Power amplifier circuit, power amplifier module

Abstract

The present invention comprises: a first distributor that distributes input signals into first input signals and second input signals; an amplification circuit that includes a pair of amplifiers electrically connected in parallel, amplifies the first input signals and outputs output signals to an output terminal; a control amplifier that amplifies the second input signals and outputs, to the amplification circuit, control signals that control the load impedance of the amplification circuit; and a first impedance matching unit that includes a transmission line transformer electrically connected in series between the amplification circuit and the control amplifier.

Description

[Technical field]

[0001] The present disclosure relates to a power amplifier circuit and a power amplifier module. [Background technology]

[0002] 2. Description of the Related Art There is known a load modulated balanced amplifier (LMBA) that includes a main amplifier including a pair of amplifiers and a control amplifier that controls the load impedance of the main amplifier (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Pat. No. 10,404,224 Summary of the Invention [Problem to be solved by the invention]

[0004] The LMBA described in Patent Document 1 has a configuration assuming a 50Ω termination for base stations. Since this LMBA assumes a 50Ω termination, no impedance matching circuit is provided. However, in this configuration, a large difference occurs between the maximum output voltages of the main amplifier and the control amplifier at the coupler end where the output signal of the main amplifier and the output signal of the control amplifier are combined (see FIG. 10). That is, in order to improve the output efficiency of this LMBA, it is necessary to provide an impedance matching circuit between the control amplifier and the main amplifier to increase the output voltage of the control amplifier. However, providing such an impedance matching circuit in the LMBA causes a problem that the bandwidth of the LMBA becomes narrower.

[0005] Therefore, an object of the present disclosure is to provide a power amplifier circuit having characteristics that enable a wider bandwidth and improved output efficiency. [Means for solving the problem]

[0006] A power amplifier circuit according to one aspect of the present invention includes a first divider that divides an input signal into a first input signal and a second input signal, an amplifier circuit including a pair of amplifiers electrically connected in parallel, amplifying the first input signal and outputting an output signal to an output terminal, a control amplifier that amplifies the second input signal and outputs a control signal to the amplifier circuit for controlling a load impedance of the amplifier circuit, and a first impedance matching unit including a transmission line transformer electrically connected in series between the amplifier circuit and the control amplifier. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a power amplifier circuit having characteristics capable of widening a band and improving output efficiency. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a diagram illustrating a configuration example of a power amplification module. [Diagram 2] FIG. 1 is a diagram showing an example of the structure of a parallel plate coupler that is a combiner. [Diagram 3] FIG. 1 is a diagram showing an example of the structure of a λ / 4 line coupler that is a combiner. [Figure 4] FIG. 1 is a diagram illustrating an example of the structure of a branch-line coupler that is a combiner. [Diagram 5] FIG. 1 is a diagram showing an example of the structure of a lumped constant coupler that is a combiner. [Figure 6] FIG. 1 is a diagram illustrating an example of the configuration of a communication device incorporating a power amplification module. [Figure 7] FIG. 13 is a diagram illustrating an example of a current input to a combiner. [Figure 8] 13 is a graph showing an example of the relationship between input power and efficiency of a power amplifier module according to a modified example. [Figure 9] 13 is a graph showing an example of the relationship between input power and efficiency of a power amplifier module according to a modified example. [Figure 10]1 is a graph showing an example of the relationship between input power and output power of the LMBA according to Patent Document 1. [Figure 11] FIG. 1 is a diagram illustrating an example of a configuration of a power amplifier module according to a comparative example. [Figure 12] FIG. 13 is a diagram illustrating a configuration example of a power amplification module according to a second modified example. [Figure 13] 1 is a graph showing frequency characteristics of a parallel plate coupler. [Figure 14] 13 is a graph showing the relationship between the phase of a signal input to a control amplifier and the phase of a signal input to a second amplifier in a power amplification module in a second modified example. [Figure 15] FIG. 13 is a diagram showing a modified example of a power amplifier module according to a second modified example. [Figure 16] FIG. 13 is a diagram illustrating a configuration example of a power amplification module according to a third modified example. [Figure 17] 13 is a graph showing the relationship between the phase of the signal output from the control amplifier and the phase of the signal output from the second amplifier in the combiner in the third modification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, each embodiment of the present disclosure will be described with reference to the drawings. Hereinafter, the same reference numerals denote the same circuit elements, and duplicated descriptions will be omitted.

[0010] ===Configuration of the power amplifier module 100 according to this embodiment=== The configuration of the power amplifier module 100 will be described with reference to FIG. 1. FIG. 1 is a diagram showing an outline of the configuration of the power amplifier module 100. The power amplifier module 100 is mounted on a mobile communication device such as a mobile phone, for example, amplifies the power of an input signal RFin to a level required for transmitting the power to a base station or a terminal, and outputs the amplified signal RFout. The input signal RFin is a radio frequency (RF) signal modulated according to a predetermined communication method by, for example, an RFIC (Radio Frequency Integrated Circuit) or the like. The communication standard of the input signal RFin includes, for example, 2G (second generation mobile communication system), 3G (third generation mobile communication system), 4G (fourth generation mobile communication system), 5G (fifth generation mobile communication system), LTE (Long Term Evolution)-FDD (Frequency Division Duplex), LTE-TDD (Time Division Duplex), LTE-Advanced, or LTE-Advanced Pro, and the frequency is, for example, about several hundred MHz to several tens of GHz. Note that the communication standard and frequency of the input signal RFin are not limited to these.

[0011] The power amplifier module 100 includes, for example, a drive amplifier 110, a first distributor 120, a balanced amplifier circuit 130, a control amplifier 140, an impedance matching section 150, and an impedance matching section 160.

[0012] The components of the power amplifier module 100 will now be described.

[0013] The drive amplifier 110 amplifies, for example, an input radio frequency RF signal (hereinafter referred to as an "input signal RFin") and outputs an amplified signal (hereinafter referred to as a "signal RF1"). The frequency of the signal RFin is, for example, about several GHz. The drive amplifier 110 is configured with, but is not limited to, a bipolar transistor such as a heterojunction bipolar transistor (HBT) or a transistor such as a field effect transistor (MOSFET) or the like. Note that a first amplifier 132, a second amplifier 133, and a control amplifier 140 described later are also configured in a similar manner.

[0014] The first distributor 120 distributes, for example, the signal RF1 output from the drive amplifier 110 into a signal (hereinafter referred to as "signal RF11") to be output to the balanced amplifier circuit 130 and a signal (hereinafter referred to as "signal RF12") to be output to the control amplifier 140. The first distributor 120 may have a function of adjusting at least one of the amplitude and phase of the current in the signal RF12 based on the characteristics (e.g., frequency, amplitude, phase, etc.) of the signal RF1. The first distributor 120 may be configured to include, for example, a distributed constant circuit such as a coupled line 3 dB coupler or a Wilkinson type distributor. Note that the first distributor 120 may realize the functions of distributing the signal RF1, adjusting the amplitude of the signal RF12, and adjusting the phase of the signal RF12, respectively, by different components. Also, the control amplifier 140 described later may be configured to realize the functions of adjusting the amplitude of the signal RF12 and adjusting the phase of the current.

[0015] The balanced amplifier circuit 130 includes, for example, a second distributor 131, a first amplifier 132, a second amplifier 133, and a combiner 134.

[0016] The second divider 131 divides, for example, the signal RF11 divided by the first divider 120 into a signal RF11a input to the first amplifier 132 and a signal RF11b input to the second amplifier 133. Here, the phase of the signal RF11a may be delayed by approximately 90 degrees from the phase of the signal RF11b. Approximately 90 degrees includes, for example, a range of +45 degrees to -45 degrees with 90 degrees as the center. The second divider 131 may be, for example, a distributed constant circuit such as a parallel plate coupler, a λ / 4 line coupler, a coupled line 3 dB coupler, or a blind coupler, or a Wilkinson type divider. The second divider 131 is electrically connected to a reference potential through, for example, a resistor 135.

[0017] The first amplifier 132 is, for example, an amplifier that amplifies the input signal RF11a and outputs the amplified signal. The first amplifier 132 is biased to, for example, class AB. That is, the first amplifier 132 amplifies the input signal and outputs the amplified signal regardless of the power level of the input signal, such as a small instantaneous input power.

[0018] The second amplifier 133 is, for example, an amplifier that amplifies the input signal RF11b and outputs an amplified signal. The second amplifier 133 is, for example, an amplifier that is biased at the same operating point class as the first amplifier 132, and is biased to class AB here.

[0019] The combiner 134 combines, for example, the amplified signal output from the first amplifier 132 and the amplified signal output from the second amplifier 133, and outputs the output signal RFout. The combiner 134 has, for example, a characteristic impedance that is approximately equal to the load impedances of the first amplifier 132 and the second amplifier 133. The load impedance refers to the impedance when the load side (the output terminal 102 side) is seen from the balanced amplifier circuit 130. The combiner 134 may be, for example, a parallel plate coupler, a λ / 4 line coupler, a coupled line 3 dB coupler, or a branch line coupler. That is, in the power amplifier module 100, by using the combiner 134 that exhibits a low characteristic impedance, an impedance matching circuit for the first amplifier 132 and the second amplifier 133 can be omitted, and therefore, miniaturization can be achieved.

[0020] The parallel plate coupler will be described with reference to FIG. 2. FIG. 2 is a diagram showing an example of the structure of the parallel plate coupler that is the combiner 134. As shown in FIG. 2, the parallel plate coupler is composed of one plate 134a and the other plate 134b that faces the plate 134a in parallel. An output terminal of the first amplifier 132 is electrically connected to one corner C1 of the plate 134a. An output terminal 102 is electrically connected to a corner C2 diagonally opposite to the corner C1 of the plate 134a, for example, through an impedance matching unit 160. In addition, a control amplifier 140 is connected to a corner C3 of the other plate 134b that overlaps with the corner C1 of the plate 134a in a direction overlapping the corner C1 of the plate 134a. An output terminal of the second amplifier 133 is electrically connected to a corner C4 of the plate 134b opposite to the corner C3 to which the control amplifier 140 is connected. When the combiner 134 is a parallel plate coupler, the power amplifier module 100 is miniaturized.

[0021] The λ / 4 line coupler will be described with reference to FIG. 3. FIG. 3 is a diagram showing an example of the structure of a λ / 4 line coupler that is the combiner 134. As shown in FIG. 3, the λ / 4 line coupler is formed of a pair of electromagnetically coupled λ / 4 lines. One end of the λ / 4 line 134c is electrically connected to the output terminal of the control amplifier 140, and the other end is connected to the output terminal of the second amplifier 133. The other λ / 4 line 134d is electrically connected to the output terminal of the first amplifier 132, and the other end is electrically connected to the output terminal 102 through, for example, an impedance matching unit 160. When the combiner 134 is a λ / 4 line coupler, a low impedance can be maintained in a wide band.

[0022] The branch line coupler will be described with reference to FIG. 4. FIG. 4 is a diagram showing an example of the structure of the branch line coupler that is the combiner 134. As shown in FIG. 4, the branch line coupler is formed by arranging and coupling λ / 4 lines 134e to 134h symmetrically in the vertical and horizontal directions. A coupling point between the λ / 4 line 134e and the λ / 4 line 134f is electrically connected to the output terminal of the first amplifier 132. A coupling point between the λ / 4 line 134f and the λ / 4 line 134g is electrically connected to the output terminal 102 through, for example, an impedance matching unit 160. A coupling point between the λ / 4 line 134g and the λ / 4 line 134h is electrically connected to the output terminal of the control amplifier 140. A coupling point between the λ / 4 line 134h and the λ / 4 line 134e is electrically connected to the output terminal of the second amplifier 133. When the combiner 134 is a branch line coupler, a low impedance can be maintained at a high frequency such as a millimeter wave.

[0023] The lumped constant coupler will be described with reference to FIG. 5. FIG. 5 is a diagram showing an example of the structure of a lumped constant coupler that is the combiner 134. As shown in FIG. 5, the lumped constant coupler includes a pair of magnetically coupled inductors 134i and 134j, one end of the pair of inductors 134i and 134j is connected by a capacitor 134k, and the other end is connected by a capacitor 134l. One end of the inductor 134i is electrically connected to the output terminal of the control amplifier 140. One end of the inductor 134j is electrically connected to the output terminal of the first amplifier 132. The other end of the inductor 134i is electrically connected to the output terminal of the second amplifier 133. The other end of the inductor 134j is electrically connected to the output terminal 102, for example, through an impedance matching unit 160. When the combiner 134 is a lumped constant coupler, a low impedance can be maintained in a low frequency band.

[0024] The control amplifier 140 generates, for example, a control signal S for controlling the load impedance of the balanced amplifier circuit 130. cont For example, the control amplifier 140 amplifies the signal RF12 adjusted by the first distributor 120 based on the characteristics of the signal RF1, and outputs the control signal S contThe controlled amplifier 140 is biased, for example, in class AB.

[0025] In this way, in the power amplifier module 100, the amplifiers constituting the balanced amplifier circuit 130 and the control amplifier 140 are configured as class AB amplifiers with the same operating point, which makes the design easier.

[0026] The impedance matching section 150 is configured with a transmission line transformer, and converts the impedance at a predetermined conversion ratio (here, as an example, "12:1"). The impedance matching section 150 is electrically connected between the control amplifier 140 and the balanced amplifier circuit 130. The impedance matching section 150 matches the load impedance of the control amplifier 140 with the input impedance of the combiner 134 of the balanced amplifier circuit 130. The power amplifier module 100 can achieve a wide bandwidth by configuring the impedance matching circuit with a transmission line transformer.

[0027] 1, the transmission-line transformer of the impedance matching unit 150 includes, for example, a main line L1 and a sub-line L2. The transmission-line transformer may be formed, for example, on the surface of each layer of a multi-layer board, and the main line L1 and the sub-line L2 may be arranged so as to overlap in the stacking direction. A control signal S output from the control amplifier 140 is connected to one end of the main line L1. cont A power supply Vcc may be supplied to one end of the sub-line L2. In other words, the power supply Vcc may be electrically connected to one end of the sub-line L2 of the transmission line transformer of the impedance matching unit 150. The other end of the sub-line L2 is electrically connected to the other end of the main line L1. That is, the impedance matching unit 150 receives the converted control signal S cont Output.

[0028] The impedance matching unit 160 is configured with a transmission line transformer, and converts the impedance at a predetermined conversion ratio (here, as an example, "1:14"). The impedance matching unit 160 is electrically connected between the balanced amplifier circuit 130 and the output terminal 102. The impedance matching unit 160 matches the load impedance with the load impedance of the combiner 134 of the balanced amplifier circuit 130. By configuring the impedance matching circuit with a transmission line transformer, the power amplifier module 100 can achieve a wide bandwidth.

[0029] As shown in FIG. 1, the transmission line transformer of the impedance matching unit 160 includes, for example, a main line L3 and a sub-line L4. The transmission line transformer may be formed, for example, on the surface of each layer of a multilayer board, and the main line L3 and the sub-line L4 may be arranged so as to overlap each other vertically. An output signal output from the balanced amplifier circuit 130 may be supplied to one end of the main line L3. A power supply Vcc may be supplied to one end of the sub-line L4. In other words, the power supply Vcc may be electrically connected to one end of the sub-line L4 of the transmission line transformer of the impedance matching unit 160. The other end of the sub-line L4 is electrically connected to the other end of the main line L3. That is, the impedance matching unit 160 outputs an output signal converted from the other end of the main line L3 by impedance conversion due to electromagnetic coupling energy from the sub-line L4 to the main line L3.

[0030] As described above, the power amplifier module 100 may have a power supply Vcc connected to one end of the sub-line (e.g., the sub-line L2 or the sub-line L4) of the transmission line transformer. In this case, the transmission line transformer has an impedance conversion function and also functions as a power supply line. This allows the power amplifier module 100 to be made smaller.

[0031] With reference to FIG. 11, the miniaturization of the power amplifier module 100 compared to the power amplifier module 1000 according to the comparative example will be described. FIG. 11 is a diagram showing an example of the configuration of the power amplifier module 1000 according to the comparative example. As shown in FIG. 11, in the power amplifier module 1000 according to the comparative example, a matching circuit 1500 (not connected to the power supply Vcc) is provided at the output terminal of the control amplifier 1400, and a matching circuit 1600 (not connected to the power supply Vcc) is also provided between the balanced amplifier circuit 1300 and the output terminal 1020. Furthermore, in the power amplifier module 1000, the first amplifier 1320, the second amplifier 1330, and the control amplifier 1400 are each electrically connected to the power supply Vcc through inductors L10, L11, and L12.

[0032] In contrast, in the power amplifier module 100, the transmission line transformer of the impedance matching unit 150 has a function as a matching circuit for matching the impedance between the control amplifier 140 and the combiner 134, and a function as wiring for electrically connecting each of the second amplifier 133 and the control amplifier 140 to a power supply Vcc. Also, in the power amplifier module 100, the transmission line transformer of the impedance matching unit 160 has a function as a matching circuit for matching the impedance between the balanced amplifier circuit 130 and the output terminal 102 (load impedance), and a function as wiring for electrically connecting the first amplifier 132 to a power supply Vcc. As a result, the power amplifier module 100 has fewer components than the power amplifier module 1000, and can be made smaller in size.

[0033] In addition, some of the components of the power amplifier module 100 may be formed on-chip (for example, a silicon semiconductor chip or a III-V compound semiconductor chip). Specifically, for example, the drive amplifier 110, the first distributor 120, the balanced amplifier circuit 130, the control amplifier 140, and the impedance matching section 150 may be formed on-chip in the power amplifier module 100. This can avoid unnecessary parasitic inductance from occurring in the output of the balanced amplifier circuit 130 and the control amplifier 140, so that the characteristics of the power amplifier module 100 can be maintained. For example, when the signal RFin is in a high frequency band such as the 6 GHz band, the impedance matching section 160 may also be formed on-chip. This can suppress deviations in impedance matching due to parasitic inductance in the impedance matching section 160. In this embodiment, for example, a circuit including components formed on-chip may be called a "power amplifier circuit".

[0034] Next, a configuration of a communication device 10 incorporating the power amplifier module 100 will be described with reference to Fig. 6. Fig. 6 is a diagram showing an example of a configuration of a communication device 10 incorporating the power amplifier module 100. As shown in Fig. 6, the communication device 10 includes, for example, the power amplifier module 100, a switch 200, a filter circuit 300, a switch 400, and a multiplexer 500.

[0035] The switches 200 and 400 each include, for example, an input terminal and a plurality of output terminals, and may be, for example, a matrix switch that can electrically connect each of the plurality of input terminals to at least one of the plurality of output terminals.

[0036] The filter circuit 300 is, for example, a circuit that attenuates a signal in a predetermined frequency band. The filter circuit 300 may be, for example, a low-pass filter, a band-pass filter, a band elimination filter, a high-pass filter, or the like.

[0037] The multiplexer 500 is, for example, a filter circuit that separates an output signal RFout of a predetermined frequency band output from the power amplifier module 100 and a signal of a predetermined frequency band received by the antenna ANT.

[0038] ===Operation of power amplifier module 100=== Next, the operation of the power amplifier module 100 will be described with reference to Fig. 1 and Fig. 7. Fig. 7 is a diagram showing an example of a current input to the combiner 134.

[0039] 1, the drive amplifier 110 receives a signal RFin through an input terminal 101. The drive amplifier 110 amplifies the signal RFin and outputs a signal RF1 to the first distributor 120. The first distributor 120 distributes the signal RF1 into a signal RF11 that is output to the balanced amplifier circuit 130 and a signal RF12 that is output to the control amplifier 140. The first distributor 120 may output, for example, the signal RF12 that has been adjusted based on the characteristics of the signal RF1 to the control amplifier 140.

[0040] In addition, the control signal S cont may be generated so that its power level decreases as the power level of the output signal RFout output from the power amplifier module 100 increases. cont may be input to the balanced amplifier circuit 130 to dynamically adjust the load impedance of the balanced amplifier circuit 130 in accordance with the power level of the output signal RFout.

[0041] A control amplifier 140 amplifies the signal RF12 to generate a control signal S cont The control signal S cont is input to the balanced amplifier circuit 130 through the impedance matching section 150. The impedance matching section 150 (e.g., conversion ratio "12:1") matches the load impedance of the control amplifier 140 (e.g., "42.0Ω") to the impedance of the impedance matching section 160 of the balanced amplifier circuit 130 (described later) (e.g., "3.5Ω").

[0042] In the balanced amplifier circuit 130, the second distributor 131 distributes the signal RF11 into a signal RF11a to be output to the first amplifier 132 and a signal RF11b to be output to the second amplifier 133. The first amplifier 132 amplifies the signal RF11a and outputs the amplified signal. The second amplifier 133 amplifies the signal RF11b and outputs the amplified signal. The combiner 134 combines the amplified signals amplified by the first amplifier 132 and the second amplifier 133. At this time, the combiner 134 is supplied with a control signal S cont is input to adjust the load impedance of the balanced amplifier circuit 130.

[0043] Here, with reference to Fig. 7, a description will be given of how the load impedance of the balanced amplifier circuit 130 is adjusted by interaction between the balanced amplifier circuit 130 and the control amplifier 140 in the power amplifier module 100. In the power amplifier module 100, a signal (hereinafter, "control signal S cont ") to the balanced amplifier circuit 130, thereby adjusting the load impedance of the balanced amplifier circuit 130. The combiner 134 shown in FIG. 7 is, for example, a 3 dB hybrid coupler. In FIG. 7, for example, V L is the impedance of the load, and V CA denotes the output voltage of the control amplifier 140, and V BA1 indicates the output voltage of the second amplifier 133, and V BA2 denotes the output voltage of the first amplifier 132, and I CA denotes the current supplied by the control amplifier 140, and e j φ is I CA indicates the phase of I BA denotes the current supplied from the first amplifier 132, and jI BA indicates the current supplied from the second amplifier 133, and Z0 indicates the characteristic impedance of the combiner 134. In the circuit shown in FIG. 7, for example, the determinant shown in equation (1) holds. When equation (1) is solved, for example, the relationship shown in equation (2) holds. As shown in equation (2), in the power amplifier module 100, the control signal S output from the control amplifier 140 contBy adjusting the amplitude and phase of BA1 ,Z BA2 is adjusted.

number

number

[0044] In formula (2), Z BA1 indicates the load impedance of the first amplifier 132 in the balanced amplifier circuit 130. BA2 indicates the load impedance of the second amplifier 133 in the balanced amplifier circuit 130. Z0 indicates the characteristic impedance of the combiner 134, and indicates an impedance equal to the load impedance of the control amplifier 140.

[0045] That is, the power amplifier module 100 outputs a current I CA By adjusting the amplitude and phase of the control signal S, the load impedance of the first amplifier 132 and the load impedance of the second amplifier 133 in the balanced amplifier circuit 130 can be adjusted while the load impedances of the first amplifier 132 and the second amplifier 133 are equal to each other. cont It is possible to adjust the load impedance of the balanced amplifier circuit 130 by inputting the input signal . This makes it possible to control the load impedance of the balanced amplifier circuit 130 so as to maintain high efficiency in the back-off of the power amplifier module 100.

[0046] ===Modifications of the power amplification module 100=== <<First Modification>> Modifications of the power amplifier module 100 will be described with reference to Fig. 8 and Fig. 9. Fig. 8 and Fig. 9 are graphs showing an example of the relationship between the input power and the efficiency of the power amplifier module 100 according to the modification. In Fig. 8 and Fig. 9, the horizontal axis represents the power ratio P BO The vertical axis indicates the output efficiency E ffShows.

[0047] In the above, the first amplifier 132, the second amplifier 133 and the control amplifier 140 are biased in class AB, but in the power amplifier module 100 according to the modified example, the first amplifier 132 and the second amplifier 133 may be biased in class AB, and the control amplifier 140 may be biased in class C. This allows the control amplifier 140 to start up when the first amplifier 132 and the second amplifier 133, which are biased in class AB, are saturated, thereby improving efficiency. Specifically, as shown in FIG. 8, the power ratio P BO When the input impedance is -6 dB, the control amplifier 140 operates, thereby making it possible to maintain efficiency. Furthermore, in this configuration, the conversion ratios of the transmission line transformers of the impedance matching section 150 and the impedance matching section 160 can be reduced. This allows the impedance matching section 150 and the impedance matching section 160 to have a wider bandwidth and be made smaller in size.

[0048] In the power amplifier module 100 according to the modified example, the control amplifier 140 may be biased in class AB, and the first amplifier 132 and the second amplifier 133 may be biased in class C. This allows the first amplifier 132 and the second amplifier 133 to rise when the control amplifier 140 is saturated, thereby maintaining efficiency. Specifically, as shown in FIG. 9, the power ratio P BO When the gain is −6 dB, the first amplifier 132 and the second amplifier 133 operate, thereby making it possible to maintain efficiency.

[0049] <<Second Modification>> A power amplifier module 100a according to a second modification will be described with reference to Figs. 12, 13, and 14. Fig. 12 is a diagram showing a configuration example of the power amplifier module 100a according to the second modification. Fig. 13 is a graph showing the frequency characteristics of a parallel plate coupler. In Fig. 13, the horizontal axis shows the normalized frequency, and the vertical axis shows the phase difference between two signals. Fig. 14 is a graph showing the relationship between the phase of a signal input to the control amplifier 140 and the phase of a signal input to the second amplifier 133 in the power amplifier module 100a according to the second modification. In Fig. 14, the horizontal axis shows the normalized frequency, and the vertical axis shows the phase difference between the two signals.

[0050] As shown in Fig. 12, in the power amplifier module 100a, the first amplifier 132 and the second amplifier 133 are biased to class AB, and the control amplifier 140 is biased to class AB. Compared to the power amplifier module 100, the first divider 120a in the power amplifier module 100a includes a divider 121a, a capacitor 122a, an inductor 123a, an inductor 124a, and a capacitor 125a. In the power amplifier module 100a, the combiner 134 is configured as a parallel plate coupler. It is preferable that the second divider 131 in the power amplifier module 100a is configured as a parallel plate coupler. In addition, each of the "flat plates" (for example, one flat plate 134a shown in FIG. 2 and the other flat plate 134b facing parallel to the flat plate 134a) that face each other to form a parallel plate coupler refers to a plate whose main surface facing the other flat plate has an area larger than the area of ​​its side surface that does not face the other flat plate.

[0051] The distributor 121a distributes the signal RF1 into a signal RF11 (first input signal) and a signal RF12 (second input signal). The distributor 121a is configured with a parallel plate coupler formed of a pair of plates arranged in parallel facing each other. Note that the distributor 121a may be a λ / 4 line coupler, but is preferably a parallel plate coupler from the viewpoint of miniaturization.

[0052] The capacitor 122a is connected in series to one of the flat plates of the distribution unit 121a and passes the signal RF11 to the second distributor 131. The inductor 123a is shunt-connected to one of the flat plates. In other words, the inductor 123a is connected in series between the one of the flat plates and the reference potential.

[0053] Inductor 124a is connected in series to the other plate of distribution section 121 and passes signal RF12 to control amplifier 140. Capacitor 125a is shunt-connected to the other plate, i.e., capacitor 125a is connected in series between the other plate and the reference potential.

[0054] As shown in Fig. 13, the parallel plate coupler can split into two signals with a phase difference of approximately 90 degrees regardless of frequency. As shown in Fig. 13, it can be seen that the parallel plate coupler (dashed line) has better frequency characteristics than the branch line coupler (chain line).

[0055] That is, in the power amplifier module 100a, two signals whose phases have been adjusted and distributed by the parallel plate coupler, the capacitor, and the inductor are combined by the parallel plate coupler of the combiner 134. As a result, as shown in Fig. 14, the power amplifier module 100a can adjust the phase difference between the signal (RF12) input to the control amplifier 140 and the signal (RF11a) input to the second amplifier 133 to be, for example, approximately 45 degrees (solid line) so as to optimally control the load impedance of the balanced amplifier circuit 130 with respect to the phase difference of 90 degrees (dashed line) between the signals (RF11a, RF11b) input to the second amplifier 133.

[0056] In this way, as shown in equation (2), the power amplifier module 100a receives the current I CA By adjusting the phase of the input signal, the load impedance of the balanced amplifier circuit 130 can be optimally controlled.

[0057] Here, a further modified example of the power amplifier module 100a according to the second modified example will be described with reference to Fig. 15. Fig. 15 is a diagram showing a modified example of the power amplifier module 100a according to the second modified example.

[0058] 15, even if the first amplifier 132 and the second amplifier 133 are biased to class C, the power amplifier module 100a can obtain the frequency characteristics shown in FIG. 14, and can control the load impedance of the balanced amplifier circuit 130. This allows the power amplifier module 100a to improve output efficiency by widening the band.

[0059] <<Third Modification>> A power amplifier module 100b according to a third modification will be described with reference to Fig. 16 and Fig. 17. Fig. 16 is a diagram showing a configuration example of the power amplifier module 100b according to the third modification. Fig. 17 is a graph showing the relationship between the phase of a signal input to the control amplifier 140 and the phase of a signal input to the second amplifier 133 in the power amplifier module 100b in the third modification. In Fig. 17, the horizontal axis indicates normalized frequency, and the vertical axis indicates the phase difference between the two signals.

[0060] As shown in Fig. 16, the control amplifier 140 in the power amplifier module 100b is biased to class C, unlike the power amplifier module 100a according to the second modification. The first divider 120a in the power amplifier module 100b includes a divider 121b, an inductor 122b, a capacitor 123b, a capacitor 124b, and an inductor 125b. In the power amplifier module 100b, the combiner 134 is configured as a parallel plate coupler. It is preferable that the second divider 131 in the power amplifier module 100b is configured as a parallel plate coupler.

[0061] The distributor 121b is similar to the distributor 121a, and therefore a description thereof will be omitted.

[0062] Inductor 122b is connected in series to one of the flat plates of distribution unit 121b and passes signal RF11 to second distributor 131. Capacitor 123b is shunt-connected to one of the flat plates. In other words, capacitor 123b is connected in series between one of the flat plates and the reference potential.

[0063] Capacitor 124b is connected in series to the other plate of distribution section 121 and passes signal RF12 to control amplifier 140. Inductor 125b is shunt-connected to the other plate, i.e., inductor 125b is connected in series between the other plate and the reference potential.

[0064] In the power amplifier module 100b, the two signals whose phases have been adjusted and distributed by the parallel plate coupler, the capacitor, and the inductor are combined by the parallel plate coupler of the combiner 134. As a result, as shown in Fig. 17, the power amplifier module 100b can adjust the phase difference between the signal (RF12) input to the control amplifier 140 and the signal (RF11a) input to the second amplifier 133 to be, for example, around 135 degrees (solid line) so as to optimally control the load impedance of the balanced amplifier circuit 130 with respect to the phase difference of 90 degrees (dashed line) between the signals (RF11a, RF11b) input to the second amplifier 133.

[0065] In this way, as shown in equation (2), the power amplifier module 100b receives the current I CA By adjusting the phase of the amplifier 100, it is possible to optimally control the load impedance of the balanced amplifier circuit 130. As a result, the power amplifier module 100b can improve the output efficiency by widening the band.

[0066] ===Summary=== Hereinafter, as an example, it will be explicitly stated that in the power amplifier module 100, the signal RF11 corresponds to the “first input signal” in the claims, the signal RF12 corresponds to the “second input signal” in the claims, the balanced amplifier circuit 130 corresponds to the “amplifier circuit” in the claims, the first amplifier 132 and the second amplifier 133 correspond to the “pair of amplifiers” in the claims, the main line L1 corresponds to the “first main line” in the claims, the sub-line L2 corresponds to the “first sub-line” in the claims, the impedance matching section 150 corresponds to the “first impedance matching section” in the claims, the impedance matching section 160 corresponds to the “second impedance matching section” in the claims, the main line L3 corresponds to the “second main line” in the claims, the sub-line L4 corresponds to the “second sub-line” in the claims, the signal RF11a corresponds to the “first signal” in the claims, and the signal RF11b corresponds to the “second signal” in the claims.

[0067] A power amplifier module 100 according to an exemplary embodiment of the present disclosure includes a first divider 120 that divides an input signal (here, a signal RF1) into a signal RF11 and a signal RF12, a pair of a first amplifier 132 and a second amplifier 133 that are electrically connected in parallel, a balanced amplifier circuit 130 that amplifies the signal RF11 and outputs an output signal RFout to an output terminal 102, and a control signal S that amplifies the signal RF12 and controls the load impedance of the balanced amplifier circuit 130. cont to the balanced amplifier circuit 130, and an impedance matching section 150 electrically connected in series between the balanced amplifier circuit 130 and the control amplifier 140, where the impedance matching section 150 includes a transmission line transformer. This makes it possible to widen the band and improve the output efficiency.

[0068] Moreover, the transmission line transformer of the impedance matching unit 150 of the power amplifier module 100 includes a main line L1 and a sub-line L2, the main line L1 is electrically connected in series between the balanced amplifier circuit 130 and the control amplifier 140, and one end of the sub-line L2 is electrically connected to one end of the main line L1 and the other end is electrically connected to a power supply Vcc. This makes it unnecessary to provide wiring (inductors) between the power supply Vcc and each amplifier in addition to the transmission line transformer for impedance matching, and thus the power amplifier module 100 can be made compact.

[0069] Moreover, the power amplifier module 100 further includes an impedance matching section 160 electrically connected in series between the balanced amplifier circuit 130 and the output terminal 102, and the impedance matching section 160 includes a transmission line transformer. This makes it possible to widen the band and improve the output efficiency.

[0070] Moreover, the transmission line transformer of the impedance matching unit 160 of the power amplifier module 100 includes a main line L3 and a sub-line L4, the main line L3 is electrically connected in series between the balanced amplifier circuit 130 and the output terminal 102, and one end of the sub-line L4 is electrically connected to one end of the main line L3 and the other end is electrically connected to a power supply Vcc. This makes it unnecessary to provide wiring (inductors) between the power supply Vcc and each amplifier in addition to the transmission line transformer for impedance matching, and thus the power amplifier module 100 can be made smaller.

[0071] Furthermore, the pair of first and second amplifiers 132 and 133 of the power amplifier module 100 are amplifiers of the same class as the operating point of the amplifier of the control amplifier 140. This makes it easier to design the power amplifier module 100.

[0072] Furthermore, the pair of first and second amplifiers 132 and 133 of the power amplifier module 100 are amplifiers that operate in class AB, and the control amplifier 140 is an amplifier that operates in class AB. This allows the power amplifier module 100 to achieve a wider bandwidth.

[0073] Furthermore, the pair of first and second amplifiers 132 and 133 of the power amplifier module 100 are amplifiers of a class different from the operating point of the amplifier of the control amplifier 140. This allows the power amplifier module 100 to achieve a wider bandwidth.

[0074] Moreover, the pair of first and second amplifiers 132 and 133 of the power amplifier module 100 are amplifiers that operate in class AB, and the control amplifier 140 is an amplifier that operates in class C. This allows the power amplifier module 100 to achieve a broadband.

[0075] The balanced amplifier circuit 130 of the power amplifier module 100 includes a second divider 131 that divides the signal RF11 into signals RF11a and RF11b, a first amplifier 132 that amplifies the signal RF11a divided by the second divider 131 and outputs a first output signal, a second amplifier 133 that amplifies the signal RF11b divided by the second divider 131 (second divider) and outputs a second output signal, and a combiner 134 that combines the first output signal and the second output signal to output an output signal RFout. The combiner 134 controls a control signal S cont is input. This enables the power amplifier module 100 to achieve a wider bandwidth.

[0076] Moreover, the combiner 134 (combiner) of the power amplifier module 100 is configured with a parallel plate coupler formed of a pair of plates arranged in parallel facing each other, thereby making the power amplifier module 100 more compact.

[0077] Moreover, the combiner 134 (combiner) of the power amplifier module 100 is configured with a λ / 4 line coupler formed with wiring having a line length of a quarter of the wavelength at the frequency of the input signal, which makes it possible to maintain low impedance over a wide band.

[0078] Moreover, the combiner 134 (combiner) of the power amplifier module 100 is configured with a branch line coupler, which makes it possible to maintain low impedance at high frequencies such as millimeter waves.

[0079] Moreover, the first distributor 120, the balanced amplifier circuit 130, the control amplifier 140, and the impedance matching section 150 of the power amplifier module 100 are formed on the same chip. This makes it possible to suppress deviations in impedance matching caused by parasitic inductance in the impedance matching section 160 in the power amplifier module 100.

[0080] In the power amplifier module 100a, the first distributor 120a includes a distributor 121a configured with a parallel plate coupler formed of a pair of plates arranged facing each other in parallel, which distributes a signal RF1 (input signal) into a signal RF11 (first input signal) and a signal RF12 (second input signal), a capacitor 122a (first capacitor) connected in series to one of the plates of the distributor 121a and which passes the signal RF11 (first input signal) to a balanced amplifier circuit 130 (amplifier circuit), an inductor 123a (first inductor) shunt-connected to the one plate, an inductor 124 (second inductor) connected in series to the other plate of the distributor 121a and which passes the signal RF12 (second input signal) to a control amplifier 140 (biased to class AB), and a capacitor 125a ( The balanced amplifier circuit 130 (amplifier circuit) includes a pair of amplifiers including a second divider 131 that divides a signal RF11 (first input signal) into a signal RF11a (first signal) and a signal RF11b (second signal), a first amplifier 132 that amplifies the signal RF11a (first signal) divided by the second divider 131 and outputs a first output signal, and a second amplifier 133 that amplifies the signal RF11b (second signal) divided by the second divider 131 and outputs a second output signal, and a combiner 134 that is configured by a parallel plate coupler formed of a pair of plates arranged facing each other in parallel and combines the first output signal and the second output signal to output an output signal RFout. The combiner 134 receives a control signal S cont is input. This makes it possible to widen the band and improve the output efficiency.

[0081] In the power amplifier module 100b, the first distributor 120b includes a distributor 121b formed of a pair of plates arranged in parallel facing each other and configured as a parallel plate coupler that distributes a signal RF1 (input signal) into a signal RF11 (first input signal) and a signal RF12 (second input signal), an inductor 122b (third inductor) that is connected in series to one of the plates of the distributor 121b and passes the signal RF11 (first input signal) to a balanced amplifier circuit 130 (amplifier circuit), a capacitor 123b (third capacitor) that is shunt-connected to the one of the plates, a capacitor 124b (fourth capacitor) that is connected in series to the other plate of the distributor 121b and passes the signal RF12 (second input signal) to a control amplifier 140 (biased to class C), and an inductor 125b ( and a fourth inductor), and the balanced amplifier circuit 130 (amplifier circuit) includes a pair of amplifiers including a second divider 131 that divides a signal RF11 (first input signal) into a signal RF11a (first signal) and a signal RF11b (second signal), a first amplifier 132 that amplifies the signal RF11a (first signal) divided by the second divider 131 and outputs a first output signal, and a second amplifier 133 that amplifies the signal RF11b (second signal) divided by the second divider 131 and outputs a second output signal, and a combiner 134 that is configured by a parallel plate coupler formed of a pair of plates arranged in parallel facing each other and combines the first output signal and the second output signal to output an output signal RFout, and the combiner 134 receives a control signal S cont is input. This makes it possible to widen the band and improve the output efficiency.

[0082] The above-described embodiments are intended to facilitate understanding of the present disclosure, and are not intended to limit the present disclosure. The present disclosure may be modified or improved without departing from the spirit thereof, and the present disclosure also includes equivalents thereof. In other words, even if a person skilled in the art appropriately modifies the embodiments, the embodiment is included in the scope of the present disclosure as long as it has the features of the present disclosure. The elements and their arrangements of the embodiments are not limited to those exemplified, and can be appropriately modified. [Explanation of symbols]

[0083] 100, 100a, 100b...power amplification module, 110...drive amplifier, 120, 120a, 120b...first distributor, 130...balanced amplifier circuit, 131...second distributor, 132...first amplifier, 133...second amplifier, 134...combiner, 140...control amplifier, 150...impedance matching section, 160...impedance matching section.

Claims

1. a first divider that divides an input signal into a first input signal and a second input signal; an amplifier circuit including a pair of amplifiers electrically connected in parallel, amplifying the first input signal and outputting an output signal to an output terminal; a control amplifier that amplifies the second input signal and outputs a control signal to the amplifier circuit for controlling a load impedance of the amplifier circuit; a first impedance matching unit electrically connected in series between the amplifier circuit and the control amplifier; Equipped with The first impedance matching unit includes a transmission line transformer. Power amplifier circuit.

2. the transmission line transformer of the first impedance matching unit includes a first main line and a first sub-line, the first main line is electrically connected in series between the amplifier circuit and the control amplifier; one end of the first sub-line is electrically connected to one end of the first main line, and the other end of the first sub-line is electrically connected to a power source; 2. The power amplifier circuit according to claim 1.

3. a second impedance matching section electrically connected in series between the amplifier circuit and the output terminal; The second impedance matching unit includes a transmission line transformer.

2. The power amplifier circuit according to claim 1.

4. the transmission line transformer of the second impedance matching unit includes a second main line and a second sub-line, the second main line is electrically connected in series between the amplifier circuit and the output terminal, one end of the second sub-line is electrically connected to one end of the second main line, and the other end of the second sub-line is electrically connected to a power source; 4. The power amplifier circuit according to claim 3.

5. The pair of amplifiers are of the same class as the operating point of the control amplifier.

2. The power amplifier circuit according to claim 1.

6. The pair of amplifiers are class AB amplifiers, The control amplifier is an amplifier operating in class AB.

6. The power amplifier circuit according to claim 5.

7. The pair of amplifiers are amplifiers of a different class from the operating point of the control amplifier.

2. The power amplifier circuit according to claim 1.

8. The pair of amplifiers are class AB amplifiers, The control amplifier is an amplifier operating in class C.

8. The power amplifier circuit according to claim 7.

9. The amplifier circuit includes: a second divider that divides the first input signal into a first signal and a second signal; the pair of amplifiers including a first amplifier that amplifies the first signal distributed by the second distributor and outputs a first output signal, and a second amplifier that amplifies the second signal distributed by the second distributor and outputs a second output signal; a combiner that combines the first output signal and the second output signal to output the output signal; Equipped with The control signal is input to the combiner so that a load impedance of the amplifier circuit is controlled.

2. The power amplifier circuit according to claim 1.

10. The combiner is configured with a parallel plate coupler formed of a pair of plates arranged in parallel facing each other.

10. The power amplifier circuit according to claim 9.

11. The combiner is configured with a λ / 4 line coupler formed of wiring having a line length of a quarter of the wavelength at the frequency of the input signal.

10. The power amplifier circuit according to claim 9.

12. The combiner is composed of a branch line coupler.

10. The power amplifier circuit according to claim 9.

13. 2. The power amplifier module including the power amplifier circuit according to claim 1, wherein the first divider, the amplifier circuit, the control amplifier and the first impedance matching section are formed on the same chip.

14. The first distributor is a splitter configured with a parallel plate coupler formed of a pair of plates arranged in parallel facing each other, which splits the input signal into the first input signal and the second input signal; a first capacitor connected in series to one of the flat plates of the distribution unit, the first capacitor passing the first input signal to the amplifier circuit; and a first inductor connected in shunt to the one of the flat plates; a second inductor connected in series to the other plate of the distribution section, the second inductor passing the second input signal to the control amplifier; and a second capacitor connected in shunt to the other plate. It is composed of The amplifier circuit includes: a second divider that divides the first input signal into a first signal and a second signal; the pair of amplifiers including a first amplifier that amplifies the first signal distributed by the second distributor and outputs a first output signal, and a second amplifier that amplifies the second signal distributed by the second distributor and outputs a second output signal; a combiner configured of a parallel plate coupler formed of a pair of plates arranged in parallel facing each other, the combiner combining the first output signal and the second output signal to output the output signal; Equipped with The control signal is input to the combiner so that a load impedance of the amplifier circuit is controlled.

7. The power amplifier circuit according to claim 6.

15. The first distributor is a splitter configured as a parallel plate coupler formed of a pair of parallel plates arranged facing each other, which splits the input signal into the first input signal and the second input signal; a third inductor connected in series to one of the flat plates of the distribution unit, the third inductor passing the first input signal to the amplifier circuit, and a third capacitor connected in shunt to the one of the flat plates; a fourth capacitor connected in series to the other plate of the distribution section, the fourth capacitor passing the second input signal to the control amplifier; and a fourth inductor connected in shunt to the other plate. It is composed of The amplifier circuit includes: a second divider that divides the first input signal into a first signal and a second signal; a pair of amplifiers including a first amplifier that amplifies the first signal distributed by the second distributor and outputs a first output signal, and a second amplifier that amplifies the second signal distributed by the second distributor and outputs a second output signal; a combiner configured of a parallel plate coupler formed of a pair of plates arranged in parallel facing each other, which combines the first output signal and the second output signal to output the output signal; Equipped with The control signal is input to the combiner so that a load impedance of the amplifier circuit is controlled.

9. The power amplifier circuit according to claim 8.

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