Power amplifier, power amplification device, radio frequency front-end module and electronic equipment

Abstract

The invention discloses a power amplifier, a power amplification device, a radio frequency front-end module and electronic equipment. The power amplifier comprises a power amplification circuit, a matching unit and a balun. The power amplification circuit is provided with a power supply end, a first output end and a second output end. The matching unit is connected among the first output end, the second output end and the primary side and used for improving the input impedance of the balun so that the output power of the power amplifier can be smaller than or equal to the maximum transmitting power corresponding to the preset power level. Due to the fact that the impedance of the balun is usually low, the matching unit is arranged between the balun and the power amplification circuit, the matching unit can improve the input impedance of the balun so as to reduce the output power of the power amplifier. Therefore, on the premise that the working efficiency of the power supply module is not affected, the actual output power of the power amplifier can conform to power levels specified by different power levels, so that a radio frequency front-end module provided with the power amplifier can work normally.

Description

Technical Field

[0001] The present application relates to the field of radio frequency technology, and more specifically, to a power amplifier, a power amplifier device, a radio frequency front-end module and an electronic device. Background Art

[0002] At present, RF front-end modules have been widely used in wireless communications, the Internet of Things, smart homes and other fields. They can process RF signals (for example, power amplification, modulation and demodulation, etc.) to complete the tasks of receiving and sending RF signals.

[0003] In existing RF front-end modules, the power amplifier (PA) plays a vital role in amplifying the power of RF signals. In order to improve working efficiency, PA usually uses a higher power supply voltage, but this will cause the actual output power to be much greater than the maximum transmission power specified by different power levels, thus affecting the normal operation of the RF front-end module. Summary of the invention

[0004] Embodiments of the present application provide a power amplifier, a power amplifier device, a radio frequency front-end module and an electronic device.

[0005] According to the first aspect of the present application, an embodiment of the present application provides a power amplifier, which includes a power amplifier circuit, a matching unit and a balun, and the balun includes a primary side and a secondary side coupled to each other. The power amplifier circuit is provided with a power supply end, a first output end and a second output end, the power supply end is used to connect a power supply module, the power supply voltage output by the power supply module to the power amplifier circuit is greater than a preset voltage threshold, and the first output end and the second output end are used to output a pair of radio frequency differential signals. The matching unit is connected between the first output end, the second output end and the primary side, and is used to increase the input impedance of the balun so that the output power of the power amplifier is less than or equal to the maximum transmission power corresponding to the preset power level.

[0006] The embodiment of the present application provides a power amplifier, which may include a power amplifier circuit, a matching unit and a balun. The power amplifier circuit is provided with a power supply terminal, a first output terminal and a second output terminal, and the power supply terminal is used to connect a power supply module. For example, the power supply module may be an envelope tracking (ET) power supply or an average power tracking (APT) power supply. The first output terminal and the second output terminal are used to output a pair of RF differential signals. That is, the power amplifier circuit in the present application adopts a differential structure.

[0007] Since the impedance of the balun itself is usually low, the present application sets a matching unit between the balun and the power amplifier circuit. The matching unit can increase the input impedance of the balun to reduce the output power of the power amplifier, thereby ensuring that the actual output power of the power amplifier meets the power level specified by different power levels (that is, less than or equal to the maximum transmission power specified by different power levels) without reducing the working efficiency of the power supply module, so as to ensure that the RF front-end module equipped with the power amplifier can work normally.

[0008] According to the second aspect of the present application, an embodiment of the present application further provides a power amplifier, which includes a power amplifier circuit, a matching unit and a balun, and the balun includes a primary side and a secondary side that are coupled. The power amplifier circuit is provided with a power supply end, a first output end and a second output end, the power supply end is used to connect a power supply module, and the first output end and the second output end are used to output a pair of RF differential signals. The matching unit includes a first inductor and a second inductor, the first inductor is connected between the first output end and the first end of the primary side, and the second inductor is connected between the second output end and the second end of the primary side; wherein the inductance value of the first inductor and the inductance value of the second inductor are both greater than or equal to 0.6nH.

[0009] The embodiment of the present application provides a power amplifier, which may include a power amplifier circuit, a matching unit and a balun. The power amplifier circuit is provided with a power supply terminal, a first output terminal and a second output terminal, and the power supply terminal is used to connect a power supply module. For example, the power supply module may be an envelope tracking (ET) power supply or an average power tracking (APT) power supply. The first output terminal and the second output terminal are used to output a pair of RF differential signals. That is, the power amplifier circuit in the present application adopts a differential structure.

[0010] Since the impedance of the balun itself is usually low, the present application can increase the input impedance of the balun by setting a first inductor and a second inductor between the balun and the power amplifier circuit to reduce the output power of the power amplifier. Therefore, without reducing the working efficiency of the power supply module, the actual output power of the power amplifier can meet the power level specified by different power levels (that is, less than or equal to the maximum transmission power specified by different power levels) to ensure that the RF front-end module equipped with the power amplifier can work normally.

[0011] Specifically, the inductance value of the first inductor and the inductance value of the second inductor are both greater than or equal to 0.6 nH. For example, the inductance value of the first inductor and the inductance value of the second inductor can be 0.6 nH, 0.8 nH, 1 nH, etc. Therefore, the first inductor and the second inductor in this embodiment both have relatively large inductance values, so that the input impedance of the balun can be significantly improved.

[0012] According to the third aspect of the present application, the embodiment of the present application also provides a power amplifier, which includes a power amplifier circuit, a matching unit and a balun, the balun includes an input matching capacitor, a coupled primary side and a secondary side; the primary side includes a first primary side segment, a second primary side segment and a third primary side segment, the first primary side segment, the second primary side segment and the third primary side segment are connected in series in sequence to form two ends, respectively, the first end and the second end of the primary side, and the input matching capacitor is connected between the first end and the second end. The power amplifier circuit is provided with a power supply end, a first output end and a second output end, the power supply end is used to connect the power supply module, and the first output end and the second output end are used to output a pair of RF differential signals. The matching unit includes a third inductor, a fourth inductor and a matching capacitor, one end of the third inductor is connected to the first output end, and the other end of the third inductor is connected to the common end of the first primary side segment and the second primary side segment; one end of the fourth inductor is connected to the second output end, and the other end of the fourth inductor is connected to the common end of the second primary side segment and the third primary side segment; the matching capacitor is connected between the first output end and the second output end.

[0013] The embodiment of the present application provides a power amplifier, which may include a power amplifier circuit, a matching unit and a balun. The power amplifier circuit is provided with a power supply terminal, a first output terminal and a second output terminal, and the power supply terminal is used to connect a power supply module. For example, the power supply module may be an envelope tracking (ET) power supply or an average power tracking (APT) power supply. The first output terminal and the second output terminal are used to output a pair of RF differential signals. That is, the power amplifier circuit in the present application adopts a differential structure.

[0014] Since the impedance of the balun itself is usually low, the present application can increase the input impedance of the balun by setting a third inductor and a fourth inductor between the balun and the power amplifier circuit to reduce the output power of the power amplifier. Therefore, without reducing the working efficiency of the power supply module, the actual output power of the power amplifier can meet the power level specified by different power levels (that is, less than or equal to the maximum transmission power specified by different power levels) to ensure that the RF front-end module equipped with the power amplifier can work normally.

[0015] In addition, since the other end of the third inductor is connected to the common end of the first primary segment and the second primary segment, and the other end of the fourth inductor is connected to the common end of the second primary segment and the third primary segment, the matching unit can reuse part of the inductance of the balun primary (that is, the equivalent inductance of the first primary segment and the third primary segment), thereby reducing the inductance of the third inductor and the fourth inductor, thereby reducing the area occupied by the third inductor and the fourth inductor and reducing the hardware cost of the power amplifier.

[0016] Furthermore, since the third inductor and the fourth inductor are not connected at both ends of the primary side, but are connected in the middle of the primary side, the imaginary part of the balun input impedance will be offset. Therefore, the present application connects a matching capacitor between the first output terminal and the second output terminal, and the matching capacitor can compensate for the above-mentioned imaginary part offset, so that the balun input impedance is "resistive" as a whole, so as to ensure the transmission efficiency of the RF signal.

[0017] According to the fourth aspect of the present application, an embodiment of the present application further provides a power amplifier device, which includes an envelope tracking power supply and a power amplifier, the power amplifier includes a power amplifier circuit, a matching unit and a balun, and the balun includes a primary side and a secondary side coupled to each other. The power amplifier circuit is provided with a power supply end, a first output end and a second output end, the power supply end is connected to the envelope tracking power supply, and the first output end and the second output end are used to output a pair of radio frequency differential signals. The matching unit is connected between the first output end, the second output end and the primary side, and is used to increase the input impedance of the balun so that the output power of the power amplifier is less than or equal to the maximum transmission power corresponding to the preset power level.

[0018] The embodiment of the present application provides a power amplifier device, which may include an envelope tracking power supply and a power amplifier, wherein the power amplifier includes a power amplifier circuit, a matching unit, and a balun. The power supply end of the power amplifier circuit is connected to an envelope tracking (ET) power supply, and the first output end and the second output end of the power amplifier circuit are used to output a pair of radio frequency differential signals. In other words, the power amplifier circuit in the present application adopts a differential structure.

[0019] Since the ET power supply usually outputs a higher voltage to power the power amplifier in order to improve working efficiency, and the impedance of the balun itself is usually low, the output power of the power amplifier is easily too large. The present application sets a matching unit between the balun and the power amplifier circuit to increase the input impedance of the balun to reduce the output power of the power amplifier, and then, without reducing the working efficiency of the power supply module, the actual output power of the power amplifier can meet the power level specified by different power levels (that is, less than or equal to the maximum transmission power specified by different power levels), so as to ensure that the RF front-end module equipped with the power amplifier device can work normally.

[0020] According to the fifth aspect of the present application, an embodiment of the present application further provides a radio frequency front-end module, which includes a substrate, a balun and a first chip. The balun is arranged on the substrate, and the balun includes a primary side and a secondary side that are coupled. The first chip is arranged on the substrate, and a power amplifier circuit and a matching unit are arranged in the first chip; the power amplifier circuit is provided with a power supply terminal, a first output terminal and a second output terminal, the power supply terminal is used to connect a power supply module, and the power supply voltage output by the power supply module to the power amplifier circuit is greater than a preset voltage threshold, and the first output terminal and the second output terminal are used to output a pair of radio frequency differential signals. The matching unit is connected between the first output terminal, the second output terminal and the primary side, and is used to increase the input impedance of the balun so that the output power of the power amplifier is less than or equal to the maximum transmission power corresponding to the preset power level.

[0021] An embodiment of the present application provides a radio frequency front-end module, which may include a substrate, a balun, and a first chip. A power amplifier circuit and a matching unit are provided in the first chip. The power amplifier circuit is provided with a power supply terminal, a first output terminal, and a second output terminal. The power supply terminal is used to connect a power supply module. For example, the power supply module may be an envelope tracking (ET) power supply or an average power tracking (APT) power supply. The first output terminal and the second output terminal are used to output a pair of radio frequency differential signals. In other words, the power amplifier circuit in the present application adopts a differential structure.

[0022] Since the impedance of the balun itself is usually low, the present application sets a matching unit between the balun and the power amplifier circuit. The matching unit can increase the input impedance of the balun to reduce the output power of the power amplifier, thereby ensuring that the actual output power of the power amplifier meets the power level specified by different power levels (that is, less than or equal to the maximum transmission power specified by different power levels) without reducing the working efficiency of the power supply module, so as to ensure that the RF front-end module can work normally.

[0023] According to the sixth aspect of the present application, an embodiment of the present application further provides an electronic device, which may include the above-mentioned power amplifier; or the above-mentioned power amplification device; or a radio frequency front-end module. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1It is a structural schematic diagram of a power amplifier provided in an embodiment of the present application.

[0026] Figure 2 This is another structural schematic diagram of the power amplifier provided in an embodiment of the present application.

[0027] Figure 3 This is another structural schematic diagram of the power amplifier provided in the embodiment of the present application.

[0028] Figure 4 yes Figure 3 The connection diagram of the primary side and matching unit in the power amplifier is shown.

[0029] Figure 5 This is another structural schematic diagram of the power amplifier provided in the embodiment of the present application.

[0030] Figure 6 yes Figure 5 The simulation curve of the power amplifier corresponding to the balun input impedance is shown.

[0031] Figure 7 yes Figure 5 A Smith diagram of the input impedance of the power amplifier corresponding to the balun is shown.

[0032] Figure 8 This is another structural schematic diagram of the power amplifier provided in the embodiment of the present application.

[0033] Fig. 9 yes Figure 8 The simulation curve of the power amplifier corresponding to the balun input impedance is shown.

[0034] Fig.10 yes Figure 8 A Smith diagram of the input impedance of the power amplifier corresponding to the balun is shown.

[0035] Fig.11 It is a schematic diagram of the structure of the power amplifier provided in the embodiment of the present application.

[0036] Fig.12 It is a structural diagram of the RF front-end module provided in an embodiment of the present application.

[0037] Fig.13 yes Fig.12 A structural schematic diagram of a first inductor, a second inductor and a control unit in the RF front-end module shown.

[0038] Fig.14 yes Fig.12 Another structural schematic diagram of the first inductor, the second inductor and the control unit in the RF front-end module is shown.

[0039] Fig.15It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

[0041] The embodiment of the present application provides a power amplifier 100, which is mainly used to amplify the power of an input radio frequency signal. The power amplifier 100 may be a push-pull power amplifier, a balanced power amplifier, a Doherty power amplifier, and the like.

[0042] See also Figure 1 , the power amplifier 100 may include a power amplifier circuit 10, a matching unit 30 and a balun 50. The power amplifier circuit 10 is provided with a power supply terminal 102, a first output terminal 104 and a second output terminal 106, and the power supply terminal 102 is used to connect the power supply module 200. For example, the power supply module 200 may be an envelope tracking (ET) power supply or an average power tracking (APT) power supply. The ET power supply refers to a power supply that outputs a corresponding power supply voltage by following the envelope of the radio frequency signal. The average power tracking power supply is a power supply module that automatically adjusts the operating voltage of the power amplifier according to the preset output power of the power amplifier and the power amplifier's own parameters.

[0043] Therefore, the present embodiment can dynamically adjust the power supply voltage of the power amplifier circuit 10 by setting the power supply module 200, thereby improving the working efficiency of the power amplifier circuit 10. Taking the power supply module 200 as an ET power supply as an example, the boost module in the ET power supply will output a higher power supply voltage to the power amplifier circuit 10 to improve the voltage conversion efficiency of the ET power supply and the working efficiency of the power amplifier circuit 10.

[0044] Specifically, the power supply voltage output by the power module 200 to the power amplifier circuit 10 is greater than a preset voltage threshold. The "preset voltage threshold" here can be understood as a normal voltage value, that is, a power supply voltage value commonly used by power amplifier products on the market. The "preset voltage threshold" can also be understood as the minimum battery voltage of a mobile terminal equipped with the power module 200 and the power amplifier 100. Exemplarily, the preset voltage threshold is greater than or equal to 3.4V. For example, the preset voltage threshold can be 3.4V, 3.5V, 3.6V, and so on.

[0045] In some possible embodiments, the power supply voltage output by the power module 200 to the power amplifier circuit 10 may be greater than or equal to 3.6V and less than or equal to 4V. In other possible embodiments, the power supply voltage output by the power module 200 to the power amplifier circuit 10 may be greater than or equal to 3.8V and less than or equal to 5.2V.

[0046] Optionally, the power module 200 can receive a relatively low input voltage and convert the input voltage into a supply voltage greater than a preset voltage threshold through a boost module. The power module 200 can also receive a relatively high input voltage and convert the input voltage into a supply voltage greater than a preset voltage threshold but lower than the input voltage through a buck module. The present application does not limit the voltage conversion method of the power module 200. Specifically, the input voltage of the power module 200 can be determined according to the battery voltage of the mobile terminal equipped with the power module 200, which is not specifically limited in this embodiment.

[0047] The first output terminal 104 and the second output terminal 106 are used to output a pair of RF differential signals, that is, the power amplifier circuit 10 in the present application is implemented with a differential structure, which is used to amplify the signal power of a pair of RF differential signals, and output the two RF signals after power amplification through the first output terminal 104 and the second output terminal 106. Of course, the power amplifier 100 may also include other power amplifier circuits (not shown in the figure), and the other power amplifier circuits may be arranged in the front stage of the power amplifier circuit 10 of the differential architecture, and form a multi-stage power amplifier circuit with the power amplifier circuit 10.

[0048] In this embodiment, the balun 50 is used to perform impedance matching and balanced-unbalanced conversion on a pair of RF differential signals output by the power amplifier circuit 10, that is, to convert a pair of RF differential signals into a single-ended RF signal. Specifically, the balun 50 may include a coupled primary side 52 and a secondary side 54. In some possible embodiments, the turns ratio of the secondary side 54 to the primary side 52 may be greater than or equal to 2 and less than or equal to 5. For example, the turns ratio of the secondary side 54 to the primary side 52 may be 2, 2.6, 3, 3.2, 4, 4.5, 5, and so on.

[0049] The matching unit 30 is connected between the first output terminal 104, the second output terminal 106 and the primary side 52, and is used to increase the input impedance of the balun 50 so that the output power of the power amplifier 100 is less than or equal to the maximum transmission power corresponding to the preset power level.

[0050] Since the impedance of the balun 50 itself is usually low, this embodiment sets a matching unit 30 between the balun 50 and the power amplifier circuit 10. The matching unit 30 can increase the input impedance of the balun 50 to reduce the output power of the power amplifier 100, thereby making the actual output power of the power amplifier 100 meet the power level specified by different power levels (that is, less than or equal to the maximum transmission power specified by different power levels) to ensure that the RF front-end module equipped with the power amplifier 100 can work normally.

[0051] It should be noted that in the related art, since the impedance of the balun 50 itself is usually low, it will lead to the problem that when the power amplifier 100 works at a high voltage, its actual output power is much greater than the maximum transmission power specified by different power levels. In order to ensure the normal operation of the power amplifier 100, the R&D personnel often adopt measures to reduce the input voltage of the ET power supply, and reduce the output voltage of the ET power supply (i.e., the power supply voltage of the power amplifier 100) by reducing the input voltage of the ET power supply, thereby reducing the output power of the power amplifier. However, a lower input voltage will reduce the working efficiency of the ET power supply.

[0052] Therefore, the inventors of the present application solve the above problems by setting a matching unit 30 between the balun 50 and the power amplifier circuit 10 to achieve high impedance matching of the balun 50. On the one hand, when the input impedance of the balun 50 is increased, the actual output power of the power amplifier 100 can be reduced so that the actual output power can meet the power level specified by different power levels. On the other hand, since there is no need to reduce the input voltage of the ET power supply, the working efficiency of the power module 200 can also be guaranteed.

[0053] It is not difficult to understand here that since the primary side 52 of the balun 50 is connected to the matching unit 30, the input impedance Z1 of the balun 50, the output impedance Z2 of the balun 50, and the turns ratio n of the secondary side 54 and the primary side 52 satisfy the formula: Z2 / Z1<n 2 In the case where the matching unit 30 is not added, the impedance conversion ratio of the balun is usually the square of the turns ratio. After the matching unit 30 is added in the present application, the impedance conversion ratio Z2 / Z1 between the secondary side 54 and the primary side 52 of the balun is adjusted to be less than the square of the turns ratio n, thereby increasing the impedance of the primary side 52 of the balun when the output impedance remains unchanged, so that the power of the RF signal output by the power amplifier circuit 10 is reduced after passing through the matching circuit 30 and the balun 50 (lower than passing through the balun 50 directly without passing through the matching circuit 30), thereby enabling the actual output power of the power amplifier to meet the power level specified by different power levels without reducing the working efficiency of the power supply module.

[0054] Here we explain the "power levels specified by different power classes".

[0055] In some possible embodiments, the operating frequency band of the power amplifier 100 may be a first frequency band, the first frequency band may be a high frequency band (HB), and its corresponding preset power level is PowerClass2 (PC2), and the maximum transmission power corresponding to the preset power level is 26dBm, that is, a transmission power of 400mW.

[0056] In another possible embodiment, the operating frequency band of the power amplifier 100 may be a second frequency band, and the second frequency band may be a low-medium frequency band (LMB), that is, the frequency of the first frequency band is higher than the frequency of the second frequency band. The preset power level corresponding to the second frequency band is PowerClass3 (PC3), and the maximum transmission power corresponding to the preset power level is 23dBm, that is, a transmission power of 200mW.

[0057] Specifically, the first frequency band may be 3 GHz to 6 GHz. For example, the first frequency band may include N77 frequency band, N78 frequency band, N79 frequency band, etc. The second frequency band may be 1.5 GHz to 3 GHz. For example, the second frequency band may include B1 frequency band, B2 frequency band, B34 frequency band, B38 frequency band, B39 frequency band, B40 frequency band, etc.

[0058] For example, taking the first frequency band as the N77 frequency band and the corresponding power level as PC2 (PowerClass2) as an example, when the power supply voltage output by the power module 200 to the power amplifier circuit 10 is too high, since the impedance of the balun 50 itself is usually low, if the matching unit 30 is not set, the actual output power of the power amplifier 100 will be much greater than the maximum transmission power corresponding to the power level PowerClass2 (that is, 26dBm), thereby affecting the normal transmission of the RF signal.

[0059] In order to solve the above problem, the inventor of the present application sets a matching unit 30 at the input end of the balun 50 to increase the input impedance of the balun 50, thereby reducing the actual output power of the power amplifier 100, so that the actual output power of the power amplifier 100 operating in the N77 frequency band does not exceed the maximum transmission power corresponding to PowerClass2.

[0060] The specific implementation of the power amplifier 100 is described below.

[0061] In this embodiment, the power amplifier circuit 10 may include K first transistors and K second transistors (not shown in the figure), where K is a positive integer greater than or equal to 1. Specifically, the input terminals of the K first transistors are connected in parallel to form a first input terminal, and the first input terminal is used to input a first radio frequency signal. The output terminals of the K first transistors are connected in parallel to the power supply terminal 102 and the first output terminal 104 at the same time. On the one hand, the power supply voltage is received through the power supply terminal 102; on the other hand, the first radio frequency signal after power amplification is output through the first output terminal 104.

[0062] Exemplarily, the first transistor may be a heterojunction bipolar transistor (HBT), wherein the input end of the first transistor is the base of the HBT tube, the output end of the first transistor is the collector of the HBT tube, and the emitter of the HBT tube is grounded.

[0063] Of course, the first transistor may also be a unipolar transistor, such as a metal-oxide-semiconductor field-effect transistor (MOSFET), a silicon-on-insulator (SOI) field-effect transistor, a pseudomorphic high electron mobility transistor (PHEMT), etc. This embodiment does not specifically limit this.

[0064] Similarly, the input ends of the K second transistors are connected in parallel to form a second input end, and the second input end is used to input a second RF signal. The second RF signal and the first RF signal can be a pair of RF differential signals. The output ends of the K second transistors are connected in parallel to the power supply end 102 and the second output end 106 at the same time. On the one hand, the power supply voltage is received through the power supply end 102; on the other hand, the second RF signal after power amplification is output through the second output end 106.

[0065] Exemplarily, the second transistor may be a heterojunction bipolar transistor (HBT), wherein the input end of the second transistor is the base of the HBT tube, the output end of the second transistor is the collector of the HBT tube, and the emitter of the HBT tube is grounded.

[0066] Of course, the second transistor can also be a unipolar transistor, such as a metal-oxide-semiconductor field-effect transistor (MOSFET), a silicon-on-insulator (SOI) field effect transistor, a pseudo-modulated doped heterojunction field effect transistor (Pseudomorphic HEMT), etc. This embodiment does not specifically limit this.

[0067] See also Figure 2 In some possible embodiments, the matching unit 30 may include a first inductor 310 and a second inductor 320 , wherein the first inductor 310 is connected between the first output terminal 104 and the first end 5201 of the primary side 52 , and the second inductor 320 is connected between the second output terminal 106 and the second end 5203 of the primary side 52 .

[0068] In this embodiment, by setting the first inductor 310 and the second inductor 320 between the primary side 52 of the balun 50 and the output end of the power amplifier circuit 10, the input impedance of the balun 50 can be increased without changing the bandwidth and turns ratio of the balun 50, thereby reducing the actual output power of the power amplifier 100. Even when the power supply voltage received by the power amplifier circuit 10 is high, the actual output power can meet the power level specified by different power levels. Specifically, the specific implementation of the first inductor 310 and the second inductor 320 is introduced in the following embodiments.

[0069] It is not difficult to understand here that, since the primary side 52 of the balun 50 in this embodiment is connected to the first inductor 310 and the second inductor 320, the input current I1 of the balun 50, the input voltage U1 of the balun 50, the output current I2 of the balun 50, and the output voltage U2 of the balun 50 satisfy the following formula:

[0070]

[0071] Wherein, L is the inductance value of the first inductor 310 and the inductance value of the second inductor 320, L p is the inductance value of the primary side 52, L s is the inductance of the secondary side 54, and M is the mutual inductance coefficient between the primary side 52 and the secondary side 54. Since the impedance value is equal to the voltage divided by the current, it can be seen from the above formula that after adding the first inductor 310 and the second inductor 320, the input impedance of the balun 50 is also increased.

[0072] Optionally, in Figure 2In the illustrated embodiment, the balun 50 may further include an input matching capacitor C1, a virtual ground matching capacitor C2, an output matching capacitor C3, and a ground matching capacitor C4. The input matching capacitor C1 is connected between the first end 5201 and the second end 5203. One end of the virtual ground matching capacitor C2 is connected to the midpoint of the primary side 52, and the other end is grounded. The output matching capacitor C3 is connected to one end of the secondary side 54 for outputting the RF signal, so as to be connected in series with the secondary side 54. One end of the ground matching capacitor C4 is connected to one end of the secondary side 54 for grounding, and the other end is grounded.

[0073] On the one hand, the matching capacitors C1 to C4 can play the role of "isolating DC and passing AC" to ensure the signal quality of the RF signal and prevent the DC signal from affecting the RF signal. On the other hand, the matching capacitors C1 to C4 can also play the role of adjusting impedance to ensure that the RF signal can be transmitted efficiently and stably. This embodiment does not limit the implementation method and specific values ​​of the matching capacitors C1 to C4.

[0074] See also Figure 3 and Figure 4 In some possible embodiments, the primary side 52 may include a first primary side segment 521, a second primary side segment 523, and a third primary side segment 525. The first primary side segment 521, the second primary side segment 523, and the third primary side segment 525 are connected in series in sequence to form two ends, respectively, a first end 5201 and a second end 5203 of the primary side 52. The balun 50 may also include an input matching capacitor C1, which is connected between the first end 5201 and the second end 5203.

[0075] The matching unit 30 may include a third inductor 330, a fourth inductor 340 and a matching capacitor 350. One end of the third inductor 330 is connected to the first output terminal 104, and the other end of the third inductor 330 is connected to the common end of the first primary segment 521 and the second primary segment 523. Here, "the common end of the first primary segment 521 and the second primary segment 523" refers to the node where the first primary segment 521 and the second primary segment 523 are connected. One end of the fourth inductor 340 is connected to the second output terminal 106, and the other end of the fourth inductor 340 is connected to the common end of the second primary segment 523 and the third primary segment 525. Here, "the common end of the second primary segment 523 and the third primary segment 525" refers to the node where the second primary segment 523 and the third primary segment 525 are connected. The matching capacitor 350 is connected between the first output terminal 104 and the second output terminal 106.

[0076] It should be noted that the first primary segment 521, the second primary segment 523 and the third primary segment 525 in this embodiment are named only for the convenience of describing the connection position of the third inductor 330 and the fourth inductor 340. Figure 2The first inductor 310 and the second inductor 320 are respectively connected to the two ends of the primary side 52, and the third inductor 330 and the fourth inductor 340 are respectively connected to the middle position of the primary side 52, and the third inductor 330 and the fourth inductor 340 are connected at different positions on the primary side 52. The "middle position" here can be any position of the primary side 52 except the two end points (that is, the first end 5201 and the second end 5203).

[0077] Therefore, the two connection positions corresponding to the third inductor 330 and the fourth inductor 340 on the primary side 52 divide the primary side 52 into three sections, namely, a first primary side section 521 , a second primary side section 523 and a third primary side section 525 .

[0078] Since the third inductor 330 and the fourth inductor 340 are respectively connected to the middle position of the primary side 52, the matching unit 30 can reuse part of the inductance of the balun primary side (that is, the equivalent inductance of the first primary side segment 521 and the third primary side segment 525), thereby reducing the inductance of the third inductor 330 and the fourth inductor 340, so as to save the area occupied by the matching unit 30 and reduce the hardware cost of the power amplifier 100.

[0079] Furthermore, since the third inductor 330 and the fourth inductor 340 are not connected to the two ends of the primary side 52, but are connected to the middle position of the primary side 52, the imaginary part of the balun input impedance will be offset. Therefore, the present application connects a matching capacitor 350 between the first output terminal 104 and the second output terminal 106, and the matching capacitor 350 can play a role in compensating for the above-mentioned impedance imaginary part offset, so that the balun input impedance is "resistive" as a whole, so as to ensure the transmission efficiency of the RF signal. Specifically, the specific implementation of the third inductor 330, the fourth inductor 340 and the matching capacitor 350 is introduced in the following embodiments.

[0080] It is not difficult to understand here that, since the primary side 52 of the balun 50 in this embodiment is connected to the third inductor 330 and the fourth inductor 340, the input current I1 of the balun 50, the input voltage U1 of the balun 50, the output current I2 of the balun 50, and the output voltage U2 of the balun 50 satisfy the following formula:

[0081]

[0082] Wherein, L1 is the inductance value of the third inductor 350 and the inductance value of the fourth inductor 340, L2 is the inductance value of the first primary segment 521 and the inductance value of the third primary segment 525, and L p is the inductance value of the primary side 52, L sis the inductance of the secondary side 54, and M is the mutual inductance coefficient between the primary side 52 and the secondary side 54. Since the impedance value is equal to the voltage divided by the current, it can be seen from the above formula that after adding the third inductor 330 and the fourth inductor 340, the input impedance of the balun 50 is also increased.

[0083] Optionally, in Figure 3 In the illustrated embodiment, the balun 50 may further include a virtual ground matching capacitor C2, an output matching capacitor C3, and a ground matching capacitor C4. One end of the virtual ground matching capacitor C2 is connected to the midpoint of the primary side 52, and the other end is grounded. The output matching capacitor C3 is connected to one end of the secondary side 54 for outputting the RF signal, so as to be connected in series with the secondary side 54. One end of the ground matching capacitor C4 is connected to one end of the secondary side 54 for grounding, and the other end is grounded.

[0084] On the one hand, the matching capacitors C1 to C4 can play the role of "isolating DC and passing AC" to ensure the signal quality of the RF signal and prevent the DC signal from affecting the RF signal. On the other hand, the matching capacitors C1 to C4 can also play the role of adjusting impedance to ensure that the RF signal can be transmitted efficiently and stably. This embodiment does not limit the implementation method and specific values ​​of the matching capacitors C1 to C4.

[0085] See also Figure 5 , the embodiment of the present application also provides a power amplifier 100, which may include a power amplifier circuit 10, a matching unit 30 and a balun 50. The power amplifier circuit 10 is provided with a power supply terminal 102, a first output terminal 104 and a second output terminal 106, and the power supply terminal 102 is used to connect a power supply module 200. For example, the power supply module 200 may be an envelope tracking (Envelop Track, ET) power supply or an average power tracking (Average Power Tracking, APT) power supply. For a detailed introduction to the power supply module 200, please refer to the relevant content in the above embodiment. The first output terminal 104 and the second output terminal 106 are used to output a pair of RF differential signals.

[0086] In this embodiment, the balun 50 may include a coupled primary 52 and a secondary 54. In some possible embodiments, the turns ratio of the secondary 54 to the primary 52 may be greater than or equal to 2 and less than or equal to 5. For example, the turns ratio of the secondary 54 to the primary 52 may be 2, 3, 4, 5, and so on.

[0087] The matching unit 30 may include a first inductor 310 and a second inductor 320, wherein the first inductor 310 is connected between the first output terminal 104 and the first end 5201 of the primary side 52, and the second inductor 320 is connected between the second output terminal 106 and the second end 5203 of the primary side 52. Specifically, the first inductor 310 and the second inductor 320 are used to increase the input impedance of the balun 50 so that the output power of the power amplifier 100 is less than or equal to the maximum transmission power corresponding to the preset power level. For a specific introduction to the "maximum transmission power corresponding to the preset power level", reference may be made to the relevant content in the above embodiment.

[0088] Since the impedance of the balun 50 itself is usually low, this embodiment sets the first inductor 310 and the second inductor 320 between the balun 50 and the power amplifier circuit 10, so as to increase the input impedance of the balun 50 without changing the bandwidth and turns ratio of the balun 50, thereby reducing the actual output power of the power amplifier 100. Even when the power supply voltage of the power amplifier circuit 10 is high, the actual output power of the power amplifier 100 can meet the power level specified by different power levels (that is, less than or equal to the maximum transmission power specified by different power levels), so as to ensure that the RF front-end module equipped with the power amplifier 100 can work normally.

[0089] Specifically, the inductance value of the first inductor 310 and the inductance value of the second inductor 320 are both greater than or equal to 0.6 nH. For example, the inductance value of the first inductor 310 and the inductance value of the second inductor 320 can be 0.6 nH, 0.8 nH, 1 nH, etc. Therefore, the first inductor 310 and the second inductor 320 in this embodiment both have relatively large inductance values, so that the input impedance of the balun 50 can be significantly improved.

[0090] In some possible embodiments, the inductance value of the first inductor 310 is equal to the inductance value of the second inductor 320 to ensure the balance of transmission of a pair of RF differential signals.

[0091] In some possible embodiments, the inductance value of the first inductor 310 is less than or equal to 1.4 nH. The inductance value of the second inductor 320 is less than or equal to 1.4 nH. For example, the inductance value of the first inductor 310 and the inductance value of the second inductor 320 can be 1 nH, 1.2 nH, 1.4 nH, etc. Since the inductance values ​​of the first inductor 310 and the second inductor 320 in this embodiment do not exceed 1.4 nH, it is possible to avoid the situation where the inductance values ​​of the first inductor 310 and the second inductor 320 are too large and thus affect the normal transmission of the RF signal, so as to ensure the normal operation of the power amplifier 100. Of course, in some other possible embodiments, the inductance value of the first inductor 310 is less than or equal to 1 nH. The inductance value of the second inductor 320 is less than or equal to 1 nH.

[0092] See also Figure 6 and Figure 7 , Figure 6 and Figure 7 The inventors of this application are Figure 5 The simulation results of the circuit structure shown in FIG. 3 are shown in FIG. 3 . The inductance value of the first inductor 310 is equal to the inductance value of the second inductor 320. Specifically, Figure 6 The input impedance curve of the balun 50 is shown, wherein the left figure is a real part curve corresponding to the balun input impedance when the inductance values ​​of the first inductor 310 are 0.3nH, 0.6nH and 1nH respectively; the right figure is an imaginary part curve corresponding to the balun input impedance when the inductance values ​​of the first inductor 310 are 0.3nH, 0.6nH and 1nH respectively. Figure 6 It is not difficult to see that when the inductance values ​​of the first inductor 310 are 0.3nH, 0.6nH and 1nH respectively, the imaginary impedance values ​​corresponding to the balun input impedance all vary in the range of -0.5 ohm to 1 ohm, and the difference between the three is not large. However, the real impedance value corresponding to the balun input impedance increases as the inductance value of the first inductor 310 increases.

[0093] Specifically, when the inductance value of the first inductor 310 is 0.3nH, the real part of the impedance is between 7 ohms and 8.2 ohms, and the imaginary part of the impedance is between -0.5 ohms and 0.9 ohms. When the inductance value of the first inductor 310 is 0.6nH, the real part of the impedance is between 11.3 ohms and 13 ohms, and the imaginary part of the impedance is between -0.3 ohms and 0.8 ohms. When the inductance value of the first inductor 310 is 1nH, the real part of the impedance is between 17.9 ohms and 20 ohms, and the imaginary part of the impedance is between -0.2 ohms and 0.9 ohms.

[0094] Figure 7 The Smith Chart corresponding to the balun input impedance is shown when the inductance values ​​of the first inductor 310 are 0.3nH, 0.6nH and 1nH respectively. Figure 7 It is not difficult to see that within a certain range, as the inductance value of the first inductor 310 increases, the Smith curve corresponding to the balun input impedance is closer to the center of the circle.

[0095] exist Figure 5 In the illustrated embodiment, the power amplifier circuit 10 is integrated in the first chip 12. For example, the first chip 12 may be a HBT chip. The first chip 12, the balun 50, the first inductor 310 and the second inductor 320 are all suitable for being arranged on a substrate (not shown in the figure). For example, the first chip 12 may be fixed on the substrate by a flip-chip process or a wire bonding process, and the balun 50 may be wound on the substrate by metal routing.

[0096] In some possible embodiments, the power amplifier 100 may further include a first connector 103 and a second connector 105. The first output terminal 104 of the power amplifier circuit 10 is connected to one end of the first inductor 310 through the first connector 103, and the other end of the first inductor 310 is connected to the first end 5201 of the primary side 52. The second output terminal 106 of the power amplifier circuit 10 is connected to one end of the second inductor 320 through the second connector 105, and the other end of the second inductor 320 is connected to the second end 5203 of the primary side 52.

[0097] Specifically, the first chip 12 in this embodiment is connected to the first inductor 310 arranged on the substrate through the first connector 103, and the first chip 12 is connected to the second inductor 320 arranged on the substrate through the second connector 105. As an embodiment, the first chip 12 is fixed to the substrate by a wire bonding process, and the first connector 103 and the second connector 105 can be bonding wires respectively. Specifically, the bonding wire can be a metal wire such as a copper wire or a silver wire. As another embodiment, the first chip 12 is fixed to the substrate by a flip-down process, and the first connector 103 and the second connector 105 can be bumps respectively. Specifically, the bump can be a columnar body or a sphere, and the material used can be copper or tin. Exemplarily, the bump can be a copper column or a tin ball.

[0098] In this embodiment, since the inductance value of the first inductor 310 and the inductance value of the second inductor 320 are both greater than or equal to 0.6nH, it means that the first inductor 310 and the second inductor 320 both have large inductance values, while the equivalent inductance of the bonding wire or the bump is small and insufficient to replace the first inductor 310 and the second inductor 320. As an implementation method, the first inductor 310 and the second inductor 320 can be arranged on the substrate in the form of metal traces. Specifically, the R&D personnel can adjust the inductance of the first inductor 310 and the second inductor 320 by adjusting the length of the metal traces. As another implementation method, the first inductor 310 and the second inductor 320 are arranged on the substrate in the form of surface mounted devices (SMD) to make the layout of the substrate more compact and reasonable.

[0099] Therefore, the first inductor 310 and the second inductor 320 in the present embodiment are not inductors equivalent to bonding wires or bumps, but are additional inductors that are used to increase the input impedance of the balun 50 .

[0100] In some possible embodiments, the first inductor 310 and the second inductor 320 are both adjustable inductors. Specifically, the inductance values ​​of the first inductor 310 and the second inductor 320 can be dynamically adjusted according to the output power of the RF front-end module equipped with the power amplifier 100. Among them, the greater the output power of the RF front-end module, the greater the inductance values ​​of the first inductor 310 and the second inductor 320, and the greater the input impedance of the balun 50, so as to limit the output power of the RF front-end module, so that the output power of the RF front-end module is maintained in a normal power range. Specifically, the implementation method of the first inductor 310 and the second inductor 320 as adjustable inductors is described in detail in the following embodiments.

[0101] See also Figure 8 , the embodiment of the present application also provides a power amplifier 100, which may include a power amplifier circuit 10, a matching unit 30 and a balun 50. The power amplifier circuit 10 is provided with a power supply terminal 102, a first output terminal 104 and a second output terminal 106, and the power supply terminal 102 is used to connect a power supply module 200. For example, the power supply module 200 may be an envelope tracking (Envelop Track, ET) power supply or an average power tracking (Average Power Tracking, APT) power supply. For a detailed introduction to the power supply module 200, please refer to the relevant content in the above embodiment. The first output terminal 104 and the second output terminal 106 are used to output a pair of RF differential signals.

[0102] In this embodiment, the balun 50 may include an input matching capacitor C1, a coupled primary side 52, and a secondary side 54. In some possible embodiments, the turns ratio of the secondary side 54 to the primary side 52 may be greater than or equal to 2 and less than or equal to 5. For example, the turns ratio of the secondary side 54 to the primary side 52 may be 2, 3, 4, 5, and so on.

[0103] Specifically, Figure 4 As shown, the primary side 52 may include a first primary side segment 521, a second primary side segment 523 and a third primary side segment 525. The two ends formed by connecting the first primary side segment 521, the second primary side segment 523 and the third primary side segment 525 in series in sequence are respectively a first end 5201 and a second end 5203 of the primary side 52, and the input matching capacitor C1 is connected between the first end 5201 and the second end 5203.

[0104] The matching unit 30 may include a third inductor 330, a fourth inductor 340 and a matching capacitor 350, one end of the third inductor 330 is connected to the first output terminal 104, and the other end of the third inductor 330 is connected to the common end of the first primary segment 521 and the second primary segment 523. One end of the fourth inductor 340 is connected to the second output terminal 106, and the other end of the fourth inductor 340 is connected to the common end of the second primary segment 523 and the third primary segment 525. The matching capacitor 350 is connected between the first output terminal 104 and the second output terminal 106. Specifically, the third inductor 330 and the fourth inductor 340 are used to increase the input impedance of the balun 50 so that the output power of the power amplifier 100 is less than or equal to the maximum transmission power corresponding to the preset power level. For the specific introduction of "the maximum transmission power corresponding to the preset power level", please refer to the relevant content in the above embodiment.

[0105] Since the impedance of the balun 50 itself is usually low, this embodiment sets the third inductor 330 and the fourth inductor 340 between the balun 50 and the power amplifier circuit 10, so as to increase the input impedance of the balun 50 without changing the bandwidth and turns ratio of the balun 50, thereby reducing the actual output power of the power amplifier 100. Even when the power supply voltage of the power amplifier circuit 10 is high, the actual output power of the power amplifier 100 can meet the power level specified by different power levels (that is, less than or equal to the maximum transmission power specified by different power levels), so as to ensure that the RF front-end module equipped with the power amplifier 100 can work normally.

[0106] In addition, since the other end of the third inductor 330 is connected to the common end of the first primary segment 521 and the second primary segment 523, and the other end of the fourth inductor 340 is connected to the common end of the second primary segment 523 and the third primary segment 525, the matching unit 30 can reuse part of the inductance of the balun primary (that is, the equivalent inductance of the first primary segment 521 and the third primary segment 525), thereby reducing the inductance of the third inductor 330 and the fourth inductor 340 to reduce the hardware cost of the power amplifier 100.

[0107] Furthermore, since the third inductor 330 and the fourth inductor 340 are not connected to the two ends of the primary side 52 (i.e., the first end 5201 and the second end 5203), but are connected to the middle position of the primary side 52, the imaginary part of the balun input impedance will be offset. Therefore, the present application connects a matching capacitor 350 between the first output terminal 104 and the second output terminal 106, and the matching capacitor 350 can play a role in compensating for the above-mentioned imaginary part offset, so that the balun input impedance is "resistive" as a whole, so as to ensure the transmission efficiency of the RF signal.

[0108] In some possible embodiments, the inductance value of the first primary segment 521 is equal to the inductance value of the third primary segment 525 to ensure the balance of transmission of a pair of RF differential signals.

[0109] In some possible embodiments, the ratio between the inductance value of the first primary segment 521 and the inductance value of the primary 52 is greater than or equal to 1 / 8, and less than or equal to 1 / 4. For example, the ratio may be 1 / 8, 1 / 6, 1 / 4, and so on. Therefore, in this embodiment, the common end of the first primary segment 521 and the second primary segment 523 is located at a position relatively close to the first end 5201 on the primary 52, which can avoid causing a large offset to the imaginary part of the balun input impedance. Similarly, the ratio between the inductance value of the third primary segment 525 and the inductance value of the primary 52 is greater than or equal to 1 / 8, and less than or equal to 1 / 4. For example, the ratio may be 1 / 8, 1 / 6, 1 / 4, and so on. Therefore, in this embodiment, the common end of the second primary segment 523 and the first primary segment 521 is located at a position relatively close to the second end 5203 on the primary 52, which can avoid causing a large offset to the imaginary part of the balun input impedance.

[0110] In some possible embodiments, the third inductor 330 is connected to the first connection point 5207 of the primary 52, and the first connection point 5201 is located between the first end 5201 of the primary 52 and the midpoint of the primary 52, where the "first connection point 5207" can be understood as the "common end of the first primary segment 521 and the second primary segment 523" mentioned above. The length of the line between the first end 5201 of the primary 52 and the first connection point 5207 (that is, the first primary segment 521) is the first length, and the length of the line between the first end 5201 of the primary 52 and the midpoint of the primary 52 (that is, half of the primary 52) is the second length, and the ratio between the first length and the second length is greater than or equal to 1 / 4 and less than or equal to 1 / 2. For example, the ratio can be 1 / 4, 1 / 3, 1 / 2, and so on. Therefore, in this embodiment, the first connection point 5207 is located on the primary side 52 relatively close to the first end 5201, which can avoid causing a large offset to the imaginary part of the balun input impedance.

[0111] Similarly, the fourth inductor 340 is connected to the second connection point 5209 of the primary 52, and the second connection point 5209 is located between the second end 5203 of the primary 52 and the midpoint of the primary 52, where the "second connection point 5209" can be understood as the "common end of the second primary segment 523 and the third primary segment 525" mentioned above. The length of the line between the second end 5203 of the primary 52 and the second connection point 5209 (that is, the third primary segment 525) is the third length, and the length of the line between the second end 5203 of the primary 52 and the midpoint of the primary 52 (that is, half of the primary 52) is the fourth length, and the ratio between the third length and the fourth length is greater than or equal to 1 / 4 and less than or equal to 1 / 2. For example, the ratio can be 1 / 4, 1 / 3, 1 / 2, and so on. Therefore, in this embodiment, the second connection point 5209 is located on the primary side 52 relatively close to the second end 5203, which can avoid causing a large offset to the imaginary part of the balun input impedance.

[0112] In some possible embodiments, the routing length between the first end 5201 of the primary side 52 and the first connection point 5207 (i.e., the first length) may be equal to the routing length between the second end 5203 of the primary side 52 and the second connection point 5209 (i.e., the third length) to ensure the balance of a pair of RF differential signal transmissions.

[0113] Since the matching unit 30 in this embodiment can reuse part of the inductance of the primary side of the balun (that is, the equivalent inductance of the first primary side segment 521 and the third primary side segment 525), compared with Figure 5 In the embodiment shown, when the same impedance matching is achieved, the inductance values ​​of the third inductor 330 and the fourth inductor 340 can be smaller than the inductance values ​​of the first inductor 310 and the second inductor 320, so as to reduce the layout space occupied by the third inductor 330 and the fourth inductor 340. Specifically, the inductance value of the third inductor 330 is greater than or equal to 0.3nH and less than or equal to 0.6nH. For example, the inductance value of the third inductor 330 can be 0.3nH, 0.4nH, 0.5nH, 0.6nH, etc. The inductance value of the fourth inductor 340 is greater than or equal to 0.3nH and less than or equal to 0.6nH. For example, the inductance value of the fourth inductor 340 can be 0.3nH, 0.4nH, 0.5nH, 0.6nH, etc.

[0114] In some possible embodiments, the inductance value of the third inductor 330 is equal to the inductance value of the fourth inductor 340 to ensure the balance of transmission of a pair of RF differential signals.

[0115] See also Fig. 9 and Fig.10 , Fig. 9 and Fig.10 The inventors of this application are Figure 8The simulation results of the circuit structure shown in FIG. 3 are shown in FIG. 3 . The inductance value of the third inductor 330 is equal to the inductance value of the fourth inductor 340. Specifically, Fig. 9 The figure shows the input impedance curve of the balun 50, wherein the left figure is a real part curve corresponding to the balun input impedance when the inductance values ​​of the third inductor 330 are 0nH, 0.3nH and 0.6nH respectively; the right figure is a imaginary part curve corresponding to the balun input impedance when the inductance values ​​of the third inductor 330 are 0nH, 0.3nH and 0.6nH respectively. Fig. 9 It is not difficult to see that when the inductance values ​​of the third inductor 330 are 0nH, 0.3nH and 0.6nH respectively, the imaginary impedance values ​​corresponding to the balun input impedance all vary in the range of -0.5 ohm to 1 ohm, and the difference between the three is not large. However, the real impedance value corresponding to the balun input impedance increases as the inductance value of the third inductor 330 increases.

[0116] Specifically, when the inductance value of the third inductor 330 is 0 nH, the real part of the impedance is between 4.7 ohms and 6 ohms, and the imaginary part of the impedance is between -0.2 ohms and 1 ohm. When the inductance value of the third inductor 330 is 0.3 nH, the real part of the impedance is between 10.7 ohms and 12.5 ohms, and the imaginary part of the impedance is between -0.2 ohms and 0.4 ohms. When the inductance value of the third inductor 330 is 0.6 nH, the real part of the impedance is between 17.9 ohms and 20.7 ohms, and the imaginary part of the impedance is between -0.4 ohms and 0.5 ohms.

[0117] Here combined Figure 6 It is not difficult to find that when the real part of the impedance corresponding to the balun input impedance is approximately 18 ohms to 21 ohms, the inductance value of the first inductor 310 is 1 nH, and the inductance value of the third inductor 330 is 0.6 nH. Figure 5 The first inductor 310 and the second inductor 320 in the illustrated embodiment, Figure 8 Since part of the inductance of the primary side of the balun is reused in the illustrated embodiment, the inductance of the third inductor 330 and the fourth inductor 340 can be reduced while achieving the same balun input impedance, thereby reducing the hardware cost of the power amplifier 100 .

[0118] Fig.10 The Smith Chart corresponding to the balun input impedance is shown when the inductance values ​​of the third inductor 330 are 0nH, 0.3nH and 0.6nH respectively. Fig.10 It is not difficult to see that as the inductance value of the third inductor 330 increases, the Smith curve corresponding to the balun input impedance is closer to the center of the circle.

[0119] exist Figure 8In the illustrated embodiment, the power amplifier circuit 10 is integrated in the first chip 12. For example, the first chip 12 may be a HBT chip. The first chip 12 and the balun 50 are suitable for being arranged on a substrate (not shown in the figure). For example, the first chip 12 may be fixed on the substrate by a flip-chip process or a wire bonding process, and the balun 50 may be wound on the substrate by metal routing.

[0120] In some possible embodiments, the first primary segment 521 and the third primary segment 525 may be symmetrically arranged on the substrate to ensure the balance of transmission of a pair of radio frequency differential signals.

[0121] In some possible embodiments, the third inductor 330 is a third connector 107 connected between the first chip 12 and the substrate, and the third connector 107 is used to connect the first output terminal 104 to the common end of the first primary segment 521 and the second primary segment 523. The fourth inductor 340 is a fourth connector 109 connected between the first chip 12 and the substrate, and the fourth connector 109 is used to connect the second output terminal 106 to the common end of the second primary segment 523 and the third primary segment 525.

[0122] Since the inductance of the third inductor 330 and the fourth inductor 340 is small, they can be equivalent respectively by the connectors connected between the first chip 12 and the substrate. Therefore, there is no need to set up additional inductors to save the layout space of the substrate. As an embodiment, the first chip 12 is fixed to the substrate by a wire bonding process, and the third connector 107 and the fourth connector 109 are bonding wires. Specifically, the bonding wires can be metal wires such as copper wires and silver wires. As another embodiment, the first chip 12 is fixed to the substrate by a flip-down process, and the third connector 107 and the fourth connector 109 are bumps. Specifically, the bumps can be columnar or spherical, and the material used can be copper or tin. Exemplarily, the bumps can be copper columns or tin balls.

[0123] In addition, when the third inductor 330 and the fourth inductor 340 can be equivalent to the third connector 107 and the fourth connector 109 respectively, the matching capacitor 350 can be integrated in the first chip 12 to save the layout space of the substrate.

[0124] In some possible embodiments, the third connector 107 may be used to replace a portion of the inductance of the third inductor 330, and another portion of the inductance of the third inductor 330 may be implemented by a first metal connecting wire. The first metal connecting wire here is used to connect the third connector 107 to the common end of the first primary segment 521 and the second primary segment 523. Specifically, the first metal connecting wire may be a metal routing wire or a metal jumper wire.

[0125] Similarly, the fourth connector 109 can be used to replace a portion of the inductance of the fourth inductor 340, and another portion of the inductance of the fourth inductor 340 can be implemented by a second metal connecting line. The second metal connecting line here is used to connect the fourth connector 109 to the common end of the second primary segment 523 and the third primary segment 525. Specifically, the second metal connecting line can be a metal routing line or a metal jumper line.

[0126] In some possible embodiments, the power amplifier circuit 10 is integrated into the first chip 12, and the first chip 12 and the balun 50 are suitable for being arranged on a substrate. As an implementation mode, the third inductor 330 and the fourth inductor 340 are arranged on the substrate in the form of metal traces. Specifically, the R&D personnel can adjust the inductance of the third inductor 330 and the fourth inductor 340 by adjusting the length of the metal traces. As another implementation mode, the third inductor 330 and the fourth inductor 340 are arranged on the substrate in the form of surface mount devices to make the layout of the substrate more compact and reasonable.

[0127] The embodiment of the present application also provides a power amplification device 300, which is mainly used to amplify the power of an input radio frequency signal, and may include a push-pull power amplifier, a balanced power amplifier, a Doherty power amplifier, and the like.

[0128] See also Fig.11 The power amplifier device 300 may include an envelope tracking power supply 210 and the above-mentioned power amplifier 100, and the power amplifier 100 may include a power amplifier circuit 10, a matching unit 30 and a balun 50. The power amplifier circuit 10 is provided with a power supply terminal 102, a first output terminal 104 and a second output terminal 106, and the power supply terminal 102 is connected to the envelope tracking power supply 210. For a detailed introduction to the envelope tracking power supply 210, reference may be made to the relevant contents in the above embodiments. The first output terminal 104 and the second output terminal 106 are used to output a pair of RF differential signals.

[0129] In this embodiment, the balun 50 may include a coupled primary side 52 and a secondary side 54. The matching unit 30 is connected between the first output terminal 104, the second output terminal 106 and the primary side 52, and is used to increase the input impedance of the balun 50 so that the output power of the power amplifier 100 is less than or equal to the maximum transmission power corresponding to the preset power level. For a detailed introduction to the "maximum transmission power corresponding to the preset power level", please refer to the relevant content in the above embodiment.

[0130] Since the impedance of the balun 50 itself is usually low, this embodiment provides a matching unit 30 between the balun 50 and the power amplifier circuit 10, so that the input impedance of the balun 50 can be increased without changing the bandwidth and turns ratio of the balun 50, thereby reducing the actual output power of the power amplifier 100. Even when the power supply voltage of the power amplifier circuit 10 is high, the actual output power of the power amplifier 100 can meet the power level specified by different power levels (that is, less than or equal to the maximum transmission power specified by different power levels), so as to ensure that the RF front-end module equipped with the power amplifier 100 can work normally.

[0131] Specifically, for the detailed introduction of the power amplifier circuit 10 , the matching unit 30 and the balun 50 , reference may be made to the relevant contents in the above embodiments, which will not be repeated here.

[0132] The embodiment of the present application also provides a radio frequency front-end module 400, which is a component that integrates two or more discrete devices such as a radio frequency switch, a low noise amplifier, a filter, a duplexer, a power amplifier, etc. into an independent module, thereby improving the integration and hardware performance and miniaturizing the size.

[0133] See also Fig.12 , the RF front-end module 400 may include a substrate 410, a balun 50 and a first chip 12. Among them, the balun 50 is arranged on the substrate 410, and it may include a primary side 52 and a secondary side 54 that are coupled. The first chip 12 is arranged on the substrate 410, and the first chip 12 is provided with a power amplifier circuit 10 and a matching unit 30. Specifically, the substrate 410 is roughly rectangular, and it is used to fix and support the components (for example, the balun 50, the first chip 12, etc.) in the RF front-end module 400. Specifically, the substrate 410 can be a copper-clad laminate, and the circuit can be printed on the surface of the substrate 410 by processing the copper-clad laminate with holes, chemical copper plating, electrolytic copper plating, etching, etc.

[0134] The power amplifier circuit 10 is provided with a power supply terminal 102, a first output terminal 104 and a second output terminal 106. The power supply terminal 102 is used to connect the power supply module 200. The power supply voltage output by the power supply module to the power amplifier circuit 10 is greater than a preset voltage threshold. For example, the power supply module 200 can be an envelope tracking (ET) power supply or an average power tracking (APT) power supply. Specifically, the specific introduction of the power supply module 200 can refer to the relevant content in the above embodiment. The first output terminal 104 and the second output terminal 106 are used to output a pair of RF differential signals.

[0135] The matching unit 30 is connected between the first output terminal 104, the second output terminal 106 and the primary side 52, and is used to increase the input impedance of the balun 50 so that the output power of the power amplifier 100 is less than or equal to the maximum transmission power corresponding to the preset power level. For a detailed introduction to the "maximum transmission power corresponding to the preset power level", please refer to the relevant content in the above embodiment.

[0136] Since the impedance of the balun 50 itself is usually low, this embodiment provides a matching unit 30 between the balun 50 and the power amplifier circuit 10, so that the input impedance of the balun 50 can be increased without changing the bandwidth and turns ratio of the balun 50, thereby reducing the actual output power of the power amplifier 100. Even when the power supply voltage of the power amplifier circuit 10 is high, the actual output power of the power amplifier 100 can meet the power level specified by different power levels (that is, less than or equal to the maximum transmission power specified by different power levels), so as to ensure that the RF front-end module 400 equipped with the power amplifier 100 can work normally.

[0137] Specifically, for the detailed introduction of the power amplifier circuit 10 and the balun 50 , reference may be made to the relevant contents in the above embodiments, which will not be repeated here.

[0138] In some possible embodiments, the matching unit 30 may include a first inductor 310 and a second inductor 320, wherein the first inductor 310 is connected between the first output terminal 104 and the first end of the primary side 52, and the second inductor 320 is connected between the second output terminal 106 and the second end 5203 of the primary side 52. Specifically, the specific implementation of the first inductor 310 and the second inductor 320 may refer to the relevant introduction in the above embodiments, which will not be repeated here.

[0139] In some possible embodiments, the first inductor 310 and the second inductor 320 are both adjustable inductors. The inductance values ​​of the first inductor 310 and the second inductor 320 can be dynamically adjusted according to the output power of the RF front-end module equipped with the power amplifier 100, so that the output power of the RF front-end module 400 is maintained in a normal power range.

[0140] See also Fig.13 and Fig.14The RF front-end module 400 may further include a second chip 14, which is disposed on the substrate 410. A control unit 140 is disposed in the second chip 14, and the control unit 140 is used to adjust the inductance value of the first inductor 310 and the inductance value of the second inductor 320 according to the output power of the RF front-end module. Optionally, the second chip 14 may be a silicon-on-insulator (SOI) chip or a chip based on a PHEMT (pseudo-matched high electron mobility transistor) process or a chip based on a CMOS process.

[0141] In this embodiment, the inductance value of the first inductor 310 is positively correlated with the output power of the RF front-end module 400, and the inductance value of the second inductor 320 is positively correlated with the output power of the RF front-end module 499. Specifically, the greater the output power of the RF front-end module 400, the greater the inductance values ​​of the first inductor 310 and the second inductor 320, and the greater the input impedance of the balun 50, so as to reduce the output power of the RF front-end module and avoid the occurrence of excessive output power. The smaller the output power of the RF front-end module 400, the smaller the inductance values ​​of the first inductor 310 and the second inductor 320, and the smaller the input impedance of the balun 50, so as to avoid excessive weakening of the output power of the RF front-end module, thereby improving the output efficiency of the RF signal.

[0142] Therefore, in this embodiment, by adjusting the inductance values ​​of the first inductor 310 and the second inductor 320 , the output power of the RF front-end module 400 can be maintained in a normal power range to ensure the normal operation of the RF front-end module 400 .

[0143] exist Fig.13 In the illustrated embodiment, the first inductor 310 may include M first sub-inductors 3102, where M is an integer greater than 1. For example, M may be equal to 2, 3, 4, 5, etc. The control unit 140 may include N first switches 1401, where N is an integer greater than or equal to 1 and less than or equal to M. For example, when M is equal to 4, N may be equal to 1, 2, 3, or 4.

[0144] The M first sub-inductors 3102 are sequentially connected in series and connected between the first output terminal 104 and the first terminal 5201 of the primary side 52, and the N first switches 1401 are connected in parallel with the N first sub-inductors 3102 in a one-to-one correspondence. Specifically, the inductance values ​​of the M first sub-inductors 3102 may be the same or different from each other. The first switch 1401 may be a transistor switch, for example, an HBT tube, a MOSFET tube, a field effect transistor based on an SOI substrate, and the like.

[0145] The second inductor 320 may include P second sub-inductors 3201, where P is an integer greater than 1. For example, P may be equal to 2, 3, 4, 5, etc. The control unit 140 may include Q second switches 1403, where Q is an integer greater than or equal to 1 and less than or equal to P. For example, when P is equal to 4, Q may be equal to 1, 2, 3, 4.

[0146] The P second sub-inductors 3201 are sequentially connected in series and connected between the second output terminal 106 and the second terminal 5203 of the primary side 52, and the Q second switches 1403 are connected in parallel with the Q second sub-inductors 3201 in a one-to-one correspondence. Specifically, the inductance values ​​of the P second sub-inductors 3201 may be the same or different from each other. The second switch 1403 may be a transistor switch, for example, an HBT tube, a MOSFET tube, a field effect transistor based on an SOI substrate, and the like.

[0147] exist Fig.14 In the illustrated embodiment, M first sub-inductors 3102 are connected in parallel with each other and connected between the first output terminal 104 and the first terminal 5201 of the primary side 52, and N first switches 1401 are connected in series one by one in the branches where the N first sub-inductors 3102 are located. P second sub-inductors 3201 are connected in parallel with each other and connected between the second output terminal 106 and the second terminal 5203 of the primary side 52, and Q second switches 1403 are connected in series one by one in the branches where the Q second sub-inductors 3201 are located.

[0148] exist Fig.13 and Fig.14 In the illustrated embodiment, the control unit 140 may further include a controller 1405, the controller 1405 being electrically connected to the N first switches 1401, and the controller 1405 being used to adjust the working state of the N first switches 1401 based on the output power of the RF front-end module to adjust the equivalent inductance value of the first inductor 310, wherein the working state includes an on state and an off state. The controller 1405 is also electrically connected to the Q second switches 1403, and the controller 1405 is also used to adjust the working state of the Q second switches 1403 based on the output power of the RF front-end module to adjust the equivalent inductance value of the second inductor 320.

[0149] Specifically, the controller 1405 can be a microcontroller unit (MCU), which can obtain the actual output power of the RF front-end module 400, and then determine the equivalent inductance value of the first inductor 310 and the second inductor 320, and control the working states of N first switches 1401 and Q second switches 1403 to achieve dynamic adjustment of the inductance value.

[0150] Therefore, in this embodiment, the controller 1405 controls the working state of the first switch 1401 corresponding to the first sub-inductor 3102 to control whether the first sub-inductor 3102 is connected to the inductor network corresponding to the first inductor 310, thereby realizing flexible adjustment of the equivalent inductance value of the first inductor 310. The working state of the second switch 1403 corresponding to the second sub-inductor 3201 is controlled to control whether the second sub-inductor 3201 is connected to the inductor network corresponding to the second inductor 320, thereby realizing flexible adjustment of the equivalent inductance value of the second inductor 320, so that the first inductor 310 and the second inductor 320 can be respectively regarded as adjustable inductors.

[0151] The embodiment of the present application provides a radio frequency front-end module 400, which may include a substrate 410, a balun 50 and a first chip 12. Among them, a power amplifier circuit 10 and a matching unit 30 are arranged in the first chip 12. The power amplifier circuit 10 is provided with a power supply terminal 102, a first output terminal 104 and a second output terminal 106. The power supply terminal 102 is used to connect a power supply module 200. For example, the power supply module 200 may be an envelope tracking (Envelop Track, ET) power supply or an average power tracking (Average Power Tracking, APT) power supply. The first output terminal 104 and the second output terminal 106 are used to output a pair of radio frequency differential signals. That is to say, the power amplifier circuit 10 in the present application adopts a differential structure.

[0152] Since the impedance of the balun 50 itself is usually low, the present application sets a matching unit 30 between the balun 50 and the power amplifier circuit 10. The matching unit 30 can increase the input impedance of the balun 50 to reduce the output power of the power amplifier, thereby making the actual output power of the power amplifier meet the power level specified by different power levels (that is, less than or equal to the maximum transmission power specified by different power levels) to ensure that the RF front-end module 400 can work normally.

[0153] See also Fig.15 , this embodiment also provides an electronic device 500, which may be a 4G or 5G communication device such as a smart phone, a tablet computer, or a smart watch. Specifically, the electronic device 500 may include the power amplifier 100 in the above embodiment. Alternatively, the electronic device 500 may include the power amplification device 300 in the above embodiment. Alternatively, the electronic device 500 may include the RF front-end module 400 in the above embodiment to realize the reception and transmission of RF signals. In addition, with the development of 5G technology, the requirements for the performance of RF front-end modules are getting higher and higher. The technical solution of the present application can be applied to 5G RF front-end modules to improve the communication performance of 5G communication equipment.

[0154] It should be noted here that, in the absence of conflicts, the embodiments in this specification can be combined with each other. For example, the technical features included in the power amplifier 100 can be combined with the embodiment corresponding to the power amplifier device 300, and the technical features included in the power amplifier 100 can also be combined with the embodiment corresponding to the RF front-end module 400; for another example, the technical features in one embodiment corresponding to the power amplifier 100 can be combined with another embodiment corresponding to the power amplifier 100. Exemplarily, Figure 5 The technical features of the power amplifier 100 shown can be Figure 1 or Figure 2 The technical features of the power amplifier 100 are combined with each other. Figure 8 The technical features of the power amplifier 100 shown can be Figure 1 or Figure 3 The technical features of the power amplifier 100 shown are combined with one another.

[0155] In the specification of this application, certain words are used to refer to specific components in the specification and claims. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. The specification and claims do not use the difference in name as a way to distinguish components, but use the difference in function of the components as the criterion for distinction. For example, "including" mentioned throughout the specification and claims is an open term, so it should be interpreted as "including but not limited to"; "substantially" means that those skilled in the art can solve technical problems within a certain error range and basically achieve technical effects.

[0156] In the description of the present application, it should be understood that terms such as "upper", "lower", "front", "back", "left", "right", and "inside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are merely simplified descriptions for the convenience of describing the present application. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0157] In this application, unless otherwise clearly specified or limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can be internal communication between two elements, or it can be only surface contact. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0158] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0159] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0160] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A power amplifier, characterized in that: It includes a power amplifier circuit, a matching unit and a balun, wherein the balun includes a primary side and a secondary side coupled to each other; The power amplifier circuit is provided with a power supply end, a first output end and a second output end, the power supply end is used to connect a power supply module, the power supply voltage output by the power supply module to the power amplifier circuit is greater than a preset voltage threshold, and the first output end and the second output end are used to output a pair of radio frequency differential signals; The matching unit is connected between the first output end, the second output end and the primary side, and is used to increase the input impedance of the balun so that the output power of the power amplifier is less than or equal to the maximum transmission power corresponding to the preset power level.

2. The power amplifier according to claim 1, characterized in that: The power supply module is an envelope tracking power supply or an average power tracking power supply.

3. The power amplifier according to claim 1, characterized in that: The preset voltage threshold is greater than or equal to 3.4V.

4. The power amplifier according to claim 1, characterized in that: The supply voltage is greater than or equal to 3.6V and less than or equal to 4V; or The supply voltage is greater than or equal to 3.8V and less than or equal to 5.2V.

5. The power amplifier according to claim 1, characterized in that: When the operating frequency band of the power amplifier is the first frequency band, the maximum transmission power corresponding to the preset power level is 26 dBm; When the operating frequency band of the power amplifier is the second frequency band, the maximum transmission power corresponding to the preset power level is 23 dBm; wherein the frequency of the first frequency band is higher than the frequency of the second frequency band.

6. The power amplifier according to claim 5, characterized in that: The first frequency band is 3 GHz to 6 GHz; or / and The second frequency band is 1.5 GHz to 3 GHz; or / and The turns ratio of the secondary side to the primary side is greater than or equal to 2 and less than or equal to 5.

7. The power amplifier according to any one of claims 1 to 6, characterized in that: The matching unit includes a first inductor and a second inductor, the first inductor is connected between the first output end and the first end of the primary side, and the second inductor is connected between the second output end and the second end of the primary side.

8. The power amplifier according to any one of claims 1 to 6, characterized in that: The primary side includes a first primary side segment, a second primary side segment and a third primary side segment, and two ends formed by sequentially connecting the first primary side segment, the second primary side segment and the third primary side segment in series are respectively a first end and a second end of the primary side; the balun also includes an input matching capacitor, and the input matching capacitor is connected between the first end and the second end; The matching unit comprises a third inductor, a fourth inductor and a matching capacitor, one end of the third inductor is connected to the first output end, and the other end of the third inductor is connected to a common end of the first primary segment and the second primary segment; One end of the fourth inductor is connected to the second output end, and the other end of the fourth inductor is connected to the common end of the second primary segment and the third primary segment; The matching capacitor is connected between the first output terminal and the second output terminal.

9. A power amplifier, characterized in that: It includes a power amplifier circuit, a matching unit and a balun, wherein the balun includes a primary side and a secondary side coupled to each other; The power amplifier circuit is provided with a power supply end, a first output end and a second output end, the power supply end is used to connect to a power supply module, and the first output end and the second output end are used to output a pair of radio frequency differential signals; The matching unit includes a first inductor and a second inductor, the first inductor is connected between the first output end and the first end of the primary side, and the second inductor is connected between the second output end and the second end of the primary side; wherein the inductance value of the first inductor and the inductance value of the second inductor are both greater than or equal to 0.6nH.

10. The power amplifier according to claim 9, characterized in that: The inductance value of the first inductor is less than or equal to 1.4 nH; the inductance value of the second inductor is less than or equal to 1.4 nH.

11. The power amplifier according to claim 10, characterized in that: The inductance value of the first inductor is less than or equal to 1 nH; the inductance value of the second inductor is less than or equal to 1 nH.

12. The power amplifier according to claim 9, characterized in that: The power amplifier circuit is integrated in a first chip, and the first chip, the balun, the first inductor and the second inductor are all suitable for being arranged on a substrate; The power amplifier further includes a first connector and a second connector, wherein the first output end of the power amplifier circuit is connected to one end of the first inductor through the first connector, and the other end of the first inductor is connected to the first end of the primary side; the second output end of the power amplifier circuit is connected to one end of the second inductor through the second connector, and the other end of the second inductor is connected to the second end of the primary side; Wherein, the first connecting member and the second connecting member are bonding wires; or, the first connecting member and the second connecting member are bumps.

13. The power amplifier according to claim 12, characterized in that: The first inductor and the second inductor are arranged on the substrate in the form of metal traces; or, the first inductor and the second inductor are arranged on the substrate in the form of surface mount devices.

14. The power amplifier according to any one of claims 9 to 13, characterized in that: The first inductor and the second inductor are both adjustable inductors.

15. The power amplifier according to any one of claims 9 to 13, characterized in that: The first inductor and the second inductor are used to increase the input impedance of the balun so that the output power of the power amplifier is less than or equal to the maximum transmission power corresponding to the preset power level; Among them, when the working frequency band of the power amplifier is the first frequency band, the maximum transmission power corresponding to the preset power level is 26dBm; when the working frequency band of the power amplifier is the second frequency band, the maximum transmission power corresponding to the preset power level is 23dBm; the frequency of the first frequency band is higher than the frequency of the second frequency band.

16. The power amplifier according to claim 15, characterized in that: The first frequency band is 3 GHz to 6 GHz; or / and The second frequency band is 1.5 GHz to 3 GHz; or / and The turns ratio of the secondary side to the primary side is greater than or equal to 2 and less than or equal to 5.

17. A power amplifier, characterized in that: It comprises a power amplifier circuit, a matching unit and a balun, wherein the balun comprises an input matching capacitor, a coupled primary side and a secondary side; the primary side comprises a first primary side segment, a second primary side segment and a third primary side segment, and two ends formed by sequentially connecting the first primary side segment, the second primary side segment and the third primary side segment in series are respectively a first end and a second end of the primary side, and the input matching capacitor is connected between the first end and the second end; The power amplifier circuit is provided with a power supply end, a first output end and a second output end, the power supply end is used to connect to a power supply module, and the first output end and the second output end are used to output a pair of radio frequency differential signals; The matching unit includes a third inductor, a fourth inductor and a matching capacitor, one end of the third inductor is connected to the first output end, and the other end of the third inductor is connected to the common end of the first primary segment and the second primary segment; one end of the fourth inductor is connected to the second output end, and the other end of the fourth inductor is connected to the common end of the second primary segment and the third primary segment; the matching capacitor is connected between the first output end and the second output end.

18. The power amplifier according to claim 17, characterized in that: The inductance value of the first primary segment is equal to the inductance value of the third primary segment.

19. The power amplifier according to claim 17, characterized in that: The ratio of the inductance value of the first primary segment to the total inductance value of the primary side is greater than or equal to 1 / 8 and less than or equal to 1 / 4; the ratio of the inductance value of the third primary segment to the total inductance value of the primary side is greater than or equal to 1 / 8 and less than or equal to 1 / 4; Or, the third inductor is connected to a first connection point of the primary side, the first connection point is located between the first end of the primary side and the midpoint of the primary side, the routing length between the first end of the primary side and the first connection point is a first length, the routing length between the first end of the primary side and the midpoint of the primary side is a second length, and the ratio of the first length to the second length is greater than or equal to 1 / 4 and less than or equal to 1 / 2; The fourth inductor is connected to the second connection point of the primary side, the second connection point is located between the second end of the primary side and the midpoint of the primary side, the routing length between the second end of the primary side and the second connection point is the third length, the routing length between the second end of the primary side and the midpoint of the primary side is the fourth length, and the ratio of the third length to the fourth length is greater than or equal to 1 / 4 and less than or equal to 1 / 2.

20. The power amplifier according to any one of claims 17 to 19, characterized in that: The inductance value of the third inductor is greater than or equal to 0.3 nH and less than or equal to 0.6 nH; The inductance value of the fourth inductor is greater than or equal to 0.3 nH and less than or equal to 0.6 nH.

21. The power amplifier according to any one of claims 17 to 19, characterized in that: The power amplifier circuit is integrated into a first chip, and the first chip and the balun are suitable for being arranged on a substrate; The third inductor is a third connecting member connected between the first chip and the substrate, and the third connecting member is used to connect the first output end to the common end of the first primary segment and the second primary segment; the fourth inductor is a fourth connecting member connected between the first chip and the substrate, and the fourth connecting member is used to connect the second output end to the common end of the second primary segment and the third primary segment; Wherein, the third connecting member and the fourth connecting member are bonding wires; or, the third connecting member and the fourth connecting member are bumps.

22. The power amplifier according to any one of claims 17 to 19, characterized in that: The power amplifier circuit is integrated into a first chip, and the first chip and the balun are suitable for being arranged on a substrate; The third inductor and the fourth inductor are arranged on the substrate in the form of metal traces; or, the third inductor and the fourth inductor are arranged on the substrate in the form of surface mount devices.

23. The power amplifier according to any one of claims 17 to 19, characterized in that: The third inductor and the fourth inductor are used to increase the input impedance of the balun so that the output power of the power amplifier is less than or equal to the maximum transmission power corresponding to the preset power level; Among them, when the working frequency band of the power amplifier is the first frequency band, the maximum transmission power corresponding to the preset power level is 26dBm; when the working frequency band of the power amplifier is the second frequency band, the maximum transmission power corresponding to the preset power level is 23dBm; the frequency of the first frequency band is higher than the frequency of the second frequency band.

24. The power amplifier according to claim 23, characterized in that: The first frequency band is 3 GHz to 6 GHz; or / and The second frequency band is 1.5 GHz to 3 GHz; or / and The turns ratio of the secondary side to the primary side is greater than or equal to 2 and less than or equal to 5.

25. A power amplifier device, characterized in that: It includes an envelope tracking power supply and a power amplifier, wherein the power amplifier includes a power amplification circuit, a matching unit and a balun, and the balun includes a primary side and a secondary side coupled to each other; The power amplifier circuit is provided with a power supply end, a first output end and a second output end, the power supply end is connected to the envelope tracking power supply, and the first output end and the second output end are used to output a pair of radio frequency differential signals; The matching unit is connected between the first output end, the second output end and the primary side, and is used to increase the input impedance of the balun so that the output power of the power amplifier is less than or equal to the maximum transmission power corresponding to the preset power level.

26. A radio frequency front-end module, characterized in that: include: substrate; A balun is arranged on the substrate, and the balun includes a primary side and a secondary side coupled to each other; as well as A first chip is arranged on the substrate, wherein a power amplifier circuit and a matching unit are arranged in the first chip; the power amplifier circuit is provided with a power supply end, a first output end, and a second output end, the power supply end is used to connect a power supply module, the power supply voltage output by the power supply module to the power amplifier circuit is greater than a preset voltage threshold, and the first output end and the second output end are used to output a pair of radio frequency differential signals; The matching unit is connected between the first output end, the second output end and the primary side, and is used to increase the input impedance of the balun so that the output power of the power amplifier is less than or equal to the maximum transmission power corresponding to the preset power level.

27. The radio frequency front-end module according to claim 26, characterized in that: The matching unit includes a first inductor and a second inductor, the first inductor is connected between the first output end and the first end of the primary side, and the second inductor is connected between the second output end and the second end of the primary side.

28. The radio frequency front-end module according to claim 27, characterized in that: The RF front-end module also includes a second chip, which is arranged on the substrate. A control unit is arranged in the second chip, and the control unit is used to adjust the inductance value of the first inductor and the inductance value of the second inductor according to the output power of the RF front-end module.

29. The radio frequency front-end module according to claim 28, characterized in that: The inductance value of the first inductor is positively correlated with the output power of the RF front-end module; The inductance value of the second inductor is positively correlated with the output power of the RF front-end module.

30. The radio frequency front-end module according to claim 28, characterized in that: The first inductor includes M first sub-inductors, where M is an integer greater than 1; the control unit includes N first switches, where N is an integer greater than or equal to 1 and less than or equal to M; M first sub-inductors are connected in series in sequence, and N first switches are connected in parallel with the N first sub-inductors one by one; or, M first sub-inductors are connected in parallel with each other, and N first switches are connected in series in the branches where the N first sub-inductors are located one by one; The second inductor includes P second sub-inductors, where P is an integer greater than 1; the control unit includes Q second switches, where Q is an integer greater than or equal to 1 and less than or equal to P; P second sub-inductors are connected in series in sequence, and Q second switches are connected in parallel with the Q second sub-inductors one by one; or, P second sub-inductors are connected in parallel with each other, and Q second switches are connected in series in the branch where the Q second sub-inductors are located one by one.

31. The radio frequency front-end module according to claim 30, characterized in that: The control unit further includes a controller, the controller is electrically connected to the N first switches, and the controller is used to adjust the working state of the N first switches based on the output power of the RF front-end module to adjust the equivalent inductance value of the first inductor, wherein the working state includes an on state and an off state; The controller is also electrically connected to the Q second switches, and the controller is also used to adjust the working states of the Q second switches based on the output power of the RF front-end module to adjust the equivalent inductance value of the second inductor.

32. An electronic device, characterized in that: include: A power amplifier as claimed in any one of claims 1 to 24; or, the power amplifier device as claimed in claim 25; Or, a radio frequency front-end module as described in any one of claims 26 to 31.

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