Power amplifier circuit

Abstract

A power amplifier circuit includes, on the same semiconductor substrate: a distributor that distributes an input signal into a first signal and a second signal having a phase different from that of the first signal; a first amplifier that amplifies a first branch signal branched from the first signal and outputs a first amplified signal; a second amplifier that amplifies the second branch signal and outputs a second amplified signal when a power level of the second branch signal branched from the first signal shows a given power level or more; a third amplifier that amplifies a third branch signal branched from the second signal and outputs a third amplified signal; a fourth amplifier that amplifies the fourth branch signal and outputs a fourth amplified signal when a power level of the fourth branch signal branched from the second signal shows a given power level or more; a first bias circuit that outputs a first bias voltage; a first line having a first length that connects the first bias circuit and the first amplifier; and a second line having a second length that connects the first bias circuit and the third amplifier, the second length being shorter than the first length, and the first line and the second line being formed such that a voltage drop amount of the first bias voltage between the first bias circuit and the first amplifier and a voltage drop amount of the first bias voltage between the first bias circuit and the third amplifier become substantially equal.

Description

Technical Field

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

[0002] A Doherty amplifier is a high-efficiency power amplifier. In a Doherty amplifier, generally, a carrier amplifier and a peak amplifier are connected in parallel. The carrier amplifier operates regardless of the power level of the input signal. The peak amplifier becomes cutoff when the power level of the input signal is small and becomes conductive when the power level of the input signal is large. Further, when the power level of the input signal is large, the carrier amplifier operates while maintaining saturation at the saturation output power level. That is, in the back-off state where only the carrier amplifier performs the amplification operation, since only the carrier amplifier operates, the peak amplifier does not consume unnecessary current and the efficiency is high. Further, in a differential Doherty amplifier in which the Doherty amplifiers are combined, when signals (for example, noise, etc.) having the same amplitude and the same phase are simultaneously input to each of the two amplification elements, the signals having the same amplitude and the same phase can be canceled. Thus, in the power amplifier circuit, generation of noise and harmonics of the input signal can be suppressed (for example, refer to Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: US2019 / 0165739A1 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] The differential power amplifier circuit described in Patent Document 1 includes a carrier bias circuit that supplies bias to two carrier amplifiers and a peak bias circuit that supplies bias to two peak amplifiers. In this power amplifier circuit, due to the relationship of the space on the semiconductor substrate, the wiring lengths between the carrier bias circuit and one carrier amplifier and between the carrier bias circuit and the other carrier amplifier are different when the respective components are arranged on the semiconductor substrate. Thus, in this power amplifier circuit, the voltage drop amounts of the lines from the carrier bias circuit to one carrier amplifier and from the carrier bias circuit to the other carrier amplifier are different. The same applies to the wiring lengths between the peak bias circuit and each peak amplifier. Therefore, in this power amplifier circuit, a difference in the bias points occurs between the two carrier amplifiers or between the two peak amplifiers, and thus there is a risk that the performance of each amplifier cannot be fully exhibited and the efficiency decreases.

[0008] Therefore, an object of the present disclosure is to provide a highly efficient power amplifier circuit composed of a differential Doherty amplifier.

[0009] Technical solution for solving the problem

[0010] In a power amplifier circuit according to an aspect of the present invention, on the same semiconductor substrate, there are provided: a distributor that distributes an input signal into a first signal and a second signal having a phase different from that of the first signal; a first amplifier that amplifies a first branch signal branched from the first signal and outputs a first amplified signal; a second amplifier that, when the power level of a second branch signal branched from the first signal shows a given power level or more, amplifies the second branch signal and outputs a second amplified signal; a third amplifier that amplifies a third branch signal branched from the second signal and outputs a third amplified signal; a fourth amplifier that, when the power level of a fourth branch signal branched from the second signal shows a given power level or more, amplifies the fourth branch signal and outputs a fourth amplified signal; a first bias circuit that outputs a first bias voltage; a first line of a first length that connects the first bias circuit and the first amplifier; and a second line of a second length that connects the first bias circuit and the third amplifier, the second length being shorter than the first length, and the first line and the second line are formed such that a voltage drop amount of the first bias voltage between the first bias circuit and the first amplifier and a voltage drop amount of the first bias voltage between the first bias circuit and the third amplifier become substantially equal.

[0011] Advantageous effects of the invention

[0012] According to the present disclosure, it is possible to provide a highly efficient power amplifier circuit composed of a differential Doherty amplifier. Description of the drawings

[0013] Figure 1 It is a structural diagram showing an example of the structure of a power amplifier circuit.

[0014] Figure 2 It is a diagram showing the arrangement of each component of the power amplifier circuit on a semiconductor substrate.

[0015] Figure 3 It is a diagram showing an example of the shape of the first line and the second line.

[0016] Figure 4 It is a diagram showing a first modification of the shape of the first line.

[0017] Figure 5 It is a diagram showing a second modification of the shape of the first line.

[0018] Figure 6This is a diagram of a third modified example showing the shape of the first line.

[0019] Figure 7 This is a diagram of a first modified example showing the shape of the second line.

[0020] Figure 8 This is a diagram of a second modified example showing the shape of the second line.

[0021] Figure 9 This is a diagram showing the arrangement on a semiconductor substrate of a power amplifier circuit including a resistor in its components.

[0022] Figure 10 This is a diagram showing an example of the structure of a distributor.

[0023] Figure 11 This is a diagram showing an example of a power amplifier circuit related to a first modified example.

[0024] Figure 12 This is a diagram showing an example of a power amplifier circuit related to a second modified example.

[0025] Figure 13 This is a diagram showing an example of a power amplifier circuit related to a third modified example. Detailed Description

[0026] Structure of Power Amplifier Circuit 100

[0027] The power amplifier circuit 100 is mounted on, for example, a mobile phone and is used to amplify the power of a signal transmitted to a base station. The power amplifier circuit 100 can amplify the power of signals of communication standards such as 2G (second-generation mobile communication system), 3G (third-generation mobile communication system), 4G (fourth-generation mobile communication system), 5G (fifth-generation mobile communication system), LTE (Long Term Evolution) - FDD (Frequency Division Duplex), LTE-TDD (Time Division Duplex), LTE-Advanced, LTE-Advanced Pro, 6G (sixth-generation mobile communication system), etc. In addition, the communication standards of the signals amplified by the power amplifier circuit 100 are not limited to these.

[0028] The power amplifier circuit 100 amplifies the input signal RFin and outputs the output signal RFout. The input signal is a radio frequency (RF) signal, and the frequency of the input signal is, for example, on the order of several GHz to several tens of GHz.

[0029] Reference Figure 1, the structure of the power amplifier circuit 100 will be described. Figure 1 It is a structural diagram showing an example of the structure of the power amplifier circuit 100. As Figure 1 shown, the power amplifier circuit 100 includes, for example, a driver stage amplifier 110, a splitter 111, matching circuits 113 (113a to 113d), a first phase shifter 114, a first carrier amplifier 115, a first peak amplifier 116, a second phase shifter 117, a second carrier amplifier 118, a second peak amplifier 119, a third phase shifter 120, a fourth phase shifter 121, a synthesizer 122, a first bias circuit 123, a carrier long line 124, a carrier short line 125, a second bias circuit 126, a peak long line 127, and a peak short line 128. Each component included in the power amplifier circuit 100 is formed on the same semiconductor substrate.

[0030] The driver stage amplifier 110 amplifies, for example, an input RF signal and outputs an amplified signal. In the present embodiment, the output amplified signal is referred to as "signal RFin". The frequency of the signal RFin is, for example, on the order of several GHz. The driver stage amplifier 110 is not particularly limited and includes, for example, bipolar transistors such as heterojunction bipolar transistors (HBTs) or transistors such as metal-oxide-semiconductor field effect transistors (MOSFETs). The same applies to the first carrier amplifier 115, the first peak amplifier 116, the second carrier amplifier 118, and the second peak amplifier 119 described later.

[0031] The splitter 111 is, for example, a balun, and distributes the input amplified signal RFin into a signal RF1 and a signal RF2 (phase-inverted) whose phase lags the signal RF1 by approximately 180 degrees. The signal RF1 branches into a branch signal RF11 and a branch signal RF12 in the branch portion 112a. The branch signal RF11 is input to the first peak amplifier 116 through the matching circuit 113a described later. The branch signal RF12 is input to the first carrier amplifier 115 through the first phase shifter 114 and the matching circuit 113b described later. In addition, the signal RF2 branches into a branch signal RF21 and a branch signal RF22 in the branch portion 112b. The branch signal RF21 is input to the second peak amplifier 119 through the matching circuit 113c described later. The branch signal RF22 is input to the second carrier amplifier 118 through the second phase shifter 117 and the matching circuit 113d described later. In addition, the meaning of "lags by approximately 180 degrees" in the present invention includes an adjustment range of plus or minus 45 degrees.

[0032] In this way, in the power amplifier circuit 100, the branch signal RF12 input to the first carrier amplifier 115 and the branch signal RF22 input to the second carrier amplifier 118 exhibit a phase difference of approximately 180 degrees. Moreover, in the power amplifier circuit 100, the branch signal RF11 input to the first peak amplifier 116 and the branch signal RF21 input to the second peak amplifier 119 exhibit a phase difference of approximately 180 degrees. That is, the power amplifier circuit 100 forms a differential amplifier circuit.

[0033] In addition, it has been described that the divider 111 divides the amplified signal RFin into two signals having a phase difference of approximately 180 degrees, but it is not limited thereto. For example, the divider 111 may also be a divider that divides into two signals having an arbitrary phase difference within the range of 135 degrees to 225 degrees. The structure of the divider 111 will be described later.

[0034] Each of the matching circuits (MN: Matching Network) 113 matches the impedance of each of the amplifiers 115, 116, 118, 119 with the impedance of the divider 111. The matching circuit 113 is constituted by, for example, an inductor and a capacitor. In addition, the power amplifier circuit 100 may not include all or part of the matching circuit 113. Furthermore, in the power amplifier circuit 100, for example, an amplifier may be provided instead of or together with the matching circuit 113.

[0035] The first phase shifter 114 is, for example, a phase shifter that is electrically connected between the divider 111 and the first carrier amplifier 115 and delays the phase of the branch signal RF12 by approximately 90 degrees. The first phase shifter 114 is, for example, a 1 / 4 wavelength line or a distributed constant circuit or the like. In the case where the first phase shifter 114 is a distributed constant circuit (not shown), the first phase shifter 114 is constituted by, for example, a capacitor C1, an inductor L, and a capacitor C2. Here, with respect to the capacitor C1, for example, one end is connected to the terminal of the divider 111. In addition, with respect to the inductor L, for example, one end is connected to the other end of the capacitor C1, and the other end is connected to the first carrier amplifier 115. In addition, with respect to the capacitor C2, for example, one end is connected to the connection point of the capacitor C1 and the inductor L, and the other end is connected to the ground. Thus, the distributed constant circuit can adjust the phase shift with respect to the signal by adjusting the constants of the capacitor C1, C2, and the inductor L. In addition, it is assumed that the meaning of "delaying approximately 90 degrees" in the present invention includes an adjustment range of plus or minus 45 degrees.

[0036] The first carrier amplifier 115 (the third amplifier) amplifies, for example, the branch signal RF12 input through the first phase shifter 114 and outputs an amplified signal (hereinafter referred to as "signal RFout12"). The first carrier amplifier 115 is biased, for example, in class A, class AB, or class B. That is, the first carrier amplifier 115 amplifies the input signal and outputs an amplified signal regardless of the power level of the input signal such as a small instantaneous input power.

[0037] The first peak amplifier 116 (the fourth amplifier) amplifies, for example, the input branch signal RF11 and outputs an amplified signal (hereinafter referred to as "signal RFout11"). The first peak amplifier 116 is biased, for example, in class C.

[0038] The second phase shifter 117 is, for example, a phase shifter that is electrically connected between the distributor 111 and the second carrier amplifier 118 and delays the phase of the branch signal RF22 by approximately 90 degrees. The second phase shifter 117 is, for example, a 1 / 4 wavelength line or a distributed constant circuit or the like.

[0039] The second carrier amplifier 118 (the first amplifier) amplifies, for example, the branch signal RF22 input through the second phase shifter 117 and outputs an amplified signal (hereinafter referred to as "signal RFout22"). The second carrier amplifier 118 is biased, for example, in class A, class AB, or class B. That is, the second carrier amplifier 118 amplifies the input signal and outputs an amplified signal regardless of the power level of the input signal such as a small instantaneous input power.

[0040] The second peak amplifier 119 (the second amplifier) amplifies, for example, the input branch signal RF21 and outputs an amplified signal (hereinafter referred to as "signal RFout21"). The second peak amplifier 119 is biased, for example, in class C.

[0041] In this way, in the power amplifier circuit 100, a differential amplifier circuit is formed by two carrier amplifiers 115, 118 having a phase difference of 180 degrees and two peak amplifiers 116, 119 having a phase difference of 180 degrees. The differential amplifier circuit includes a pair of two amplifying elements, and amplifies and outputs the potential difference between signals having the same amplitude and opposite phases input to the two amplifying elements respectively. Therefore, when signals having the same amplitude and the same phase (for example, noise, etc.) are simultaneously input to the two amplifying elements, the signals having the same amplitude and the same phase are canceled out. Thereby, in the power amplifier circuit 100, generation of noise and harmonics of the input signal can be suppressed.

[0042] The third phase shifter 120 is, for example, a phase shifter that is electrically connected between the first carrier amplifier 115 and the synthesizer 122 and delays the phase of the signal RFout12 by approximately 90 degrees. As a result, the electrical lengths from the distributor 111 through the first carrier amplifier 115 to the synthesizer 122 and from the distributor 111 through the second peak amplifier 119 to the synthesizer 122 become approximately the same. The third phase shifter 120 is, for example, a 1 / 4 wavelength line or a distributed constant circuit, etc.

[0043] The fourth phase shifter 121 is, for example, a phase shifter that is electrically connected between the second carrier amplifier 118 and the synthesizer 122 and delays the phase of the signal RFout22 by approximately 90 degrees. As a result, the electrical lengths from the distributor 111 through the first peak amplifier 116 to the synthesizer 122 and from the distributor 111 through the second carrier amplifier 118 to the synthesizer 122 become approximately the same. The fourth phase shifter 121 is, for example, a 1 / 4 wavelength line or a distributed constant circuit, etc.

[0044] In this way, in the power amplifier circuit 100 according to the present embodiment, for example, a Doherty amplifier circuit is formed by the first carrier amplifier 115 and the second peak amplifier 119, and a Doherty amplifier circuit is formed by the second carrier amplifier 118 and the first peak amplifier 116. As a result, the first carrier amplifier 115 operates in a region where the power level is zero or higher regardless of the power level of the input signal RFin. Moreover, the second peak amplifier 119 operates in a region where the voltage level of the input signal RFin is higher than a given level (a given power level) lower than the maximum level Vmax. That is, by combining the operations of the two amplifiers according to the power level of the input signal, the region in which the first carrier amplifier 115 operates with a saturated output becomes wider. Therefore, the power efficiency of the power amplifier circuit 100 is improved. The same operation is performed for the second carrier amplifier 118 and the first peak amplifier 116.

[0045] The synthesizer 122 is, for example, input with a signal (phase "0 degrees") synthesized by the synthesizing unit 122a, and the synthesizing unit 122a synthesizes the signal RFout11 output from the first peak amplifier 116 and the signal RFout22 output from the second carrier amplifier 118 through the fourth phase shifter 121. In addition, the synthesizer 122 is, for example, input with a signal (phase "180 degrees") synthesized by the synthesizing unit 122b, and the synthesizing unit 122b synthesizes the signal RFout12 output from the first carrier amplifier 115 through the third phase shifter 120 and the signal RFout21 output from the second peak amplifier 119. The synthesizer 122 synthesizes two signals with inverted phases and outputs a synthesized signal (hereinafter, referred to as "signal RFout").

[0046] The first bias circuit 123 is a circuit that applies a bias voltage to the first carrier amplifier 115 and the second carrier amplifier 118. The voltage value of the bias voltage can be appropriately set according to the characteristics of the first carrier amplifier 115, the second carrier amplifier 118, and the input signal. In addition, the first bias circuit 123 may also be a circuit that supplies a bias current instead of the bias voltage. That is, the first bias circuit 123 is a base bias circuit or a gate bias circuit. Hereinafter, as an example, it is assumed that the first bias circuit 123 supplies a bias voltage for explanation.

[0047] The carrier long line 124 (the first line) is a line formed of a given conductive material that connects the first bias circuit 123 and the second carrier amplifier 118. The given conductive material is, for example, copper, gold, aluminum, etc. The carrier long line 124 can be, for example, a patterned wiring formed on a semiconductor substrate or a wire. Hereinafter, the length of the carrier long line 124 is denoted as "Lc1" for explanation.

[0048] The carrier short line 125 (the second line) is, for example, a line formed of the same conductive material as the carrier long line 124 that connects the first bias circuit 123 and the first carrier amplifier 115. Hereinafter, the length of the carrier short line 125 is denoted as "Lc2" for explanation.

[0049] The carrier long line 124 and the carrier short line 125 can, for example, not only directly connect the first bias circuit 123 and the first carrier amplifier 115, the second carrier amplifier 118, but also indirectly connect the first bias circuit 123 and the first carrier amplifier 115, the second carrier amplifier 118 via other elements, etc. The carrier long line 124 and the carrier short line 125 are formed such that the voltage drop of the bias voltage between the first bias circuit 123 and the first carrier amplifier 115 and the voltage drop of the bias voltage between the first bias circuit 123 and the second carrier amplifier 118 become substantially equal. In addition, the case where one voltage drop and another voltage drop "become substantially equal" includes, for example, the case where the difference between one voltage drop and another voltage drop is within 100 mV. Thereby, the bias points between the two carrier amplifiers can be made substantially the same, and thus the efficiency of the power amplifier circuit 100 can be improved. The detailed structure of the carrier long line 124 and the carrier short line 125 will be described later.

[0050] The second bias circuit 126 is a circuit that applies a bias voltage to the first peak amplifier 116 and the second peak amplifier 119. The voltage value of the bias voltage can be appropriately set according to the characteristics of the first peak amplifier 116, the second peak amplifier 119, and the input signal. In addition, the second bias circuit 126 can also be a circuit that supplies a bias current instead of a bias voltage. That is, the second bias circuit 126 is a base bias circuit or a gate bias circuit. Hereinafter, as an example, it is assumed that the second bias circuit 126 supplies a bias voltage for explanation.

[0051] The peak long line 127 (the third line) is a line formed of a given conductive material that connects the second bias circuit 126 and the second peak amplifier 119. The given conductive material is, for example, copper, gold, aluminum, etc. Hereinafter, the length of the peak long line 127 is denoted as "Lp1" for explanation.

[0052] The peak short line 128 (the fourth line) is, for example, a line formed of the same conductive material as the peak long line 127 that connects the second bias circuit 126 and the first peak amplifier 116. Hereinafter, the length of the peak short line 128 is denoted as "Lp2" for explanation.

[0053] The peak long line 127 and the peak short line 128 can not only directly connect the second bias circuit 126 and the first peak amplifier 116, the second peak amplifier 119, but also indirectly connect the second bias circuit 126 and the first peak amplifier 116, the second peak amplifier 119 via other components, etc. The peak long line 127 and the peak short line 128 are formed such that the voltage drop of the bias voltage between the second bias circuit 126 and the first peak amplifier 116 and the voltage drop of the bias voltage between the second bias circuit 126 and the second peak amplifier 119 become substantially equal. Thereby, the bias points between the two peak amplifiers can be made substantially the same, so that the efficiency of the power amplifier circuit 100 can be improved. The detailed structure of the peak long line 127 and the peak short line 128 will be described later. Furthermore, not only the efficiency is improved, but also the output power can be increased and the distortion characteristics can be improved.

[0054] <<Structure for adjusting the bias point>>

[0055] Refer to Figure 2 and explain the structure for adjusting the bias point of the power amplifier circuit 100. Figure 2 is a diagram showing the arrangement on the semiconductor substrate of each component of the power amplifier circuit 100. In addition, in Figure 2 the structure on the output side of each amplifier (the third phase shifter 120, the fourth phase shifter 121, and the synthesizer 122) is omitted.

[0056] In the power amplifier circuit 100, the first bias circuit 123 supplies a bias voltage to the second carrier amplifier 118 through the carrier long line 124. In addition, the first bias circuit 123 supplies a bias voltage to the first carrier amplifier 115 through the carrier short line 125. At this time, the bias point in the first carrier amplifier 115 is, for example, a voltage obtained by subtracting the voltage drop amount between the first bias circuit 123 and the second carrier amplifier 118 (hereinafter referred to as the carrier long voltage drop amount) from the bias voltage supplied by the first bias circuit 123. On the other hand, the bias point in the second carrier amplifier 118 is, for example, a voltage obtained by subtracting the voltage drop amount between the first bias circuit 123 and the first carrier amplifier 115 (hereinafter referred to as the carrier short voltage drop amount) from the bias voltage supplied by the first bias circuit 123.

[0057] The second bias circuit 126 supplies a bias voltage to the second peak amplifier 119 through the peak long line 127. In addition, the second bias circuit 126 supplies a bias voltage to the first peak amplifier 116 through the peak short line 128. At this time, the bias point in the first peak amplifier 116 is, for example, a voltage obtained by subtracting the voltage drop amount between the second bias circuit 126 and the second peak amplifier 119 (hereinafter referred to as the peak long voltage drop amount) from the bias voltage supplied by the second bias circuit 126. On the other hand, the bias point in the second peak amplifier 119 is, for example, a voltage obtained by subtracting the voltage drop amount between the second bias circuit 126 and the first peak amplifier 116 (hereinafter referred to as the peak short voltage drop amount) from the bias voltage supplied by the second bias circuit 126.

[0058] Here, when the bias points of the first carrier amplifier 115 and the second carrier amplifier 118 show different voltages, the efficiency of the power amplifier circuit 100 decreases. In addition, when the bias points of the first peak amplifier 116 and the second peak amplifier 119 show different voltages, the efficiency of the power amplifier circuit 100 decreases. That is, by making the bias points of the first carrier amplifier 115 and the second carrier amplifier 118 substantially equal, and making the bias points of the first peak amplifier 116 and the second peak amplifier 119 substantially equal, the efficiency of the power amplifier circuit 100 can be improved.

[0059] However, as Figure 2As shown, in the power amplifier circuit 100, the first carrier amplifier 115, the first peak amplifier 116, the second carrier amplifier 118, and the second peak amplifier 119 are arranged in a row in a certain direction on the semiconductor substrate. In this case, for example, in order to make the carrier long voltage drop and the carrier short voltage drop approximately equal, it is necessary to arrange the first bias circuit 123 on the perpendicular bisector of the imaginary line connecting the first carrier amplifier 115 and the second carrier amplifier 118. However, in terms of the arrangement of each component of the power amplifier circuit 100, the first bias circuit 123 cannot be arranged on this perpendicular bisector. Therefore, the carrier long line 124 and the carrier short line 125 have different lengths, and thus when the carrier long line 124 and the carrier short line 125 have the same cross-sectional area, each line shows a different resistance value. That is, the carrier long voltage drop and the carrier short voltage drop become unequal. Similarly, for the peak long line 127 and the peak short line 128, when the peak long line 127 and the peak short line 128 have the same cross-sectional area, the peak long voltage drop and the peak short voltage drop become unequal.

[0060] Therefore, in the power amplifier circuit 100, the shape of at least one of the carrier long line 124 or the carrier short line 125 is adjusted so that the carrier long voltage drop and the carrier short voltage drop become approximately equal. Similarly, in the power amplifier circuit 100, the shape of at least one of the peak long line 127 or the peak short line 128 is adjusted so that the peak long voltage drop and the peak short voltage drop become approximately equal.

[0061] In addition, in the power amplifier circuit 100, a resistor can also be connected in series to the carrier short line 125 so that the carrier long voltage drop and the carrier short voltage drop become approximately equal. Similarly, in the power amplifier circuit 100, a resistor can also be connected in series to the peak short line 128 so that the peak long voltage drop and the peak short voltage drop become approximately equal.

[0062] Hereinafter, first, the detailed shapes of the carrier long line 124 and the carrier short line 125 will be described. Next, the resistor connected in series to the carrier short line 125 will be described. In addition, since the shapes of the peak long line 127 and the peak short line 128 are the same as those of the carrier long line 124 and the carrier short line 125, their description will be omitted.

[0063] Refer to Figure 3 , and the shapes of the carrier long line 124 and the carrier short line 125 will be described. Figure 3 is a diagram showing an example of the shapes of the carrier long line 124 and the carrier short line 125. In Figure 3Among them, as an example, the length direction of the line along the surface of the semiconductor substrate on which the carrier wavelength line 124 and the carrier short line 125 are provided is set as the "x direction", the width direction of the line orthogonal to the x direction is set as the "y direction", and the thickness direction of the line orthogonal to the x direction and the y direction is set as the "z direction". Hereinafter, as Figure 1 , Figure 2 shown, it is described that the length Lc1 of the carrier wavelength line 124 is longer than the length Lc2 of the carrier short line 125. In addition, in Figure 3 , the length of the width in the y direction in the line is set as "W", and the length of the thickness in the z direction is set as "t1".

[0064] As Figure 3 shown, the carrier wavelength line 124 and the carrier short line 125 are formed, for example, of a first conductor having a given conductivity on the semiconductor substrate. The carrier wavelength line 124 has, for example, a cross-sectional area (hereinafter referred to as the long line cross-sectional area) of a yz cross-section orthogonal to the x direction in at least a part of the carrier wavelength line 124. The carrier short line 125 has, for example, a cross-sectional area (hereinafter referred to as the short line cross-sectional area) of a yz cross-section orthogonal to the x direction in at least a part of the carrier short line 125. Each cross-sectional area is shown by the product of the length W of the width and the length t1 of the thickness. That is, the long line cross-sectional area of at least a part of the carrier wavelength line 124 is formed to be larger than the short line cross-sectional area of at least a part of the carrier short line 125 so that the carrier wavelength voltage drop amount and the carrier short voltage drop amount become substantially equal. In other words, the carrier wavelength line 124 and the carrier short line 125 are formed so that the resistance value of the carrier wavelength line 124 and the overall resistance value of the carrier short line 125 become substantially equal. Here, the case where one resistance value and another resistance value become substantially equal is, for example, set as the case where the difference between one resistance value and another resistance value is within 1 Ω. Specifically, for example, when the thickness (t1) of the carrier wavelength line 124 and the carrier short line 125 is the same, the width of the carrier wavelength line 124 is formed to be longer than the width of the carrier short line 125.

[0065] Furthermore, regarding the long carrier wavelength line 124 and the short carrier wavelength line 125, the cross-sections of the long carrier wavelength line 124 and the short carrier wavelength line 125 can also be formed such that the unit resistance of the first section and the unit resistance of the second section become substantially equal. The unit resistance of the first section is, for example, the resistance value of the long carrier wavelength line 124 divided by its length Lc1 per unit length when connected only through the long carrier wavelength line 124 between the first bias circuit 123 and the second carrier amplifier 118. In addition, the unit resistance of the second section is, for example, the resistance value of the short carrier wavelength line 125 divided by its line length per unit length when connected only through the short carrier wavelength line 125 between the first bias circuit 123 and the first carrier amplifier 115. Thus, in the long carrier wavelength line 124 and the short carrier wavelength line 125, the long carrier wavelength voltage drop and the short carrier wavelength voltage drop become substantially equal. Here, the case where the unit resistance of one section and the unit resistance of the other section become substantially equal is, for example, set to the case where the difference between the value of the unit resistance of one section and the value of the unit resistance of the other section is within 1 Ω.

[0066] Next, with reference to Figure 4 , a modified example of the shape of the long carrier wavelength line 124 will be described. Figure 4 FIG. shows a first modified example of the shape of the long carrier wavelength line 124. Figure 4 Shows the same x-direction, y-direction, and z-direction as Figure 3 . As Figure 4 shown, regarding the long carrier wavelength line 124, for example, at least a part thereof is formed by a first conductor 124a provided on a semiconductor substrate and a second conductor 124b laminated on the first conductor 124a. The first conductor 124a is formed of a first conductive material having a given conductivity, for example. The first conductive material is, for example, copper, gold, aluminum, etc. The second conductor 124b is formed of a second conductive material having a given conductivity, for example. The second conductive material is, for example, copper, gold, aluminum, etc., and can be the same conductive material as the first conductive material or a different conductive material from the first conductive material. Thus, when the short carrier wavelength line 125 is formed only of the first conductor 124a, for example, in the power amplifier circuit 100, compared with the short carrier wavelength line 125, the long line cross-sectional area of the long carrier wavelength line 124 is larger, so that the long carrier wavelength voltage drop can be made substantially equal to the short carrier wavelength voltage drop. In other words, in the power amplifier circuit 100, the unit resistance of the first section of the long carrier wavelength line 124 and the unit resistance of the second section of the short carrier wavelength line 125 can be made substantially equal, so that the long carrier wavelength voltage drop and the short carrier wavelength voltage drop can be made substantially equal.

[0067] In addition, although it is described above that the wavelength-carrying line 124 has a portion formed by two layers of the first conductor 124a and the second conductor 124b, it is not limited thereto. For example, the wavelength-carrying line 124 may also be formed by including three or more layers of conductors.

[0068] Next, with reference to Figure 5 , a modified example of the shape of the wavelength-carrying line 124 will be described. Figure 5 FIG. is a diagram showing a second modified example of the shape of the wavelength-carrying line 124. Figure 5 Shows the same x-direction, y-direction, and z-direction as Figure 3 . As Figure 5 shown, with respect to the wavelength-carrying line 124, for example, at least a part thereof is formed by the first conductor 124c and the second conductor 124d laminated on the first conductor 124c. The first conductor 124c is the same as the first conductor 124a of Figure 4 , so the description thereof is omitted. The second conductor 124d has the same conductive material as the second conductor 124b of Figure 4 , so the description of its conductive material is omitted. As Figure 5 shown, the second conductor 124d has, for example, a portion where the thickness in the z-direction at the end in the y-direction of the wavelength-carrying line 124 is thicker than the thickness in the z-direction at the center in the x-direction. Thus, in the case where the carrier-short line 125 is formed only by the first conductor 124c, in the power amplifier circuit 100, compared with the carrier-short line 125, the long-line cross-sectional area of the wavelength-carrying line 124 is larger, so that the amount of decrease in the wavelength-carrying voltage can be made substantially equal to the amount of decrease in the carrier-short voltage. In other words, in the power amplifier circuit 100, the unit resistance of the first section of the wavelength-carrying line 124 and the unit resistance of the second section of the carrier-short line 125 can be made substantially equal, so that the amount of decrease in the wavelength-carrying voltage can be made substantially equal to the amount of decrease in the carrier-short voltage. Further, the harmonic current flowing through the conductor has the characteristic of concentrating on the end (outer side) in the y-direction of the conductor. Therefore, by making the thickness in the z-direction of this end thicker, the power loss can be reduced.

[0069] In addition, although it is described above that the wavelength-carrying line 124 may also have a portion formed by two layers of the first conductor 124c and the second conductor 124d, it is not limited thereto. For example, the wavelength-carrying line 124 may also be formed by including three or more layers of conductors.

[0070] Next, with reference to Figure 6 , a modified example of the shape of the wavelength-carrying line 124 will be described. Figure 6 FIG. is a diagram showing a third modified example of the shape of the wavelength-carrying line 124. Figure 6 Shows the same x-direction, y-direction, and z-direction as Figure 3 ​Figure 6 As shown, regarding the carrier wavelength line 124, for example, at least a part of it is formed by a first conductor 124f and a second conductor 124g laminated on the first conductor 124f. The first conductor 124f is the same as the first conductor 124a of Figure 4 , so its description is omitted. The second conductor 124g has the same conductive material as the second conductor 124b of Figure 4 , so the description of its conductive material is omitted. As Figure 6 shown, the second conductor 124g is disposed, for example, along the x direction at at least one end in the y direction of the carrier wavelength line 124. Thus, in the case where the carrier short line 125 is formed only by the first conductor 124f, in the power amplifier circuit 100, compared with the short line cross-sectional area of the carrier short line 125, the long line cross-sectional area of the carrier wavelength line 124 can be increased, so that the carrier wavelength voltage drop amount can be made substantially equal to the carrier short voltage drop amount. In other words, in the power amplifier circuit 100, the unit resistance of the first section of the carrier wavelength line 124 and the unit resistance of the second section of the carrier short line 125 can be made substantially equal, so that the carrier wavelength voltage drop amount can be made substantially equal to the carrier short voltage drop amount. Further, the harmonic current flowing through the conductor has the characteristic of concentrating on the end (outer side) in the y direction of the conductor. Therefore, by thickening the thickness in the z direction of this end, the power loss can be reduced.

[0071] In addition, although it has been described above that the carrier wavelength line 124 may also have a part formed by two layers of the first conductor 124f and the second conductor 124g, it is not limited thereto. For example, the carrier wavelength line 124 may also be formed by including three or more layers of conductors.

[0072] Next, with reference to Figure 7 , a modified example of the shape of the carrier short line 125 will be described. Figure 7 is a diagram showing a first modified example of the shape of the carrier short line 125. Figure 7 shows the same x direction, y direction, and z direction as Figure 3 . As Figure 7 shown, regarding the carrier short line 125, for example, at least a part of it is formed by a third conductor 125a provided on the semiconductor substrate and a fourth conductor 125b laminated on the third conductor 125a. The third conductor 125a is formed of a third conductive material having a given conductivity. The third conductive material is, for example, copper, gold, aluminum, etc. The fourth conductor 125b is formed of a fourth conductive material having a given conductivity. The fourth conductive material is, for example, copper, gold, aluminum, etc., and is a conductive material having a lower conductivity than the conductivity of the third conductive material. In Figure 7In this case, for example, the thicknesses of the third conductor 125a and the fourth conductor 125b (for example, assumed to be thickness t3) are made t1. Thus, when the carrier wavelength line 124 is formed only of the first conductor 124a having a thickness of t1, in the power amplifier circuit 100, the unit resistance of the second section of the carrier short line 125 can be made substantially equal to the unit resistance of the first section of the carrier wavelength line 124. Therefore, the carrier short voltage drop amount becomes substantially equal to the carrier wavelength voltage drop amount.

[0073] In addition, although it has been described above that the carrier short line 125 may also have a portion formed of two layers, namely the third conductor 125a and the fourth conductor 125b, it is not limited thereto. For example, the carrier short line 125 may be formed including three or more conductors.

[0074] Next, with reference to Figure 8 a modification of the shape of the carrier short line 125 will be described. Figure 8 FIG. is a diagram showing a second modification of the shape of the carrier short line 125. Figure 8 shows the same x-direction, y-direction, and z-direction as Figure 3 . As Figure 8 shown, for the carrier short line 125, for example, at least a part thereof is formed of the third conductor 125c and the fourth conductor 125d laminated on the third conductor 125c. The third conductor 125c is the same as the third conductor 125a of Figure 7 , so its description is omitted. The fourth conductor 125d has the same conductive material as the fourth conductor 125b of Figure 7 , so the description of its conductive material is omitted. As Figure 8 shown, the fourth conductor 125d is provided along the x-direction at at least one end in the y-direction of the third conductor 125c. Thus, when the carrier wavelength line 124 is formed only of the first conductor 124a having a thickness of t1, in the power amplifier circuit 100, the unit resistance of the second section of the carrier short line 125 can be made substantially equal to the unit resistance of the first section of the carrier wavelength line 124. Therefore, the carrier short voltage drop amount becomes substantially equal to the carrier wavelength voltage drop amount. Furthermore, the harmonic current flowing through the conductor has the characteristic of concentrating on the end (outer side) in the y-direction of the conductor. Therefore, by making the thickness in the z-direction of this end thicker, the power loss can be reduced.

[0075] In addition, although it has been described above that the carrier wavelength line 124 may also have a portion formed of two layers, namely the third conductor 125c and the fourth conductor 125d, it is not limited thereto. For example, the carrier wavelength line 124 may be formed including three or more conductors.

[0076] Next, with reference to Figure 9, the following method will be described. That is, in the power amplifier circuit 100, in order to make the carrier long voltage drop amount and the carrier short voltage drop amount approximately equal, a resistor 129 is connected in series to the carrier short line 125. Figure 9 FIG. shows the layout on the semiconductor substrate of the power amplifier circuit 100 including the resistor 129 in its components. Regarding the method of connecting the resistor 129 in series to the peak short line 128 in order to make the peak long voltage drop amount and the peak short voltage drop amount approximately equal, it is the same as the method of connecting the resistor in series to the carrier short line 125, so its description is omitted.

[0077] In the power amplifier circuit 100, for example, in order to make the carrier long voltage drop amount and the carrier short voltage drop amount approximately equal, a resistor 129 is connected in series to the carrier short line 125. In other words, when the cross-section of the carrier long line 124 and the cross-section of the carrier short line 125 are approximately equal, by connecting a resistor to the shorter line in terms of length, the unit resistance of the second interval can be increased. In Figure 9 , by connecting a resistor to the carrier short line 125, the unit resistance of the first interval between the first bias circuit 123 and the second carrier amplifier 118 and the unit resistance of the second interval between the first bias circuit 123 and the first carrier amplifier 115 can be made approximately equal.

[0078] The resistor 129 connected in series to the carrier short line 125 is, for example, arranged on the same semiconductor substrate as other components of the power amplifier circuit 100. As Figure 9 shown, this resistor 129 can be connected to, for example, one end of the carrier short line 125, or the other end, or both ends respectively. Furthermore, this resistor 129 can also be connected in such a way that it is inserted in the middle of the carrier short line 125.

[0079] <<Structure for miniaturizing the power amplifier circuit 100>>

[0080] Next, with reference to Figure 1 , Figure 10 , the structure for miniaturizing the power amplifier circuit 100 will be described. Figure 10 FIG. shows an example of the structure of the distributor 111.

[0081] As Figure 10As shown, the distributor 111 includes, for example, a transformer 111a, a first capacitor 111b, and a second capacitor 111c. The transformer 111a is, for example, a winding transformer including an input-side winding 111a1 and an output-side winding 111a2 that perform magnetic field coupling. The transformer 111a propagates, for example, a signal input to the input-side winding 111a1 to the output-side winding 111a2. Specifically, when an input signal RFin is input to the input-side winding 111a1 of the transformer 111a, two signals with phase inversion (signal RF1 and signal RF2) are output from the output-side winding 111a2. A power supply voltage Vcc is supplied to the input-side winding 111a1 of the transformer 111a, for example. In addition, the transformer 111a can function as an impedance matcher by adjusting the winding ratio between the input-side winding 111a1 and the output-side winding 111a2. As a result, there is no need to provide a matching circuit (for example, the matching circuit 113), and the impedance can be matched by the transformer 111a formed on the semiconductor substrate. Therefore, the power amplifier circuit 100 can reduce the circuit scale. The first capacitor 111b is connected in parallel with the input-side winding 111a1, for example. The second capacitor 111c is connected in parallel with the output-side winding 111a2, for example. The first capacitor 111b and the second capacitor 111c are provided, for example, for impedance matching of the transformer 111a considering the influence of the parasitic inductance of the transformer 111a.

[0082] As Figure 1 shown, in the power amplifier circuit 100, a first Doherty amplifier is constituted by a second carrier amplifier 118 and a first peak amplifier 116, and a second Doherty amplifier is constituted by a first carrier amplifier 115 and a second peak amplifier 119. By generating two signals with phase inversion in the distributor 111 constituted by the above-mentioned balun, each Doherty amplifier can input a signal to the carrier amplifier that is 90 degrees ahead of the peak amplifier in phase through the first phase shifter 114 and the second phase shifter 117 (for example, a 1 / 4 wavelength line). That is, the power amplifier circuit 100 constituted by differential Doherty amplifiers can be miniaturized by using a balun smaller than a 1 / 4 wavelength line instead of a 1 / 4 wavelength line.

[0083] Referring Figure 11 to, a first modification of the structure for miniaturizing the power amplifier circuit will be described. Figure 11FIG. is a diagram showing an example of a power amplifier circuit 100a according to the first modification. Compared with the power amplifier circuit 100, the connection destinations of the first phase shifter 114a, the second phase shifter 117a, the third phase shifter 120a, and the fourth phase shifter 121a are different. Specifically, the first phase shifter 114a is electrically connected, for example, between the distributor 111 and the first peak amplifier 116 to delay the phase of the branch signal RF11 by approximately 90 degrees. The second phase shifter 117a is electrically connected, for example, between the distributor 111 and the second peak amplifier 119 to delay the phase of the branch signal RF21 by approximately 90 degrees. The synthesizer 122 is input, for example, with a signal (phase: "90 degrees") synthesized by the synthesizing unit 122a1. The synthesizing unit 122a1 synthesizes the signal RFout11 output from the first peak amplifier 116 and the signal RFout12 output from the first carrier amplifier 115 through the third phase shifter 120a. In addition, the synthesizer 122 is input, for example, with a signal (phase: "270 degrees") synthesized by the synthesizing unit 122b1. The synthesizing unit 122b1 synthesizes the signal RFout21 output from the second peak amplifier 119 and the signal RFout22 output from the second carrier amplifier 118 through the fourth phase shifter 121a. The synthesizer 122 synthesizes two signals with inverted phases and outputs the signal RFout.

[0084] Refer to Figure 12 , and a second modification of the structure for miniaturizing the power amplifier circuit will be described. Figure 12FIG. 0 is a diagram showing an example of a power amplifier circuit 100b according to the second modified example. Compared with the power amplifier circuit 100, the connection destinations of the first phase shifter 114b, the second phase shifter 117b, the third phase shifter 120b, and the fourth phase shifter 121b are different, and furthermore, the phase changes in the first phase shifter 114b and the second phase shifter 117b are different. The first phase shifter 114b is electrically connected, for example, between the distributor 111 and the first peak amplifier 116, and advances the phase of the branch signal RF11 by approximately 90 degrees. The second phase shifter 117b is electrically connected, for example, between the distributor 111 and the second peak amplifier 119, and advances the phase of the branch signal RF21 by approximately 90 degrees. The synthesizer 122 is input, for example, with a signal (phase: "270 degrees") synthesized by the synthesizing unit 122a, and the synthesizing unit 122a synthesizes the signal RFout11 output from the first peak amplifier 116 and the signal RFout22 output from the second carrier amplifier 118 through the fourth phase shifter 121b. In addition, the synthesizer 122 is input, for example, with a signal (phase: "90 degrees") synthesized by the synthesizing unit 122b, and the synthesizing unit 122b synthesizes the signal RFout11 output from the first carrier amplifier 115 through the third phase shifter 120b and the signal RFout22 output from the second peak amplifier 119. The synthesizer 122 synthesizes two signals with inverted phases and outputs the signal RFout. In addition, the first phase shifter 114b and the second phase shifter 117b are, for example, high-pass filters formed of distributed constant lines.

[0085] Refer to Figure 13 , and a third modified example of a structure for miniaturizing the power amplifier circuit will be described. Figure 13FIG. 0 is a diagram showing an example of the power amplifier circuit 100c according to the third modification. The power amplifier circuit 100c is different from the power amplifier circuit 100a according to the first modification in that the first phase shifter 114c and the second phase shifter 117c are different. Specifically, the first phase shifter 114c is electrically connected, for example, between the splitter 111 and the first carrier amplifier 115, and advances the phase of the branch signal RF12 by approximately 90 degrees. The second phase shifter 117c is electrically connected, for example, between the splitter 111 and the second carrier amplifier 118, and advances the phase of the branch signal RF22 by approximately 90 degrees. The synthesizer 122 is input, for example, with the signal (phase: "90 degrees") synthesized by the synthesizing unit 122a1. The synthesizing unit 122a1 synthesizes the signal RFoutl1 output from the first peak amplifier 116 and the signal RFout12 output from the first carrier amplifier 115 through the third phase shifter 120c. In addition, the synthesizer 122 is input, for example, with the signal (phase: "270 degrees") synthesized by the synthesizing unit 122b1. The synthesizing unit 122b1 synthesizes the signal RFout21 output from the second peak amplifier 119 and the signal RFout22 output from the second carrier amplifier 118 through the fourth phase shifter 121c. The synthesizer 122 synthesizes two signals with inverted phases and outputs the signal RFout.

[0086] ====Summary====

[0087] In the power amplifier circuit 100 according to this embodiment, the following components are provided on the same semiconductor substrate: a distributor 111 that distributes an input signal RFin into a signal RF2 (first signal) and a signal RF1 (second signal) having a phase different from that of the signal RF2 (first signal); a second carrier amplifier 118 (first amplifier) that amplifies a branched signal RF22 (first branched signal) branched from the signal RF2 (first signal) and outputs a signal RFout22 (first amplified signal); a second peak amplifier 119 (second amplifier) that, when the power level of a branched signal RF21 (second branched signal) branched from the signal RF2 (first signal) shows a given power level or more, amplifies the branched signal RF21 (second branched signal) and outputs a signal RFout21 (second amplified signal); a first carrier amplifier 115 (third amplifier) that amplifies a branched signal RF12 (third branched signal) branched from the signal RF1 (second signal) and outputs a signal RFout12 (third amplified signal); a first peak amplifier 116 (fourth amplifier) that, when the power level of a branched signal RF11 (fourth branched signal) branched from the signal RF1 (second signal) shows a given power level or more, amplifies the branched signal RF11 (fourth branched signal) and outputs a signal RFout11 (fourth amplified signal); a first bias circuit 123 that outputs a first bias voltage; a carrier wavelength line 124 (first line) of a first length that connects the first bias circuit 123 and the second carrier amplifier 118 (first amplifier); and a carrier short line 125 (second line) of a second length that connects the first bias circuit 123 and the first carrier amplifier 115 (third amplifier), the second length being shorter than the first length, and the carrier wavelength line 124 (first line) and the carrier short line 125 (second line) are formed such that the voltage drop amount of the first bias voltage between the first bias circuit 123 and the second carrier amplifier 118 (first amplifier) and the voltage drop amount of the first bias voltage between the first bias circuit 123 and the first carrier amplifier 115 (third amplifier) become substantially equal. As a result, the efficiency of the power amplifier circuit 100 is improved. In addition, it is possible to increase the power of the output power and improve the distortion characteristics.

[0088] In addition, in the power amplifier circuit 100 according to this embodiment, on the same semiconductor substrate, there are also provided: a second bias circuit 126 that outputs a second bias voltage; a peak long line 127 (third line) with a third length that connects the second bias circuit 126 and the second peak amplifier 119 (second amplifier); and a peak short line 128 (fourth line) with a fourth length that connects the second bias circuit 126 and the first peak amplifier 116 (fourth amplifier). The fourth length is shorter than the third length. The peak long line 127 (third line) and the peak short line 128 (fourth line) are formed such that the voltage drop of the second bias voltage between the second bias circuit 126 and the second peak amplifier 119 (second amplifier) and the voltage drop of the second bias voltage between the second bias circuit 126 and the first peak amplifier 116 (fourth amplifier) become substantially equal. Thereby, the efficiency of the power amplifier circuit 100 is improved. Furthermore, not only is the efficiency improved, but also the output power can be increased and the distortion characteristics can be improved.

[0089] In addition, in the power amplifier circuit 100 according to this embodiment, the carrier long line 124 (first line) includes a first portion having a first cross-sectional area in a cross-section orthogonal to the length direction of the carrier long line 124 (first line), and the carrier short line 125 (second line) includes a second portion having a second cross-sectional area in a cross-section orthogonal to the length direction of the carrier short line 125 (second line). The first cross-sectional area is larger than the second cross-sectional area. Thereby, the bias points of the two amplifiers in a differential relationship can be made to coincide, and thus the efficiency of the power amplifier circuit 100 is improved.

[0090] In addition, in the power amplifier circuit 100 according to this embodiment, the first portion of the carrier long line 124 (first line) is formed of a first number of layers of 2 or more, and the second portion of the carrier short line 125 (second line) is formed of a second number of layers less than the first number. Thereby, by appropriately adjusting the resistance of the lines, the bias points of the two amplifiers in a differential relationship can be made to coincide, and thus the efficiency of the power amplifier circuit 100 is improved. Furthermore, not only is the efficiency improved, but also the output power can be increased and the distortion characteristics can be improved.

[0091] In addition, in the power amplifier circuit 100 according to the present embodiment, the first portion of the carrier wavelength line 124 (first line) is formed by a first conductor 124c and a second conductor 124d. The first conductor 124c is formed of a given conductive material. The second conductor 124d is laminated on the first conductor 124c and is formed of a given conductive material. The end portion of the second conductor 124d in the y direction (width direction) orthogonal to the x direction (length direction) of the carrier wavelength line 124 (first line) has a thickness in the thickness direction orthogonal to the x direction (length direction) and the y direction (width direction) that is thicker than the thickness at the central portion of the second conductor 124d in the y direction (width direction). Thereby, by appropriately adjusting the resistance of the line, the bias points of the two amplifiers in a differential relationship can be made to coincide, and thus the efficiency of the power amplifier circuit 100 is improved. Further, by thickening the thickness of the end portion of the second conductor 124d in the z direction, power loss can be reduced.

[0092] In addition, in the power amplifier circuit 100 according to the present embodiment, the first portion of the carrier wavelength line 124 (first line) is formed by a first conductor 124f and a second conductor 124g. The first conductor 124f is formed of a given conductive material. The second conductor 124g is laminated on the first conductor 124f and is formed of a given conductive material. The end portion of the second conductor 124g in the y direction (width direction) orthogonal to the x direction (length direction) of the carrier wavelength line 124 (first line) is provided along the x direction (length direction). Thereby, by appropriately adjusting the resistance of the line, the bias points of the two amplifiers in a differential relationship can be made to coincide, and thus the efficiency of the power amplifier circuit 100 is improved. Further, by thickening the thickness of the end portion of the carrier wavelength line 124 in the z direction, power loss can be reduced.

[0093] In addition, in the power amplifier circuit 100 according to the present embodiment, the first portion of the carrier wavelength line 124 (first line) is formed of 1 or more first number of layers, and the second portion of the carrier short line 125 (second line) is formed of a second number of layers that is more than the first number. Thereby, the unit resistance of the second section of the carrier short line 125 can be made substantially equal to the unit resistance of the first section of the carrier wavelength line 124. That is, the carrier short voltage drop amount becomes substantially equal to the carrier wavelength voltage drop amount, and thus the bias points of the two amplifiers in a differential relationship can be made to coincide.

[0094] In addition, in the power amplifier circuit 100 according to the present embodiment, the second part of the carrier short circuit line 125 (second line) is formed by a third conductor 125c and a fourth conductor 125d. The third conductor 125c is formed of a given conductive material. The fourth conductor 125d is laminated on the third conductor 125c and is formed of a given conductive material. The end portion of the fourth conductor 125d in the y direction (width direction) orthogonal to the x direction (length direction) of the carrier short circuit line 125 (second line) has a thickness in the z direction (thickness direction) orthogonal to the x direction (length direction) and the y direction (width direction) that is thicker than the thickness at the central portion of the fourth conductor 125d in the y direction (width direction). Thereby, by appropriately adjusting the resistance of the line, the bias points of the two amplifiers in a differential relationship can be made consistent, so the efficiency of the power amplifier circuit 100 is improved. Furthermore, by making the thickness of the end portion of the fourth conductor 125d in the z direction thicker, power loss can be reduced.

[0095] In addition, in the power amplifier circuit 100 according to the present embodiment, the second part of the carrier short circuit line 125 (second line) is formed by a third conductor 125c and a fourth conductor 125d. The third conductor 125c is formed of a given conductive material. The fourth conductor 125d is laminated on the third conductor 125c and is formed of a given conductive material. The end portion of the fourth conductor 125d in the y direction (width direction) orthogonal to the x direction (length direction) of the carrier short circuit line 125 (second line) is arranged along the x direction (length direction). Thereby, by appropriately adjusting the resistance of the line, the bias points of the two amplifiers in a differential relationship can be made consistent, so the efficiency of the power amplifier circuit 100 is improved. Furthermore, by making the thickness of the end portion of the carrier short circuit line 125 in the z direction thicker, power loss can be reduced.

[0096] In addition, in the power amplifier circuit 100 according to the present embodiment, a resistor 129 is further provided on the same semiconductor substrate and is connected in series with the carrier short circuit line 125 (second line) between the first bias circuit 123 and the first carrier amplifier 115 (third amplifier). Thereby, the unit resistance of the first section between the first bias circuit 123 and the second carrier amplifier 118 and the unit resistance of the second section between the first bias circuit 123 and the first carrier amplifier 115 can be made substantially equal. That is, the carrier short voltage drop amount becomes substantially equal to the carrier long voltage drop amount, so the bias points of the two amplifiers in a differential relationship can be made consistent.

[0097] In addition, in the power amplifier circuit 100 according to the present embodiment, the peak long line 127 (the third line) includes a third portion having a third cross-sectional area in a cross-section orthogonal to the x-direction (the length direction) of the peak long line 127 (the third line), and the peak short line 128 (the fourth line) includes a portion having a fourth cross-sectional area in a cross-section orthogonal to the x-direction (the length direction) of the peak short line 128 (the fourth line), and the third cross-sectional area is larger than the fourth cross-sectional area. Thereby, the bias points of the two amplifiers in a differential relationship can be made consistent, so the efficiency of the power amplifier circuit 100 is improved. Furthermore, not only is the efficiency improved, but also the power of the output power can be increased and the distortion characteristics can be improved.

[0098] In addition, in the power amplifier circuit 100 according to the present embodiment, the third portion of the peak long line 127 (the third line) is formed of a third number of layers of 2 or more, and the fourth portion of the peak short line 128 (the fourth line) is formed of a fourth number of layers less than the first number. Thereby, by appropriately adjusting the resistance of the line, the bias points of the two amplifiers in a differential relationship can be made consistent, so the efficiency of the power amplifier circuit 100 is improved. Furthermore, not only is the efficiency improved, but also the power of the output power can be increased and the distortion characteristics can be improved.

[0099] In addition, in the power amplifier circuit 100 according to the present embodiment, the third portion of the peak long line 127 (the third line) is formed of a fifth conductor (corresponding to the first conductor 124c) and a sixth conductor (corresponding to the second conductor 124d). The fifth conductor (corresponding to the first conductor 124c) is formed of a given conductive material, the sixth conductor (corresponding to the second conductor 124d) is laminated on the fifth conductor (corresponding to the first conductor 124c) and is formed of a given conductive material, and the sixth conductor (corresponding to the second conductor 124d) has a portion in the thickness direction orthogonal to the x-direction (the length direction) and the y-direction (the width direction) at the end in the y-direction (the width direction) orthogonal to the x-direction (the length direction) of the peak long line 127 (the third line) that is thicker than the thickness at the center in the y-direction (the width direction) of the sixth conductor (corresponding to the second conductor 124d). Thereby, by appropriately adjusting the resistance of the line, the bias points of the two amplifiers in a differential relationship can be made consistent, so the efficiency of the power amplifier circuit 100 is improved. Furthermore, by making the thickness of the sixth conductor in the z-direction at the end thicker, the power loss can be reduced.

[0100] In addition, in the power amplifier circuit 100 according to the present embodiment, the third part of the peak long line 127 (the third line) is formed by a fifth conductor (corresponding to the first conductor 124f) and a sixth conductor (corresponding to the second conductor 124g). The fifth conductor (corresponding to the first conductor 124f) is formed of a given conductive material. The sixth conductor (corresponding to the second conductor 124g) is laminated on the fifth conductor (corresponding to the first conductor 124f) and is formed of a given conductive material. The end of the sixth conductor (corresponding to the second conductor 124g) in the y direction (width direction) orthogonal to the x direction (length direction) of the peak long line 127 (the third line) is arranged along the x direction (length direction). Accordingly, by appropriately adjusting the resistance of the line, the bias points of the two amplifiers in a differential relationship can be made consistent, and thus the efficiency of the power amplifier circuit 100 is improved. Further, by increasing the thickness of the end of the peak long line 127 in the z direction, power loss can be reduced.

[0101] In addition, in the power amplifier circuit 100 according to the present embodiment, the third part of the peak long line 127 (the third line) is formed of 1 or more third number of layers, and the fourth part of the peak short line 128 (the fourth line) is formed of a fourth number of layers larger than the first number. Accordingly, the unit resistance of the fourth section of the peak short line 128 can be made substantially equal to the unit resistance of the third section of the peak long line 127. That is, the peak short voltage drop amount becomes substantially equal to the peak long voltage drop amount, and thus the bias points of the two amplifiers in a differential relationship can be made consistent.

[0102] In addition, in the power amplifier circuit 100 according to the present embodiment, the fourth part of the peak short line 128 (the fourth line) is formed by a seventh conductor (corresponding to the third conductor 125c) and an eighth conductor (corresponding to the fourth conductor 125d). The seventh conductor (corresponding to the third conductor 125c) is formed of a given conductive material. The eighth conductor (corresponding to the fourth conductor 125d) is laminated on the seventh conductor (corresponding to the third conductor 125) and is formed of a given conductive material. The end of the eighth conductor (corresponding to the fourth conductor 125d) in the thickness direction orthogonal to the x direction (length direction) and the y direction (width direction) of the peak short line 128 (the fourth line) has a part that is thicker than the thickness of the central part of the eighth conductor (corresponding to the fourth conductor 125d) in the y direction (width direction). Accordingly, by appropriately adjusting the resistance of the line, the bias points of the two amplifiers in a differential relationship can be made consistent, and thus the efficiency of the power amplifier circuit 100 is improved. Further, by increasing the thickness of the end of the eighth conductor in the z direction, power loss can be reduced.

[0103] In addition, in the power amplifier circuit 100 according to this embodiment, the fourth part of the peak short circuit line 128 (the fourth line) is formed by the seventh conductor (equivalent to the third conductor 125c) and the eighth conductor (equivalent to the fourth conductor 125d). The seventh conductor (equivalent to the third conductor 125c) is formed of a given conductive material. The eighth conductor (equivalent to the fourth conductor 125d) is laminated on the seventh conductor (equivalent to the third conductor 125c) and is formed of a given conductive material. The end of the eighth conductor (equivalent to the fourth conductor 125d) in the y direction (width direction) orthogonal to the x direction (length direction) of the peak short circuit line 128 (the fourth line) is arranged along the x direction (length direction). Thus, by appropriately adjusting the resistance of the line, the bias points of the two amplifiers in a differential relationship can be made consistent, and therefore the efficiency of the power amplifier circuit 100 is improved. Furthermore, by thickening the thickness of the end of the peak short circuit line 128 in the z direction, the power loss can be reduced.

[0104] In addition, in the power amplifier circuit 100 according to this embodiment, a resistor connected in series with the peak short circuit line 128 (the fourth line) is further provided on the same semiconductor substrate between the second bias circuit 126 and the first peak amplifier 116 (the fourth amplifier). Thereby, the unit resistance of the third section between the second bias circuit 126 and the second peak amplifier 119 and the unit resistance of the fourth section between the second bias circuit 126 and the first peak amplifier 116 can be made substantially equal. That is, the peak short voltage drop amount becomes substantially equal to the peak long voltage drop amount, and therefore the bias points of the two amplifiers in a differential relationship can be made consistent.

[0105] In addition, the power amplifier circuit 100 according to this embodiment further includes: second phase shifters 117, 117c (phase shifters) connected between the distributor 111 and the second carrier amplifier 118 (the first amplifier) to change the phase of the branch signal RF22 (the first branch signal); and first phase shifters 114, 114c (phase shifters) connected between the distributor 111 and the first carrier amplifier 115 (the third amplifier) to change the phase of the branch signal RF12 (the third branch signal). Thereby, the number of 1 / 4 wavelength lines can be reduced, and therefore the power amplifier circuit 100 can be miniaturized.

[0106] In addition, the power amplifier circuit 100 according to the present embodiment further includes: second phase shifters 117a and 117b (phase shifters) connected between the splitter 111 and the second peak amplifier 119 (second amplifier) to change the phase of the branch signal RF21 (second branch signal); and first phase shifters 114a and 114b (phase shifters) connected between the splitter 111 and the first peak amplifier 116 (fourth amplifier) to change the phase of the branch signal RF11 (fourth branch signal). Thereby, the number of quarter-wavelength lines can be reduced, and thus the power amplifier circuit 100 can be miniaturized.

[0107] In addition, the splitter 111 of the power amplifier circuit 100 according to the present embodiment is a balun. Thereby, the number of quarter-wavelength lines can be reduced, and thus the power amplifier circuit 100 can be miniaturized.

[0108] The embodiments described above are for facilitating the understanding of the present disclosure and are not intended to limit the interpretation of the present disclosure. The present disclosure can be changed or improved without departing from its gist, and the present disclosure includes its equivalents. That is, as long as the features of the present disclosure are possessed, embodiments in which those skilled in the art have appropriately made design changes to the embodiments are also included in the scope of the present disclosure. The elements and their configurations included in the embodiments are not limited to the illustrated elements and their configurations and can be changed appropriately.

[0109] Description of Reference Numerals

[0110] 100: Power amplifier circuit; 111: Splitter; 114: First phase shifter; 117: Second phase shifter; 115: First carrier amplifier; 116: First peak amplifier; 118: Second carrier amplifier; 119: Second peak amplifier; 120: Third phase shifter; 121: Fourth phase shifter; 122: Combiner; 123: First bias circuit; 124: Carrier wavelength line; 125: Carrier short line; 126: Second bias circuit; 127: Peak long line; 128: Peak short line.

Claims

1. A power amplifier circuit, wherein: on the same semiconductor substrate, there are provided: a distributor that distributes an input signal into a first signal and a second signal having a phase different from that of the first signal; a first amplifier that amplifies a first branch signal branched from the first signal and outputs a first amplified signal; a second amplifier that, when the power level of a second branch signal branched from the first signal shows a given power level or more, amplifies the second branch signal and outputs a second amplified signal; a third amplifier that amplifies a third branch signal branched from the second signal and outputs a third amplified signal; a fourth amplifier that, when the power level of a fourth branch signal branched from the second signal shows a given power level or more, amplifies the fourth branch signal and outputs a fourth amplified signal; a first bias circuit that outputs a first bias voltage; a first line with a first length that connects the first bias circuit and the first amplifier; and a second line with a second length that connects the first bias circuit and the third amplifier, the second length being shorter than the first length, wherein the first line and the second line are formed such that the difference in the voltage drop of the first bias voltage between the first bias circuit and the first amplifier and the voltage drop of the first bias voltage between the first bias circuit and the third amplifier is within 100 mV.

2. The power amplifier circuit according to claim 1, wherein: on the same semiconductor substrate, there is further provided: a second bias circuit that outputs a second bias voltage; a third line with a third length that connects the second bias circuit and the second amplifier; and a fourth line with a fourth length that connects the second bias circuit and the fourth amplifier, the fourth length being shorter than the third length, wherein the third line and the fourth line are formed such that the difference in the voltage drop of the second bias voltage between the second bias circuit and the second amplifier and the voltage drop of the second bias voltage between the second bias circuit and the fourth amplifier is within 100 mV.

3. The power amplifier circuit according to claim 1 or claim 2, wherein: the first line includes a first portion having a first cross-sectional area in a cross-section orthogonal to the length direction of the first line, the second line includes a second portion having a second cross-sectional area in a cross-section orthogonal to the length direction of the second line, the first cross-sectional area is larger than the second cross-sectional area.

4. The power amplifier circuit according to claim 3, wherein: the first portion of the first line is formed of 2 or more first numbers of layers, the second portion of the second line is formed of a second number of layers less than the first number.

5. The power amplifier circuit according to claim 4, wherein: the first portion of the first line is formed of a first conductor and a second conductor, the first conductor is formed of a given conductive material, and the second conductor is laminated on the first conductor and is formed of a given conductive material, The end portion of the second conductor in the width direction orthogonal to the length direction of the first line has a thickness in the thickness direction orthogonal to the length direction and the width direction, which is thicker than the thickness at the central portion of the second conductor in the width direction.

6. The power amplifier circuit according to claim 4, wherein The first portion of the first line is formed by a first conductor and a second conductor. The first conductor is formed of a given conductive material, and the second conductor is laminated on the first conductor and formed of a given conductive material. The end portion of the second conductor in the width direction orthogonal to the length direction of the first line is provided along the length direction.

7. The power amplifier circuit according to claim 3, wherein The first portion of the first line is formed of one or more first numbers of layers. The second portion of the second line is formed of a second number of layers that is more than the first number.

8. The power amplifier circuit according to claim 7, wherein The second portion of the second line is formed by a third conductor and a fourth conductor. The third conductor is formed of a given conductive material, and the fourth conductor is laminated on the third conductor and formed of a given conductive material. The end portion of the fourth conductor in the width direction orthogonal to the length direction of the second line has a thickness in the thickness direction orthogonal to the length direction and the width direction, which is thicker than the thickness at the central portion of the fourth conductor in the width direction.

9. The power amplifier circuit according to claim 7, wherein The second portion of the second line is formed by a third conductor and a fourth conductor. The third conductor is formed of a given conductive material, and the fourth conductor is laminated on the third conductor and formed of a given conductive material. The end portion of the fourth conductor in the width direction orthogonal to the length direction of the second line is provided along the length direction.

10. The power amplifier circuit according to claim 1 or claim 2, wherein On the same semiconductor substrate, a resistor is further provided, which is connected in series with the second line between the first bias circuit and the third amplifier.

11. The power amplifier circuit according to claim 2, wherein The third line includes a third portion having a third cross-sectional area in a cross-section orthogonal to the length direction of the third line. The fourth line includes a fourth portion having a fourth cross-sectional area in a cross-section orthogonal to the length direction of the fourth line. The third cross-sectional area is larger than the fourth cross-sectional area.

12. The power amplifier circuit according to claim 11, wherein The third portion of the third line is formed of two or more third numbers of layers. The fourth portion of the fourth line is formed of a fourth number of layers that is less than the third number.

13. The power amplifier circuit according to claim 12, wherein The third portion of the third line is formed by a fifth conductor and a sixth conductor. The fifth conductor is formed of a given conductive material, and the sixth conductor is laminated on the fifth conductor and formed of a given conductive material. The end portion of the sixth conductor in the width direction orthogonal to the length direction of the third line has a thickness in the thickness direction orthogonal to the length direction and the width direction, which is thicker than the thickness at the central portion of the sixth conductor in the width direction.

14. The power amplifier circuit according to claim 12, wherein The third portion of the third line is formed by a fifth conductor and a sixth conductor. The fifth conductor is formed of a given conductive material, and the sixth conductor is laminated on the fifth conductor and formed of a given conductive material. The end portion of the sixth conductor in the width direction orthogonal to the length direction of the third line is arranged along the length direction.

15. The power amplifier circuit according to claim 11, wherein The third portion of the third line is formed by a third number of layers of 1 or more. The fourth portion of the fourth line is formed by a fourth number of layers more than the third number.

16. The power amplifier circuit according to claim 15, wherein The fourth portion of the fourth line is formed by a seventh conductor and an eighth conductor. The seventh conductor is formed of a given conductive material, and the eighth conductor is laminated on the seventh conductor and formed of a given conductive material. The end portion of the eighth conductor in the width direction orthogonal to the length direction of the fourth line has a thickness in the thickness direction orthogonal to the length direction and the width direction, which is thicker than the thickness at the central portion of the eighth conductor in the width direction.

17. The power amplifier circuit according to claim 15, wherein The fourth portion of the fourth line is formed by a seventh conductor and an eighth conductor. The seventh conductor is formed of a given conductive material, and the eighth conductor is laminated on the seventh conductor and formed of a given conductive material. The end portion of the eighth conductor in the width direction orthogonal to the length direction of the fourth line is arranged along the length direction.

18. The power amplifier circuit according to any one of claims 11 to 17, wherein On the same semiconductor substrate, a resistor connected in series with the fourth line between the second bias circuit and the fourth amplifier is further provided.

19. The power amplifier circuit according to claim 1 or claim 2, wherein It further includes: A phase shifter connected between the distributor and the first amplifier and changing the phase of the first branch signal; and A phase shifter connected between the distributor and the third amplifier and changing the phase of the third branch signal.

20. The power amplifier circuit according to claim 1 or claim 2, wherein It further includes: A phase shifter connected between the distributor and the second amplifier and changing the phase of the second branch signal; and A phase shifter connected between the distributor and the fourth amplifier and changing the phase of the fourth branch signal.

21. The power amplifier circuit according to claim 19, wherein The distributor is a balun.

22. A power amplifier circuit, wherein On the same semiconductor substrate, there are provided: A distributor that distributes an input signal into a first signal and a second signal having a phase different from that of the first signal; A first amplifier that amplifies a first branched signal branched from the first signal and outputs a first amplified signal; A second amplifier that, when a power level of a second branched signal branched from the first signal shows a given power level or more, amplifies the second branched signal and outputs a second amplified signal; A third amplifier that amplifies a third branched signal branched from the second signal and outputs a third amplified signal; A fourth amplifier that, when a power level of a fourth branched signal branched from the second signal shows a given power level or more, amplifies the fourth branched signal and outputs a fourth amplified signal; A first bias circuit that outputs a first bias voltage; A first line of a first length that connects the first bias circuit and the first amplifier; And A second line of a second length that connects the first bias circuit and the third amplifier, the second length being shorter than the first length, The first line includes a first portion having a first cross-sectional area in a cross-section orthogonal to the length direction of the first line, The second line includes a second portion having a second cross-sectional area in a cross-section orthogonal to the length direction of the second line, The first cross-sectional area is larger than the second cross-sectional area.

23. The power amplifier circuit according to claim 22, wherein On the same semiconductor substrate, there is further provided: A second bias circuit that outputs a second bias voltage; A third line of a third length that connects the second bias circuit and the second amplifier; and A fourth line of a fourth length that connects the second bias circuit and the fourth amplifier, the fourth length being shorter than the third length, The third line and the fourth line are formed such that a difference between a voltage drop of the second bias voltage between the second bias circuit and the second amplifier and a voltage drop of the second bias voltage between the second bias circuit and the fourth amplifier is within 100 mV.

24. The power amplifier circuit according to claim 22 or claim 23, wherein The first portion of the first line is formed of a first number of layers of 2 or more, The second portion of the second line is formed of a second number of layers less than the first number.

25. The power amplifier circuit according to claim 24, wherein The first portion of the first line is formed of a first conductor and a second conductor, The first conductor is formed of a given conductive material, and the second conductor is laminated on the first conductor and is formed of a given conductive material, The second conductor has a portion at an end in a width direction orthogonal to the length direction of the first line and having a thickness in a thickness direction orthogonal to the length direction and the width direction that is thicker than a thickness at a central portion in the width direction of the second conductor.

26. The power amplifier circuit according to claim 24, wherein The first part of the first line is formed by a first conductor and a second conductor. The first conductor is formed of a given conductive material, and the second conductor is laminated on the first conductor and formed of a given conductive material. An end of the second conductor in a width direction orthogonal to a length direction of the first line is provided along the length direction.

27. The power amplifier circuit according to claim 22 or claim 23, wherein the first part of the first line is formed of a first number of layers of 1 or more, the second part of the second line is formed of a second number of layers greater than the first number.

28. The power amplifier circuit according to claim 27, wherein the second part of the second line is formed by a third conductor and a fourth conductor. The third conductor is formed of a given conductive material, and the fourth conductor is laminated on the third conductor and formed of a given conductive material. An end of the fourth conductor in a width direction orthogonal to a length direction of the second line has a portion that is thicker in a thickness direction orthogonal to both the length direction and the width direction than a thickness at a central portion of the fourth conductor in the width direction.

29. The power amplifier circuit according to claim 27, wherein the second part of the second line is formed by a third conductor and a fourth conductor. The third conductor is formed of a given conductive material, and the fourth conductor is laminated on the third conductor and formed of a given conductive material. An end of the fourth conductor in a width direction orthogonal to a length direction of the second line is provided along the length direction.

30. The power amplifier circuit according to claim 22 or claim 23, wherein a resistor connected in series with the second line is further provided on the same semiconductor substrate between the first bias circuit and the third amplifier.

31. The power amplifier circuit according to claim 23, wherein the third line includes a third part having a third cross-sectional area in a cross-section orthogonal to a length direction of the third line, the fourth line includes a fourth part having a fourth cross-sectional area in a cross-section orthogonal to a length direction of the fourth line, and the third cross-sectional area is larger than the fourth cross-sectional area.

32. The power amplifier circuit according to claim 31, wherein the third part of the third line is formed of a third number of layers of 2 or more, the fourth part of the fourth line is formed of a fourth number of layers less than the third number.

33. The power amplifier circuit according to claim 32, wherein the third part of the third line is formed by a fifth conductor and a sixth conductor. The fifth conductor is formed of a given conductive material, and the sixth conductor is laminated on the fifth conductor and formed of a given conductive material. An end of the sixth conductor in a width direction orthogonal to a length direction of the third line has a portion that is thicker in a thickness direction orthogonal to both the length direction and the width direction than a thickness at a central portion of the sixth conductor in the width direction.

34. The power amplifier circuit according to claim 32, wherein, the third part of the third line is formed by a fifth conductor and a sixth conductor, the fifth conductor is formed of a given conductive material, the sixth conductor is laminated on the fifth conductor and is formed of a given conductive material, an end portion of the sixth conductor in a width direction orthogonal to the length direction of the third line is provided along the length direction.

35. The power amplifier circuit according to claim 31, wherein, the third part of the third line is formed of a third number of layers of 1 or more, the fourth part of the fourth line is formed of a fourth number of layers more than the third number.

36. The power amplifier circuit according to claim 35, wherein, the fourth part of the fourth line is formed by a seventh conductor and an eighth conductor, the seventh conductor is formed of a given conductive material, the eighth conductor is laminated on the seventh conductor and is formed of a given conductive material, an end portion of the eighth conductor in a width direction orthogonal to the length direction of the fourth line has a portion thicker in a thickness direction orthogonal to the length direction and the width direction than a thickness at a central portion in the width direction of the eighth conductor.

37. The power amplifier circuit according to claim 35, wherein, the fourth part of the fourth line is formed by a seventh conductor and an eighth conductor, the seventh conductor is formed of a given conductive material, the eighth conductor is laminated on the seventh conductor and is formed of a given conductive material, an end portion of the eighth conductor in a width direction orthogonal to the length direction of the fourth line is provided along the length direction.

38. The power amplifier circuit according to any one of claims 31 to 37, wherein, a resistor connected in series with the fourth line between the second bias circuit and the fourth amplifier is further provided on the same semiconductor substrate.

39. The power amplifier circuit according to claim 22 or claim 23, wherein, further provided with: a phase shifter connected between the distributor and the first amplifier and changing the phase of the first branch signal; and a phase shifter connected between the distributor and the third amplifier and changing the phase of the third branch signal.

40. The power amplifier circuit according to claim 22 or claim 23, wherein, further provided with: a phase shifter connected between the distributor and the second amplifier and changing the phase of the second branch signal; and a phase shifter connected between the distributor and the fourth amplifier and changing the phase of the fourth branch signal.

41. The power amplifier circuit according to claim 39, wherein, the distributor is a balun.

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