Patent Publication Number: US-10778169-B2

Title: Power amplification module

Description:
This is a continuation of U.S. patent application Ser. No. 16/116,999 filed on Aug. 30, 2018, which is a continuation of U.S. patent application Ser. No. 15/451,702, filed on Mar. 7, 2017, entitled “POWER AMPLIFICATION MODULE”, which is a division of U.S. patent application Ser. No. 15/092,395, filed on Apr. 6, 2016, entitled “POWER AMPLIFICATION MODULE”, which claims priority to Japanese Patent Application 2015-092997, filed on Apr. 30, 2015. The contents of these applications are incorporated by reference herein in their entireties. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     1. Field of the Disclosure 
     The present disclosure relates to a power amplification module. 
     2. Description of the Related Art 
     A power amplification module is used in a mobile communication device such as a cellular phone in order to amplify the power of a signal to be transmitted to a base station. In such a power amplification module, the gain may be switched in accordance with the output level in order to improve the power addition efficiency. In the power amplification circuit disclosed in Japanese Unexamined Patent Application Publication No. 2002-151982 for example, the gain of the power amplification circuit is adjusted by controlling the bias in accordance with the output level. 
     Although the gain can be adjusted by controlling the bias, the width of the adjustable range is limited. In recent years, it has been demanded that the gain be further reduced at the time of a low power output mode in power amplification modules that operate in a high power output mode or a low power output mode, and it is difficult to realize such a reduction by controlling only the bias. In addition, a configuration has been considered in which a low power output mode amplification circuit and a high power output mode amplification circuit are provided separately from each other and the signal paths are switched between using a switch in accordance with the power output mode, but the characteristics are degraded by the presence of such a switch along the signal paths. 
     BRIEF SUMMARY OF THE DISCLOSURE 
     The present disclosure was made in light of such circumstances and it is an object thereof to reduce the gain at the time of a low power output mode and prevent the degradation of the characteristics in a power amplification module that operates in a high power output mode or a low power output mode. 
     A power amplification module according to a preferred embodiment of the present disclosure includes: a first amplification circuit that amplifies a first signal and outputs the amplified first signal as a second signal; a second amplification circuit that amplifies the second signal and outputs the amplified second signal as a third signal; and a feedback circuit that re-inputs/feeds back the second signal outputted from the first amplification circuit to the first amplification circuit as the first signal. The operation of the first amplification circuit is halted and the first signal passes through the feedback circuit and is outputted as the second signal at the time of a low power output mode. 
     According to the preferred embodiment of the present disclosure, it is possible to increase the size of a gain reduction at the time of a low power output mode and suppress the degradation of the characteristics in a power amplification module that operates in a high power output mode or a low power output mode. 
     Other features, elements, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the preferred embodiments of the present disclosure with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  illustrates an example configuration of a transmission unit that includes a power amplification module according to an embodiment of the present disclosure; 
         FIG. 2  illustrates an example of the configuration of a power amplification module; 
         FIG. 3  illustrates an example of a feedback circuit; 
         FIG. 4  illustrates another example of the configuration of the power amplification module; 
         FIG. 5  illustrates another example of the configuration of the power amplification module; 
         FIG. 6  illustrates another example of the configuration of the power amplification module; 
         FIG. 7  illustrates another example of the configuration of the power amplification module; 
         FIG. 8  illustrates another example of the configuration of the power amplification module; 
         FIG. 9  illustrates another example of the configuration of the power amplification module; 
         FIG. 10  illustrates another example of the configuration of the power amplification module; 
         FIG. 11  illustrates another example of the configuration of the power amplification module; 
         FIG. 12  illustrates an example of a feedback circuit; and 
         FIG. 13  illustrates another example of the configuration of the power amplification module. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     Hereafter, an embodiment of the present disclosure will be described while referring to the drawings.  FIG. 1  illustrates an example configuration of a transmission unit that includes a power amplification module according to an embodiment of the present disclosure. A transmission unit  100  is for example used in a mobile communication device such as a cellular phone in order to transmit various signals such as speech and data to a base station. Although such a mobile communication device would also be equipped with a reception unit for receiving signals from the base station, the description of such a reception unit will be omitted here. 
     As illustrated in  FIG. 1 , the transmission unit  100  includes a modulator  110 , a power amplification module  120 , a front end unit  130  and an antenna  140 . 
     The modulator  110  modulates an input signal on the basis of a modulation scheme such as high speed uplink packet access (HSUPA) or long term evolution (LTE) and generates a radio frequency (RF) signal for performing wireless transmission. The RF signal has a frequency of around several hundred MHz to several GHz, for example. 
     The power amplification module  120  amplifies the power of the RF signal (RF IN ) outputted from the modulator  110  up to the level that is required to transmit the RF signal to the base station, and outputs the amplified signal (RF OUT ). The power amplification module  120  operates in a power output mode that corresponds to a power output mode control voltage V MODE . The power output mode may be a low power output mode (LPM) or a high power output mode (HPM), for example. 
     The front end unit  130  filters the amplified signal and switches a reception signal received from the base station. The amplified signal outputted from the front end unit  130  is transmitted to the base station via the antenna  140 . 
       FIG. 2  illustrates an example of the configuration of the power amplification module  120 . A power amplification module  120 A includes power amplification circuits PA 1 , PA 2  and PA 3 , a feedback circuit  200 , bias circuits  201 ,  202  and  203 , inductors  211 ,  212  and  213 , matching networks (MN)  221 ,  222  and  223  and a bias control circuit  230 . 
     The power amplification circuits PA 1 , PA 2  and PA 3  are circuits that amplify an RF signal and are formed of amplification transistors. The amplification transistors are for example bipolar transistors such as heterojunction bipolar transistors. The power amplification circuits PA 1 , PA 2  and PA 3  of the power amplification module  120 A form a three-stage amplification circuit. The power amplification circuit PA 1  (first amplification circuit) amplifies an input signal (first signal) and outputs the amplified signal (second signal). The power amplification circuit PA 2  (second amplification circuit) amplifies the signal from the power amplification circuit PA 1  (second signal) and outputs the amplified signal (third signal). The power amplification circuit PA 3  (third amplification circuit) amplifies the signal from the power amplification circuit PA 2  (third signal) and outputs the amplified signal (fourth signal). 
     The feedback circuit  200  forms a feedback path from the output (collector) of the power amplification circuit PA 1  to the input (base) of the power amplification circuit PA 1 . The feedback circuit  200  is provided in order to adjust (reduce) the gain of the power amplification circuit PA 1 . 
       FIG. 3  illustrates an example of the feedback circuit  200 . As illustrated in  FIG. 3 , the feedback circuit  200  can be formed of a resistor  300  and a capacitor  301  (CR feedback circuit) connected in series with each other between the output and the input of the power amplification circuit PA 1 . 
     The configuration of the feedback circuit  200  illustrated in  FIG. 3  is merely an example and the configuration of the feedback circuit  200  is not limited to this configuration. For example, the feedback circuit  200  may instead be formed of a resistor (DC feedback circuit) as described later with reference to  FIG. 12 . However, since DC feedback is performed in the case where the feedback circuit  200  is formed of a resistor, it is necessary to provide a capacitor that is comparatively large in size around the feedback point (around point X in  FIG. 3 ). Therefore, by adopting the configuration illustrated in  FIG. 3  for the feedback circuit  200 , an increase in the size of the power amplification module  120 A can be suppressed. 
     The bias circuits  201 ,  202  and  203  are circuits for supplying bias currents to the power amplification circuits PA 1 , PA 2  and PA 3  and each includes a bias circuit transistor. Specifically, in the bias circuit  201  (first bias circuit), a bias control voltage V BIAS1  is supplied to the base of the bias circuit transistor and a bias current (first bias current) that corresponds to the bias control voltage V BIAS1  is outputted from the emitter of the transistor. The bias current outputted from the bias circuit  201  is supplied to the base of the transistor that forms the power amplification circuit PA 1 . Similarly, the bias circuit  202  (second bias circuit) outputs a bias current (second bias current) that corresponds to a bias control voltage V BIAS2 . Furthermore, the bias circuit  203  (third bias circuit) outputs a bias current (third bias current) that corresponds to a bias control voltage V BIAS3 . 
     The matching networks  221 ,  222 ,  223  are circuits for matching impedances between circuits. The matching networks  221 ,  222 ,  223  are formed using capacitors and inductors, for example. 
     The bias control circuit  230  outputs the bias control voltages V BIAS1 , V BIAS2  and V BIAS3  for controlling the bias currents. The bias control voltages V BIAS1 , V BIAS2  and V BIAS3  are supplied to the bias circuits  201 ,  202  and  203 , respectively. The bias control circuit  230  controls the bias control voltages V BIAS1 , V BIAS2  and V BIAS3  on the basis of the power output mode control voltage V MODE . 
     Specifically, the following settings are made. A voltage at which a transistor forming a bias circuit is switched on is defined as a high level and a voltage lower than this level is defined as a low level. The bias control circuit  230  makes all of the bias control voltages V BIAS1 , V BIAS2  and V BIAS3  be at the high level at the time of the high power output mode. In addition, the bias control circuit  230  makes the bias control voltages V BIAS2  and V BIAS3  be at the high level and makes the bias control voltage V BIAS1  be at the low level at the time of the low power output mode. 
     An example of the operation of the power amplification module  120 A will be described. 
     In the case of the high power output mode, the bias control circuit  230  makes all of the bias control voltages V BIAS1 , V BIAS2  and V BIAS3  be at the high level. That is, the bias control circuit  230  supplies the bias currents generated by the bias circuits  201 ,  202  and  203  to the power amplification circuits PA 1 , PA 2  and PA 3 , respectively. Thus, in the power amplification module  120 A, all the power amplification circuits PA 1 , PA 2  and PA 3  operate. Thus, the RF signal (RF IN ) is amplified by a three-stage amplification circuit constituted by the power amplification circuits PA 1 , PA 2  and PA 3 . 
     In the case of the low power output mode, the bias control circuit  230  makes the bias control voltages V BIAS2  and V BIAS3  be at the high level and makes the bias control voltage V BIAS1  be at the low level. In other words, the bias control circuit  230  supplies the bias currents generated by the bias circuits  202  and  203  to the power amplification circuits PA 2  and PA 3 , respectively, and halts the supply of a bias current to the power amplification circuit PA 1 . Thus, in the power amplification module  120 A, the power amplification circuits PA 2  and PA 3  operate and the power amplification circuit PA 1  is halted. Since the power amplification circuit PA 1  is halted, the RF signal inputted to the power amplification circuit PA 1  passes through the feedback circuit  200  and is outputted to the power amplification circuit PA 2 . Therefore, the RF signal is amplified by a two-stage amplification circuit constituted by the power amplification circuits PA 2  and PA 3 . 
     Thus, in the power amplification module  120 A, the gain can be made lower in the case of the low power output mode than in the case of the high power output mode since the power amplification circuit PA 1  is halted in the low power output mode. By halting the power amplification circuit PA 1 , the size of the gain reduction achieved at the time of the low power output mode can be made larger than that achieved when the size of the bias current is controlled. In addition, in the power amplification module  120 A, since there is no switch along the path of the RF signal, the degradation of the characteristics can be suppressed. 
     In the power amplification module  120 A, it is also possible to make the size of the gain reduction even larger by halting the supply of a bias circuit to some of a plurality of parallel-connected transistors (fingers) that form the power amplification circuit PA 3  in the case of the low power output mode. The same applies to other embodiments described below. 
     In addition, in the power amplification module  120 A, a feedback circuit may be provided in the second stage and in the third stage. 
     Furthermore, although a three-stage amplification circuit has been adopted in the power amplification module  120 A, the number of the stages of the amplification circuit is not limited to three, and a two-stage amplification circuit (configuration without power amplification circuit PA 3 ) or an amplification circuit with four or more stages may be adopted. 
       FIG. 4  illustrates another example of the configuration of the power amplification module  120 . Constituent elements that are the same as those of the power amplification module  120 A illustrated in  FIG. 2  are denoted by the same symbols and the description thereof is omitted. As illustrated in  FIG. 4 , a power amplification module  120 B includes a bias control voltage generating circuit  400  and a switch  401  instead of the bias control circuit  230  of the power amplification module  120 A. 
     The bias control voltage generating circuit  400  generates a bias control voltage V BIAS  for controlling a bias current. The bias control voltage V BIAS  is supplied to the bias circuits  201 ,  202  and  203 . The bias circuits  201 ,  202  and  203  supply a bias current that corresponds to the bias control voltage V BIAS  to the power amplification circuits PA 1 , PA 2  and PA 3 , respectively. 
     The switch  401  (bias control circuit) controls the supply of the bias control voltage V BIAS  to the bias circuit  201  on the basis of the power output mode control voltage V MODE . 
     Specifically, in the case of the high power output mode, the switch  401  is turned on and the bias control voltage V BIAS  is supplied to the bias circuit  201 . In addition, in the case of the low power output mode, the switch  401  is turned off and the supply of the bias control voltage V BIAS  to the bias circuit  201  is halted. The switch  401  can be formed of a MOSFET, for example. Other switches described later can be similarly formed of a MOSFET, for example. 
     Since the details of the operation of the power amplification module  120 B are the same as those of the operation of the power amplification module  120 A, the description thereof is omitted. 
       FIG. 5  illustrates another example of the configuration of the power amplification module  120 . Constituent elements that are the same as those of the power amplification module  120 B illustrated in  FIG. 4  are denoted by the same symbols and the description thereof is omitted. As illustrated in  FIG. 5 , a power amplification module  120 C further includes switches  402  and  403  in addition to the configuration of the power amplification module  120 B. 
     The switches  401 ,  402  and  403  (bias control circuits) respectively control the supply of the bias control voltage V BIAS  to the bias circuits  201 ,  202  and  203  on the basis of power output mode control voltages V MODE1  and V MODE2 . 
     Specifically, in the case of the high power output mode, the switches  401 ,  402  and  403  are all turned on. In this case, the bias control voltage V BIAS  is supplied to the bias circuits  201 ,  202  and  203 . In addition, in the case of the low power output mode, the switch  401  is turned off and the switches  402  and  403  are turned on. In this case, the supply of the bias control voltage V BIAS  to the bias circuit  201  is halted. 
     Since the details of the operation of the power amplification module  120 C are the same as those of the operation of the power amplification module  120 A, the description thereof is omitted. 
       FIG. 6  illustrates another example of the configuration of the power amplification module  120 . Constituent elements that are the same as those of the power amplification module  120 B illustrated in  FIG. 4  are denoted by the same symbols and the description thereof is omitted. As illustrated in  FIG. 6 , in a power amplification module  120 D, the switch  401  controls the supply of a bias current outputted from the bias circuit  201  to the power amplification circuit PA 1  on the basis of the power output mode control voltage V MODE . 
     Specifically, in the case of the high power output mode, the switch  401  is turned on. In this case, a bias current is supplied to the power amplification circuits PA 1 , PA 2  and PA 3  from the bias circuits  201 ,  202  and  203 , respectively. In addition, in the case of the low power output mode, the switch  401  is turned off. In this case, the supply of the bias current to the power amplification circuit PA 1  is halted. 
     Since the details of the operation of the power amplification module  120 D are the same as those of the operation of the power amplification module  120 A, the description thereof is omitted. 
       FIG. 7  illustrates another example of the configuration of the power amplification module  120 . Constituent elements that are the same as those of the power amplification module  120 C illustrated in  FIG. 5  or the power amplification module  120 D illustrated in  FIG. 6  are denoted by the same symbols and the description thereof is omitted. 
     As illustrated in  FIG. 7 , in a power amplification module  120 E, the switches  401 ,  402  and  403  (bias control circuits) respectively control the supply of a bias current to the power amplification circuits PA 1 , PA 2  and PA 3  on the basis of the power output mode control voltages V MODE1  and V MODE2 . 
     Specifically, in the case of the high power output mode, the switches  401 ,  402  and  403  are all turned on. In this case, a bias current is supplied to all of the power amplification circuits PA 1 , PA 2  and PA 3 . In addition, in the case of the low power output mode, the switch  401  is turned off and the switches  402  and  403  are turned on. In this case, the supply of the bias current to the power amplification circuit PA 1  is halted. 
     Since the details of the operation of the power amplification module  120 E are the same as those of the operation of the power amplification module  120 A, the description thereof is omitted. 
       FIG. 8  illustrates another example of the configuration of the power amplification module  120 . Constituent elements that are the same as those of the power amplification module  120 B illustrated in  FIG. 4  are denoted by the same symbols and the description thereof is omitted. 
     As illustrated in  FIG. 8 , a power amplification module  120 F includes bias control voltage generating circuits  800  and  810  instead of the bias control voltage generating circuit  400  of the power amplification module  120 B. The bias control voltage generating circuit  800  generates a bias control voltage V BIAS1  to be supplied to the bias circuit  201 . The bias control voltage generating circuit  810  generates a bias control voltage V BIAS2  to be supplied to the bias circuits  202  and  203 . The switch  401  controls the supply of a power supply voltage V CC  to the bias control voltage generating circuit  800  on the basis of the power output mode control voltage V MODE . 
     Specifically, in the case of the high power output mode, the switch  401  is turned on. In this case, a bias current is supplied to the power amplification circuits PA 1 , PA 2  and PA 3  from the bias circuits  201 ,  202  and  203 , respectively. In addition, in the case of the low power output mode, the switch  401  is turned off. In this case, the operation of the bias control voltage generating circuit  800  is halted and the supply of the bias current to the power amplification circuit PA 1  is halted. 
     Since the details of the operation of the power amplification module  120 F are the same as those of the operation of the power amplification module  120 A, the description thereof is omitted. 
       FIG. 9  illustrates another example of the configuration of the power amplification module  120 . Constituent elements that are the same as those of the power amplification module  120 F illustrated in  FIG. 8  are denoted by the same symbols and the description thereof is omitted. 
     As illustrated in  FIG. 9 , in a power amplification module  120 G, the switch  401  controls the supply of a ground voltage to the bias control voltage generating circuit  800  on the basis of the power output mode control voltage V MODE . 
     Specifically, in the case of the high power output mode, the switch  401  is turned on. In this case, a bias current is supplied to the power amplification circuits PA 1 , PA 2  and PA 3  from the bias circuits  201 ,  202  and  203 , respectively. In addition, in the case of the low power output mode, the switch  401  is turned off. In this case, the operation of the bias control voltage generating circuit  800  is halted and the supply of the bias current to the power amplification circuit PA 1  is halted. 
     Since the details of the operation of the power amplification module  120 G are the same as those of the operation of the power amplification module  120 A, the description thereof is omitted. 
       FIG. 10  illustrates another example of the configuration of the power amplification module  120 . Constituent elements that are the same as those of the power amplification module  120 B illustrated in  FIG. 4  are denoted by the same symbols and the description thereof is omitted. 
     As illustrated in  FIG. 10 , in a power amplification module  120 H, the switch  401  controls the operation of the power amplification circuit PA 1  on the basis of the power output mode control voltage V MODE . The switch  401  is connected in series with the transistor that forms the power amplification circuit PA 1 . At the time of the high power output mode, the switch  401  is turned on and therefore the power amplification circuit PA 1  operates. On the other hand, at the time of the low power output mode, the switch  401  is turned off and therefore the operation of the power amplification circuit PA 1  is halted. Thus, the operation of the power amplification circuit PA 1  may be controlled by controlling the supply of a ground voltage or a power supply voltage, rather than by controlling the supply of a bias current. 
     Since the details of the operation of the power amplification module  120 H are the same as those of the operation of the power amplification module  120 A, the description thereof is omitted. 
       FIG. 11  illustrates another example of the configuration of the power amplification module  120 . Constituent elements that are the same as those of the power amplification module  120 A illustrated in  FIG. 2  are denoted by the same symbols and the description thereof is omitted. 
     As illustrated in  FIG. 11 , a power amplification module  120 J includes a feedback circuit  1100  instead of the feedback circuit  200  of the power amplification module  120 A. The feedback circuit  1100  (second feedback circuit) forms a feedback path from the output (collector) of the power amplification circuit PA 2  to the input (base) of the power amplification circuit PA 2 . The feedback circuit  1100  is provided in order to adjust (reduce) the gain of the power amplification circuit PA 2 . 
       FIG. 12  illustrates an example of the feedback circuit  1100 . As illustrated in  FIG. 12 , the feedback circuit  1100  can be formed of a resistor  1200  (DC feedback circuit) connected between the output and the input of the power amplification circuit PA 2 . A capacitor  1210  can be provided between the input of the power amplification circuit PA 2  and the resistor  1200 , as illustrated in  FIG. 12 . The capacitor  1210  may be the part of the matching network  221  or may be provided separate to the matching network  221 . 
     The configuration of the feedback circuit  1100  illustrated in  FIG. 12  is merely an example and the configuration of the feedback circuit  1100  is not limited to this configuration. For example, the feedback circuit  1100  can be configured as a CR feedback circuit as illustrated in  FIG. 3 . However, a DC feedback circuit is stable over a wider frequency band (particularly low frequency band) compared to a CR feedback circuit. Accordingly, by adopting the configuration illustrated in  FIG. 12  for the feedback circuit  1100 , the characteristics of the power amplification module  120 J can be improved. 
     An example of the operation of the power amplification module  120 J will be described. 
     In the case of the high power output mode, the bias control circuit  230  makes all of the bias control voltages V BIAS1 , V BIAS2  and V BIAS3  be at the high level. That is, the bias control circuit  230  supplies the bias currents generated by the bias circuits  201 ,  202  and  203  to the power amplification circuits PA 1 , PA 2  and PA 3 , respectively. Accordingly, all the power amplification circuits PA 1 , PA 2  and PA 3  operate in the power amplification module  120 J. Thus, the RF signal (RF IN ) is amplified by a three-stage amplification circuit constituted by the power amplification circuits PA 1 , PA 2  and PA 3 . 
     In the case of the low power output mode, the bias control circuit  230  makes the bias control voltages V BIAS1  and V BIAS3  be at the high level and makes the bias control voltage V BIAS2  be at the low level. In other words, the bias control circuit  230  supplies the bias currents generated by the bias circuits  201  and  203  to the power amplification circuits PA 1  and PA 3 , respectively, and halts the supply of a bias current to the power amplification circuit PA 2 . Thus, in the power amplification module  120 J, the power amplification circuits PA 1  and PA 3  operate and the power amplification circuit PA 2  is halted. Since the power amplification circuit PA 2  is halted, the RF signal inputted to the power amplification circuit PA 2  passes through the feedback circuit  1100  and is outputted to the power amplification circuit PA 3 . Therefore, the RF signal is amplified by a two-stage amplification circuit constituted by the power amplification circuits PA 1  and PA 3 . 
     Thus, in the power amplification module  120 J, the gain can be made lower in the case of the low power output mode than in the case of the high power output mode since the power amplification circuit PA 2  is halted in the low power output mode. By halting the power amplification circuit PA 2 , the size of the gain reduction achieved at the time of the low power output mode can be made larger than that achieved when the size of the bias current is controlled. In addition, in the power amplification module  120 J, since there is no switch along the path of the RF signal, the degradation of the characteristics can be suppressed. 
     Furthermore, in the power amplification module  120 J, since the operation of the first stage power amplification circuit PA 1 , which serves as the input terminal of the RF signal, is not halted at the time of the low power output mode, the input impedance seen by RF IN  does not change. Therefore, the degradation of the voltage standing wave ratio (VSWR) can be suppressed. 
     In the power amplification module  120 J, it is also possible to make the size of the gain reduction even larger by halting the supply of a bias circuit to some of a plurality of parallel-connected transistors (fingers) that form the power amplification circuit PA 3  in the case of the low power output mode, similarly to as in the power amplification module  120 A. In particular, in the power amplification module  120 J, when the operation of the second-stage power amplification circuit PA 2  is halted, the gain peak shifts toward the low-frequency side, but the input capacitance of the third-stage power amplification circuit PA 3  is reduced and the gain peak can be returned toward the high-frequency side by halting the operation of the part of the third-stage power amplification circuit PA 3 . 
     Furthermore, in the power amplification module  120 J, a feedback circuit may be provided in the first stage and in the third stage. 
     Furthermore, although a three-stage amplification circuit has been adopted in the power amplification module  120 J, the number of the stages of the amplification circuit is not limited to three, and a two-stage amplification circuit (configuration without power amplification circuit PA 3 ) or an amplification circuit with four or more stages may be adopted. In addition, the supply of a bias current can also be controlled using a switch, similarly to as in the power amplification modules  120 B to  120 G. 
       FIG. 13  illustrates another example of the configuration of the power amplification module  120 . Constituent elements that are the same as those of the power amplification module  120 A illustrated in  FIG. 2  or the power amplification module  120 J illustrated in  FIG. 11  are denoted by the same symbols and the description thereof is omitted. 
     A power amplification module  120 K includes a circuit for amplifying an RF signal (RF INH ) of a comparatively high frequency band (first frequency band) and a circuit for amplifying an RF signal (RF INL ) of a comparatively low frequency band (second frequency band). 
     In the power amplification module  120 K, the high-frequency-band RF signal (RF INH ) is amplified using a configuration that is the same as the power amplification module  120 A illustrated in  FIG. 2 . Specifically, a bias control circuit  230 H (first bias control circuit) controls bias control voltages V BIAS1 H, V BIAS2 H and V BIAS3 H on the basis of a power output mode control voltage V MODEH  such that a power amplification circuit PA 1 H (first amplification circuit), a power amplification circuit PA 2 H (second amplification circuit) and a power amplification circuit PA 3 H (third power amplification circuit) all operate in the case of the high power output mode. In addition, the bias control circuit  230 H controls the bias control voltages V BIAS1H , V BIAS2H  and V BIAS3H  on the basis of the power output mode control voltage V MODEH  such that the operation of the power amplification circuit PA 1 H is halted and the RF signal RF INH  is outputted to the power amplification circuit PA 2 H via the feedback circuit  200  (first feedback circuit) in the case of the low power output mode. 
     In the power amplification module  120 K, the low-frequency-band RF signal (RF INL ) is amplified using a configuration that is the same as the power amplification module  120 J illustrated in  FIG. 11 . Specifically, a bias control circuit  230 L (second bias control circuit) controls bias control voltages V BIAS1L , V BIAS2L  and V BIAS3L  on the basis of a power output mode control voltage V MODEL  such that a power amplification circuit PA 1 L (fourth amplification circuit), a power amplification circuit PA 2 L (fifth amplification circuit) and a power amplification circuit PA 3 L (sixth power amplification circuit) all operate in the case of the high power output mode. In addition, the bias control circuit  230 L controls the bias control voltages V BIAS1L , V BIAS2L  and V BIAS3L  on the basis of the power output mode control voltage V MODEL  such that the operation of the power amplification circuit PA 2 L is halted and an output signal of the power amplification circuit PA 1 L is outputted to the power amplification circuit PA 3 L via the feedback circuit  1100  (second feedback circuit) in the case of the low power output mode. 
     The power amplification module  120 K is provided with the high-frequency-band bias control circuit  230 H and the low-frequency-band bias control circuit  230 L, but a bias control circuit may be commonly used for both the high frequency band and the low frequency band. 
     In addition, in the power amplification module  120 K, it is also possible to make the size of the gain reduction even larger by halting the supply of a bias circuit to some of a plurality of parallel-connected transistors (fingers) that form the power amplification circuits PA 3 H and PA 3 L in the case of the low power output mode, similarly to as in the power amplification modules  120 A and  120 J. 
     In the power amplification module  120 K, the power amplification circuit that stops operating at the time of the low power output mode is the second-stage power amplification circuit PA 2 L in the low-frequency-band circuit. Therefore, since the first-stage power amplification circuit PA 1 L does not stop operating at the time of the low power output mode, the degradation of the voltage standing wave ratio can be suppressed. 
     On the other hand, the power amplification circuit that stops operating at the time of the low power output mode is the first-stage power amplification circuit PA 1 H in the high-frequency-band circuit. Although it is possible to make the power amplification circuit that stops operating at the time of the low power output mode be the second-stage power amplification circuit PA 2 H similarly to as in the low-frequency-band circuit, in this case, the gain peak would be shifted toward the low-frequency side when the operation of the power amplification circuit PA 2  is halted. The size of a change in the gain peak increases as the frequency becomes higher due to the effect of the impedance of a capacitor (Z=1/ωC) and the impedance of an inductor (Z=ωL). Consequently, by making the power amplification circuit that stops operating at the time of the low power output mode in the high-frequency-band circuit be the first-stage power amplification circuit PA 1 H rather than the second-stage power amplification circuit PA 2 H, it is possible to suppress the degradation of the characteristics. 
     Exemplary embodiments of the present disclosure have been described above. In the power amplification module  120 A, the gain can be greatly reduced at the time of the low power output mode by halting the operation of the first-stage power amplification circuit PA 1  and causing the RF signal to bypass the first-stage power amplification circuit PA 1  via the feedback circuit  200 . In addition, since there is no switch along the path of the RF signal, the degradation of the characteristics can be suppressed. The same applies to the power amplification modules  120 B to  120 G. 
     Furthermore, by configuring the feedback circuit  200  as a CR feedback circuit in the power amplification module  120 A, an increase in the size of the power amplification module  120 A can be suppressed compared to the case where the feedback circuit  200  is configured as a DC feedback circuit. This is because in the case of DC feedback, two capacitors are required to prevent a DC voltage from flowing out toward RF in  and to prevent a DC voltage from flowing out toward the first-stage power amplification circuit PA 1  and since the two capacitors need to let the RF signal pass therethrough, the capacitances of the capacitors need to be large. Consequently, compared with CR feedback, two capacitors having a large capacitance (large in size) need to be used and an increase in the size of the module occurs. In contrast, in the case of CR feedback, no DC voltage returning from the feedback circuit flows toward RF in  and therefore the DC voltage can be directly returned to RF in . In order to prevent the RF in  signal from entering the CR feedback circuit, the capacitance of the capacitor used in CR feedback needs to be made small. As a result, comparing DC feedback and CR feedback, although two capacitors are needed in both types of feedback, the size of the capacitor in the CR feedback can be reduced. It is possible to reduce the size of the power amplifier module  120 A. 
     Furthermore, in the power amplification module  120 A, the size of the gain reduction can be increased by halting the operation of some of the transistors (fingers) that form the third-stage power amplification circuit PA 3  at the time of the low power output mode. 
     In addition, in the power amplification module  120 J, the gain can be greatly reduced at the time of the low power output mode by halting the operation of the second-stage power amplification circuit PA 2  and causing the RF signal to bypass the second-stage power amplification circuit PA 2  via the feedback circuit  1100 . In addition, since there is no switch along the path of the RF signal, the degradation of the characteristics can be suppressed. Furthermore, since the power amplification circuit that is stopped at the time of the low power output mode is the second-stage power amplification circuit PA 2  rather than the first-stage power amplification circuit PA 1 , the degradation of the voltage standing wave ratio can be suppressed. 
     In addition, in the power amplification module  120 J, the feedback circuit  1100  is configured to perform DC feedback, and therefore the degradation of the characteristics can be suppressed over a wider frequency band than in the case of CR feedback. 
     Furthermore, in the power amplification module  120 A, the size of the gain reduction can be increased by halting the operation of some of the transistors (fingers) that form the third-stage power amplification circuit PA 3  at the time of the low power output mode. 
     In addition, in the power amplification module  120 K, by halting the operation of the first-stage power amplification circuit PA 1 H and causing the RF signal to bypass the first-stage power amplification circuit PA 1 H via the feedback circuit  200  at the time of the low power output mode in the high-frequency-band circuit, the same effect as in the power amplification module  120 A can be obtained. In addition, in the power amplification module  120 K, by halting the operation of the second-stage power amplification circuit PA 2 L and causing the RF signal to bypass the second-stage power amplification circuit PA 2 L via the feedback circuit  1100  at the time of the low power output mode in the low-frequency-band circuit, the same effect as in the power amplification module  120 H can be obtained. 
     In particular, in the power amplification module  120 K, by making the power amplification circuit that stops operating at the time of the low power output mode in the high-frequency-band circuit be the first-stage power amplification circuit PA 1 H rather than the second-stage power amplification circuit PA 2 H, it is possible to suppress the degradation of the characteristics. 
     The embodiments described above are for enabling easy understanding of the present disclosure and are not to be interpreted as limiting the present disclosure. The present disclosure can be modified or improved without departing from the gist of the disclosure and the equivalents to the present disclosure are also included in the present disclosure. In other words, appropriate design modifications made to the embodiments by one skilled in the art are included in the scope of the present disclosure so long as the modifications have the characteristics of the present disclosure. For example, the elements included in the embodiments and the arrangements, materials, conditions, shapes, sizes and so forth of the elements are not limited to those exemplified in the embodiments and can be appropriately modified. In addition, the elements included in the embodiments can be combined as much as technically possible and such combined elements are also included in the scope of the present disclosure so long as the combined elements have the characteristics of the present disclosure. 
     While preferred embodiments of the disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the disclosure. The scope of the disclosure, therefore, is to be determined solely by the following claims.