Power amplifier circuit

Abstract

The power amplifier circuit includes: a carrier amplifier that amplifies a first signal and outputs a first amplified signal from a first output terminal; a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs a second amplified signal from a second output terminal; a first inductor having a first end connected to the first output terminal and a second end connected to a first node; a first capacitor having a first end connected to the first node and a second end connected to ground; a second inductor having a first end connected to the second output terminal and a second end connected to a second node; a second capacitor having a first end connected to the second node and a second end connected to ground; a third inductor having a first end connected to the first node and a second end connected to a third node connected to a load; and a third capacitor having a first end connected to the second node and a second end connected to the third node.

Description

Technical Field

[0001] The invention relates to a power amplifier circuit. Background Art

[0002] There is a Doherty amplifier including a carrier amplifier and a peak amplifier (see, for example, Patent Document 1). There is also a semiconductor power amplifier including a balanced amplifier (see, for example, Patent Document 2).

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-29239

[0006] Patent Document 2: Japanese Patent Application Publication No. 2014-225791 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] When the Doherty amplifier described in Patent Document 1 is used, although high efficiency can be achieved, a 1 / 4 wavelength line is required, and the occupied area becomes larger. On the other hand, when the balanced amplifier described in Patent Document 2 is used, although resistance to load impedance variation can be obtained, efficiency is degraded. In other words, it is difficult to obtain a power amplifier circuit that achieves both high efficiency and high resistance to load impedance variation.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a power amplifier circuit that can achieve miniaturization, high efficiency, and high resistance to load impedance fluctuations.

[0010] Technical solutions to solve problems

[0011] A power amplifier circuit according to one aspect of the present invention includes: a carrier amplifier that amplifies a first signal and outputs a first amplified signal from a first output terminal; a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs a second amplified signal from a second output terminal; a first inductor having a first end connected to the first output terminal and a second end connected to a first node; a first capacitor having a first end connected to the first node and a second end connected to ground; a second inductor having a first end connected to the second output terminal and a second end connected to a second node; a second capacitor having a first end connected to the second node and a second end connected to ground; a third inductor having a first end connected to the first node and a second end connected to a third node connected to a load; and a third capacitor having a first end connected to the second node and a second end connected to the third node.

[0012] A power amplifier circuit according to another aspect of the present invention includes: a carrier amplifier that amplifies a first signal and outputs a first amplified signal from a first output terminal; a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs a second amplified signal from a second output terminal; a first inductor having a first end connected to the first output terminal and a second end connected to a first node; a first capacitor having a first end connected to the first node and a second end connected to ground; a second inductor having a first end connected to the second output terminal and a second end connected to a second node; a second capacitor having a first end connected to the second node and a second end connected to ground; and a 90-degree hybrid coupler having a first input port connected to the first node and supplied with the first amplified signal, a second input port connected to the second node and supplied with the second amplified signal, an output port connected to a third node connected to a load and outputting an output signal, and an isolation port.

[0013] A power amplifier circuit according to another aspect of the present invention includes: a carrier amplifier that amplifies a first signal and outputs a first amplified signal from a first output terminal; a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs a second amplified signal from a second output terminal; a first capacitor having a first end connected to the first output terminal and a second end connected to a first node; a first inductor having a first end connected to the first node and a second end connected to ground; a second capacitor having a first end connected to the second output terminal and a second end connected to a second node; a second inductor having a first end connected to the second node and a second end connected to ground; a third capacitor having a first end connected to the first node and a second end connected to a third node connected to a load; and a third inductor having a first end connected to the second node and a second end connected to the third node.

[0014] A power amplifier circuit according to another aspect of the present invention includes: a carrier amplifier that amplifies a first signal and outputs a first amplified signal from a first output terminal; a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs a second amplified signal from a second output terminal; a first capacitor having a first end connected to the first output terminal and a second end connected to a first node; a first inductor having a first end connected to the first node and a second end connected to ground; a second capacitor having a first end connected to the second output terminal and a second end connected to a second node; a second inductor having a first end connected to the second node and a second end connected to ground; and a 90-degree hybrid coupler having a first input port connected to the first node and supplied with the first amplified signal, a second input port connected to the second node and supplied with the second amplified signal, an output port connected to a third node connected to a load and outputting an output signal, and an isolation port.

[0015] A power amplifier circuit according to another aspect of the present invention includes: a carrier amplifier that amplifies a first signal and outputs a first amplified signal from a first output terminal; a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs a second amplified signal from a second output terminal; a first inductor having a first end connected to the first output terminal and a second end connected to a first node connected to a load; a first capacitor having a first end connected to the first node and a second end connected to ground; a second inductor having a first end connected to the second output terminal and a second end connected to a second node; a third capacitor having a first end connected to the second node and a second end connected to the first node; and a fifth inductor and a second capacitor connected in series between the second node and ground.

[0016] Effects of the Invention

[0017] According to the present invention, it is possible to provide a power amplifier circuit that can achieve miniaturization, high efficiency, and high resistance to load impedance fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a circuit diagram of the power amplifier circuit 101.

[0019] Figure 2 is a circuit diagram of a power amplifier circuit 900 as a reference example.

[0020] Figure 3 1 is a diagram showing simulation results of frequency characteristics of phase changes between output terminals in the power amplifier circuit 900 .

[0021] Figure 41 is a diagram showing simulation results of frequency characteristics of phase changes between output terminals in the power amplifier circuit 101 .

[0022] Figure 5 1 is a diagram showing simulation results of frequency characteristics of the phase difference between signals in the power amplifier circuit 900 .

[0023] Figure 6 1 is a diagram showing simulation results of frequency characteristics of the phase difference between signals in the power amplifier circuit 101 .

[0024] Figure 7 is a circuit diagram of a power amplifier circuit 901 as a reference example.

[0025] Figure 8 1 is a diagram showing simulation results of gain characteristics in the power amplifier circuit 101 .

[0026] Fig. 9 3 is a diagram showing simulation results of gain characteristics in the power amplifier circuit 900 .

[0027] Fig.10 : is a diagram showing the simulation result of the gain characteristic in the power amplifier circuit 901.

[0028] Fig.11 1 is a diagram showing simulation results of efficiency characteristics in the power amplifier circuit 101 .

[0029] Fig.12 : is a diagram showing the simulation results of the efficiency characteristics in the power amplifier circuit 900 .

[0030] Fig.13 : is a diagram showing the simulation results of the efficiency characteristics in the power amplifier circuit 901.

[0031] Fig.14 1 is a diagram showing the simulation result of the output power change of the impedance Zc in the power amplifier circuit 101 on the Smith chart.

[0032] Fig.15 1 is a diagram showing the simulation results of the output power change of the impedance Zc in the power amplifier circuit 900 on the Smith chart.

[0033] Fig.16 1 is a diagram showing the simulation result of the output power change of the impedance Zc in the power amplifier circuit 901 on the Smith chart.

[0034] Fig.17 1 is a diagram showing the simulation result of the output power change of the impedance Zp in the power amplifier circuit 101 on the Smith chart.

[0035] Fig.181 is a diagram showing the simulation results of the output power change of the impedance Zp in the power amplifier circuit 900 on the Smith chart.

[0036] Fig.19 1 is a diagram showing the simulation result of the output power change of the impedance Zp in the power amplifier circuit 901 on the Smith chart.

[0037] Fig. 20 1 is a diagram showing the simulation results of the change of the impedance Zc in the power amplifier circuit 101 with respect to the load phase on the Smith chart.

[0038] Fig.21 1 is a diagram showing the simulation results of the change of the impedance Zp in the power amplifier circuit 101 with respect to the load phase on the Smith chart.

[0039] Fig. 22 1 is a diagram showing an example of load variation characteristics of the power added efficiency in the power amplifier circuit 101 .

[0040] Fig.23 is a circuit diagram of the power amplifier circuit 111.

[0041] Fig.24 is a circuit diagram of the power amplifier circuit 102 .

[0042] Fig.25 1 is a diagram showing simulation results of frequency characteristics of phase changes between output terminals in the power amplifier circuit 102 .

[0043] Fig.26 1 is a diagram showing simulation results of frequency characteristics of the phase difference between signals in the power amplifier circuit 102 .

[0044] Fig. 27 902 is a circuit diagram of a power amplifier circuit 902 as a reference example.

[0045] Fig.28 1 is a diagram showing simulation results of gain characteristics in the power amplifier circuit 102 .

[0046] Fig.29 : is a diagram showing the simulation result of the gain characteristic in the power amplifier circuit 902.

[0047] Fig.30 1 is a diagram showing simulation results of efficiency characteristics in the power amplifier circuit 102 .

[0048] Fig.31 9 is a diagram showing simulation results of efficiency characteristics in the power amplifier circuit 902 .

[0049] Fig.321 is a diagram showing the simulation result of the output power change of the impedance Zc in the power amplifier circuit 102 on the Smith chart.

[0050] Fig.33 1 is a diagram showing the simulation result of the output power change of the impedance Zc in the power amplifier circuit 902 on the Smith chart.

[0051] Fig.34 1 is a diagram showing the simulation result of the output power change of the impedance Zp in the power amplifier circuit 102 on the Smith chart.

[0052] Fig.35 1 is a diagram showing the simulation result of the output power change of the impedance Zp in the power amplifier circuit 902 on the Smith chart.

[0053] Fig.36 is a circuit diagram of the power amplifier circuit 112.

[0054] Fig.37 is a circuit diagram of the power amplifier circuit 122.

[0055] Fig.38 is a circuit diagram of the power amplifier circuit 132.

[0056] Fig.39 1 is a diagram showing an example of load variation characteristics of the power added efficiency in the power amplifier circuit 132 .

[0057] Fig.40 is a circuit diagram of the power amplifier circuit 141.

[0058] Fig.41 202v is a diagram showing an example of the capacitor 202v.

[0059] Fig.42 183v is a diagram showing an example of capacitor 183v.

[0060] Fig.43 1 is a diagram showing the simulation result of the frequency change of the impedance Zp in the power amplifier circuit 141 on the Smith chart.

[0061] Fig.44 1 is a diagram showing the simulation result of the frequency change of the impedance Zc in the power amplifier circuit 141 on the Smith chart.

[0062] Fig.45 1 is a diagram showing the simulation result of the frequency change of the impedance ZP2 in the power amplifier circuit 141 on the Smith chart.

[0063] Fig.46 1 is a diagram showing the simulation result of the frequency change of the impedance ZP1 in the power amplifier circuit 141 on the Smith chart.

[0064] Fig.47 1 is a diagram showing an example of frequency variation of loss in the LC circuit 181 . DETAILED DESCRIPTION

[0065] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same reference numerals are given to the same elements, and repeated descriptions are omitted as much as possible.

[0066] [First embodiment]

[0067] The power amplifier circuit 101 according to the first embodiment will be described. Figure 1 1 is a circuit diagram of the power amplifier circuit 101. Figure 1 As shown, the power amplifier circuit 101 includes a carrier amplifier 51 , a peak amplifier 52 , LC circuits 61 and 62 , and a 90-degree hybrid coupler 71 .

[0068] The LC circuit 61 includes a capacitor 201 (first capacitor) and an inductor 211 (first inductor). The LC circuit 62 includes a capacitor 202 (second capacitor) and an inductor 212 (second inductor).

[0069] The 90-degree hybrid coupler 71 includes capacitors 203 (third capacitor) and 204 (fourth capacitor), and inductors 213 (third inductor) and 214 (fourth inductor).

[0070] The carrier amplifier 51 amplifies the signal RF1 (first signal), and outputs an amplified signal RF3 (first amplified signal) from an output terminal 51 a (first output terminal).

[0071] The peak amplifier 52 amplifies the signal RF2 (second signal) having a phase different from that of the signal RF1 , and outputs an amplified signal RF4 (second amplified signal) from the output terminal 52 a .

[0072] Specifically, the signals RF1 and RF2 are, for example, radio frequency (RF) signals. The signals RF1 and RF2 are signals generated by dividing an input signal by a divider (not shown). The phase of the signal RF1 and the phase of the signal RF2 immediately after being output from the divider are, for example, identical.

[0073] The signal RF2 is supplied to the peak amplifier 52 via a 1 / 4 wavelength line (not shown), while the signal RF1 is directly supplied to the carrier amplifier 51. Therefore, the phase of the signal RF2 supplied to the peak amplifier 52 is delayed by approximately 90 degrees compared to the phase of the signal RF1 supplied to the carrier amplifier 51.

[0074] The output terminal 51a of the carrier amplifier 51 is connected to the ground via the capacitor 301. The output terminal 52a of the peak amplifier 52 is connected to the ground via the capacitor 302. The capacitors 301 and 302 are, for example, parasitic capacitances or capacitances provided for controlling harmonics.

[0075] The LC circuit 61 is connected between the output terminal 51a of the carrier amplifier 51 and the input port Pin1 in the 90-degree hybrid coupler 71. Specifically, the inductor 211 (first inductor) in the LC circuit 61 has a first end connected to the output terminal 51a and a second end connected to the node N1 (first node). The capacitor 201 has a first end connected to the node N1 and a second end connected to the ground.

[0076] The LC circuit 62 is connected between the output terminal 52a of the peak amplifier 52 and the input port Pin2 in the 90-degree hybrid coupler 71. Specifically, the inductor 212 in the LC circuit 62 has a first end connected to the output terminal 52a and a second end connected to the node N2 (second node). The capacitor 202 has a first end connected to the node N2 and a second end connected to the ground.

[0077] The inductor 213 in the 90-degree hybrid coupler 71 has a first end connected to the node N1 and having an input port Pin1 (first input port) to which the amplified signal RF3 is supplied, and a second end connected to the node N3 (third node) and having an output port Pout. The node N3 is connected to the ground via the load 86. The output signal RFout synthesized by the amplified signals RF3 and RF4 is output from the output port Pout to the load 86 via the node N3.

[0078] The capacitor 203 has a first end connected to the node N2 and having an input port Pin2 (a second input port) to which the amplified signal RF4 is supplied, and a second end connected to the node N3 .

[0079] The capacitor 204 has a first end connected to the node N1 and a second end serving as an isolation port Piso. The isolation port Piso is not connected to any circuit element outside the 90-degree hybrid coupler 71. That is, the isolation port Piso is not directly connected to any circuit element other than the capacitor 204 and the inductor 214 included in the 90-degree hybrid coupler 71.

[0080] The inductor 214 has a first end connected to the node N2 and a second end connected to the second end of the capacitor 204 , and is electromagnetically coupled to the inductor 213 .

[0081] Figure 2 is a circuit diagram of a power amplifier circuit 900 as a reference example. Figure 2As shown, the power amplifier circuit 900 is a conventional Doherty amplifier circuit. Figure 1 Compared with the power amplifier circuit 101 shown in the figure, a quarter wavelength line 42 is provided instead of the LC circuits 61 and 62 , the 90-degree hybrid coupler 71 , and the capacitors 301 and 302 .

[0082] The 1 / 4 wavelength line 42 has a first end connected to the output terminal 51a of the carrier amplifier 51 and a second end connected to the output terminal 52a of the peak amplifier 52. The node N3 is connected to the output terminal 52a.

[0083] Figure 3 9 is a diagram showing the simulation results of the frequency characteristics of the phase change between the output terminals in the power amplifier circuit 900. In addition, the vertical axis shows the phase change between the output terminals with the unit set to "°". The horizontal axis shows the frequency of the amplified signals RF3 and RF4. The phase change between the output terminals is the phase change of the amplified signal RF3 when the amplified signal RF3 is passed from the output terminal 51a of the carrier amplifier 51 to the output terminal 52a of the peak amplifier 52 through the 1 / 4 wavelength line 42.

[0084] like Figure 3 As shown, in the power amplifier circuit 900, the phase change between the output terminals of the amplified signal RF3 is approximately 90 degrees in the range of 1.68 GHz to 1.98 GHz.

[0085] Figure 4 1 is a diagram showing the simulation result of the frequency characteristic of the phase change between the output terminals in the power amplifier circuit 101. In addition, the vertical axis shows the phase change between the output terminals with the unit set to "°". The horizontal axis shows the frequency of the amplified signals RF3 and RF4. The phase change between the output terminals in this case is the phase change of the amplified signal RF3 when the amplified signal RF3 is transmitted from the output terminal 51a of the carrier amplifier 51 to the output terminal 52a of the peak amplifier 52 through the nodes N1 and N2.

[0086] In the power amplifier circuit 101, the magnitude of the phase change between the output terminals of the amplified signal RF3 is greater than 45 degrees and less than 135 degrees. Figure 4 As shown, the magnitude of the phase change between output terminals of the amplified signal RF3 is greater than or equal to 60 degrees and less than or equal to 90 degrees in the range of 1.68 GHz to 1.98 GHz. That is, the phase change between output terminals of the same magnitude as that in the power amplifier circuit 900 can be achieved.

[0087] Figure 59 is a diagram showing the simulation results of the frequency characteristics of the phase difference between signals in the power amplifier circuit 900. In addition, the vertical axis shows the phase difference between signals with the unit set to "°". The horizontal axis shows the frequency of the amplified signals RF3 and RF4. The phase difference between signals shows the difference between the phase change when the amplified signal RF3 output from the output terminal 51a of the carrier amplifier 51 passes through the 1 / 4 wavelength line 42 and the load 86 and the phase change when the amplified signal RF4 output from the output terminal 52a of the peak amplifier 52 passes through the load 86.

[0088] like Figure 5 As shown, in the power amplifier circuit 900, the phase difference between signals is approximately 90 degrees in the range of 1.68 GHz to 1.98 GHz.

[0089] Figure 6 1 is a diagram showing the simulation result of the frequency characteristic of the phase difference between signals in the power amplifier circuit 101. In addition, the vertical axis shows the phase difference between signals with the unit set to "°". The horizontal axis shows the frequency of the amplified signals RF3 and RF4 with the unit set to "GHz". The phase difference between signals in this case shows the difference between the phase change when the amplified signal RF3 output from the output terminal 51a of the carrier amplifier 51 passes through the nodes N1 and N3 and the load 86 and the phase change when the amplified signal RF4 output from the output terminal 52a of the peak amplifier 52 passes through the nodes N2 and N3 and the load 86.

[0090] In the power amplifier circuit 101, the phase difference between the signals is greater than 60 degrees and less than 120 degrees. Figure 6 As shown in FIG. 1 , the magnitude of the phase difference between signals is approximately 90 degrees in the range of 1.68 GHz to 1.98 GHz. That is, a phase difference between signals of the same magnitude as that in the power amplifier circuit 900 can be achieved.

[0091] Figure 7 is a circuit diagram of a power amplifier circuit 901 as a reference example. Figure 7 As shown, the power amplifier circuit 901 is Figure 1 The power amplifier circuit 101 shown is a circuit in which the LC circuits 61 and 62 are not provided.

[0092] Figure 8 , Fig. 9 as well as Fig.10 1 and 10 are diagrams showing simulation results of gain characteristics in power amplifier circuits 101, 900, and 901. The vertical axis shows the gain of the power amplifier circuit in dB. The horizontal axis shows the power of the output signal RFout in dBm (hereinafter sometimes referred to as output power).

[0093] Figure 8 to Figure 10The gain characteristics shown are the gain characteristics when the idle current to the peak amplifier 52 is throttled (hereinafter, sometimes referred to as the Doherty operation). In addition, the frequency of the signal RF1 and the signal RF2 is 1.8 GHz. The gain characteristics in the power amplifier circuit 101 (see Figure 8 ) is the gain characteristic of the power amplifier circuit 900 (refer to Fig. 9 ) to the same extent.

[0094] Fig.11 , Fig.12 as well as Fig.13 1 and 2 are diagrams showing simulation results of efficiency characteristics in the power amplifier circuits 101, 900, and 901. The vertical axis shows the power added efficiency of the power amplifier circuit in "%". The horizontal axis shows the output power in "dBm".

[0095] Figure 11 to Figure 13 The efficiency characteristics shown are those in the Doherty operation. The frequencies of the signals RF1 and RF2 are 1.8 GHz. The output power shown by the dotted line is the power actually used in the power amplifier circuits 101, 900, and 901 (hereinafter, sometimes referred to as actually used power).

[0096] The power added efficiency of power amplifier circuit 101 when actually using power is greater than the power added efficiency of power amplifier circuit 901 when actually using power. In addition, the power added efficiency of power amplifier circuit 101 when actually using power is about the same as the power added efficiency of power amplifier circuit 900 when actually using power.

[0097] Fig.14 , Fig.15 as well as Fig.16 1 and 2 are diagrams showing, on a Smith chart, simulation results of output power changes of impedance Zc in the power amplifier circuits 101, 900, and 901. Impedance Zc is an impedance when the load 86 is viewed from the output terminal 51a of the carrier amplifier 51.

[0098] Figure 14 to Figure 16 The output power change of the impedance Zc shown is the output power change during the Doherty action. The frequency of the signal RF1 and the signal RF2 is 1.8 GHz. When the real number component of the impedance Zc is large, the power added efficiency becomes larger. In addition, the direction of the arrow shown by the dotted line is the direction in which the output power increases.

[0099] In the power amplifier circuit 901 having only the 90-degree hybrid coupler 71, the impedance Zc varies along the imaginary axis (refer to Fig.16 On the other hand, in the power amplifier circuit 900, the impedance Zc changes along the real axis, showing that the power added efficiency is large (refer to Fig.15 ).

[0100] In the power amplifier circuit 101 provided with the low-pass filter circuit of the LC circuits 61 and 62, the output power variation of the impedance Zc can be made close to the output power variation in the power amplifier circuit 900 (refer to Fig.14 as well as Fig.15 ).

[0101] Fig.17 , Fig.18 as well as Fig.19 1 and 2 are diagrams showing, on the Smith chart, simulation results of output power changes of impedance Zp in the power amplifier circuits 101, 900, and 901. Impedance Zp is an impedance when the load 86 is viewed from the output terminal 52a of the peak amplifier 52.

[0102] Figure 17 to Figure 19 The output power change of the impedance Zp shown is the output power change during the Doherty action. The frequency of the signal RF1 and the signal RF2 is 1.8 GHz. When the real number component of the impedance Zp is large, the power added efficiency becomes larger. In addition, the direction of the arrow shown by the dotted line is the direction in which the output power increases.

[0103] In the power amplifier circuit 901 having only the 90-degree hybrid coupler 71, the impedance Zp varies along the imaginary axis (refer to Fig.19 On the other hand, in the power amplifier circuit 900, the impedance Zp changes along the real axis, showing that the power added efficiency is large (refer to Fig.18 ).

[0104] In the power amplifier circuit 101 provided with the low-pass filter circuit of the LC circuits 61 and 62, the output power change of the impedance Zp can be made close to the output power change in the power amplifier circuit 900 (refer to Fig.17 as well as Fig.18 ).

[0105] Fig. 20 as well as Fig.21 1 and 2 are diagrams showing simulation results of changes in impedances Zc and Zp in the power amplifier circuit 101 with respect to load phase, respectively, on a Smith chart. Fig. 22 1 is a diagram showing an example of load variation characteristics of the power added efficiency in the power amplifier circuit 101. The vertical axis shows the power added efficiency of the power amplifier circuit in units of "%. The horizontal axis shows the phase at the antenna 86a end in units of "°", showing the phase when the VSVR (Voltage Standing Wave Ratio) is 2.

[0106] like Figure 20 to Figure 22As shown in FIG. 1 , in the power amplifier circuit 101, the signals RF1 and RF2 having a phase difference of approximately 90 degrees are amplified by the carrier amplifier 51 and the peak amplifier 52, respectively. Fig.21 The output impedance Zp of the peak amplifier 52 is easily shifted toward the short circuit SH as shown in FIG. Fig. 20 The output impedance Zc of the carrier amplifier 51 shown is shifted toward the open circuit OP by approximately the same amount.

[0107] Therefore, if Fig. 22 As shown, the variation of the power added efficiency of the power amplifier circuit 101 shown by the curve Cg can be suppressed compared with the variation of the power added efficiency of the amplifier circuit including the conventional amplifier such as the differential amplifier or the two-stage amplifier shown by the curve Cn. That is, the load variation tolerance of the power amplifier circuit 101 can be improved compared with the load variation tolerance of the conventional amplifier circuit.

[0108] In this embodiment, the 90-degree hybrid coupler 71 is described as being formed of the capacitors 203 and 204 and the inductors 213 and 214, but the present invention is not limited thereto. The 90-degree hybrid coupler 71 may be formed of four quarter-wavelength lines connected in a ring shape.

[0109] [Second embodiment]

[0110] The power amplifier circuit 111 according to the second embodiment is described. In the second embodiment and thereafter, the description of the matters common to the first embodiment is omitted, and only the differences are described. In particular, the same effects brought about by the same structure are not mentioned one by one in each embodiment.

[0111] Fig.23 1 is a circuit diagram of the power amplifier circuit 111. Fig.23 As shown in FIG. 1 , the power amplifier circuit 111 is different from the power amplifier circuit 101 according to the first embodiment in that an LC circuit 171 is provided instead of the 90-degree hybrid coupler 71 .

[0112] LC circuit 171 includes capacitor 205 (third capacitor) and inductor 215 (third inductor). Inductor 215 has a first end connected to node N1 and a second end connected to node N3. Capacitor 205 has a first end connected to node N2 and a second end connected to node N3.

[0113] The capacitor 303 has a first end connected to the power supply voltage VCC and a second end connected to the ground. The line 313 has a first end connected to the power supply voltage VCC and a second end connected to the output terminal 51a of the carrier amplifier 51. The line 314 has a first end connected to the power supply voltage VCC and a second end connected to the output terminal 52a of the peak amplifier 52. In addition, the capacitor 303 and the lines 313 and 314 may also be provided in the power amplifier circuit 101.

[0114] The output terminal 51a of the carrier amplifier 51 is connected to the ground via the capacitor 301 and the line 311. The output terminal 52a of the peak amplifier 52 is connected to the ground via the capacitor 302 and the line 312.

[0115] Thus, even with a structure in which the LC circuit 171 is simpler than the 90-degree hybrid coupler 71, it is possible to achieve characteristics equivalent to those of the power amplifier circuit 101. In other words, in the power amplifier circuit 111, it is possible to achieve characteristics equivalent to those of the power amplifier circuit 101. Fig.11 The power amplifier circuit 101 shown has the same power added efficiency.

[0116] [Third embodiment]

[0117] A power amplifier circuit 102 according to the third embodiment will be described. Fig.24 is a circuit diagram of the power amplifier circuit 102. Fig.24 As shown in FIG. 1 , the connection method of each element of the power amplifier circuit 102 according to the third embodiment is similar to that of the first embodiment. Figure 1 The power amplifier circuit 101 shown is different.

[0118] The capacitor 201 in the LC circuit 61 has a first end connected to the output terminal 51a and a second end connected to the node N1. The inductor 211 has a first end connected to the node N1 and a second end connected to the ground.

[0119] The capacitor 202 in the LC circuit 62 has a first end connected to the output terminal 52a and a second end connected to the node N2. The inductor 212 has a first end connected to the node N2 and a second end connected to the ground.

[0120] The inductor 213 in the 90-degree hybrid coupler 71 has a first end connected to the node N2 and serving as an input port Pin2 to which the amplified signal RF4 is supplied, and a second end connected to the node N3 and serving as an output port Pout.

[0121] The capacitor 203 has a first end connected to the node N1 and serving as an input port Pin1 to which the amplified signal RF3 is supplied, and a second end connected to the node N3 .

[0122] The capacitor 204 has a first end connected to the node N2 and a second end serving as an isolation port Piso. The isolation port Piso is not connected to any circuit element outside the 90-degree hybrid coupler 71 .

[0123] The inductor 214 has a first end connected to the node N1 and a second end connected to the second end of the capacitor 204 , and is electromagnetically coupled to the inductor 213 .

[0124] Fig.25 1 is a diagram showing the simulation results of the frequency characteristics of the phase change between the output terminals in the power amplifier circuit 102. In addition, the vertical axis shows the phase change between the output terminals with the unit set to "°". The horizontal axis shows the frequency of the amplified signals RF3 and RF4. The phase change between the output terminals in this case is Figure 4 The phase changes are shown to be the same between the output terminals.

[0125] In the power amplifier circuit 102, the magnitude of the phase change between the output terminals of the amplified signal RF3 is greater than 45 degrees and less than 135 degrees. Fig.25 As shown in FIG. 1 , the magnitude of the phase change between the output terminals of the amplified signal RF3 is greater than 50 degrees and less than 115 degrees in the range of 1.68 GHz to 1.98 GHz. That is, the phase change between the output terminals in the power amplifier circuit 900 (see FIG. 1 ) can be achieved. Figure 3 ) to the same degree of phase change between the output terminals.

[0126] Fig.26 1 is a diagram showing the simulation results of the frequency characteristics of the phase difference between signals in the power amplifier circuit 102. In addition, the vertical axis shows the phase difference between signals with the unit set to "°". The horizontal axis shows the frequency of the amplified signals RF3 and RF4. Figure 6 The phase differences between the signals shown are the same.

[0127] In the power amplifier circuit 101, the phase difference between the signals is greater than 60 degrees and less than 120 degrees. Fig.26 As shown in FIG. 1 , the magnitude of the phase difference between the signals is greater than 90 degrees and less than 115 degrees in the range of 1.68 GHz to 1.98 GHz. That is, the phase difference between the signals in the power amplifier circuit 900 (see FIG. 1 ) can be achieved. Figure 5 ) have the same degree of phase difference between signals.

[0128] Fig. 27 is a circuit diagram of a power amplifier circuit 902 as a reference example. Fig. 27 As shown, the power amplifier circuit 902 is Fig.24 The power amplifier circuit 102 shown is a circuit in which the LC circuits 61 and 62 are not provided.

[0129] Fig.28 as well as Fig.29 1 and 10 are diagrams showing simulation results of gain characteristics in the power amplifier circuits 102 and 902, respectively. Fig.28 as well as Fig.29 The expression method and Figure 8 to Figure 10 same.

[0130] Fig.28 as well as Fig.29 The gain characteristics shown are the gain characteristics in the Doherty operation. In addition, the frequency of the signal RF1 and the signal RF2 is 1.8 GHz. The gain characteristics in the power amplifier circuit 102 (refer to Fig.28 ) is greater than the gain characteristic of the power amplifier circuit 902 (refer to Fig.29 ), and is the same as the gain characteristic in the power amplifier circuit 900 ( Fig. 9 Reference) to the same extent.

[0131] Fig.30 as well as Fig.31 1 and 10 are diagrams showing simulation results of efficiency characteristics in the power amplifier circuits 102 and 902, respectively. Fig.30 as well as Fig.31 The expression method and Figure 11 to Figure 13 same.

[0132] Fig.30 as well as Fig.31 The efficiency characteristics shown are those in the Doherty operation. The frequencies of the signals RF1 and RF2 are 1.8 GHz. The output power shown by the dotted line is the actual power used.

[0133] The power added efficiency of the power amplifier circuit 102 when actually using the power is greater than the power added efficiency of the power amplifier circuit 902 when actually using the power. In addition, the power added efficiency of the power amplifier circuit 102 when actually using the power is about the same as the power added efficiency of the power amplifier circuit 900 when actually using the power.

[0134] Fig.32 as well as Fig.33 1 and 10 are graphs showing simulation results of output power changes of impedance Zc in power amplifier circuits 102 and 902 on Smith charts, respectively.

[0135] Fig.32 as well as Fig.33 The output power change of the impedance Zc shown is the output power change during the Doherty action. The frequency of the signal RF1 and the signal RF2 is 1.8 GHz. In addition, the direction of the arrow shown by the dotted line is the direction in which the output power increases.

[0136] In the power amplifier circuit 902 having only the 90-degree hybrid coupler 71, the impedance Zc varies along the imaginary axis (refer to Fig.33 ).

[0137] In the power amplifier circuit 102 provided with the high-pass filter circuit of the LC circuits 61 and 62, the output power variation of the impedance Zc can be made close to the output power variation in the power amplifier circuit 900 (refer to Fig.14 as well as Fig.32 ).

[0138] Fig.34 as well as Fig.35 1 and 10 are diagrams showing simulation results of output power changes of impedance Zp in power amplifier circuits 102 and 902 on Smith charts, respectively.

[0139] Fig.34 as well as Fig.35 The output power change of the impedance Zp shown is the output power change during the Doherty action. The frequency of the signal RF1 and the signal RF2 is 1.8 GHz. In addition, the direction of the arrow shown by the dotted line is the direction in which the output power increases.

[0140] In the power amplifier circuit 902 having only the 90-degree hybrid coupler 71, the impedance Zp varies along the imaginary axis (refer to Fig.35 ).

[0141] In the power amplifier circuit 102 provided with the high-pass filter circuit of the LC circuits 61 and 62, the output power variation of the impedance Zp can be made close to the output power variation in the power amplifier circuit 900 (refer to Fig.17 as well as Fig.34 ).

[0142] In this embodiment, the 90-degree hybrid coupler 71 is described as being formed of the capacitors 203 and 204 and the inductors 213 and 214, but the present invention is not limited thereto. The 90-degree hybrid coupler 71 may be formed of four quarter-wavelength lines connected in a ring shape.

[0143] [Fourth embodiment]

[0144] The power amplifier circuit 112 according to the fourth embodiment will be described. Fig.36 is a circuit diagram of the power amplifier circuit 112. Fig.36 As shown in FIG. 1 , the power amplifier circuit 112 is different from the power amplifier circuit 102 according to the third embodiment in that an LC circuit 171 is provided instead of the 90-degree hybrid coupler 71 .

[0145] LC circuit 171 includes capacitor 205 (third capacitor) and inductor 215 (third inductor). Capacitor 205 has a first end connected to node N1 and a second end connected to node N3. Inductor 215 has a first end connected to node N2 and a second end connected to node N3.

[0146] Capacitor 303 and lines 311-314 are respectively Fig.23 The capacitor 303 and the lines 311 to 314 in the power amplifier circuit 111 are shown to be the same.

[0147] As described above, even with a configuration in which the LC circuit 171 which is simpler than the 90-degree hybrid coupler 71 is provided, characteristics equivalent to those of the power amplifier circuit 102 can be achieved.

[0148] [Fifth embodiment]

[0149] The power amplifier circuit 122 according to the fifth embodiment will be described. Fig.37 1 is a circuit diagram of the power amplifier circuit 122. Fig.37 As shown, the power amplifier circuit 122 is different from the power amplifier circuit 102 according to the third embodiment in that the capacitance of the capacitor in the 90-degree hybrid coupler 71 is made variable.

[0150] The power amplifier circuit 122 and Fig.24 Compared with the power amplifier circuit 102 shown in the figure, a 90-degree hybrid coupler 72 and an LC circuit 81 are provided instead of the 90-degree hybrid coupler 71 and the capacitors 301 and 302 .

[0151] 90 degree hybrid coupler 72 with Fig.24 Compared with the 90-degree hybrid coupler 71 shown in the figure, capacitors 203 v (third capacitor) and 204 v (fourth capacitor) are included instead of the capacitors 203 and 204. The capacitance of the capacitor 203 v and the capacitance of the capacitor 204 v are each variable.

[0152] The LC circuit 81 includes an inductor 82 and a capacitor 83, and is provided between the node N3 and a load 86 (not shown). The inductor 82 has a first end connected to the output port Pout of the 90-degree hybrid coupler 72 and a second end connected to the load 86. The capacitor 83 has a first end connected to the second end of the inductor 82 and a second end connected to the ground.

[0153] By adjusting the capacitance of the capacitor 203v and the capacitance of the capacitor 204v, the frequency characteristic of the phase change between the output terminals in the power amplifier circuit 122 can be changed. Fig.25 The frequency characteristics of the phase change between the output terminals shown are shifted in the vertical axis direction.

[0154] By appropriately adjusting the capacitance of the capacitor 203v and the capacitance of the capacitor 204v according to the frequency band of the signals RF1 and RF2, it is possible to realize an optimum phase change between the output terminals in the frequency band. Thus, the power amplifier circuit 122 can operate satisfactorily in a wide band.

[0155] In addition, in the present embodiment, the configuration of the power amplifier circuit 122 is described in which the capacitances of the capacitors 203 and 204 of the 90-degree hybrid coupler 71 in the power amplifier circuit 102 are made variable, but the present invention is not limited thereto. A configuration in which the capacitances of the capacitors 203 and 204 of the 90-degree hybrid coupler 71 in the power amplifier circuit 101 are made variable may also be adopted.

[0156] [Sixth embodiment]

[0157] The power amplifier circuit 132 according to the sixth embodiment will be described. Fig.38 1 is a circuit diagram of the power amplifier circuit 132. Fig.38 As shown, the power amplifier circuit 132 is different from the power amplifier circuit 102 according to the third embodiment in that the isolation port Piso in the 90-degree hybrid coupler 71 can be connected to the ground via a resistor element.

[0158] The power amplifier circuit 132 and Fig.24 Compared with the power amplifier circuit 102 shown in the figure, an LC circuit 81 , a switch 401 , and a resistor 402 are provided instead of the capacitors 301 and 302 .

[0159] In the power amplifier circuit 132 , the resistor element 402 and the switch 401 are connected in series between the isolation port Piso of the 90-degree hybrid coupler 71 and the ground.

[0160] In this embodiment, the switch 401 has a first end connected to the isolation port Piso of the 90-degree hybrid coupler 71 and a second end connected to the ground via the resistor 402. Alternatively, the first end of the switch 401 may be connected to the isolation port Piso via the resistor 402 and the second end of the switch 401 may be connected to the ground.

[0161] The LC circuit 81 includes an inductor 82 and a capacitor 83, and is provided between the node N3 and the antenna 86a (load). The inductor 82 has a first end connected to the output port Pout of the 90-degree hybrid coupler 72 and a second end connected to the antenna 86a. The capacitor 83 has a first end connected to the second end of the inductor 82 and a second end connected to the ground.

[0162] When the switch 401 is in the on state and the isolation port Piso is connected to the ground via the resistor element 402 , the power amplifier circuit 132 operates in the first mode (hereinafter sometimes referred to as the balanced mode).

[0163] When the switch 401 is in the off state and the isolation port Piso is electrically disconnected from the ground, the power amplifier circuit 132 operates in the second mode (hereinafter sometimes referred to as the Doherty mode).

[0164] Fig.39 1 is a diagram showing an example of load variation characteristics of the power added efficiency in the power amplifier circuit 132. Fig.39 The expression method and Fig. 22 same.

[0165] Curves Cd and Cb respectively show changes in the power added efficiency when the phase at the antenna 86a end is changed in the Doherty mode and the balanced mode.

[0166] The curve Cr shows changes in the power added efficiency when the phase at the antenna 86 a end is changed in an amplifier circuit including a conventional amplifier such as a differential amplifier or a two-stage amplifier (hereinafter, sometimes referred to as a conventional amplifier circuit).

[0167] The curve Cr shows a power added efficiency close to 50 at a phase of 90°, but shows a power added efficiency of about 30 at a phase of 270°. Therefore, in the conventional amplifier circuit, the power added efficiency changes greatly when the phase at the antenna 86a end changes.

[0168] Curve Cb shows that the power added efficiency is 35 or more when the phase changes by 360 degrees, and the fluctuation range of the power added efficiency falls within about 3. Therefore, the balanced mode is a mode suitable for the specification requiring small characteristic fluctuation with respect to the impedance of the load at the antenna 86a end.

[0169] Although the variation range of the power added efficiency of curve Cd is slightly larger than that of curve Cb, the power added efficiency is large over all phases. In addition, the variation range of the power added efficiency of curve Cd is smaller than that of curve Cr. Therefore, the Doherty mode is a mode suitable for maintaining a certain characteristic variation range with respect to the impedance of the load at the antenna 86a end while requiring a good power added efficiency.

[0170] In addition, in the present embodiment, the configuration of the power amplifier circuit 132 is described in which the resistor element 402 and the switch 401 are connected in series between the isolation port Piso of the 90-degree hybrid coupler 71 and the ground in the power amplifier circuit 102, but the present invention is not limited thereto. The power amplifier circuit 101 may also be configured in which the resistor element 402 and the switch 401 are connected in series between the isolation port Piso of the 90-degree hybrid coupler 71 and the ground.

[0171] [Seventh embodiment]

[0172] The power amplifier circuit 141 according to the seventh embodiment will be described. Fig.40 1 is a circuit diagram of the power amplifier circuit 141. Fig.23 In the power amplifier circuit 111 shown, it may be difficult to control the load impedance of the carrier amplifier 51 and the peak amplifier 52 in the second harmonic frequency band during the inverse class F operation. Therefore, the harmonic distortion characteristics may deteriorate.

[0173] In this embodiment, the power amplifier circuit 141 and Fig.23 Compared with the power amplifier circuit 111 shown in the figure, the differences are the circuit structure of the LC circuit 62, the absence of the inductor 215, and the further provision of the LC circuit 181.

[0174] Compared with the LC circuit 62 in the power amplifier circuit 111 , the LC circuit 62 in the power amplifier circuit 141 includes a capacitor 202 v (a second capacitor) instead of the capacitor 202 , and further includes an inductor 225 (a fifth inductor).

[0175] The inductor 212 in the power amplifier circuit 141 has a first end connected to the output terminal 52 a of the peak amplifier 52 and a second end connected to the node N2 .

[0176] The inductor 225 and the capacitor 202v are connected in series between the node N2 and the ground.

[0177] In this embodiment, the inductor 225 has a first end connected to the node N2 and a second end connected to the ground via the capacitor 202v. Alternatively, the first end of the inductor 225 may be connected to the node N2 via the capacitor 202v and the second end of the inductor 225 may be connected to the ground.

[0178] Fig.41 2 is a diagram showing an example of capacitor 202v. Fig.41As shown, the electrostatic capacitance of the capacitor 202v is variable. In this embodiment, the capacitor 202v includes capacitors 2021 and 2022 and a switch 2023. For example, the electrostatic capacitance of the capacitor 2021 is greater than the electrostatic capacitance of the capacitor 2022.

[0179] The capacitor 2021 has a first end connected to the second end of the inductor 225 and a second end connected to the ground. The capacitor 2022 has a first end connected to the second end of the inductor 225 and a second end connected to the ground via the switch 2023. Alternatively, the first end of the capacitor 2022 may be connected to the second end of the inductor 225 via the switch 2023 and the second end of the capacitor 2022 may be connected to the ground.

[0180] The power amplifier circuit 141 can be used in a high frequency mode and a low frequency mode, for example. The high frequency mode and the low frequency mode are respectively suitable for amplifying input signals of a first frequency band and an input signal of a second frequency band. Here, the second frequency band is lower than the first frequency band. The first frequency band and the second frequency band are, for example, approximately frequency bands of 0.7 to 0.9 GHz.

[0181] The switch 2023 is turned off in the high frequency mode and turned on in the low frequency mode, respectively. That is, the electrostatic capacitance of the capacitor 202v in the low frequency mode is larger than the electrostatic capacitance of the capacitor 202v in the high frequency mode.

[0182] like Fig.40 As shown, the capacitor 205 (third capacitor) has a first end connected to the node N2 and a second end connected to the node N1 via the node N3 .

[0183] The LC circuit 181 is connected between the node N3 and the load 86. Specifically, the LC circuit 181 includes a tank circuit 182, a capacitor 185v, and a capacitor 186. The tank circuit 182 includes a capacitor 183v (a fifth capacitor) and an inductor 184 (a sixth inductor).

[0184] The capacitor 186 in the LC circuit 181 has a first end and a second end connected to the node N3. The capacitor 186 blocks a DC component of the amplified signal obtained by combining the amplified signals RF3 and RF4.

[0185] The inductor 184 in the tank circuit 182 has a first end connected to the second end of the capacitor 186 and a second end connected to the ground through the load 86 .

[0186] The capacitor 183 v has a first end connected to the second end of the capacitor 186 and a second end connected to the second end of the inductor 184 .

[0187] Fig.421 is a diagram showing an example of capacitor 183v. Fig.42 As shown, the electrostatic capacitance of the capacitor 183v is variable. In this embodiment, the capacitor 183v includes capacitors 1831 and 1832 and a switch 1833. For example, the electrostatic capacitance of the capacitor 1831 is greater than the electrostatic capacitance of the capacitor 1832.

[0188] Capacitor 1831 has a first end connected to the second end of capacitor 186 and a second end connected to the second end of inductor 184. Capacitor 1832 has a first end connected to the second end of capacitor 186 and a second end connected to the second end of inductor 184 via switch 1833. Alternatively, a configuration may be adopted in which the first end of capacitor 1832 is connected to the second end of capacitor 186 via switch 1833 and the second end of capacitor 1832 is connected to the second end of inductor 184.

[0189] The switch 1833 is turned off in the high frequency mode and turned on in the low frequency mode, respectively. That is, the electrostatic capacitance of the capacitor 183v in the low frequency mode is larger than the electrostatic capacitance of the capacitor 183v in the high frequency mode.

[0190] like Fig.40 As shown, the capacitor 185v has a first end connected to the second end of the inductor 184 and a second end connected to the ground. The capacitor 185v transforms impedance.

[0191] The electrostatic capacitance of the capacitor 185v is variable. In the present embodiment, the capacitor 185v has the same structure as the capacitor 202v. The electrostatic capacitance of the capacitor 185v in the low frequency mode is larger than the electrostatic capacitance of the capacitor 185v in the high frequency mode.

[0192] Fig.43 as well as Fig.44 1 and 2 are diagrams showing simulation results of frequency changes in impedances Zp and Zc in the power amplifier circuit 141 on Smith charts.

[0193] exist Fig.43 Graphs FHZp, FLZp, HHZp, and HLZp are shown in FIG. Graphs FHZp and FLZp respectively show changes in impedance Zp for fundamental waves in the first and second frequency bands. Graphs HHZp and HLZp respectively show changes in impedance Zp for second harmonics based on fundamental waves in the first and second frequency bands.

[0194] exist Fig.44Graphs FHZc, FLZc, HHZc, and HLZc are shown in FIG. Graphs FHZc and FLZc respectively show changes in impedance Zc for fundamental waves in the first and second frequency bands. Graphs HHZc and HLZc respectively show changes in impedance Zc for second harmonics based on fundamental waves in the first and second frequency bands.

[0195] Fig.45 1 is a diagram showing the simulation result of the frequency change of the impedance ZP2 in the power amplifier circuit 141 on the Smith chart. Fig.45 Graphs FHZP2, FLZP2, HHZP2, and HLZP2 are shown in FIG. 1 . Graphs FHZP2 and FLZP2 show changes in impedance ZP2 for fundamental waves in the first and second frequency bands, respectively. Graphs HHZP2 and HLZP2 show changes in impedance ZP2 for second harmonics based on fundamental waves in the first and second frequency bands, respectively. Here, impedance ZP2 is an impedance when the carrier amplifier 51 and the peak amplifier 52 are viewed from the capacitor 186.

[0196] Fig.46 1 is a diagram showing the simulation result of the frequency change of the impedance ZP1 in the power amplifier circuit 141 on the Smith chart. Fig.46 Graphs FHZP1, FLZP1, HHZP1, and HLZP1 are shown in FIG. Graphs FHZP1 and FLZP1 show changes in impedance ZP1 for fundamental waves in the first frequency band and the second frequency band, respectively. Graphs HHZP1 and HLZP1 show changes in impedance ZP1 for second harmonics based on fundamental waves in the first frequency band and the second frequency band, respectively. Here, impedance ZP1 is an impedance when load 86 is viewed from node N3.

[0197] like Fig.43 as well as Fig.44 As shown, the curves FHZp, FLZp, FHZc, and FLZc are located in the vicinity of 1.0+0.0j. That is, control can be performed so that the impedances Zp and Zc with respect to the fundamental wave become the same as the characteristic impedance.

[0198] The curves HHZp, HLZp, HHZc, and HLZc are located near the open circuit OP. That is, control can be performed so that the magnitudes of the impedances Zp and Zc with respect to the second harmonic become larger.

[0199] like Fig.45 As shown, according to the output configuration of the peak amplifier 52, the LC circuit 62 also includes the inductor 225 (refer to Fig.40 ), the curves HHZP2 and HLZP2 are located near the short circuit SH. That is, the impedance ZP2 with respect to the second harmonic is small.

[0200] On the other hand, according to the structure in which the tank circuit 182 is provided between the node N3 and the load 86 (see Fig.40 ),like Fig.46 As shown, control can be performed so that the curves HHZP1 and HLZP1 are located near the open circuit OP.

[0201] Thus, the phase difference between the impedance ZP2 for the second harmonic and the impedance ZP1 for the second harmonic can be made approximately 180°. That is, the phase difference between the traveling wave in the second harmonic that is transmitted from the carrier amplifier 51 and the peak amplifier 52 toward the load 86 and the phase difference between the reflected wave that is reflected by the traveling wave and transmitted toward the carrier amplifier 51 and the peak amplifier 52 can be made approximately 180°. Thus, the traveling wave and the reflected wave of the second harmonic cancel each other out, and thus the deterioration of the harmonic distortion characteristic can be suppressed.

[0202] Fig.47 1 is a diagram showing an example of frequency change in loss in the LC circuit 181. The vertical axis shows loss in "dBm" and the horizontal axis shows frequency in "GHz".

[0203] exist Fig.47 The curves LLs and HLs are shown in FIG. The curve LLs shows the frequency change of the loss when the signal passes through the LC circuit 181 when the capacitor 185v has the electrostatic capacitance in the low frequency mode.

[0204] The curve HLs shows the frequency change of the loss when the signal passes through the LC circuit 181 in the case where the capacitor 185v has the electrostatic capacitance in the high frequency mode.

[0205] like Fig.47 As shown, in the fundamental wave frequency band FB, the capacitor 185v is mainly switched, thereby being able to suppress the loss when the fundamental wave passes through the LC circuit 181 in both the high frequency mode and the low frequency mode.

[0206] In the second harmonic frequency band HB, by mainly switching the capacitor 183 v, the second harmonic based on the fundamental wave can be well attenuated in both the high frequency mode and the low frequency mode.

[0207] Furthermore, according to the configuration in which the low-frequency mode and the high-frequency mode can be switched by the capacitors 183 v and 185 v, it is possible to suppress degradation of the transmission characteristics of the fundamental wave in a wide frequency band while satisfactorily attenuating the second harmonic based on the fundamental wave.

[0208] In addition, in the present embodiment, the electrostatic capacitance of the capacitors 183v, 185v, and 202v is described as variable, but the present invention is not limited to this and may be a structure in which at least one of the electrostatic capacitance of the capacitors 183v, 185v, and 202v is fixed.

[0209] The above is a description of an exemplary embodiment of the present invention. In the power amplifier circuits 101 and 111, the carrier amplifier 51 amplifies the signal RF1 and outputs the amplified signal RF3 from the output terminal 51a. The peak amplifier 52 amplifies the signal RF2 having a phase different from that of the signal RF1 and outputs the amplified signal RF4 from the output terminal 52a. The inductor 211 has a first end connected to the output terminal 51a and a second end connected to the node N1. The capacitor 201 has a first end connected to the node N1 and a second end connected to the ground. The inductor 212 has a first end connected to the output terminal 52a and a second end connected to the node N2. The capacitor 202 has a first end connected to the node N2 and a second end connected to the ground. The inductors 213 and 215 have a first end connected to the node N1 and a second end connected to the node N3 connected to the load 86. The capacitors 203 and 205 have a first end connected to the node N2 and a second end connected to the node N3.

[0210] In a structure where the inductors 211 and 212 and the capacitors 201 and 202 are not provided, it is difficult to adjust the phase difference between the signals and the phase change between the output terminals. As described above, according to a structure in which the inductor 211 in series between the output terminal 51a and the node N1, the capacitor 201 connected to the shunt of the node N1, the inductor 212 in series between the output terminal 52a and the node N2, and the capacitor 202 connected to the shunt of the node N2 are provided, the phase difference between the signals and the phase change between the output terminals can be appropriately adjusted. Thus, an operation close to that of a Doherty amplifier circuit can be achieved to improve the power added efficiency, and the change in the power added efficiency relative to the load impedance change can be suppressed. In addition, since a 1 / 4 wavelength line is not used, the circuit scale of the power amplifier circuits 101 and 111 can be reduced. Therefore, a power amplifier circuit that can achieve miniaturization, high efficiency, and high tolerance to load impedance changes can be provided.

[0211] In the power amplifier circuit 101, the carrier amplifier 51 amplifies the signal RF1 and outputs the amplified signal RF3 from the output terminal 51a. The peak amplifier 52 amplifies the signal RF2 having a phase different from that of the signal RF1 and outputs the amplified signal RF4 from the output terminal 52a. The inductor 211 has a first end connected to the output terminal 51a and a second end connected to the node N1. The capacitor 201 has a first end connected to the node N1 and a second end connected to the ground. The inductor 212 has a first end connected to the output terminal 52a and a second end connected to the node N2. The capacitor 202 has a first end connected to the node N2 and a second end connected to the ground. The 90-degree hybrid coupler 71 has an input port Pin1 connected to the node N1 and supplied with the amplified signal RF3, an input port Pin2 connected to the node N2 and supplied with the amplified signal RF4, an output port Pout connected to the node N3 connected to the load 86 and outputting the output signal RFout, and an isolation port Piso.

[0212] In a structure where inductors 211 and 212 and capacitors 201 and 202 are not provided, it is difficult to adjust the phase difference between signals and the phase change between output terminals. As described above, according to a structure in which an inductor 211 in series between the output terminal 51a and the node N1, a capacitor 201 connected to the shunt of the node N1, an inductor 212 in series between the output terminal 52a and the node N2, and a capacitor 202 connected to the shunt of the node N2 are provided, the phase difference between signals and the phase change between output terminals can be appropriately adjusted. Thus, an action close to that of a Doherty amplifier circuit can be achieved to improve the power added efficiency, and the change in the power added efficiency relative to the load impedance change can be suppressed. In addition, since a 1 / 4 wavelength line is not used, the circuit scale of the power amplifier circuit 101 can be reduced. Therefore, a power amplifier circuit that can achieve miniaturization, high efficiency and high tolerance to load impedance changes can be provided. In addition, since no termination resistor is connected to the isolation port Piso, the output matching loss caused by the termination resistor can be suppressed. Furthermore, by using the 90-degree hybrid coupler 71 , it is possible to improve the adjustment accuracy of the phase difference between signals and the phase change between output terminals.

[0213] In the power amplifier circuits 102 and 112, the carrier amplifier 51 amplifies the signal RF1 and outputs the amplified signal RF3 from the output terminal 51a. The peak amplifier 52 amplifies the signal RF2 having a phase different from that of the signal RF1 and outputs the amplified signal RF4 from the output terminal 52a. The capacitor 201 has a first end connected to the output terminal 51a and a second end connected to the node N1. The inductor 211 has a first end connected to the node N1 and a second end connected to the ground. The capacitor 202 has a first end connected to the output terminal 52a and a second end connected to the node N2. The inductor 212 has a first end connected to the node N2 and a second end connected to the ground. The capacitors 203 and 205 have a first end connected to the node N1 and a second end connected to the node N3 connected to the load 86. The inductors 212 and 215 have a first end connected to the node N2 and a second end connected to the node N3.

[0214] In a structure in which the inductors 211 and 212 and the capacitors 201 and 202 are not provided, it is difficult to adjust the phase difference between the signals and the phase change between the output terminals. As described above, according to a structure in which a capacitor 201 in series between the output terminal 51a and the node N1, a shunt inductor 211 connected to the node N1, a capacitor 202 in series between the output terminal 52a and the node N2, and a shunt inductor 212 connected to the node N2 are provided, the phase difference between the signals and the phase change between the output terminals can be appropriately adjusted. Thus, an operation close to that of a Doherty amplifier circuit can be achieved to improve the power added efficiency, and the change in the power added efficiency relative to the load impedance change can be suppressed. In addition, since a 1 / 4 wavelength line is not used, the circuit scale of the power amplifier circuits 102 and 112 can be reduced. Therefore, a power amplifier circuit that can achieve miniaturization, high efficiency, and high tolerance to load impedance changes can be provided.

[0215] In the power amplifier circuit 102, the carrier amplifier 51 amplifies the signal RF1 and outputs the amplified signal RF3 from the output terminal 51a. The peak amplifier 52 amplifies the signal RF2 having a phase different from that of the signal RF1 and outputs the amplified signal RF4 from the output terminal 52a. The capacitor 201 has a first end connected to the output terminal 51a and a second end connected to the node N1. The inductor 211 has a first end connected to the node N1 and a second end connected to the ground. The capacitor 202 has a first end connected to the output terminal 52a and a second end connected to the node N2. The inductor 212 has a first end connected to the node N2 and a second end connected to the ground. The 90-degree hybrid coupler 71 has an input port Pin1 connected to the node N1 and supplied with the amplified signal RF3, an input port Pin2 connected to the node N2 and supplied with the amplified signal RF4, an output port Pout connected to the node N3 connected to the ground through the load 86 and outputting the output signal RFout, and an isolation port Piso.

[0216] In a structure where the inductors 211 and 212 and the capacitors 201 and 202 are not provided, it is difficult to adjust the phase difference between the signals and the phase change between the output terminals. As described above, according to a structure in which a capacitor 201 in series between the output terminal 51a and the node N1, a shunt inductor 211 connected to the node N1, a capacitor 202 in series between the output terminal 52a and the node N2, and a shunt inductor 212 connected to the node N2 are provided, the phase difference between the signals and the phase change between the output terminals can be appropriately adjusted. Thus, an operation close to that of a Doherty amplifier circuit can be achieved to improve the power added efficiency, and the change in the power added efficiency relative to the load impedance change can be suppressed. In addition, since a 1 / 4 wavelength line is not used, the circuit scale of the power amplifier circuit 102 can be reduced. Therefore, a power amplifier circuit that can achieve miniaturization, high efficiency and high tolerance to load impedance changes can be provided. In addition, since no termination resistor is connected to the isolation port Piso, the output matching loss caused by the termination resistor can be suppressed. Furthermore, by using the 90-degree hybrid coupler 71 , it is possible to improve the adjustment accuracy of the phase difference between signals and the phase change between output terminals.

[0217] In the power amplifier circuit 101, the capacitor 204 has a first end connected to the node N1 and a second end serving as the isolation port Piso. The inductor 214 has a first end connected to the node N2 and a second end connected to the second end of the capacitor 204. Furthermore, the inductor 213 and the inductor 214 are electromagnetically coupled.

[0218] According to such a configuration, the 90-degree hybrid coupler 71 can be realized by the capacitors 203 and 204 and the inductors 213 and 214 without using a 1 / 4 wavelength line, so that the circuit scale of the power amplifier circuit 101 can be reduced. In addition, by realizing the 90-degree hybrid coupler 71, the adjustment accuracy of the phase difference between signals and the phase change between output terminals can be improved.

[0219] In the power amplifier circuit 102, the capacitor 204 has a first end connected to the node N2 and a second end serving as the isolation port Piso. The inductor 214 has a first end connected to the node N1 and a second end connected to the second end of the capacitor 204. Furthermore, the inductor 213 and the inductor 214 are electromagnetically coupled.

[0220] According to such a configuration, the 90-degree hybrid coupler 71 can be realized by the capacitors 203 and 204 and the inductors 213 and 214 without using a 1 / 4 wavelength line, so that the circuit scale of the power amplifier circuit 102 can be reduced. In addition, by realizing the 90-degree hybrid coupler 71, the adjustment accuracy of the phase difference between signals and the phase change between output terminals can be improved.

[0221] In addition, in the power amplifier circuits 101, 102, 111 and 112, the difference between the phase change of the amplified signal RF3 output from the output terminal 51a when passing through the node N1, the node N3 and the load 86 and the phase change of the amplified signal RF4 output from the output terminal 52a when passing through the node N2, the node N3 and the load 86 is greater than 60 degrees and less than 120 degrees.

[0222] According to such a structure, the phase difference between signals in the power amplifier circuits 101, 102, 111 and 112 can be made equal to the phase difference between signals in the power amplifier circuits 900 with a smaller circuit scale than the power amplifier circuit 900 which is a conventional Doherty amplifier circuit using a 1 / 4 wavelength line 42.

[0223] In the power amplifier circuits 101 , 102 , 111 , and 112 , the magnitude of the phase change of the amplified signal RF3 when the amplified signal RF3 is transmitted from the output terminal 51 a to the output terminal 52 a via the nodes N1 and N2 is greater than or equal to 45 degrees and less than or equal to 135 degrees.

[0224] According to such a structure, the phase change between the output terminals of the power amplifier circuits 101, 102, 111 and 112 can be made equal to the phase change between the output terminals of the power amplifier circuits 900 with a smaller circuit scale than the power amplifier circuit 900 which is a conventional Doherty amplifier circuit using a 1 / 4 wavelength line 42.

[0225] Furthermore, in the power amplifier circuit 122, the capacitance of the capacitor 203v and the capacitance of the capacitor 204v are each variable.

[0226] By adjusting the capacitance of the capacitor 203v and the capacitance of the capacitor 204v in this way, the frequency characteristics of the phase change between the output terminals in the power amplifier circuit 122 can be changed. Specifically, by appropriately adjusting the capacitance of the capacitor 203v and the capacitance of the capacitor 204v according to the frequency band of the signals RF1 and RF2, the most appropriate phase change between the output terminals can be achieved in the frequency band. Thus, the power amplifier circuit 122 can operate well in a wide band.

[0227] Furthermore, in the power amplifier circuit 132 , the switch 401 and the resistor 402 are connected in series between the isolation port Piso and the ground.

[0228] According to such a structure, by turning on the switch 401, it is possible to operate as a balanced amplifier. Thus, the power amplifier circuit 132 can be operated in a balanced mode suitable for the specification requiring small characteristic variation with respect to the impedance of the load at the antenna 86a end. In addition, by turning off the switch 401, it is possible to operate as an amplifier circuit equivalent to the power amplifier circuit 102. Thus, the power amplifier circuit 132 can be operated in a Doherty mode suitable for the specification requiring good power added efficiency.

[0229] In the power amplifier circuit 141, the carrier amplifier 51 amplifies the signal RF1 and outputs the amplified signal RF3 from the output terminal 51a. The peak amplifier 52 amplifies the signal RF2 having a phase different from that of the signal RF1 and outputs the amplified signal RF4 from the output terminal 52a. The inductor 211 has a first end connected to the output terminal 51a and a second end connected to the node N1 connected to the load 86. The capacitor 201 has a first end connected to the node N1 and a second end connected to the ground. The inductor 212 has a first end connected to the output terminal 52a and a second end connected to the node N2. The capacitor 205 has a first end connected to the node N2 and a second end connected to the node N1. The inductor 225 and the capacitor 202v are connected in series between the node N2 and the ground.

[0230] As described above, according to the structure in which the inductor 225 and the capacitor 202v are connected in series between the node N2 and the ground, the impedance Zp and Zc about the second harmonic based on the fundamental wave can be made close to the open circuit OP. As a result, the power of the second harmonic output to the load 86 side can be reduced, so the deterioration of the harmonic distortion characteristics can be suppressed. In addition, in the structure in which the inductors 211, 212 and 225 and the capacitors 201 and 202v are not provided, it is difficult to adjust the phase difference between the signals and the phase change between the output terminals. As described above, according to the structure in which the inductor 211 in series between the output terminal 51a and the node N1, the capacitor 201 of the shunt connected to the node N1, the inductor 212 in series between the output terminal 52a and the node N2, and the inductor 225 and the capacitor 202v connected in series between the node N2 and the ground are provided, the phase difference between the signals and the phase change between the output terminals can be appropriately adjusted. Thus, it is possible to achieve an operation close to that of a Doherty amplifier circuit, thereby improving the power added efficiency, and suppressing the change in the power added efficiency with respect to the load impedance change. In addition, since a 1 / 4 wavelength line is not used, the circuit scale of the power amplifier circuit 141 can be reduced. Furthermore, according to the power amplifier circuit 111 (see Fig.23 ) is not provided in the power amplifier circuit 141, the circuit scale of the power amplifier circuit 141 can be further reduced. Therefore, a power amplifier circuit that can achieve miniaturization, high efficiency, and high resistance to load impedance fluctuations can be provided.

[0231] In the power amplifier circuit 141, the inductor 184 has a first end connected to the node N1 and a second end connected to the load 86. The capacitor 183v has a first end connected to the first end of the inductor 184 and a second end connected to the second end of the inductor 184.

[0232] When the impedance ZP2 when the carrier amplifier 51 and the peak amplifier 52 are viewed from the capacitor 186 is located near the short circuit SH by configuring the LC circuit 62 including the inductor 225, the impedance ZP1 when the load 86 is viewed from the node N3 can be made close to the open circuit OP, and the phase difference between the impedance ZP2 with respect to the second harmonic and the impedance ZP1 with respect to the second harmonic can be made approximately 180°. This can suppress the deterioration of the harmonic distortion characteristics.

[0233] Furthermore, in the power amplifier circuit 141, the electrostatic capacitance of the capacitor 202v is variable.

[0234] In this way, by changing the capacitance of the capacitor 202v to change the resonance frequency of the inductor 225 and the capacitor 202v, the frequency band in which the second harmonic based on the fundamental wave is well attenuated can be widened while suppressing degradation of the pass characteristic of the fundamental wave.

[0235] Furthermore, in the power amplifier circuit 141, the electrostatic capacitance of the capacitor 183v is variable.

[0236] In this way, by changing the capacitance of the capacitor 183 v to change the resonance frequency of the inductor 184 and the capacitor 183 v , it is possible to widen the frequency band in which the second harmonic based on the fundamental wave is well attenuated while suppressing degradation of the pass characteristic of the fundamental wave.

[0237] In addition, each embodiment described above is used to make the present invention easy to understand, and is not used to limit the interpretation of the present invention. The present invention can be changed / improved without departing from its main purpose, and the present invention also includes its equivalent. That is, the embodiments to which those skilled in the art have appropriately applied design changes to each embodiment are also included in the scope of the present invention as long as they have the features of the present invention. For example, each element and its configuration, material, condition, shape, size, etc. possessed by each embodiment are not limited to the illustrated content, and can be appropriately changed. In addition, each embodiment is illustrative, and it is self-evident that partial replacement or combination of the structure shown in different embodiments can be performed, and they are also included in the scope of the present invention as long as they include the features of the present invention.

[0238] <1>

[0239] A power amplifier circuit comprising:

[0240] The carrier amplifier amplifies the first signal and outputs the first amplified signal from the first output terminal;

[0241] a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs the second amplified signal from a second output terminal;

[0242] a first inductor having a first end connected to the first output terminal and a second end connected to the first node;

[0243] a first capacitor having a first end connected to the first node and a second end connected to ground;

[0244] a second inductor having a first end connected to the second output terminal and a second end connected to the second node;

[0245] a second capacitor having a first end connected to the second node and a second end connected to ground;

[0246] a third inductor having a first end connected to the first node and a second end connected to a third node connected to the load; and

[0247] The third capacitor has a first end connected to the second node and a second end connected to the third node.

[0248] <2>

[0249] A power amplifier circuit comprising:

[0250] The carrier amplifier amplifies the first signal and outputs the first amplified signal from the first output terminal;

[0251] a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs the second amplified signal from a second output terminal;

[0252] a first inductor having a first end connected to the first output terminal and a second end connected to the first node;

[0253] a first capacitor having a first end connected to the first node and a second end connected to ground;

[0254] a second inductor having a first end connected to the second output terminal and a second end connected to the second node;

[0255] a second capacitor having a first end connected to the second node and a second end connected to ground; and

[0256] The 90-degree hybrid coupler includes a first input port connected to the first node and supplied with the first amplified signal, a second input port connected to the second node and supplied with the second amplified signal, an output port connected to a third node connected to a load and outputting an output signal, and an isolation port.

[0257] <3>

[0258] A power amplifier circuit comprising:

[0259] The carrier amplifier amplifies the first signal and outputs the first amplified signal from the first output terminal;

[0260] a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs the second amplified signal from a second output terminal;

[0261] a first capacitor having a first end connected to the first output terminal and a second end connected to the first node;

[0262] a first inductor having a first end connected to the first node and a second end connected to ground;

[0263] a second capacitor having a first end connected to the second output terminal and a second end connected to the second node;

[0264] a second inductor having a first end connected to the second node and a second end connected to the ground;

[0265] a third capacitor having a first end connected to the first node and a second end connected to a third node connected to the load; and

[0266] The third inductor has a first end connected to the second node and a second end connected to the third node.

[0267] <4>

[0268] A power amplifier circuit comprising:

[0269] The carrier amplifier amplifies the first signal and outputs the first amplified signal from the first output terminal;

[0270] a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs the second amplified signal from a second output terminal;

[0271] a first capacitor having a first end connected to the first output terminal and a second end connected to the first node;

[0272] a first inductor having a first end connected to the first node and a second end connected to ground;

[0273] a second capacitor having a first end connected to the second output terminal and a second end connected to the second node;

[0274] a second inductor having a first end connected to the second node and a second end connected to the ground; and

[0275] The 90-degree hybrid coupler includes a first input port connected to the first node and supplied with the first amplified signal, a second input port connected to the second node and supplied with the second amplified signal, an output port connected to a third node connected to a load and outputting an output signal, and an isolation port.

[0276] <5>

[0277] according to <1> The power amplifier circuit described herein, wherein:

[0278] The power amplifier circuit also has:

[0279] a fourth capacitor having a first end connected to the first node and a second end serving as an isolation port; and

[0280] a fourth inductor having a first end connected to the second node and a second end connected to the second end of the fourth capacitor,

[0281] The third inductor and the fourth inductor are electromagnetically coupled.

[0282] <6>

[0283] according to <3> The power amplifier circuit described herein, wherein:

[0284] The power amplifier circuit also has:

[0285] a fourth capacitor having a first end connected to the second node and a second end serving as an isolation port; and

[0286] a fourth inductor having a first end connected to the first node and a second end connected to the second end of the fourth capacitor,

[0287] The third inductor and the fourth inductor are electromagnetically coupled.

[0288] <7>

[0289] according to <1> to <6> A power amplifier circuit as described in any one of the above, wherein:

[0290] A difference between a phase change of the first amplified signal output from the first output terminal when passing through the first node, the third node, and the load and a phase change of the second amplified signal output from the second output terminal when passing through the second node, the third node, and the load is greater than or equal to 60 degrees and less than or equal to 120 degrees.

[0291] <8>

[0292] according to <1> to <7> A power amplifier circuit as described in any one of the above, wherein:

[0293] When the first amplified signal passes from the first output terminal through the first node and the second node to the second output terminal, a phase change of the first amplified signal is set to be greater than or equal to 45 degrees and less than or equal to 135 degrees.

[0294] <9>

[0295] according to <5> or <6> The power amplifier circuit described herein, wherein:

[0296] The capacitance of the third capacitor and the capacitance of the fourth capacitor are each variable.

[0297] <10>

[0298] according to <2> , <4> , <5> or <6> The power amplifier circuit described herein, wherein:

[0299] The power amplifier circuit further includes a resistor element and a switch connected in series between the isolation port and ground.

[0300] <11>

[0301] A power amplifier circuit comprising:

[0302] The carrier amplifier amplifies the first signal and outputs the first amplified signal from the first output terminal;

[0303] a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs the second amplified signal from a second output terminal;

[0304] a first inductor having a first end connected to the first output terminal and a second end connected to a first node connected to a load;

[0305] a first capacitor having a first end connected to the first node and a second end connected to ground;

[0306] a second inductor having a first end connected to the second output terminal and a second end connected to the second node;

[0307] a third capacitor having a first end connected to the second node and a second end connected to the first node; and

[0308] The fifth inductor and the second capacitor are connected in series between the second node and the ground.

[0309] <12>

[0310] according to <11> The power amplifier circuit described herein, wherein:

[0311] The power amplifier circuit also has:

[0312] a sixth inductor having a first end connected to the first node and a second end connected to the load; and

[0313] The fifth capacitor has a first end connected to the first end of the sixth inductor and a second end connected to the second end of the sixth inductor.

[0314] <13>

[0315] according to <11> or <12> The power amplifier circuit described herein, wherein:

[0316] The electrostatic capacitance of the second capacitor is variable.

[0317] <14>

[0318] according to <12> The power amplifier circuit described herein, wherein:

[0319] The electrostatic capacitance of the fifth capacitor is variable.

[0320] Description of Reference Numerals

[0321] 42: 1 / 4 wavelength line;

[0322] 51: carrier amplifier;

[0323] 51a: output terminal;

[0324] 52: Peak amplifier;

[0325] 52a: output terminal;

[0326] 61, 62: LC circuit;

[0327] 71, 72: 90 degree hybrid coupler;

[0328] 81: LC circuit;

[0329] 82: Inductor;

[0330] 83: Capacitor;

[0331] 86: load;

[0332] 86a: Antenna;

[0333] 101, 102, 111, 112, 122, 132, 141, 900, 901, 902, 903: power amplifier circuit;

[0334] 171, 172, 181: LC circuit;

[0335] 182: Trough Road;

[0336] 183v, 185v, 186: capacitors;

[0337] 1831, 1832: capacitors;

[0338] 1833: switch;

[0339] 184: Inductor;

[0340] 201, 202, 202v, 203, 203v, 204, 204v, 205: capacitors;

[0341] 2021, 2022: Capacitors;

[0342] 2023: Switch;

[0343] 211, 212, 213, 214, 215, 225: inductors;

[0344] 301, 302, 303: capacitors;

[0345] 311, 312, 313, 314: lines;

[0346] 315: Inductor;

[0347] 401: switch;

[0348] 402: resistance element;

[0349] N1, N2, N3: nodes;

[0350] Pin1, Pin2: input port;

[0351] Pout: output port;

[0352] Piso: Isolation port.

Claims

1. A power amplifier circuit, comprising: The carrier amplifier amplifies the first signal and outputs the first amplified signal from the first output terminal; a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs the second amplified signal from a second output terminal; a first inductor having a first end connected to the first output terminal and a second end connected to the first node; a first capacitor having a first end connected to the first node and a second end connected to ground; a second inductor having a first end connected to the second output terminal and a second end connected to the second node; a second capacitor having a first end connected to the second node and a second end connected to ground; a third inductor having a first end connected to the first node and a second end connected to a third node connected to the load; and The third capacitor has a first end connected to the second node and a second end connected to the third node.

2. A power amplifier circuit, comprising: The carrier amplifier amplifies the first signal and outputs the first amplified signal from the first output terminal; a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs the second amplified signal from a second output terminal; a first inductor having a first end connected to the first output terminal and a second end connected to the first node; a first capacitor having a first end connected to the first node and a second end connected to ground; a second inductor having a first end connected to the second output terminal and a second end connected to the second node; a second capacitor having a first end connected to the second node and a second end connected to ground; and The 90-degree hybrid coupler has a first input port connected to the first node and supplied with the first amplified signal, a second input port connected to the second node and supplied with the second amplified signal, an output port connected to a third node connected to a load and outputting an output signal, and an isolation port.

3. A power amplifier circuit, comprising: The carrier amplifier amplifies the first signal and outputs the first amplified signal from the first output terminal; a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs the second amplified signal from a second output terminal; a first capacitor having a first end connected to the first output terminal and a second end connected to the first node; a first inductor having a first end connected to the first node and a second end connected to ground; a second capacitor having a first end connected to the second output terminal and a second end connected to the second node; a second inductor having a first end connected to the second node and a second end connected to the ground; a third capacitor having a first end connected to the first node and a second end connected to a third node connected to the load; and The third inductor has a first end connected to the second node and a second end connected to the third node.

4. A power amplifier circuit, comprising: The carrier amplifier amplifies the first signal and outputs the first amplified signal from the first output terminal; a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs the second amplified signal from a second output terminal; a first capacitor having a first end connected to the first output terminal and a second end connected to the first node; a first inductor having a first end connected to the first node and a second end connected to ground; a second capacitor having a first end connected to the second output terminal and a second end connected to the second node; a second inductor having a first end connected to the second node and a second end connected to the ground; and The 90-degree hybrid coupler has a first input port connected to the first node and supplied with the first amplified signal, a second input port connected to the second node and supplied with the second amplified signal, an output port connected to a third node connected to a load and outputting an output signal, and an isolation port.

5. The power amplifier circuit according to claim 1, wherein: The power amplifier circuit also has: a fourth capacitor having a first end connected to the first node and a second end serving as an isolation port; and a fourth inductor having a first end connected to the second node and a second end connected to the second end of the fourth capacitor, The third inductor and the fourth inductor are electromagnetically coupled.

6. The power amplifier circuit according to claim 3, wherein: The power amplifier circuit also has: a fourth capacitor having a first end connected to the second node and a second end serving as an isolation port; and a fourth inductor having a first end connected to the first node and a second end connected to the second end of the fourth capacitor, The third inductor and the fourth inductor are electromagnetically coupled.

7. The power amplifier circuit according to any one of claims 1 to 6, wherein: A difference between a phase change of the first amplified signal output from the first output terminal when passing through the first node, the third node, and the load and a phase change of the second amplified signal output from the second output terminal when passing through the second node, the third node, and the load is greater than or equal to 60 degrees and less than or equal to 120 degrees.

8. The power amplifier circuit according to any one of claims 1 to 7, wherein: When the first amplified signal passes from the first output terminal through the first node and the second node to the second output terminal, a phase change of the first amplified signal is set to be greater than or equal to 45 degrees and less than or equal to 135 degrees.

9. The power amplifier circuit according to claim 5 or 6, wherein: The capacitance of the third capacitor and the capacitance of the fourth capacitor are each variable.

10. The power amplifier circuit according to claim 2, 4, 5 or 6, wherein: The power amplifier circuit further includes a resistor element and a switch connected in series between the isolation port and ground.

11. A power amplifier circuit comprising: The carrier amplifier amplifies the first signal and outputs the first amplified signal from the first output terminal; a peak amplifier that amplifies a second signal having a phase different from that of the first signal and outputs the second amplified signal from a second output terminal; a first inductor having a first end connected to the first output terminal and a second end connected to a first node connected to a load; a first capacitor having a first end connected to the first node and a second end connected to ground; a second inductor having a first end connected to the second output terminal and a second end connected to the second node; a third capacitor having a first end connected to the second node and a second end connected to the first node; and The fifth inductor and the second capacitor are connected in series between the second node and the ground.

12. The power amplifier circuit according to claim 11, wherein: The power amplifier circuit also has: a sixth inductor having a first end connected to the first node and a second end connected to the load; and The fifth capacitor has a first end connected to the first end of the sixth inductor and a second end connected to the second end of the sixth inductor.

13. The power amplifier circuit according to claim 11 or 12, wherein: The electrostatic capacitance of the second capacitor is variable.

14. The power amplifier circuit according to claim 12, wherein: The electrostatic capacitance of the fifth capacitor is variable.

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