回路と、
    　前記複数の高周波電力増幅器のうちオン状態の高周波電力増幅器の出力信号を合算して出力する電力合成回路と、
    を有する電力増幅器の増幅方法であって、
    　前記振幅制御回路により前記高周波位相変調信号の振幅変調を前記複数の高周波電力増幅器のオン・オフを切り替えることで行い、
    前記電力制御回路により前記高周波位相変調信号の平均出力電力を前記オン状態の高周波電力増幅器の飽和出力電力を制御することで調整し、
    　前記電力合成回路により前記複数の高周波電力増幅器のうちオン状態の高周波電力増幅器の出力信号を合算して出力する、
    することを特徴とする電力増幅器の増幅方法。     A plurality of high-frequency power amplifiers that amplify the high-frequency phase modulation signal obtained by up-converting the phase modulation component of the high-frequency modulation signal included in the high-frequency modulation signal to a carrier frequency band;
    An amplitude control circuit that quantizes an amplitude modulation signal including an amplitude modulation component included in the high frequency modulation signal and controls on / off of the plurality of high frequency power amplifiers based on the quantized amplitude modulation signal;
    A power control circuit for controlling saturation output power of the plurality of high-frequency power amplifiers based on an external power control signal;
    A power combining circuit for adding and outputting the output signals of the on-state high-frequency power amplifier among the plurality of high-frequency power amplifiers;
    A method for amplifying a power amplifier comprising:
    The amplitude control circuit performs amplitude modulation of the high-frequency phase modulation signal by switching on and off the plurality of high-frequency power amplifiers,
    Adjusting the average output power of the high-frequency phase modulation signal by controlling the saturation output power of the on-state high-frequency power amplifier by the power control circuit,
    The output signal of the on-state high-frequency power amplifier among the plurality of high-frequency power amplifiers is summed and output by the power combining circuit.
    A method for amplifying a power amplifier.
  7. 請求項１乃至５のいずれか１項に記載の電力増幅器を有する電波送信機であって、
    　電力制御信号、Ｉ信号及びＱ信号を生成するデジタルベースバンド回路と、前記Ｉ信号及びＱ信号に基づいて前記振幅変調信号及び前記高周波位相変調信号を生成する極座標変換回路とを有し、
    　前記電力増幅器の振幅制御回路は、前記極座標変換回路からの前記振幅変調信号に基づいて前記複数の高周波電力増幅器のオン・オフを制御し、
    　前記複数の高周波電力増幅器は、前記極座標変換回路からの前記高周波位相変調信号を増幅し、
    　前記電力制御回路は、前記デジタルベースバンド回路からの前記電力制御信号に基づいて前記複数の高周波電力増幅器の飽和出力電力を制御することを特徴とする電波送信機。
    　     A radio wave transmitter having the power amplifier according to any one of claims 1 to 5,
    A digital baseband circuit for generating a power control signal, an I signal and a Q signal, and a polar coordinate conversion circuit for generating the amplitude modulation signal and the high frequency phase modulation signal based on the I signal and the Q signal,
    The amplitude control circuit of the power amplifier controls on / off of the plurality of high frequency power amplifiers based on the amplitude modulation signal from the polar coordinate conversion circuit,
    The plurality of high frequency power amplifiers amplifies the high frequency phase modulation signal from the polar coordinate conversion circuit,
    The radio power transmitter, wherein the power control circuit controls saturation output power of the plurality of high frequency power amplifiers based on the power control signal from the digital baseband circuit.
PCT/JP2009/060695 2008-06-13 2009-06-11 Power amplifier and amplification method thereof, and radio wave transmitter using same WO2009151097A1 (en)

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