WO2008044276A1 - Electric power amplifying apparatus - Google Patents

Abstract

An electric power amplifying apparatus that can be applied even to a multimode terminal supporting various modulation schemes and that exhibits a high efficiency and a low distortion. In this electric power amplifying apparatus, when a baseband signal of an RF band is inputted to a coupler (101), an envelope detector (102) becomes isolated from the coupler (101) to detect envelope information of the baseband signal. A peak determining part (104) determines a peak electric power from the envelope information, while an average processing part (103) determines, from the envelope information, an average electric power within a predetermined time period. An amplifier control part (109) changes, based on the peak electric power and the average electric power, both the power supply voltage of a transistor (107) and the load impedance of the output side thereof seen from an output matching circuit (108). Further, the gain of a variable gain amplifier is adjusted, based on the average electric power, in accordance with the variation in amplification factor of the transistor (107) such that the total gain of the electric power amplifying apparatus is constant.

Description

 Specification

 Power amplifier

 Technical field

 TECHNICAL FIELD [0001] The present invention relates to a power amplifying apparatus that is applied to a mobile communication terminal and the like and amplifies an RF (Radio Frequency) signal.

 Background art

 Conventionally, in amplifiers used in mobile communication terminals that perform transmission power control, power supply voltage control and load impedance control of the amplifier are performed together as a method for realizing high efficiency with a small distortion and a wide dynamic range. A method is known (see, for example, Patent Document 1). FIG. 1 is a block diagram showing an example of a conventional power amplifier. As shown in FIG. 1, the power amplifier mainly includes an input power sensor 1, a force bra 2, a variable gain amplifier 3, an input matching circuit 4, a transistor 5, an output matching circuit 6, and a power supply circuit 7. It is composed.

 In this power amplifying apparatus, an input power sensor 1 is supplied to a variable gain amplifier 3 RF

 When the average power of the input signal in the (Radio Frequency) band is detected and determined that the average power is small, the DC voltage supplied from the power supply circuit 7 to the transistor 5 is lowered, and at the same time, the load impedance is increased. Then, a load impedance control signal is transmitted from the power supply circuit 7 to the output matching circuit 6 to perform impedance control. In this way, the amplitude of the output voltage can be increased by increasing the load impedance, and as a result, the distortion characteristics can be improved.

 [0004] On the other hand, when the input power sensor 1 determines that the average power of the input signal supplied to the variable gain amplifier 3 is large, the DC voltage supplied from the power supply circuit 7 to the transistor 5 is increased to increase the power. By reducing the load impedance, the amplitude of the output voltage can be made smaller than the breakdown voltage of the transistor 5 even at high power, and the power amplification with less distortion and high efficiency can be achieved while improving the reliability. Can be done.

Here, the reason why low distortion and high efficiency can be realized by performing power supply voltage control and load impedance control of the transistor amplifier together will be described. Figure Fig. 2 is a characteristic diagram showing the voltage-current characteristics and load characteristics of the transistor amplifier. (A) is when power supply voltage control is performed when the average power of the input signal is large, and (b) is the average power of the input signal. (C) shows the respective characteristics when power supply voltage control and load impedance control are performed when the average power of the input signal is small. In each characteristic diagram, the horizontal axis represents the drain voltage (vd) of the transistor amplifier, and the vertical axis represents the drain current (id).

[0006] As shown in Fig. 2 (a), when the power supply voltage control is performed when the average power of the input signal is large, the amplification characteristic has a good linearity as in the load line (A). However, if the power supply voltage control is performed when the average power of the input signal is small, the load characteristic is the load line (B) shown in Fig. 2 (b), so voltage (vd) -current (id) The linearity is lost in the rising region of the and the distortion characteristics deteriorate. In other words, linearity is degraded simply by controlling the power supply voltage according to the average power level of the input signal (or the output power level).

[0007] Therefore, as shown in Fig. 2 (c), when the average power of the input signal decreases, the load impedance is increased from the load line (B) to the load line (C) (that is, id-vd By reducing the slope of the characteristics, the ratio of the rising area of voltage (vd) —current (id) occupied by the load line (C) is reduced to improve linearity. In other words, the distortion characteristics can be improved and high efficiency can be realized by performing both the power supply voltage control and the load impedance control. The gain change at this time is compensated by the VGA in the driver stage.

 Patent Document 1: Japanese Unexamined Patent Publication No. 2000-174559

 Disclosure of the invention

 Problems to be solved by the invention

、たのでは、変調方式が変化した場合に歪特性が 劣化してしまうおそれがある。特に、 PAPRの異なる変調信号では歪特性の劣化は 著しくなる。さらには、ノックオフが必要となるため送信機の効率が劣化してしまうお それがある。 However, in the conventional power amplifying device described in Patent Document 1 above, it is assumed that the peak power to average power ratio (PAPR) of the input signal changes when the modulation method changes. Since the amplitude of the output voltage is generated as described above, the distortion characteristics are deteriorated. For example, even in communication using the same frequency band in a multimode terminal, PAPR differs depending on the type of communication mode, such as WCDMA, HSDPA, 3.9G. Therefore, just like the average power of the input signal as in the conventional power amplifier.

However, if the modulation method changes, the distortion characteristics may deteriorate. In particular, the distortion characteristics are significantly degraded in modulated signals with different PAPR. Furthermore, the efficiency of the transmitter may deteriorate due to the need for knockoff.

 [0009] An object of the present invention is to provide a high-efficiency and low-distortion power amplifying apparatus that can be applied even to a multimode terminal that supports various modulation schemes, and a radio transmission apparatus using the power amplifying apparatus. It is to be.

 Means for solving the problem

The power amplifying device of the present invention is a power amplifying device that amplifies the power of the RF signal, and is based on the variable gain amplifier that variably amplifies the power of the RF signal and the magnitude of the power supply voltage! / The transistor amplifies the RF signal, the impedance matching circuit for adjusting the load impedance of the RF signal, and the saturation voltage and the peak power of the transistor are equal based on the peak power of the RF signal. The power supply voltage is controlled as described above, and the load impedance of the impedance matching circuit is controlled based on the peak power of the RF signal so as to satisfy the matching condition that allows the transistor to output the maximum power, thereby obtaining the average power of the RF signal. And a control means for controlling the gain of the variable gain amplifier so that the total gain is constant.

 The invention's effect

 According to the present invention, the power supply voltage and the load impedance of the transistor are changed based on the peak power and the average power of the RF signal corresponding to the modulation mode. This allows the transistor to perform power amplification in an optimum state corresponding to each modulation mode. Therefore, even in a multi-mode portable terminal in which the modulation mode method is varied, RF signal power amplification can be performed with high efficiency and low distortion. As a result, a wireless signal with high efficiency and low distortion can be transmitted from the wireless transmission device.

 Brief Description of Drawings

 FIG. 1 is a configuration diagram showing an example of a conventional power amplification device.

 [Figure 2] Characteristic diagram showing the voltage-current characteristics and load characteristics of a transistor amplifier

[Fig. 3] Voltage and current characteristics of an amplifying transistor applied to the power amplifying device of the present invention Characteristic diagram showing load characteristics

 [Fig. 4] Characteristic diagram showing the voltage-current characteristics and load characteristics of the amplifying transistor when the modulation mode changes and the peak power of the input signal changes in the power amplifying device of the present invention. [Fig. 5] Implementation of the present invention Block diagram showing the configuration of the power amplifying device according to Embodiment 1

 FIG. 6 is a circuit diagram showing an example of a variable load impedance circuit included in the output matching circuit of the power amplification device shown in FIG.

 [Fig. 7] Characteristic diagram showing the operation of the variable load impedance circuit shown in Fig. 6.

 FIG. 8 is a block diagram showing a configuration of a power amplifying device according to Embodiment 2 of the present invention.

 FIG. 9 is a block diagram showing a configuration of a power amplifying device according to Embodiment 3 of the present invention.

 FIG. 10 is a block diagram showing a configuration of a power amplifying device according to Embodiment 4 of the present invention.

 FIG. 11 is a block diagram showing a configuration of a wireless transmission apparatus according to Embodiment 5 of the present invention.

 FIG. 12 is a block diagram showing a configuration of a radio transmission apparatus according to Embodiment 6 of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

 <Summary of the invention>

 The power amplifying device of the present invention controls the power supply voltage and load impedance of the transistor using the peak power of the RF signal that is not just the average power of the RF signal input to the power amplifying device. As a result, it is compensated that the power is amplified without generating distortion in the peak power, so that the distortion characteristics do not deteriorate. In addition, the power amplifying device of the present invention compensates for variations in the amplification factor due to power supply voltage control and load impedance control based on the average power. As a result, even if the amplification factor fluctuates, it is possible to realize transmission power with an accurate power level corresponding to the power supply voltage and the load impedance. Furthermore, the power amplifying apparatus of the present invention uses TPC (transmission power control) information as average power, and uses TPC information + PAPR (peak power to average power ratio) information as peak power. As a result, it is possible to perform amplification with low distortion and high efficiency even in a multimode terminal by preserving and maintaining the PAPR value for each modulation mode.

Here, the concept of power supply voltage control and load impedance control in an amplifying transistor applied to the power amplifying device of the present invention will be described. Fig. 3 is a characteristic diagram showing the voltage-current characteristics and load characteristics of the amplifying transistor applied to the power amplifier of the present invention. The horizontal axis represents the drain voltage (vd), and the vertical axis represents the drain current (id).

 In FIG. 3, a load line (A) indicates a current swing when the power is large, and a load line (B) indicates a current swing when the power is small. The rising region (C) of voltage (vd) -current (id) shows the region where the linearity of the amplifying transistor is lost and the distortion characteristics deteriorate. That is, by adjusting the drain voltage (vd) so that the swing of the current is just below the saturation of the amplification transistor according to the magnitude of the power, the power can be reduced even when the load line (A) is high. High-efficiency amplification can be performed while maintaining good linearity even with a small load line (B).

 FIG. 4 is a characteristic diagram showing the voltage-current characteristics and load characteristics of the amplifying transistor when the modulation mode changes and the peak power of the input signal changes in the power amplification device of the present invention. The axis represents the drain voltage (vd), and the vertical axis represents the drain current (id). The modulation mode includes a modulation scheme, the number of code multiplexes, a channel configuration, a peak suppression parameter, and the like. As shown in Fig. 4, when the peak power is large, the current swing is increased as shown in the load line (A) (that is, the slope of the load line is increased), and when the peak power is small, the load line (B) In this way, the swing of the current is reduced, that is, the load line slope is moderated.

 [0017] In this way, if the current swing is changed by controlling the magnitude of the load impedance according to the modulation mode, the rising region (C) of voltage (vd)-current (id) should be used. Therefore, good linearity can be maintained even when the power is large or small. In other words, by changing the load line according to the magnitude of peak power, highly efficient power amplification can be performed without distorting the input signal even in a multimode terminal.

[0018] That is, the power amplification device of the present invention can efficiently amplify even at low power by controlling the power supply voltage according to the magnitude of power in the basic form. In addition, by changing the load impedance according to the peak power, high efficiency can be maintained while ensuring good linearity. As a control method at this time, it is sufficient to have one power-to-power voltage correspondence table regardless of the modulation method. Further, in the power amplifying device of the present invention, the variable on the input side is changed so that the gain of the entire power amplifying device does not change by changing the load impedance that controls the load impedance according to the peak power. The gain is finely adjusted by a gain amplifier.

 Next, some specific embodiments of the power amplifying device according to the present invention will be described in detail. Note that, in the drawings used in the following embodiments, the same components are denoted by the same reference numerals, and redundant descriptions are omitted as much as possible.

 <Embodiment 1>

 First, the configuration of the power amplifying apparatus according to Embodiment 1 of the present invention will be described. FIG. 5 is a block diagram showing a configuration of the power amplifying apparatus according to Embodiment 1 of the present invention. The power amplifying device of the first embodiment shown in FIG. 5 includes a force bra 101, an envelope detector 102, an average processing unit 103, a peak detecting unit 104, a variable gain amplifier 105, an input matching circuit 106, and an amplification transistor 107. The output matching circuit 108 and the amplifier control unit 109 are provided.

 The force bra 101 has a function of inputting an RF band signal and extracting a part of the RF signal. The envelope detector 102 has a function of extracting the RF modulation wave force envelope information extracted from the force bra 101. The average processing unit 103 has a function of obtaining the average power of the RF signal from the envelope information extracted by the envelope detector 102. The peak detection unit 104 has a function of detecting peak power within a predetermined time interval by prescribing the envelope information power extracted by the envelope detector 102.

 The variable gain amplifier 105 has a function of changing the power amplification factor of the input RF signal to a desired value in accordance with the fluctuation of the amplification factor of the transistor 107. The input matching circuit 106 has a function of matching the impedance on the input side of the power amplifier. The amplifier transistor 107 has a function of changing the saturation power in accordance with the magnitude of the power supply voltage input from the amplifier control unit 109. The output matching circuit 108 includes an impedance variable circuit (not shown) and has a function of changing the load impedance based on a control signal from the amplifier control unit 109. The amplifier control unit 109 inputs the average power obtained by the average processing unit 103 and the peak power obtained by the peak detection unit 104, and the amplification factor of the variable gain amplifier 105, the power supply voltage of the transistor 107, and the load impedance. It has a function to change and.

In such a configuration, the power amplifying apparatus shown in FIG. Based on the peak power and the average power obtained by the average processing unit 103, the power supply voltage and the load impedance of the transistor 107 are changed, and further, based on the average power obtained by the average processing unit 103, The gain of the variable gain amplifier 105 can be adjusted according to the fluctuation of the amplification factor of the transistor 107 so that the total gain is constant.

Next, the operation of the power amplifying apparatus according to Embodiment 1 shown in FIG. 5 will be described. In the RF input line, a power bra 101 is provided at the input stage of the power amplifying device including the variable gain amplifier 105, the input matching circuit 106, the transistor 107, and the output matching circuit 108, and the input RF signal (hereinafter referred to as input signal). ) Is removed by force bra 101. The input signal extracted by the force bra 101 is extracted as envelope information of the RF modulated wave by the envelope detector 102 and input to the average processing unit 103 and the peak detection unit 104.

 [0025] The average processing unit 103 outputs average power from the extracted envelope information, and the peak detection unit 104 detects peak power within a predetermined time interval. The average processing unit 103 and the peak detection unit 104 may perform analog processing or digital processing for the deviation. When performing digital processing, the output of the analog envelope detector 102 may be converted into a digital signal by an AZD converter or the like as necessary. In addition, the length of the time interval specified in advance is preferably the maximum time during which the average power does not fluctuate. For example, it is desirable to use the transmission power control (TPC) control period or the time of one frame of the radio transmission signal.

 [0026] Average power output from average processing unit 103 and maximum power output from peak detection unit 104

 Both (peak power) are input to the amplifier control unit 109. Then, the amplifier control unit 109 adjusts the amplification factor of the variable gain amplifier 105 and the power supply voltage of the transistor 107 based on the input average power and peak power, and reduces the input matching circuit 106 and the output matching circuit 108. And adjust one impedance. Normally, the impedances of both the input matching circuit 106 and the output matching circuit 108 are adjusted.

An adjustment procedure by the amplifier control unit 109 at this time will be described. First, the amplifier control unit 109 calculates a peak power value Pout_peak and an average power value Pout_avg expected as an amplifier output of the transistor 107 from the input peak power value Pin_peak and average power value Pin_avg. calculate. Here, when the expected average power value Pout_avg of the output is known, the following equation (1) is established.

 Pout— peak = Pin— peak + (Pout— ave— Pin— avg) (1)

[0028] When the gain G of the amplifier of the transistor 107 is known, the average power value Pout_avg and the peak power value Pout_peak expected as the output of the amplifier of the transistor 107 are expressed by the following equations (2 ) And formula (3).

 Pout— avg = Pin— avg + G (2)

 Pout— peak = Pin— peak + G (3)

[0029] Next, when the peak power value Pout_peak expected as the output of the amplifier of the transistor 107 is equal to the maximum output power of the transistor 107, the power supply voltage is adjusted to be equal to the rated voltage of the transistor 107, and the transistor The output impedance of the output matching circuit 108 is adjusted so that the matching condition that the 107 amplifiers can output the maximum power is satisfied.

[0030] If the peak power value Pout_peak expected as the output of the amplifier of the transistor 107 is smaller than the maximum output power of the transistor 107, the power supply voltage is made lower than the rated voltage of the transistor 107, and the output matching circuit 108 Increase the output impedance. In other words, by lowering the power supply voltage and increasing the output impedance, the substantial saturation power of the transistor 107 amplifier becomes lower than the maximum output power of the transistor 107, and the input peak power value and the transistor 107 amplifier Can be made equal to the actual saturation power. In addition, since the amplifier of the transistor 107 operates near the saturated power, the transistor 107 can operate with high efficiency. Further, since the peak power becomes equal to the substantial saturation power, no distortion occurs in the peak power, so that the amplifier of the transistor 107 can be reduced in distortion.

Further, by controlling the load impedance, the gain G (= Pout_avg−Pin_avg) of the amplifier of the transistor 107 can be increased. Furthermore, the gain G of the amplifier of the transistor 107 can also be changed by changing the power supply voltage. These changes (that is, changes in gain G) adjust the amplification factor of variable gain amplifier 105 so that the expected output power can be obtained, and input appropriate power to input matching circuit 106 of transistor 107. In other words, the total gain as a power amplifying device is constant. The gain of the variable gain amplifier 105 is adjusted in accordance with the fluctuation of the amplification factor of the transistor 107.

 FIG. 6 is a circuit diagram showing an example of a load impedance variable circuit included in the output matching circuit 108 of the power amplification device shown in FIG. FIG. 7 is a characteristic diagram showing the operation of the variable load impedance circuit shown in FIG. In FIG. 7, the horizontal axis represents the load impedance adjustment terminal voltage Vz (V) shown in FIG. 6, and the vertical axis represents the load impedance Z (Ω) in view of the input side force of the load impedance variable circuit shown in FIG.

 [0033] The variable load impedance circuit shown in FIG. 6 has a configuration in which a T-type LC circuit and an isolator 110 are connected in series, and a variable capacitor C110 is formed by a parallel capacitor and a varactor diode !, The By changing the load impedance adjustment terminal voltage Vz of the variable capacitance capacitor C110 in FIG. 6 according to the control voltage of the amplifier control unit 109 in FIG. 5, the load impedance can be varied by changing the capacitance of the variable capacitance capacitor C110. it can. In other words, by controlling the load impedance adjustment terminal voltage Vz of the variable capacitance capacitor C110 in FIG. 6, for example, as shown in FIG. 7, the load impedance Z can be arbitrarily changed within the range of 50 Ω force to 150 Ω. .

 That is, in the power amplifying apparatus shown in FIG. 5, the power supply voltage of the transistor 107 and the load impedance are controlled by the peak power in a predetermined section of the envelope in the input RF signal. In addition, variations in the amplification factor of the transistor 107 are compensated by average power and peak power. At this time, the average power and peak power calculation sections are held for a certain period of time (for example, a burst section).

 <Embodiment 2>

 FIG. 8 is a block diagram showing the configuration of the power amplifying apparatus according to Embodiment 2 of the present invention. The power amplifying device according to the second embodiment shown in FIG. 8 includes a force bra 101, an envelope detector 102, an average processing unit 103, and a peak detecting unit 104 from the power amplifying device according to the first embodiment shown in FIG. The configuration is removed. That is, the power amplifying device according to the second embodiment shown in FIG. 8 includes a variable gain amplifier 105, an input matching circuit 106, a transistor 107, an output matching circuit 108, and an amplifier control unit 109a.

In such a configuration, amplifier control section 109a receives a TPC signal and a PAPR signal as input signal information, instead of having information on average power value and peak power value. A Based on the input TPC signal and PAPR signal, the amplifier control unit 109a obtains the peak power value Pout_peak and the average power value Pout_avg expected as the output of the amplifier of the transistor 107, using the following equations (4) and (5): Calculate by Other processes are the same as those in the first embodiment.

 [0037] Pout— peak = TPC value + PAPR value (4)

 Pout— avg = TPC value (5)

 That is, the average power value Pout_avg expected as the output of the transistor 107 amplifier is calculated from the TPC signal (ie, TPC command), and the peak power value expected as the output of the transistor 107 amplifier is calculated. The Pout_peak information is calculated from the TPC signal and PAPR signal.

 [0039] The PAPR value may be calculated from the PAPR signal extracted from the digital baseband signal, or may be the theoretical maximum power value for each modulation mode stored in the table. However, in the case of a fixed mode terminal, the PAPR information is held in ROM etc. inside the amplifier control unit 109a!

 In this way, when amplifier control section 109a inputs the TPC signal and PAPR signal, average power and peak power can be obtained without complicating the configuration of the analog section.

. Then, based on the average power and peak power, the power supply voltage and load impedance of the transistor 107 are changed, and the total gain of the power amplifying device is kept constant to match the fluctuation of the amplification factor of the transistor 107. Thus, the gain of the variable gain amplifier can be adjusted. This makes it possible to achieve low distortion and highly efficient amplification even in a multimode terminal.

<Embodiment 3>

FIG. 9 is a block diagram showing the configuration of the power amplifying apparatus according to Embodiment 3 of the present invention. The power amplifying device of the third embodiment shown in FIG. 9 is configured such that the power amplifying device power of the first embodiment shown in FIG. That is, the power amplifying device according to the third embodiment shown in FIG. 9 includes a force bra 101, an envelope detector 102, an average processing unit 103, a variable gain amplifier 105, an input matching circuit 106, a transistor 107, an output matching circuit 108, And an amplifier control unit 109b. That is, since the power amplifying apparatus of Embodiment 3 does not have a peak detection unit, information on peak power is not input to amplifier control unit 109b. Therefore, an external PAPR signal and average power information from the average processing unit 103 are input to the amplifier control unit 109b.

 [0043] The amplifier control unit 109b uses the average power Pin_avg input from the average processing unit 103 and the PAPR signal input from the outside, and the peak power value Pout_peak and the average power value expected as the output of the amplifier of the transistor 107 Pout_avg is calculated by the following formulas (6) and (7). Other processes are the same as those in the first embodiment.

 Pout— avg = Pin— avg + G (6)

 Pout— peak = Pin— avg + G + PAPR value (7)

[0044] In the power amplifying device of the third embodiment, the average power information is also calculated by averaging the output of the envelope detector 102 by the average processing unit 103, and the peak power information is the baseband information. Signal power Information power of calculated PAPR signal and average power value is calculated.

[0045] Note that the PAPR value may be calculated from the PAPR signal extracted from the digital baseband signal, or may be the theoretical maximum power value for each modulation mode stored in the table. However, in the case of a fixed mode terminal, the PAPR information is held in ROM etc. inside the amplifier control unit 109b! /, Or even! /.

 [0046] In the power amplifying device of Embodiment 3, since the actually observed average power is used, load impedance control can be performed with higher accuracy. Highly efficient power amplification can be performed.

 <Embodiment 4>

FIG. 10 is a block diagram showing the configuration of the power amplifying apparatus according to Embodiment 4 of the present invention. The power amplifying device in the fourth embodiment shown in FIG. 10 differs from the power amplifying device in the first embodiment shown in FIG. 5 in that the average processing unit 103 and the peak detecting unit 104 are not present. The PAPR calculation unit 112 is provided and the TPC signal is input to the amplifier control unit 109c. That is, the power amplifying device of the fourth embodiment shown in FIG. 10 includes a force bra 101, an envelope detector 102, a PAPR calculation unit 112, a variable gain amplifier 105, an input matching circuit 106, The configuration includes a transistor 107, an output matching circuit 108, and an amplifier control unit 109c.

 That is, a force bra 101 is provided on the RF input side, a part of the input RF signal is taken out, and the envelope detector 102 detects the envelope of the RF signal. Then, from the result information obtained by detecting the envelope, the PAPR calculation unit 112 obtains PAPR (peak power to average power ratio). The PAPR obtained by the PAPR calculation unit 112 is used as PAPR information for the amplifier control unit 109c. On the other hand, a TPC signal is extracted from the outside (baseband part) and input to the amplifier control part 109c. Other processes are the same as those in the second embodiment.

 [0049] According to the power amplifying apparatus of the fourth embodiment, since the actually observed PAPR is used, the power of the transistor 107 is more accurately detected without being affected by the difference between the digital and analog PAPR. Voltage and load impedance can be controlled. In addition, even if the input baseband section (not shown) is in multimode, low distortion and high-efficiency amplification can be achieved even in multimode without changing the configuration of the analog section. .

 <Embodiment 5>

 In the fifth embodiment, a radio transmission apparatus provided with the power amplification apparatus of the second embodiment will be described. FIG. 11 is a block diagram showing the configuration of the radio transmitting apparatus according to Embodiment 5 of the present invention. This radio transmission apparatus includes a modulation unit 121, a modulation mode control unit 122, a DZA conversion unit 123, a frequency conversion unit 124, and a PAPR measurement in addition to the amplifier unit 113 constituting the power amplification device of the second embodiment shown in FIG. Unit 125, PAPR delay unit 126, transmission power control unit 127, and TPC delay unit 128. That is, the wireless transmission device in FIG. 11 shows the overall configuration including the baseband unit of the multimode terminal and the power amplification device.

[0051] Modulation section 121 has a function of generating a digital baseband signal (modulation signal) with a transmission data power. The modulation mode control unit 122 has a function of instructing the modulation unit 121 to switch to a desired modulation mode. For example, the modulation mode control unit 122 can instruct switching to a modulation scheme, the number of multiplexed codes, a channel configuration, a peak suppression parameter, and the like. The DZA converter 123 is a digital base unit generated by the modulator 121. A function to convert a baseband signal into an analog baseband signal is provided. The frequency converter 124 has a function of converting an analog baseband signal into an RF band signal.

 [0052] PAPR measurement section 125 has a function of measuring a PAPR value, which is a ratio of the average power and peak power of a digital baseband signal, and inputting it to PAPR delay section 126. The PAPR delay unit 126 includes a PAPR signal input from the PAPR measurement unit 125 to the amplifier control unit 109a of the amplifier unit 113, and the variable gain amplifier 105 of the amplifier unit 113 via the DZA conversion unit 123 via the frequency conversion unit 124. It has a function to adjust the delay time difference with the RF signal input to. The transmission power control unit 127 has a function of generating a TPC signal including average power information of the RF signal and inputting it to the TPC delay unit 128. The TPC delay unit 128 is a variable gain amplifier of the amplifier unit 113 via the TPC signal input from the transmission power control unit 127 to the amplifier control unit 109a of the amplifier unit 113 and the frequency conversion unit 124 from the Ό / Α conversion unit 123. It has a function to adjust the delay time difference with the RF signal input to 105.

 Next, the operation of the radio transmitting apparatus according to Embodiment 5 shown in FIG. 11 will be described.

 When the transmission data is received by the modulation unit 121, the transmission data is modulated into a desired mode by the modulation unit 121 based on an instruction from the modulation mode control unit 122, and is converted into a digital baseband signal from the modulation unit 121. Is output. The digital baseband signal output from modulation section 121 is distributed and input to PAPR measurement section 125 and DZA conversion section 123.

 The digital baseband signal input to the PAPR measurement unit 125 is measured by a PAPR measurement unit 125 for a PAPR value that is a ratio of average power to peak power. Then, the PAPR signal corresponding to the PAPR value is input to the PAPR delay unit 126, the delay time difference from the RF signal input to the variable gain amplifier 105 of the amplifier unit 113 is adjusted, and input to the amplifier control unit 109a. .

[0055] On the other hand, the digital baseband signal input to the DZ A converter 123 is converted into an analog baseband signal, and the analog baseband signal is further converted into an RF signal by the frequency converter 124 to be amplified. Input to variable gain amplifier 105 of unit 113. The TPC signal output from the transmission power control unit 127 is input to the TPC delay unit 128. The delay time difference from the RF signal input to the variable gain amplifier 105 of the amplifier 113 is adjusted and input to the amplifier controller 109a.

 In this way, the PAPR signal and the TPC signal are modulated by the PAPR delay unit 126 and the TPC delay unit 128 in the digital unit and the analog unit including the modulation unit 121, the DZA conversion unit 123, and the frequency conversion unit 124. The signal is delayed by the delay time received, and input to the amplifier controller 109a at a timing synchronized with the modulation signal. The RF output that is the output of the amplifier unit 113 is transmitted as a radio signal to an antenna (not shown). Note that the operation of the amplifier unit 113 that receives the RF signal, the PAPR signal, and the TPC signal of the multi-mode terminal power is the same as the operation described in the second embodiment, and therefore, a duplicate description is omitted.

 With such a configuration, the operation of modulation section 121 is changed to a desired mode by switching WCDMA, HSDPA, or the like by modulation mode control section 122. At this time, even if the PAPR of the modulation signal changes, the PAPR measurement unit 125 measures the PAPR of the modulation signal each time, and transmits the PAPR signal together with the TPC signal from the transmission power control unit 127 to the amplifier control unit 109a. Even if the modulation mode changes, wireless signals can be transmitted with high efficiency without degrading the distortion characteristics.

 <Embodiment 6>

 FIG. 12 is a block diagram showing the configuration of the radio transmitting apparatus according to Embodiment 6 of the present invention. The wireless transmission device of Embodiment 6 shown in FIG. 12 is different from the wireless transmission device of Embodiment 5 shown in FIG. 11 in that the PAPR value for each modulation mode is stored instead of the PAPR measurement unit 125. The table 129 is provided. That is, the mode signal output from the modulation mode control unit 122 is input to the PAPR table 129, and the PAPR value for each modulation mode stored in advance is selected from the PAPR table 129 corresponding to the mode signal. Then, the PAPR signal corresponding to the selected PAPR value is input to amplifier control section 109 after delay adjustment by PAPR delay section 126a. Subsequent operations are the same as those described in the second embodiment, and a duplicate description is omitted.

That is, in the wireless transmission device of the sixth embodiment, the PAPR value is referred to PAPR table 129 based on the mode information transmitted by modulation mode control unit 122 that does not directly measure the PAPR value. Looking for. Then, the PAPR signal corresponding to the PAPR value is The signal is input to the amplifier control unit 109a of the amplifier unit 113 together with the PC signal. As a result, even when the modulation mode changes, it is possible to transmit a radio signal with high efficiency without degrading the distortion characteristics. The operation after amplifier 113 is the same as that of the fifth embodiment.

[0060] <Summary>

 That is, the power amplifying device of the present invention performs load impedance control and power supply voltage control of the transistor 107 using average power and peak power. At this time, the average power is used to compensate for variations in the gain of the transistor 107, and the peak power is used to optimize the magnitude of the output voltage swing of the transistor 107! /.

 [0061] As information used for controlling the power supply voltage and load impedance of the transistor 107, the instantaneous power of the RF signal is detected by the envelope detector 102, and this is averaged by the average processing unit 103 and the peak detection unit 104. The extracted information is divided into power and peak power. Instead of using the envelope detector 102, the average power and peak power may be obtained directly using the average power sensor and peak power sensor. Furthermore, TPC information and PAPR information may be acquired by performing PAPR detection at the analog stage, or by performing PAPR detection at the digital stage. It is also possible to have a PAPR table for each modulation mode that does not directly detect PAPR information, and obtain PAPR information corresponding to the modulation mode from the PAPR table.

 [0062] As a control method for the power amplifying device, a control method for determining the magnitude of the load impedance corresponding to the magnitude of the peak power, and an increase / decrease in the load impedance based on the difference in PAPR from the basic mode. There is a way to control.

 Industrial applicability

[0063] According to the power amplification device and the wireless transmission device of the present invention, high efficiency and low distortion can be realized by performing power supply voltage control and load impedance control corresponding to the modulation mode. It can be effectively used for multi-mode portable terminals.

Claims

The scope of the claims  [1] A power amplification device for amplifying the power of an RF signal,  A variable gain amplifier that variably amplifies the power of the RF signal;  A transistor for amplifying the RF signal based on the magnitude of the power supply voltage;  An impedance matching circuit for adjusting a load impedance of the RF signal; and, based on a peak power of the RF signal, the power supply voltage is controlled so that a saturation voltage of the transistor is equal to the peak power, and the RF signal Based on the peak power, the load impedance of the impedance matching circuit is controlled so that the transistor has a matching condition that can output the maximum power, and the total gain is constant based on the average power of the RF signal. And a control means for controlling the gain of the variable gain amplifier so that [2] Mean power calculating means for calculating an average power of the RF signal;  The power amplifying apparatus according to claim 1, further comprising: a peak power calculating unit that detects a peak power of the RF signal.  3. The power amplifying apparatus according to claim 1, wherein the control means obtains peak power and average power of the RF signal based on a transmission power value and a peak power to average power ratio.  [4] comprising an average power calculation means for calculating an average power of the RF signal,  The power amplifying apparatus according to claim 1, wherein the control means obtains a peak power of the RF signal based on the average power and a peak power to average power ratio.  5. The power amplifying apparatus according to claim 3, further comprising a peak power to average power ratio calculating means for calculating a peak power to average power ratio of the RF signal.