Doherty power amplification circuit, radio frequency front-end module and electronic equipment

Abstract

The embodiment of the invention provides a Doherty power amplification circuit, a radio frequency front-end module and electronic equipment. The Doherty power amplification circuit comprises a first power amplification unit, a second power amplification unit, a first coupler, a first impedance circuit and a second impedance circuit, the first coupler comprises a first straight-through end, a first coupling end, a first output end and a first isolation end, the first straight-through end is connected with the output end of the first power amplification unit, the first coupling end is connected with the output end of the second power amplification unit, and the first output end is used for outputting a radio frequency signal; the first isolation end is electrically connected with the first impedance circuit. The first output end is electrically connected with the second impedance circuit, and the circuit structure of the second impedance circuit is different from that of the first impedance circuit. According to the Doherty power amplification circuit, the power synthesis efficiency of the Doherty power amplification circuit can be improved, the bandwidth of the Doherty power amplification circuit is expanded, and miniaturization of the Doherty power amplification circuit is facilitated.

Description

Technical Field

[0001] This application relates to the field of radio frequency technology, and in particular to a Dougherty power amplifier circuit, a radio frequency front-end module, and electronic equipment. Background Technology

[0002] With the rapid development of new-generation information technology, technologies in various sub-fields are constantly being updated and improved, placing higher demands on the performance indicators of radio frequency power amplifiers. The Dougherty power amplifier circuit in related technologies can be combined using a phase-shifting network. However, the bandwidth of the radio frequency power amplifier under this architecture is limited by the phase-shifting network, making it difficult to achieve wideband requirements and resulting in significant application limitations. Summary of the Invention

[0003] This application provides a Dougherty power amplifier circuit, an RF front-end module, and an electronic device, which can at least extend the bandwidth of the Dougherty power amplifier circuit.

[0004] In a first aspect, embodiments of this application provide a Dougherty power amplifier circuit, characterized in that the Dougherty power amplifier circuit comprises: First power amplifier unit; Second power amplifier unit; A first coupler, comprising a first through terminal, a first coupling terminal, a first output terminal, and a first isolation terminal, wherein the first through terminal is connected to the output terminal of the first power amplifier unit, the first coupling terminal is connected to the output terminal of the second power amplifier unit, and the first output terminal is used to output a radio frequency signal; and The first impedance circuit, wherein the first isolation terminal is electrically connected to the first impedance circuit; The second impedance circuit is electrically connected to the first output terminal, and the circuit structure of the second impedance circuit is different from that of the first impedance circuit.

[0005] Secondly, embodiments of this application provide a Dougherty power amplifier circuit, characterized in that it includes: First power amplifier unit; Second power amplifier unit; A first coupler, comprising a first through terminal, a first coupling terminal, a first output terminal, and a first isolation terminal, wherein the first through terminal is connected to the output terminal of the first power amplifier unit, the first coupling terminal is connected to the output terminal of the second power amplifier unit, and the first output terminal is used to output a radio frequency signal; and The first impedance circuit, wherein the first isolation terminal is electrically connected to the first impedance circuit; The operating frequency band of the Dougherty power amplifier circuit includes a first frequency band and a second frequency band, wherein the first frequency band and the second frequency band do not overlap or at least partially overlap; the resistance value of the first impedance circuit of the Dougherty power amplifier circuit in the first frequency band is different from the resistance value of the first impedance circuit of the Dougherty power amplifier circuit in the second frequency band.

[0006] Thirdly, embodiments of this application provide a radio frequency front-end module, characterized in that it includes: A first power amplifier unit and a second power amplifier unit; the first power amplifier unit is configured as a peak amplifier and the second power amplifier unit is configured as a carrier amplifier; or the first power amplifier unit is configured as a carrier amplifier and the second power amplifier unit is configured as a peak amplifier. A first coupler, comprising a first through terminal, a first coupling terminal, a first output terminal, and a first isolation terminal, wherein the first through terminal is connected to the output terminal of the first power amplifier unit, the first coupling terminal is connected to the output terminal of the second power amplifier unit, and the first output terminal is used to output a radio frequency signal; and The first impedance circuit, wherein the first isolation terminal is electrically connected to the first impedance circuit; The first impedance circuit includes at least a first branch and a second branch. The first end of the first branch and the first end of the second branch are both connected to the first isolation terminal, and the second end of the first branch and the second end of the second branch are both grounded.

[0007] Fourthly, embodiments of this application provide an electronic device, which includes the aforementioned Dougherty power amplifier circuit or the aforementioned radio frequency front-end module.

[0008] This application provides a Dougherty power amplifier circuit, an RF front-end module, and an electronic device. The Dougherty power amplifier circuit includes a first power amplifier unit, a second power amplifier unit, a first coupler, a first impedance circuit, and a second impedance circuit. The first coupler includes a first through terminal, a first coupling terminal, a first output terminal, and a first isolation terminal. The first through terminal is connected to the output terminal of the first power amplifier unit, and the first coupling terminal is connected to the output terminal of the second power amplifier unit. The first output terminal is used to output RF signals. The first isolation terminal is electrically connected to the first impedance circuit. The first output terminal is electrically connected to the second impedance circuit, and the circuit structure of the second impedance circuit is different from that of the first impedance circuit. This ensures that the two RF signals corresponding to the first and second power amplifier units have the same phase or a phase difference within an acceptable range at the first output terminal of the first coupler, thereby improving power combining efficiency. The bandwidth advantage of the first coupler can be utilized, and the bandwidth of the Dougherty power amplifier circuit can be expanded by differentiating the first and second impedance circuits. The structure is relatively simple, which is beneficial for the miniaturization of the Dougherty power amplifier circuit.

[0009] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the disclosure of the embodiments of this application. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of a Dougherty power amplifier circuit provided in an embodiment of this application; Figure 2 This is a schematic diagram of a Dougherty power amplifier in the prior art; Figure 3 This is a schematic diagram of the Dougherty power amplifier circuit in some embodiments of this application; Figures 4 to 5 This is a schematic diagram of the first impedance circuit in some embodiments of this application; Figures 6 to 7 This is a schematic diagram of the Dougherty power amplifier circuit in some embodiments of this application; Figure 8 This is a schematic block diagram of a Dougherty power amplifier circuit provided in another embodiment of this application; Figure 9 This is a schematic block diagram of a radio frequency front-end module provided in an embodiment of this application; Figure 10 This is a schematic block diagram of a radio frequency front-end module according to one embodiment of this application; Figure 11 This is a schematic block diagram of an electronic device provided in an embodiment of this application.

[0012] Explanation of reference numerals in the attached figures: 10. First power amplifier unit; 20. Second power amplifier unit; 30. First coupler; P31. First through terminal; P32. First coupling terminal; P33. First output terminal; P34. First isolation terminal; 40. First impedance circuit; 41. First branch; 411. First impedance device; K1. First switch; 42. Second branch; 421. Second impedance device; K2. Second switch; 43. Switching circuit; 50. Second impedance circuit; 60. Third power amplifier unit; 70. Second coupler; P71. Second input terminal; P72. Second through terminal; P73. Second coupling terminal; 80. Power divider; 90. Phase shifter. Detailed Implementation

[0013] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0014] It should be understood that this application can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this application to those skilled in the art. In the drawings, for clarity, the dimensions of layers and regions, as well as their relative dimensions, may be exaggerated. The same reference numerals denote the same elements throughout.

[0015] To fully understand this application, detailed structures and steps will be presented in the following description to illustrate the technical solutions proposed in this application. Preferred embodiments of this application are described in detail below; however, in addition to these detailed descriptions, this application may have other implementation methods.

[0016] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0017] Please see Figure 1 , Figure 1 This is a schematic block diagram of a Doherty PowerAmplifier (DPA) provided in an embodiment of this application.

[0018] like Figure 1 As shown, the Doherty power amplifier circuit includes: a first power amplifier unit 10, a second power amplifier unit 20, a first coupler 30, a first impedance circuit 40, and a second impedance circuit 50.

[0019] The first coupler 30 includes a first through terminal P31, a first coupling terminal P32, a first output terminal P33, and a first isolation terminal P34. The first through terminal P31 is connected to the output terminal of the first power amplifier unit 10, the first coupling terminal P32 is connected to the output terminal of the second power amplifier unit 20, and the first output terminal P33 is used to output radio frequency signals. The first isolation terminal P34 is electrically connected to the first impedance circuit 40. The first output terminal P33 is electrically connected to the second impedance circuit 50, and the circuit structure of the second impedance circuit 50 is different from that of the first impedance circuit 40.

[0020] In some embodiments, the first power amplification unit 10 in the Dougherty power amplifier circuit is used to amplify the power of the first radio frequency signal, and the second power amplification unit 20 is used to amplify the power of the second radio frequency signal. The phase of the second radio frequency signal is different from the phase of the first radio frequency signal. For example, the phase of the second radio frequency signal differs from the phase of the first radio frequency signal by 80 to 100 degrees. For ease of explanation, this application embodiment mainly uses a phase difference of 90 degrees between the second and first radio frequency signals as an example for illustration.

[0021] The first coupler 30 can be used as a power combiner to combine the RF signal output from the first power amplifier unit 10 and the RF signal output from the second power amplifier unit 20. By differentiating the circuit structures of the first impedance circuit 40 and the second impedance circuit 50, the reflection phase characteristics of the first isolation terminal P34 and the first output terminal P33 of the first coupler 30 can be adjusted respectively, so that the two RF signals have the same phase or the phase difference is within an acceptable range (such as less than or equal to 10 degrees) at the first output terminal P33 of the first coupler 30, thereby improving the power combining efficiency.

[0022] The first impedance circuit 40 is connected to the first isolation terminal P34 of the first coupler 30, which can effectively absorb reflected power and reduce the interference of reflected signals on the phase of radio frequency signals, thereby improving the purity of the synthesized signal. By specifically setting the impedance of the first impedance circuit 40, the first impedance circuit 40 can achieve impedance matching in a wider frequency band. The second impedance circuit 50 is connected to the first output terminal P33 of the first coupler 30, which can also achieve precise matching of the characteristic impedance of the first coupler 30 and improve power transmission efficiency. Thus, the Dougherty power amplifier circuit can operate in a wider bandwidth range and achieve the purpose of expanding the bandwidth of the Dougherty power amplifier circuit.

[0023] like Figure 2 The diagram shows a schematic of a Dougherty power amplifier, which can be called a voltage-combining type Dougherty power amplifier. This Dougherty power amplifier requires adding a phase-shifting network (such as an LC phase-shifting network or a π-type inductor-capacitor phase-shifting network) to the output of one of the power amplification units, and then combining the two RF signals through a balun. The bandwidth of this architecture is limited by the phase-shifting network, making it difficult to achieve broadband applications.

[0024] The Dougherty power amplifier circuit of this application embodiment can utilize the bandwidth advantage of the first coupler 30, and extend the bandwidth of the Dougherty power amplifier circuit by differentiating the first impedance circuit 40 and the second impedance circuit 50; and compared to Figure 2 According to the related technologies shown, the Dougherty power amplifier circuit of this application embodiment does not require a phase shifting network, and its structure is relatively simple, which is conducive to the miniaturization of the Dougherty power amplifier circuit and the miniaturization of the RF front-end module using the Dougherty power amplifier circuit.

[0025] In some implementations, the Dougherty power amplifier circuit operates in a frequency band that includes a first frequency band and a second frequency band, wherein the first frequency band and the second frequency band do not overlap or at least partially overlap. The Dougherty power amplifier circuit can operate over a wider bandwidth and can support multiple frequency bands. For example, the first frequency band and the second frequency band can be different frequency bands in the high-frequency band (HB), or the first frequency band and the second frequency band can be different frequency bands in the medium-frequency band (MB), or the first frequency band and the second frequency band can be different frequency bands in the low-frequency band (LB); or the first frequency band is a frequency band in the high-frequency band and the second frequency band is a frequency band in the medium-frequency band; or the first frequency band is a frequency band in the medium-frequency band and the second frequency band is a frequency band in the high-frequency band; or the first frequency band is a frequency band in the medium-frequency band and the second frequency band is a frequency band in the low-frequency band; or the first frequency band is a frequency band in the low-frequency band and the second frequency band is a frequency band in the high-frequency band.

[0026] For example, the operating frequency band of the Dougherty power amplifier circuit includes a first frequency band and a second frequency band. The first frequency band is the 4.8GHz-4.96GHz band, and the second frequency band is the 3.3GHz-4.2GHz band. For instance, the first frequency band may include the N79 band, and the second frequency band may include the N77 band. The operating frequency band of the Dougherty power amplifier circuit may be referred to as the Sub6GHz band.

[0027] For example, the operating frequency band of the Dougherty power amplifier circuit includes a first frequency band and a second frequency band. The first frequency band is the 2.5GHz-2.7GHz band, and the second frequency band is the 2.3GHz-2.4GHz band. For instance, the first frequency band may include the N41 band, and the second frequency band may include the N40 band. The operating frequency band of the Dougherty power amplifier circuit may be referred to as the Sub3GHz band.

[0028] For example, the operating frequency band of the Dougherty power amplifier circuit includes a first frequency band and a second frequency band, which may partially overlap. For example, the first frequency band is the 2.45GHz-2.7GHz band, and the second frequency band is the 2.3GHz-2.5GHz band.

[0029] In some embodiments, the first power amplification unit 10 is a peaking amplifier, and the second power amplification unit 20 is a carrier amplifier. For example, the peaking amplifier amplifies the power of a first radio frequency (RF) signal, and the carrier power amplification unit amplifies the power of a second RF signal. The phase of the second RF signal leads the phase of the first RF signal. In this embodiment, the phase of the second RF signal leads the phase of the first RF signal by 80 to 100 degrees, such as 80, 85, 90, 95, or 100 degrees; preferably, the phase of the second RF signal leads the phase of the first RF signal by 90 degrees.

[0030] In other embodiments, the first power amplification unit 10 is a carrier amplifier, and the second power amplification unit 20 is a peak amplifier. For example, the carrier amplifier amplifies the power of the first radio frequency signal, and the peak power amplification unit amplifies the power of the second radio frequency signal. The phase of the second radio frequency signal lags behind the phase of the first radio frequency signal. In this embodiment, the phase of the second radio frequency signal lags behind the phase of the first radio frequency signal by 80 to 100 degrees, such as 80, 85, 90, 95, or 100 degrees; preferably, the phase of the second radio frequency signal lags behind the phase of the first radio frequency signal by 90 degrees.

[0031] When the Dougherty power amplifier circuit is working, the carrier amplifier is always on and operates in Class AB or Class B bias; the peak amplifier is only turned on after the input power reaches the input power threshold and usually operates in Class C bias; when the Dougherty power amplifier circuit has low power input, only the carrier amplifier is working and the peak amplifier is off.

[0032] In some implementations, the first coupler 30 may include a 3dB orthogonal coupler. For example, a 3dB quadrature coupler may include multiple inductors and capacitors, such as inductor L1, inductor L2, capacitor C1, and capacitor C2; one end of inductor L1 is connected to the first through terminal P31 of the 3dB quadrature coupler, and the other end of inductor L1 is connected to the first output terminal P33 of the 3dB quadrature coupler, and inductor L1 is responsible for signal transmission; one end of inductor L2 is connected to the first coupling terminal P32 of the 3dB quadrature coupler, and the other end of inductor L2 is connected to the first isolation terminal P34 of the 3dB quadrature coupler, and inductor L2 is responsible for signal coupling and isolation; one end of capacitor C1 is connected to the first through terminal P31, and the other end of capacitor C2 is connected to the first coupling terminal P32, and capacitor C1 can be used to match impedance and / or adjust the electrical characteristics of the signal path; one end of capacitor C2 is connected to the first output terminal P33, and the other end of capacitor C2 is connected to the first isolation terminal P34, and capacitor C2 can be used to adjust the frequency response and / or isolate the signal.

[0033] In some implementations, the 3dB quadrature coupler may include a multi-stage coupler, which can increase the bandwidth of the 3dB quadrature coupler to further increase the bandwidth of the Dougherty power amplifier circuit.

[0034] In some embodiments, the resistance value R2 of the second impedance circuit 50 is greater than or equal to the resistance value R0 of the characteristic impedance of the first coupler 30. In the embodiments of this application, the resistance value R2 of the second impedance circuit 50 is 100% to 160% of the resistance value R0 of the characteristic impedance of the first coupler 30, such as 100%, 105%, 110%, 120%, 130%, 155%, and 160%. For example, at the target frequency, the resistance value R2 of the second impedance circuit 50 is equal to the resistance value R0 of the characteristic impedance of the first coupler 30. This allows the second impedance circuit 50 to achieve precise matching with the resistance value R0 of the characteristic impedance of the first coupler 30, improving power transmission efficiency; for example, the resistance value R0 of the characteristic impedance of the first coupler 30 at the target frequency can be 50 ohms or 30 ohms, but it is not limited to these.

[0035] In this embodiment of the application, when setting the second impedance circuit 50, the second impedance circuit 50 may further include a matching circuit, which includes a matching inductor or a matching capacitor, so as to adjust and make its resistance value the same as the resistance value of the characteristic impedance of the first coupler 30 by setting the matching inductor or capacitor.

[0036] In this embodiment of the application, the circuit structure of the first impedance circuit 40 is different from that of the second impedance circuit 50. The difference in circuit structure can refer to the different circuit topologies of the first impedance circuit 40 and the second impedance circuit 50.

[0037] For example, the first impedance circuit 40 includes at least a first resistor R10, a first impedance device 411 and a first switch K1 arranged in series, and one end of the first impedance device 411 is electrically connected to the first isolation terminal P34, and one end of the first switch K1 is grounded. The first impedance device 411 is a capacitor or an inductor, while the topology of the second impedance circuit 50 is different. For example, the second impedance circuit 50 can be a topology where a single impedance device is connected in series between the first output terminal P33 and the output terminal of the Dougherty power amplifier circuit; or a topology where a resistor and an impedance device are connected in series without a switch; or a topology where at least two impedance devices are connected in series between the first output terminal P33 and the output terminal of the Dougherty power amplifier circuit without a resistor or a switch. Alternatively, the second impedance circuit 50 can be a topology where two impedance devices are connected in parallel between the first output terminal P33 and the output terminal of the Dougherty power amplifier circuit; or a topology where at least one impedance device is connected in series between the first output terminal P33 and the output terminal of the Dougherty power amplifier circuit, with one end of the at least one impedance device connected between the first output terminal P33 and the output terminal of the Dougherty power amplifier circuit and the other end grounded. The impedance device can be a capacitor or an inductor.

[0038] For example, the first impedance circuit 40 can also be configured as a first resistor R10 and a first impedance device 411 connected in series, wherein one end of the first impedance device 411 is electrically connected to the first isolation terminal P34, one end of the first resistor R10 is grounded, and the first impedance device 411 is configured as a capacitor. The topology of the second impedance circuit 50 is different from this. For example, the second impedance circuit 50 can be a topology in which a single impedance device is connected in series between the first output terminal P33 and the output terminal of the Dougherty power amplifier circuit, or a topology in which at least two impedance devices are connected in series between the first output terminal P33 and the output terminal of the Dougherty power amplifier circuit without including resistors or switches; another example is that the second impedance circuit 50 can be a topology in which two impedance devices are connected in parallel between the first output terminal P33 and the output terminal of the Dougherty power amplifier circuit; yet another example is that the second impedance circuit 50 can be a topology in which at least one impedance device is connected in series between the first output terminal P33 and the output terminal of the Dougherty power amplifier circuit, and one end of the at least one impedance device is connected between the first output terminal P33 and the output terminal of the Dougherty power amplifier circuit, and the other end is grounded. The impedance device can be a capacitor or an inductor.

[0039] In some embodiments, the second impedance circuit 50 includes a capacitor and an inductor, wherein the connection method of the capacitor and the inductor can be set according to their matching requirements, so that the second impedance circuit 50 can perform better impedance matching.

[0040] For example, in one topology, one end of the inductor is connected to the first output terminal P33, and the other end of the inductor is grounded; the capacitor is connected in parallel with the inductor, or the capacitor is connected in series between one end of the inductor and the first output terminal P33, or the capacitor is connected in series between the first output terminal P33 and the output terminal of the Dougherty power amplifier.

[0041] In another topology, one end of the capacitor is connected to the first output terminal P33, the other end of the capacitor is grounded, and an inductor is connected in series between one end of the capacitor and the first output terminal, or in series between the first output terminal P33 and the output terminal of the Dougherty power amplifier.

[0042] In another topology, the second impedance circuit 50 may further include multiple capacitors and / or multiple inductors. The connection of the multiple capacitors and multiple inductors can be a combination of the two topologies described above. For example, at least one capacitor and at least one inductor are connected in series between the first output terminal P33 and the output terminal of the Dougherty power amplifier. Additionally, one end of at least one capacitor is connected to a node between the first output terminal P33 and the output terminal of the Dougherty power amplifier, and the other end is grounded; and / or one end of at least one inductor is connected to a node between the first output terminal P33 and the output terminal of the Dougherty power amplifier, and the other end is grounded.

[0043] In some embodiments, the first power amplification unit 10 is a peak amplifier, and the second power amplification unit 20 is a carrier amplifier. Within the operating frequency band of the Dougherty power amplifier circuit, the resistance value of the first impedance circuit 40 is less than or equal to 50 ohms; for example, the resistance value of the first impedance circuit 40 can be 50 ohms, 45 ohms, 40 ohms, 35 ohms, 30 ohms, 25 ohms, 20 ohms, 15 ohms, 10 ohms, 5 ohms, 3 ohms, 2 ohms, or 1 ohm. Preferably, within the operating frequency band of the Dougherty power amplifier circuit, the resistance value of the first impedance circuit 40 at the target frequency is less than or equal to 5 ohms; for example, within the operating frequency band of the Dougherty power amplifier circuit, the resistance value of the first impedance circuit 40 at the target frequency is equal to or close to 0, i.e., the first impedance circuit 40 is in a short-circuit state at the target frequency. The target frequency is greater than the lowest frequency in the operating frequency band and less than the highest frequency in the operating frequency band.

[0044] In the case where the first power amplification unit 10 is a peak amplifier and the second power amplification unit 20 is a carrier amplifier, the phase of the second radio frequency signal corresponding to the second power amplification unit 20 leads the phase of the first radio frequency signal corresponding to the first power amplification unit 10. In this embodiment, the phase of the second radio frequency signal corresponding to the second power amplification unit 20 leads the phase of the first radio frequency signal corresponding to the first power amplification unit 10 by 80 to 100 degrees, such as 80, 85, 90, 95, or 100 degrees; preferably, the phase of the second radio frequency signal leads the phase of the first radio frequency signal by 90 degrees; the first impedance circuit 40 has a small resistance in the operating frequency band of the Dougherty power amplification circuit and / or is in a short-circuit state at the target frequency, which enables the two radio frequency signals to have the same phase or a phase difference within an acceptable range, such as less than or equal to 10 degrees, so as to improve the power combining efficiency.

[0045] For example, the difference between the target frequency and the intermediate frequency is less than or equal to 0.2 GHz, where the intermediate frequency is the average of the lowest and highest frequencies in the operating band. The difference could be any one of 0.2 GHz, 0.15 GHz, 0.1 GHz, or 0 GHz.

[0046] For example, the target frequency can be equal to the mid-frequency of the operating frequency band; for instance, the operating frequency band of the Dougherty power amplifier circuit includes a first frequency band and a second frequency band, where the first frequency band is 4.8GHz-4.96GHz and the second frequency band is 3.3GHz-4.2GHz, and the target frequency can be equal to 4.2GHz; or, for instance, the operating frequency band of the Dougherty power amplifier circuit includes a first frequency band and a second frequency band, where the first frequency band is 2.5GHz-2.7GHz and the second frequency band is 2.3GHz-2.4GHz, and the target frequency can be equal to 2.5GHz. By setting the resistance value of the first impedance circuit 40 at this target frequency to be less than or equal to 50 ohms (e.g., less than or equal to 5 ohms), for example, the resistance value of the first impedance circuit 40 at the mid-frequency of the operating frequency band is equal to or close to 0, the resistance value of the first impedance circuit 40 at different frequencies throughout the entire operating frequency band can be kept small, thus ensuring that the Dougherty power amplifier circuit has high power combining efficiency at different frequencies throughout the entire operating frequency band.

[0047] For example, the target frequency is the same as the center frequency of the first coupler 30. For instance, the difference between the center frequency and the intermediate frequency of the first coupler 30 is [-0.2GHz, 0.2GHz], where the intermediate frequency is the average of the lowest frequency in the first frequency band and the highest frequency in the second frequency band; for instance, the center frequency of the first coupler 30 is the same as or close to the intermediate frequency of the operating frequency band.

[0048] Taking the center frequency of the first coupler 30 as equal to the mid-frequency of the operating frequency band of the Dougherty power amplifier circuit as an example, at this target frequency, the power combining efficiency of the first coupler 30 is higher, and the resistance value of the first impedance circuit 40 is lower; this enables the Dougherty power amplifier circuit to have higher power combining efficiency at the target frequency, and also has high power combining efficiency at different frequencies throughout the entire operating frequency band. Moreover, the bandwidth advantage of the first coupler 30 (such as a 3dB quadrature coupler) can be utilized to expand the bandwidth of the Dougherty power amplifier circuit.

[0049] For example, in an implementation where the phase of the second radio frequency signal leads the phase of the first radio frequency signal by 80 to 100 degrees, and / or the first power amplifier unit 10 is a peak amplifier and the second power amplifier unit 20 is a carrier amplifier, in the operating frequency band of the Dougherty power amplifier circuit, the resistance value of the first impedance circuit 40 is R1, and the resistance value of the characteristic impedance of the first coupler 30 is R0, wherein:

[0050]

[0051] This indicates the phase shift angle corresponding to the frequency in the operating frequency band. express The corresponding phase factor.

[0052] By setting the impedance of the first impedance circuit 40 and the resistance value R0 of the characteristic impedance of the first coupler 30 to satisfy the formula, the Dougherty power amplifier circuit can have higher power combining efficiency at the target frequency and higher power combining efficiency at different frequencies throughout the entire operating frequency band; and can make the two radio frequency signals corresponding to the first power amplifier unit 10 and the second power amplifier unit 20 have the same phase or the phase difference within an acceptable range (such as less than or equal to 10 degrees) at the first output terminal P33 of the first coupler 30, so as to improve the power combining efficiency.

[0053] For example, in the operating frequency band of the Dougherty power amplifier circuit, the resistance value R1 of the first impedance circuit 40 at the target frequency (such as the center frequency of the first coupler 30) is equal to 0, and the first impedance circuit 40 is in a short-circuit state, that is... .

[0054] For example, the first coupler 30 can be set according to the operating frequency band of the Dougherty power amplifier circuit. The phase shift angle corresponding to the first coupler 30 is related to the characteristics of the first coupler 30 itself and the frequency; that is, different frequencies correspond to different phase shift angles. Based on the above formula, according to the phase shift angles corresponding to different frequencies... The resistance value R0 of the characteristic impedance of the first coupler 30 can determine the specific impedance of the first impedance circuit 40 at different frequencies. By adjusting the impedance of the first impedance circuit 40 to be equal to this specific impedance, so that the impedance of the first impedance circuit 40 corresponds to the current frequency or the current frequency band (such as the first frequency band or the second frequency band), the resistance value of the first impedance circuit 40 at different frequencies can be small, such as equal to 0 or close to 0, so as to ensure that the Dougherty power amplifier circuit has high power combining efficiency at different frequencies.

[0055] In other embodiments, the first power amplification unit 10 is a carrier amplifier, and the second power amplification unit 20 is a peak amplifier. In the operating frequency band of the Dougherty power amplifier circuit, the resistance value of the first impedance circuit 40 is greater than or equal to 1000 ohms. Further, in the operating frequency band of the Dougherty power amplifier circuit, the resistance value of the first impedance circuit 40 at the target frequency is greater than or equal to 5000 ohms. For example, in the operating frequency band of the Dougherty power amplifier circuit, the resistance value of the first impedance circuit 40 at the target frequency is greater than or equal to 10000 ohms or even higher, for example, the first impedance circuit 40 is in an open-circuit state at the target frequency. The target frequency is greater than the lowest frequency in the operating frequency band and less than the highest frequency in the operating frequency band.

[0056] In the case where the first power amplification unit 10 is a carrier amplifier and the second power amplification unit 20 is a peak amplifier, the phase of the second radio frequency signal corresponding to the second power amplification unit 20 lags behind the phase of the first radio frequency signal corresponding to the first power amplification unit 10 by 80 to 100 degrees, such as 80, 85, 90, 95, or 100 degrees; preferably, the phase of the second radio frequency signal lags behind the phase of the first radio frequency signal by 90 degrees; the first impedance circuit 40 has a large resistance in the operating frequency band of the Dougherty power amplification circuit and / or is in an open circuit state at the target frequency, which enables the two radio frequency signals to have the same phase or a phase difference within an acceptable range (such as less than or equal to 10 degrees) at the first output terminal P33 of the first coupler 30, so as to improve the power combining efficiency.

[0057] For example, the difference between the target frequency and the intermediate frequency is less than or equal to 0.2 GHz, where the intermediate frequency is the average of the lowest and highest frequencies in the operating band; such as the difference being any one of 0.2 GHz, 0.15 GHz, 0.1 GHz, or 0 GHz. For instance, the target frequency can be equal to the intermediate frequency of the operating band. By setting the resistance value of the first impedance circuit 40 at the target frequency to be greater than or equal to 1000 ohms (e.g., greater than or equal to 5000 ohms), the resistance value of the first impedance circuit 40 can be relatively large at different frequencies throughout the operating band. For example, if the resistance value of the first impedance circuit 40 at the intermediate frequency of the operating band is greater than or equal to 5000 ohms, the resistance value of the first impedance circuit 40 at different frequencies throughout the operating band can be relatively large (e.g., all greater than or equal to 2000 ohms), ensuring that the Dougherty power amplifier circuit has high power combining efficiency at different frequencies throughout the operating band.

[0058] For example, the target frequency is the same as the center frequency of the first coupler 30. The center frequency of the first coupler 30 can be equal to the mid-frequency of the operating band of the Dougherty power amplifier circuit. For example, at this target frequency, the power combining efficiency of the first coupler 30 is higher, and the resistance value of the first impedance circuit 40 is higher, which enables the Dougherty power amplifier circuit to have higher power combining efficiency at the target frequency and higher power combining efficiency at different frequencies throughout the entire operating band.

[0059] For example, in an embodiment where the phase of the second radio frequency signal lags the phase of the first radio frequency signal by 80 to 100 degrees, and / or the first power amplifier unit 10 is a carrier amplifier and the second power amplifier unit 20 is a peak amplifier, in the operating frequency band of the Dougherty power amplifier circuit, the resistance value of the first impedance circuit 40 is R1, and the resistance value of the characteristic impedance of the first coupler 30 is R0, wherein:

[0060]

[0061] This indicates the phase shift angle corresponding to the frequency in the operating frequency band. express The corresponding phase factor.

[0062] By setting the impedance of the first impedance circuit 40 and the resistance value R0 of the characteristic impedance of the first coupler 30 to satisfy the formula, the Dougherty power amplifier circuit can have higher power combining efficiency at the target frequency and higher power combining efficiency at different frequencies throughout the entire operating frequency band; and can make the two radio frequency signals corresponding to the first power amplifier unit 10 and the second power amplifier unit 20 have the same phase or the phase difference within an acceptable range (such as less than or equal to 10 degrees) at the first output terminal P33 of the first coupler 30, so as to improve the power combining efficiency.

[0063] For example, in the operating frequency band of the Dougherty power amplifier circuit, the resistance of the first impedance circuit 40 at the target frequency (such as the center frequency of the first coupler 30) is infinite, and the first impedance circuit 40 is in an open-circuit state, i.e. .

[0064] For example, the first coupler 30 can be configured according to the operating frequency band of the Dougherty power amplifier circuit, based on the above formula and according to the phase shift angle corresponding to different frequencies. The resistance value R0 of the characteristic impedance of the first coupler 30 can determine the specific impedance of the first impedance circuit 40 at different frequencies. By adjusting the impedance of the first impedance circuit 40 to be equal to this specific impedance, so that the impedance of the first impedance circuit 40 corresponds to the current frequency or the current frequency band (such as the first frequency band or the second frequency band), the resistance value of the first impedance circuit 40 can be relatively large at different frequencies, such as greater than or equal to 5000 ohms, so as to ensure that the Dougherty power amplifier circuit has high power combining efficiency at different frequencies. While realizing the advantages of circuit bandwidth, it can also ensure the accurate matching of the impedance of the Dougherty power amplifier circuit at different frequency bands, thereby improving the performance of the Dougherty power amplifier circuit.

[0065] In some embodiments, the impedance of the first impedance circuit 40 is adjustable. For example, the first impedance circuit 40 includes one of a resistor, an inductor, a capacitor, and a switch. By switching the switch, one of the resistor, inductor, and capacitor is connected to the first isolation terminal P34 of the first coupler 30, so that the impedance of the first impedance circuit 40 corresponds to the current frequency or the current frequency band (such as the first frequency band or the second frequency band).

[0066] In some implementations, the resistance value of the first impedance circuit 40 in the first frequency band is different from that in the second frequency band; and / or, the capacitance value of the first impedance circuit 40 in the first frequency band is different from that in the second frequency band; and / or, the inductance value of the first impedance circuit 40 in the first frequency band is different from that in the second frequency band. By adjusting the impedance characteristics of the first impedance circuit 40 to correspond to the current frequency band in different frequency bands, it is possible to ensure that the two RF signals corresponding to the first power amplification unit 10 and the second power amplification unit 20 of the Dougherty power amplifier circuit are in phase at the first output terminal P33 in the first frequency band or that the phase difference is within an acceptable range. Similarly, it is possible to ensure that the two RF signals corresponding to the first power amplification unit 10 and the second power amplification unit 20 of the Dougherty power amplifier circuit are in phase at the first output terminal P33 in the second frequency band or that the phase difference is within an acceptable range. This ensures high power combining efficiency in both frequency bands and achieves the goal of expanding the bandwidth of the Dougherty power amplifier circuit.

[0067] In some embodiments, the first impedance circuit 40 can be switched to a first state or a second state; when the operating frequency band of the Dougherty power amplifier circuit is the first frequency band, the first impedance circuit 40 switches to the first state; when the operating frequency band of the Dougherty power amplifier circuit is the second frequency band, the first impedance circuit 40 switches to the second state; wherein, the resistance value of the first impedance circuit 40 in the first state is different from the resistance value of the first impedance circuit 40 in the second state; and / or, the capacitance value of the first impedance circuit 40 in the first state is different from the capacitance value of the first impedance circuit 40 in the second state; and / or the inductance value of the first impedance circuit 40 in the first state is different from the inductance value of the first impedance circuit 40 in the second state.

[0068] By switching the state of the first impedance circuit 40 in different frequency bands, the impedance characteristics of the first impedance circuit 40 correspond to the current frequency band. For example, when working in the first frequency band, the first impedance circuit 40 switches to the first state, at which time the impedance of the first impedance circuit 40 is the optimal impedance corresponding to the first frequency band (e.g., when the phase of the second radio frequency signal leads the phase of the first radio frequency signal by 90 degrees, the resistance value at the middle frequency of the first frequency band is 0; or when the phase of the second radio frequency signal lags the phase of the first radio frequency signal by 90 degrees, the resistance value at the middle frequency of the first frequency band is greater than or equal to 5000 ohms). When working in the second frequency band, the first impedance circuit 40 switches to the second state, at which time the impedance of the first impedance circuit 40 is the optimal impedance corresponding to the second frequency band (e.g., when the phase of the second radio frequency signal leads the phase of the first radio frequency signal by 90 degrees, the resistance value at the middle frequency of the second frequency band is 0; or when the phase of the second radio frequency signal lags the phase of the first radio frequency signal by 90 degrees, the resistance value at the middle frequency of the second frequency band is greater than or equal to 5000 ohms). This design ensures that the two radio frequency signals corresponding to the first power amplification unit 10 and the second power amplification unit 20 are in the same phase or have an acceptable phase difference at the first output terminal P33 in the first frequency band, and also ensures that the two radio frequency signals corresponding to the first power amplification unit 10 and the second power amplification unit 20 are in the same phase or have an acceptable phase difference at the first output terminal P33 in the second frequency band. This guarantees high power combining efficiency in both frequency bands and achieves the goal of expanding the bandwidth of the Dougherty power amplifier circuit.

[0069] In some implementations, please refer to Figure 3 The first impedance circuit 40 includes at least a first branch 41 and a second branch 42. The first end of both the first branch 41 and the first end of both the second branch 42 are connected to a first isolation terminal P34. The second ends of both the first branch 41 and the second end of both the second branch 42 are grounded. The impedance of the first branch 41 is not equal to the impedance of the second branch 42. For example, the first impedance device 411 includes a capacitor, and the second impedance device 421 includes an inductor; and / or the first branch 41 includes a first resistor R10, and the second branch 42 includes a second resistor R20, the resistance values ​​of the first resistor R10 and the second resistor R20 being not equal.

[0070] For example, the first branch 41 includes at least a first impedance device 411 and a first switch K1 connected in series, and the second branch 42 includes at least a second impedance device 421 and a second switch K2 connected in series; the first isolation terminal P34 is grounded through the first impedance device 411 and the first switch K1 connected in series, and the first isolation terminal P34 is grounded through the second impedance device 421 and the second switch K2 connected in series, and at most one of the first switch K1 and the second switch K2 is closed.

[0071] By switching the closing of different switches, such as closing the first switch K1 or the second switch K2, the state and impedance of the first impedance circuit 40 can be switched. For example, when the operating frequency band of the Dougherty power amplifier circuit is the first frequency band, the first switch K1 is closed and the second switch K2 is open; when the operating frequency band of the Dougherty power amplifier circuit is the second frequency band, the second switch K2 is closed and the first switch K1 is open. This ensures that the two RF signals corresponding to the first power amplification unit 10 and the second power amplification unit 20 are in phase at the first output terminal P33 or have an acceptable phase difference when the Dougherty power amplifier circuit is in the first frequency band, and also ensures that the two RF signals corresponding to the first power amplification unit 10 and the second power amplification unit 20 are in phase at the first output terminal P33 or have an acceptable phase difference when the Dougherty power amplifier circuit is in the second frequency band, thus ensuring high power combining efficiency in both frequency bands. While realizing the advantages of wide bandwidth, it also ensures accurate impedance matching of the Dougherty power amplifier circuit in different frequency bands, thereby improving the performance of the Dougherty power amplifier circuit.

[0072] For example, the first power amplifier unit 10 and the second power amplifier unit 20 are integrated on an RF power amplifier chip. The first coupler 30 and the first impedance device 411 and the second impedance device 421 are disposed on a substrate. The first switch K1 and the second switch K2 are integrated on a control chip or a switch chip. The RF power amplifier chip, the control chip, or the switch chip are disposed on the substrate. The first power amplifier unit 10 and the second power amplifier unit 20 can be connected to corresponding pads on the substrate via pins on the RF power amplifier chip. The pads can be connected to the first coupler 30 via metal traces and / or bonding wires on the substrate. The first coupler 30 can be connected to the first impedance device 411 and the second impedance device 421 on the substrate via metal traces on the substrate. The first switch K1 and the second switch K2 can be connected to corresponding pads on the substrate via pins on the control chip or the switch chip. The pads can be connected to the first impedance device 411 and the second impedance device 421 on the substrate via metal traces on the substrate. By integrating the first power amplifier unit 10 and the second power amplifier unit 20 into the RF power amplifier chip, and integrating the first switch K1 and the second switch K2 into the control chip or switch chip, the layout of the Dougherty power amplifier circuit can be facilitated. For example, the RF power amplifier chip, control chip or switch chip, and the first coupler 30, the first impedance device 411, and the second impedance device 421 can be arranged on the substrate, reducing the area required by the devices corresponding to the Dougherty power amplifier circuit and contributing to the miniaturization of the substrate. Moreover, integrating the first switch K1 and the second switch K2 into the control chip or switch chip can also simplify the manufacturing process of the RF power amplifier chip and reduce the size of the first switch K1 and the second switch K2, further reducing the area required by the devices corresponding to the Dougherty power amplifier circuit and contributing to the miniaturization of the substrate.

[0073] In other examples, such as Figure 4As shown, the first impedance circuit 40 includes a first branch 41, a second branch 42, and a switching circuit 43. The first branch 41 includes at least a first impedance device 411, and the second branch 42 includes a second impedance device 421. For example, the first impedance device 411 includes a capacitor, and the second impedance device 421 includes an inductor. For example, the first branch 41 may also include a first resistor R10, which is connected in series with the first impedance device 411; the second branch 42 may also include a second resistor R20, which is connected in series with the second impedance device 421. The switching circuit 43 is electrically connected to the first branch 41 and the second branch 42. The switching circuit 43 is used to switch the electrical connection between the first branch 41 and the first isolation terminal P34, or to switch the electrical connection between the second branch 42 and the first isolation terminal P34. By controlling the switching circuit 43 to switch the electrical connection between the first branch 41 and the first isolation terminal P34, or to switch the electrical connection between the second branch 42 and the first isolation terminal P34, the state and impedance of the first impedance circuit 40 can be switched. For example, when the Dougherty power amplifier circuit operates in the first frequency band, the control switch circuit 43 switches the first branch 41 to be electrically connected to the first isolation terminal P34; when the Dougherty power amplifier circuit operates in the second frequency band, the control switch circuit 43 switches the second branch 42 to be electrically connected to the first isolation terminal P34. This ensures that the two radio frequency signals corresponding to the first power amplification unit 10 and the second power amplification unit 20 are in phase or have an acceptable phase difference at the first output terminal P33 when the Dougherty power amplifier circuit operates in the first frequency band, and also ensures that the two radio frequency signals corresponding to the first power amplification unit 10 and the second power amplification unit 20 are in phase or have an acceptable phase difference at the first output terminal P33 when the Dougherty power amplifier circuit operates in the second frequency band. This guarantees high power combining efficiency in both frequency bands and achieves the goal of expanding the bandwidth of the Dougherty power amplifier circuit.

[0074] In some embodiments, the first power amplification unit 10 is a peak amplifier, and the second power amplification unit 20 is a carrier amplifier; the first impedance circuit 40 can be switched between a first state and a second state. At least a portion of the frequencies in the first frequency band are greater than the center frequency of the first coupler 30, and at least a portion of the frequencies in the second frequency band are less than the center frequency of the first coupler 30; in the first state, the first impedance circuit 40 includes a grounded capacitor, and in the second state, the first impedance circuit 40 includes a grounded inductor. For an example, please refer to... Figure 3In the first impedance circuit 40, the first impedance device 411 of the first branch 41 includes a capacitor, and the second impedance device 421 of the second branch 42 includes an inductor. When the operating frequency band of the Dougherty power amplifier circuit is the first frequency band, the first switch K1 of the first branch 41 is closed, and the first impedance circuit 40 includes a grounded capacitor; when the operating frequency band of the Dougherty power amplifier circuit is the second frequency band, the second switch K2 of the second branch 42 is closed, and the first impedance circuit 40 includes a grounded inductor.

[0075] For example, in one embodiment, the first frequency band is 4.8GHz-4.96GHz, the second frequency band is 3.3GHz-4.2GHz, and the center frequency of the first coupler 30 is 4.2GHz. In embodiments where the phase of the second radio frequency signal leads the phase of the first radio frequency signal by 80 to 100 degrees, and / or the first power amplifier unit 10 is a peak amplifier and the second power amplifier unit 20 is a carrier amplifier, by including a grounded capacitor in the first impedance circuit 40 in the first frequency band, the resistance value of the first impedance circuit 40 in the first frequency band can be less than or equal to 50 ohms; by including a grounded inductor in the first impedance circuit 40 in the second frequency band, the resistance value of the first impedance circuit 40 in the first frequency band can also be less than or equal to 50 ohms. That is, the resistance value of the first impedance circuit 40 can be small at different frequencies throughout the entire operating frequency band (including the first and second frequency bands), ensuring that the Dougherty power amplifier circuit has high power combining efficiency at different frequencies throughout the entire operating frequency band, and achieving the goal of expanding the bandwidth of the Dougherty power amplifier circuit.

[0076] In another embodiment, the first frequency band is 2.5GHz-2.7GHz, the second frequency band is 2.3GHz-2.4GHz, and the center frequency of the first coupler 30 is 2.5GHz. In the implementation where the phase of the second radio frequency signal leads the phase of the first radio frequency signal by 80 to 100 degrees, and / or the first power amplifier unit 10 is a peak amplifier and the second power amplifier unit 20 is a carrier amplifier, by including a grounded capacitor in the first impedance circuit 40 in the first frequency band, the resistance value of the first impedance circuit 40 in the first frequency band can be less than or equal to 50 ohms; by including a grounded inductor in the first impedance circuit 40 in the second frequency band, the resistance value of the first impedance circuit 40 in the first frequency band can also be less than or equal to 50 ohms. That is, the resistance value of the first impedance circuit 40 can be small at different frequencies throughout the entire operating frequency band (including the first and second frequency bands), ensuring that the Dougherty power amplifier circuit has high power combining efficiency at different frequencies throughout the entire operating frequency band, and achieving the goal of expanding the bandwidth of the Dougherty power amplifier circuit.

[0077] In other embodiments, the first power amplification unit 10 is a carrier amplifier, the second power amplification unit 20 is a peak amplifier, and the first impedance circuit 40 can be switched to a first state or a second state. At least a portion of the frequencies in the first frequency band are greater than the center frequency of the first coupler 30, and at least a portion of the frequencies in the second frequency band are less than the center frequency of the first coupler 30; in the first state, the first impedance circuit 40 includes a grounded inductor, and in the second state, the first impedance circuit 40 includes a grounded capacitor. For example, when the operating frequency band of the Dougherty power amplifier circuit is the first frequency band, the switch corresponding to the branch in the first impedance circuit 40 with the inductor connected in series is closed, such that the first impedance circuit 40 includes a grounded inductor; when the operating frequency band of the Dougherty power amplifier circuit is the second frequency band, the switch corresponding to the branch in the first impedance circuit 40 with the capacitor connected in series is closed, such that the first impedance circuit 40 includes a grounded capacitor.

[0078] In the implementation where the phase of the second radio frequency signal lags the phase of the first radio frequency signal by 80 to 100 degrees, and / or the first power amplifier unit 10 is a carrier amplifier and the second power amplifier unit 20 is a peak amplifier, by setting the first impedance circuit 40 to include a grounded inductor in the first frequency band, the resistance value of the first impedance circuit 40 in the first frequency band can be less than or equal to 50 ohms; by setting the first impedance circuit 40 to include a grounded carrier in the second frequency band, the resistance value of the first impedance circuit 40 in the first frequency band can also be less than or equal to 50 ohms. That is, the resistance value of the first impedance circuit 40 can be small at different frequencies throughout the entire operating frequency band (including the first and second frequency bands), so as to ensure that the Dougherty power amplifier circuit has high power combining efficiency at different frequencies throughout the entire operating frequency band.

[0079] In other implementations, please refer to Figure 5 The operating frequency band of the Dougherty power amplifier circuit includes a third frequency band, and the center frequency of the first coupler 30 is the same as the center frequency corresponding to the third frequency band. In the third frequency band, the first impedance circuit 40 is set to open circuit or short circuit. Optionally, the first impedance circuit 40 may not include a switch, and the structure is simpler. For example, the circuit structure of the first impedance circuit 40 is fixed, which is easy to implement.

[0080] For example, the third frequency band can be the first frequency band, such as the 4.8GHz-4.96GHz band, but it is not limited to this. For example, the third frequency band can also be the second frequency band.

[0081] For example, the third frequency band may include the first frequency band and the second frequency band. The center frequency of the first coupler 30 is the same as the center frequency of the third frequency band. For example, the first frequency band is the 4.8GHz-4.96GHz band, the second frequency band is the 3.3GHz-4.2GHz band, and the center frequency of the first coupler 30 is 4GHz (approximately equal to the midpoint of 3.3GHz-4.96GHz, 4.13GHz).

[0082] For example, in an implementation where the phase of the second RF signal leads the phase of the first RF signal by 80 to 100 degrees, and / or the first power amplifier unit 10 is a peak amplifier and the second power amplifier unit 20 is a carrier amplifier, in the case where the operating frequency band of the Dougherty power amplifier circuit is the third frequency band, the Dougherty power amplifier unit operates in one frequency band, and the first impedance circuit 40 is set to short-circuit; this makes the two RF signals corresponding to the first power amplifier unit 10 and the second power amplifier unit 20 have the same phase or the phase difference is within an acceptable range at the first output terminal P33 of the first coupler 30, so as to improve the power combining efficiency.

[0083] For example, in an implementation where the phase of the second RF signal lags the phase of the first RF signal by 80 to 100 degrees, and / or the first power amplifier unit 10 is a carrier amplifier and the second power amplifier unit 20 is a peak amplifier, in the case where the operating frequency band of the Dougherty power amplifier circuit is the third frequency band, the first impedance circuit 40 is set to an open circuit; so that the two RF signals corresponding to the first power amplifier unit 10 and the second power amplifier unit 20 have the same phase or the phase difference is within an acceptable range at the first output terminal P33 of the first coupler 30, thereby improving the power combining efficiency.

[0084] In some implementations, please refer to Figure 6The Dougherty power amplifier circuit further includes: a third power amplifier unit 60 and a second coupler 70; the third power amplifier unit 60 is used to amplify the power of the input radio frequency signal, and the second coupler 70 includes at least a second input terminal P71, a second through terminal P72, and a second coupling terminal P73. The second input terminal P71 is connected to the output terminal of the third power amplifier unit 60; the second through terminal P72 is connected to the input terminal of the first power amplifier unit 10, and the second coupling terminal P73 is connected to the input terminal of the second power amplifier unit 20; or the second through terminal P72 is connected to the input terminal of the second power amplifier unit 20, and the second coupling terminal P73 is connected to the input terminal of the first power amplifier unit 10. In this embodiment, the second coupler 70 is different from the first coupler 30. Specifically, in this embodiment, when the second coupler 70 is set, the center frequency of the second coupler 70 may be different from the center frequency corresponding to the first coupler 30. The second coupler 70 splits the radio frequency signal output from the single-ended third power amplifier unit 60 into two radio frequency signals with a phase difference of 70 degrees to 110 degrees. The Dougherty power amplifier circuit is used to perform power combining and amplification on the two radio frequency signals output from the second coupler 70.

[0085] In other implementations, please refer to Figure 7 The Dougherty power amplifier circuit also includes a power divider 80 and a phase shifter 90. The power divider 80 includes an input terminal and two output terminals. The power divider 80 is used to split the input radio frequency signal into two radio frequency signals, and the two output terminals are used to output the two radio frequency signals. One output terminal of the power divider 80 is connected to the input terminal of the first power amplifier unit 10, and the other output terminal of the power divider 80 is connected to the input terminal of the second power amplifier unit 20 via the phase shifter 90; or one output terminal of the power divider 80 is connected to the input terminal of the second power amplifier unit 20, and the other output terminal of the power divider 80 is connected to the input terminal of the first power amplifier unit 10 via the phase shifter 90. The power divider 80 splits one radio frequency signal into two radio frequency signals. One of the radio frequency signals is phase-shifted by the phase shifter 90, which is for example, a phase shifter 90 with a phase difference of 80 to 100 degrees (such as 90 degrees). This can result in two radio frequency signals with a phase difference of 80 to 100 degrees. The Dougherty power amplifier circuit is used to combine and amplify the two radio frequency signals.

[0086] The Dougherty power amplifier circuit provided in this application includes a first power amplifier unit 10, a second power amplifier unit 20, a first coupler 30, a first impedance circuit 40, and a second impedance circuit 50. The first coupler 30 includes a first through terminal P31, a first coupling terminal P32, a first output terminal P33, and a first isolation terminal P34. The first through terminal P31 is connected to the output terminal of the first power amplifier unit 10, the first coupling terminal P32 is connected to the output terminal of the second power amplifier unit 20, and the first output terminal P33 is used to output radio frequency signals. The first isolation terminal P34 is electrically connected to the first impedance circuit 40. The first output terminal P33 is electrically connected to the second impedance circuit 50, and the circuit structure of the second impedance circuit 50 is different from that of the first impedance circuit 40. This design ensures that the two radio frequency signals corresponding to the first power amplification unit 10 and the second power amplification unit 20 are in the same phase or have an acceptable phase difference at the first output terminal P33 of the first coupler 30, thereby improving power combining efficiency. The bandwidth advantage of the first coupler 30 can be utilized, and the bandwidth of the Dougherty power amplifier circuit can be expanded by differentiating the first impedance circuit 40 and the second impedance circuit 50. The structure is relatively simple, which is conducive to the miniaturization of the Dougherty power amplifier circuit.

[0087] Please refer to the foregoing embodiments. Figure 8 ,like Figure 8 The diagram shown is a schematic of a Dougherty power amplifier circuit provided in another embodiment of this application.

[0088] like Figure 8 As shown, the Dougherty power amplifier circuit includes: First power amplifier unit 10; Second power amplifier unit 20; A first coupler 30 includes a first through terminal P31, a first coupling terminal P32, a first output terminal P33, and a first isolation terminal P34. The first through terminal P31 is connected to the output terminal of the first power amplifier unit 10, the first coupling terminal P32 is connected to the output terminal of the second power amplifier unit 20, and the first output terminal P33 is used to output radio frequency signals. The first impedance circuit 40, the first isolation terminal P34 is electrically connected to the first impedance circuit 40; The operating frequency band of the Dougherty power amplifier circuit includes a first frequency band and a second frequency band. The first frequency band and the second frequency band do not overlap or at least partially overlap. The resistance value of the first impedance circuit 40 of the Dougherty power amplifier circuit in the first frequency band is different from the resistance value of the first impedance circuit 40 of the Dougherty power amplifier circuit in the second frequency band.

[0089] The Dougherty power amplifier circuit of this application embodiment can utilize the bandwidth advantage of the first coupler 30, so that the first impedance circuit 40 has different resistance values ​​in the first frequency band or the second frequency band. This allows the two radio frequency signals corresponding to the first power amplification unit 10 and the second power amplification unit 20 to be in phase at the first output terminal P33 or have an acceptable phase difference in the first frequency band. It also allows the two radio frequency signals corresponding to the first power amplification unit 10 and the second power amplification unit 20 to be in phase at the first output terminal P33 or have an acceptable phase difference in the second frequency band. This ensures high power combining efficiency in both frequency bands and achieves the purpose of expanding the bandwidth of the Dougherty power amplifier circuit.

[0090] In some embodiments, the first impedance circuit 40 can be switched to a first state or a second state. When the operating frequency band of the Dougherty power amplifier circuit is the first frequency band, the first impedance circuit 40 switches to the first state; when the operating frequency band of the Dougherty power amplifier circuit is the second frequency band, the first impedance circuit 40 switches to the second state. The resistance value of the first impedance circuit 40 in the first state is different from the resistance value of the first impedance circuit 40 in the second state; and / or, the capacitance value of the first impedance circuit 40 in the first state is different from the capacitance value of the first impedance circuit 40 in the second state; and / or the inductance value of the first impedance circuit 40 in the first state is different from the inductance value of the first impedance circuit 40 in the second state. Specifically, in one embodiment, the resistance value corresponding to the first impedance circuit 40 switching to the first state is greater than the resistance value corresponding to the first impedance circuit 40 switching to the second state. This achieves the advantage of wide bandwidth while ensuring accurate impedance matching of the Dougherty power amplifier circuit in different frequency bands, thereby improving the performance of the Dougherty power amplifier circuit.

[0091] In some embodiments, the first power amplification unit 10 is a peak amplifier and the second power amplification unit 20 is a carrier amplifier; at least a portion of the frequencies in the first frequency band are greater than the center frequency of the first coupler 30, and at least a portion of the frequencies in the second frequency band are less than the center frequency of the first coupler 30; in a first state, the first impedance circuit 40 includes a grounded capacitor, and in a second state, the first impedance circuit 40 includes a grounded inductor.

[0092] In other embodiments, the first power amplification unit 10 is a carrier amplifier, the second power amplification unit 20 is a peak amplifier, at least a portion of the frequencies in the first frequency band are greater than the center frequency of the first coupler 30, and at least a portion of the frequencies in the second frequency band are less than the center frequency of the first coupler 30; in the first state, the first impedance circuit 40 includes a grounded inductor, and in the second state, the first impedance circuit 40 includes a grounded capacitor.

[0093] In some embodiments, the first frequency band includes a 4.8GHz-4.96GHz band, and the second frequency band includes a 3.3GHz-4.2GHz band; in the first frequency band, the first impedance circuit 40 includes a grounded capacitor, and in the second frequency band, the first impedance circuit 40 includes a grounded inductor. For example, the first power amplifier unit 10 is a peak amplifier, and the second power amplifier unit 20 is a carrier amplifier; in the first frequency band, the first impedance circuit 40 includes a grounded capacitor, and in the second frequency band, the first impedance circuit 40 includes a grounded inductor.

[0094] Please refer to the foregoing embodiments. Figure 9 ,like Figure 9 The diagram shown is a schematic block diagram of a radio frequency front-end module provided in an embodiment of this application; the radio frequency front-end module includes the aforementioned Dougherty power amplifier circuit.

[0095] The radio frequency front-end module includes: a first power amplifier unit 10 and a second power amplifier unit 20, a first coupler 30 and a first impedance circuit 40.

[0096] The first power amplifier unit 10 is configured as a peak amplifier and the second power amplifier unit 20 is configured as a carrier amplifier; or the first power amplifier unit 10 is configured as a carrier amplifier and the second power amplifier unit 20 is configured as a peak amplifier.

[0097] The first coupler 30 includes a first through terminal P31, a first coupling terminal P32, a first output terminal P33, and a first isolation terminal P34. The first through terminal P31 is connected to the output terminal of the first power amplifier unit 10, the first coupling terminal P32 is connected to the output terminal of the second power amplifier unit 20, the first output terminal P33 is used to output radio frequency signals, and the first isolation terminal P34 is electrically connected to the first impedance circuit 40.

[0098] The first impedance circuit 40 includes at least a first branch 41 and a second branch 42. The first end of the first branch 41 and the first end of the second branch 42 are both connected to the first isolation terminal P34, and the second end of the first branch 41 and the second end of the second branch 42 are both grounded.

[0099] In some implementations, the resistance value of the first branch 41 is different from the resistance value of the second branch 42; and / or, the capacitance value of the first branch 41 is different from the capacitance value of the second branch 42; and / or, the inductance value of the first branch 41 is different from the inductance value of the second branch 42.

[0100] For example, the first impedance device 411 includes a capacitor, the second impedance device 421 includes an inductor; and / or the first branch 41 includes a first resistor R10, the second branch 42 includes a second resistor R20, and the resistance value of the first resistor R10 is not equal to the resistance value of the second resistor R20.

[0101] In the RF front-end module of this application embodiment, the Dougherty power amplifier circuit can utilize the bandwidth advantage of the first coupler 30; by setting the first impedance circuit 40, the matching requirements of different frequency bands can be met. Specifically, the first impedance circuit 40 includes at least a first branch 41 and a second branch 42. The Dougherty power amplifier circuit can switch between the first branch 41 and the second branch 42 to connect to the first isolation terminal P34 in different frequency bands. In this application embodiment, by switching at the first isolation terminal P34, the two RF signals corresponding to the first power amplification unit 10 and the second power amplification unit 20 can be in the same phase or have an acceptable phase difference at the first output terminal P33 in different frequency bands, ensuring high power combining efficiency in different frequency bands and achieving the purpose of expanding the bandwidth of the Dougherty power amplifier circuit and the RF front-end module; moreover, while realizing the bandwidth advantage of the circuit, it can also ensure accurate impedance matching of the Dougherty power amplifier circuit and the RF front-end module in different frequency bands, thereby improving the performance of the RF front-end module.

[0102] In some embodiments, the RF front-end module further includes a second impedance circuit 50, with the first output terminal P33 electrically connected to the second impedance circuit 50; the first power amplifier unit 10 is configured as a peak amplifier, and the second power amplifier unit 20 is configured as a carrier amplifier. In the operating frequency band of the RF front-end module, the resistance value of the first impedance circuit 40 is R1, and the resistance value of the characteristic impedance of the first coupler 30 is R0, wherein:

[0103]

[0104] This indicates the phase shift angle corresponding to a frequency in the operating frequency band. express The corresponding phase factor.

[0105] In other embodiments, the RF front-end module further includes a second impedance circuit 50, with the first output terminal P33 electrically connected to the second impedance circuit 50; the first power amplifier unit 10 is configured as a carrier amplifier, and the second power amplifier unit 20 is configured as a peak amplifier. At the operating frequency band of the RF front-end module, the resistance value of the first impedance circuit 40 is R1, and the resistance value of the characteristic impedance of the first coupler 30 is R0, wherein:

[0106]

[0107] This indicates the phase shift angle corresponding to a frequency in the operating frequency band. express The corresponding phase factor.

[0108] In some embodiments, the first branch 41 includes at least a first impedance device 411 and a first switch K1 connected in series, and the second branch 42 includes at least a second impedance device 421 and a second switch K2 connected in series; the first isolation terminal P34 is grounded through the first impedance device 411 and the first switch K1 connected in series, and the first isolation terminal P34 is grounded through the second impedance device 421 and the second switch K2 connected in series, and at most one of the first switch K1 and the second switch K2 is closed.

[0109] In other embodiments, the first impedance circuit 40 includes a first branch 41, a second branch 42, and a switching circuit 43. The first branch 41 includes at least a first impedance device 411, and the second branch 42 includes a second impedance device 421. For example, the first impedance device 411 includes a capacitor, and the second impedance device 421 includes an inductor. For example, the first branch 41 may also include a first resistor R10 connected in series with the first impedance device 411; the second branch 42 may also include a second resistor R20 connected in series with the second impedance device 421. The switching circuit 43 is electrically connected to the first branch 41 and the second branch 42, and is used to switch the electrical connection between the first branch 41 and the first isolation terminal P34 or to switch the electrical connection between the second branch 42 and the first isolation terminal P34.

[0110] In some embodiments, the first impedance circuit 40 can be switched to a first state or a second state; when the operating frequency band of the RF front-end module is the first frequency band, the first impedance circuit 40 switches to the first state; when the operating frequency band of the RF front-end module is the second frequency band, the first impedance circuit 40 switches to the second state, and the resistance value of the first impedance circuit 40 in the first state is different from the resistance value of the first impedance circuit 40 in the second state; and / or, the capacitance value of the first impedance circuit 40 in the first state is different from the capacitance value of the first impedance circuit 40 in the second state; and / or the inductance value of the first impedance circuit 40 in the first state is different from the inductance value of the first impedance circuit 40 in the second state.

[0111] In some implementations, the RF front-end module may also include at least one RF switch, low-noise amplifier, filter, etc., which can be integrated into a single module to improve integration and performance and reduce size.

[0112] In some implementations, such as Figure 10As shown, the radio frequency front-end module includes a substrate and radio frequency front-end circuits arranged on the substrate. The radio frequency front-end circuits may include switching circuits, filters, low-noise amplifiers and radio frequency power amplifiers between the radio frequency receiving port RX, the radio frequency transmitting port TX and the antenna port, and form a radio frequency signal transmission path through the above radio frequency devices.

[0113] The RF front-end circuit can choose to send RF signals to the antenna port or receive RF signals from the antenna port, thereby amplifying, filtering, and other processing of RF analog signals.

[0114] In one implementation, the RF front-end module may include multiple chips, at least one of which is an RF power amplifier chip integrating the aforementioned RF power amplifier. Furthermore, the RF front-end module may also include at least one other chip such as a low-noise amplifier chip, a control chip, a switching chip, or a filter chip.

[0115] For example, different chips can be manufactured using different processes. For instance, low-noise amplifier chips and control chips can be manufactured using at least one of silicon-on-insulator (SOI) technology, high-electron-mobility transistor (HEMT) technology, and pseudomorphic HEMT (PHEMT) technology. Radio frequency power amplifier chips can be manufactured using HBT (Heterojunction bipolar transistor) technology, also known as HBT chips, and control chips can be manufactured using CMOS technology, also known as CMOS chips.

[0116] For example, the RF front-end module may also include a filter chip, which may integrate one or more filters to form a single filter, duplexer or multiplexer for filtering RF signals.

[0117] The specific principle and implementation of the RF front-end module provided in this application embodiment are similar to the Dougherty power amplifier circuit in the foregoing embodiment, and will not be repeated here. Furthermore, any parts not mentioned in this application embodiment can be referred to the relevant descriptions in the foregoing embodiments, and will not be repeated here.

[0118] Please refer to the foregoing embodiments. Figure 11 ,like Figure 11 The diagram shown is a schematic block diagram of an electronic device according to another embodiment of this application. The electronic device includes the aforementioned Dougherty power amplifier circuit; or includes the aforementioned radio frequency front-end module.

[0119] The electronic device can be a mobile phone, tablet computer, vehicle terminal and other communication device. Of course, it can also be other communication devices with communication functions, such as drones or satellites. The embodiments of this application do not limit the specific types of electronic devices.

[0120] The specific principles and implementation methods of the electronic devices provided in this application are similar to those of the Dougherty power amplifier circuit or RF front-end module in the foregoing embodiments, and will not be repeated here. Furthermore, any parts not mentioned in this application's embodiments can be referred to the relevant descriptions in the foregoing embodiments, and will not be repeated here.

[0121] It should be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application.

[0122] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or portion discussed below may be referred to as a second element, component, area, layer, or portion.

[0123] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below,” “under,” or “below” other elements or features will be oriented “above” other elements or features. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0124] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0125] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A Dougherty power amplifier circuit, characterized in that, The Doherty power amplifier circuit includes: First power amplifier unit; Second power amplifier unit; A first coupler, comprising a first through terminal, a first coupling terminal, a first output terminal, and a first isolation terminal, wherein the first through terminal is connected to the output terminal of the first power amplifier unit, the first coupling terminal is connected to the output terminal of the second power amplifier unit, and the first output terminal is used to output a radio frequency signal; and The first impedance circuit, wherein the first isolation terminal is electrically connected to the first impedance circuit; The second impedance circuit is electrically connected to the first output terminal, and the circuit structure of the second impedance circuit is different from that of the first impedance circuit.

2. The Dougherty power amplifier circuit according to claim 1, characterized in that, The operating frequency band of the Doherty power amplifier circuit includes a first frequency band and a second frequency band, wherein the first frequency band and the second frequency band do not overlap or at least partially overlap; The resistance value of the first impedance circuit in the first frequency band is different from that in the second frequency band; and / or, the capacitance value of the first impedance circuit in the first frequency band is different from that in the second frequency band; and / or, the inductance value of the first impedance circuit in the first frequency band is different from that in the second frequency band.

3. The Dougherty power amplifier circuit according to claim 1, characterized in that, The first power amplification unit is a peak amplifier, and the second power amplification unit is a carrier amplifier. In the operating frequency band of the Dougherty power amplification circuit, the resistance value of the first impedance circuit is less than or equal to 50 ohms. Alternatively, the first power amplification unit is a carrier amplifier, the second power amplification unit is a peak amplifier, and the resistance value of the first impedance circuit is greater than or equal to 1000 ohms in the operating frequency band of the Dougherty power amplification circuit.

4. The Dougherty power amplifier circuit according to claim 3, characterized in that, The first power amplification unit is a peak amplifier, the second power amplification unit is a carrier amplifier, and the resistance of the first impedance circuit at the target frequency is less than or equal to 5 ohms; or The first power amplification unit is a carrier amplifier, the second power amplification unit is a peak amplifier, and the resistance value of the first impedance circuit at the target frequency is greater than or equal to 5000 ohms. The target frequency is greater than the lowest frequency in the operating frequency band, and the target frequency is less than the highest frequency in the operating frequency band.

5. The Dougherty power amplifier circuit according to claim 4, characterized in that, The difference between the target frequency and the intermediate frequency is less than or equal to 0.2 GHz, and the intermediate frequency is the average of the lowest frequency and the highest frequency in the operating frequency band.

6. The Dougherty power amplifier circuit according to claim 4, characterized in that, The target frequency is the same as the center frequency of the first coupler.

7. The Dougherty power amplifier circuit according to claim 1, characterized in that, The first power amplification unit is used to amplify the power of the first radio frequency signal, and the second power amplification unit is used to amplify the power of the second radio frequency signal, wherein the phase of the second radio frequency signal leads the phase of the first radio frequency signal by 80 to 100 degrees. At the operating frequency band of the Dougherty power amplifier circuit, the resistance value of the first impedance circuit is R1, and the resistance value of the characteristic impedance of the first coupler is R0, wherein: This indicates the phase shift angle corresponding to the frequency in the operating frequency band. express The corresponding phase factor.

8. The Dougherty power amplifier circuit according to claim 1, characterized in that, The first power amplification unit is used to amplify the power of the first radio frequency signal, and the second power amplification unit is used to amplify the power of the second radio frequency signal. The phase of the second radio frequency signal lags behind the phase of the first radio frequency signal by 80 to 100 degrees. At the operating frequency band of the Dougherty power amplifier circuit, the resistance value of the first impedance circuit is R1, and the resistance value of the characteristic impedance of the first coupler is R0, wherein: This indicates the phase shift angle corresponding to the frequency in the operating frequency band. express The corresponding phase factor.

9. The Dougherty power amplifier circuit according to claim 1, characterized in that, The resistance value of the second impedance circuit is greater than or equal to the resistance value of the characteristic impedance of the first coupler.

10. The Dougherty power amplifier circuit according to claim 9, characterized in that, The resistance value of the second impedance circuit is 100% to 160% of the resistance value of the characteristic impedance of the first coupler.

11. The Dougherty power amplifier circuit according to any one of claims 1-8, characterized in that, The first impedance circuit can be switched to a first state or a second state; When the operating frequency band of the Dougherty power amplifier circuit is the first frequency band, the first impedance circuit switches to the first state; when the operating frequency band of the Dougherty power amplifier circuit is the second frequency band, the first impedance circuit switches to the second state, and the resistance value of the first impedance circuit in the first state is different from the resistance value of the first impedance circuit in the second state; and / or, the capacitance value of the first impedance circuit in the first state is different from the capacitance value of the first impedance circuit in the second state; and / or the inductance value of the first impedance circuit in the first state is different from the inductance value of the first impedance circuit in the second state.

12. The Dougherty power amplifier circuit according to claim 11, characterized in that, The first power amplifier unit is a peak amplifier, and the second power amplifier unit is a carrier amplifier; At least a portion of the frequencies in the first frequency band are greater than the center frequency of the first coupler, and at least a portion of the frequencies in the second frequency band are less than the center frequency of the first coupler; in the first state, the first impedance circuit includes a grounded capacitor, and in the second state, the first impedance circuit includes a grounded inductor.

13. The Dougherty power amplifier circuit according to claim 11, characterized in that, The first power amplification unit is a carrier amplifier, the second power amplification unit is a peak amplifier, at least a portion of the frequencies in the first frequency band are greater than the center frequency of the first coupler, and at least a portion of the frequencies in the second frequency band are less than the center frequency of the first coupler; in the first state, the first impedance circuit includes a grounded inductor, and in the second state, the first impedance circuit includes a grounded capacitor.

14. The Dougherty power amplifier circuit according to claim 11, characterized in that, The difference between the center frequency and the intermediate frequency of the first coupler is [-0.2GHz, 0.2GHz], where the intermediate frequency is the average of the lowest frequency in the first frequency band and the highest frequency in the second frequency band.

15. The Dougherty power amplifier circuit according to any one of claims 1-8, characterized in that, The first impedance circuit includes at least a first branch and a second branch. The first end of the first branch and the first end of the second branch are both connected to the first isolation terminal, and the second end of the first branch and the second end of the second branch are both grounded.

16. The Dougherty power amplifier circuit according to claim 15, characterized in that, The first branch includes at least a first impedance device and a first switch connected in series, and the second branch includes at least a second impedance device and a second switch connected in series; the first isolation terminal is grounded through the first impedance device and the first switch connected in series, and the first isolation terminal is grounded through the second impedance device and the second switch connected in series, and at most one of the first switch and the second switch is closed; or The first impedance circuit includes a first branch, a second branch, and a switching circuit. The first branch includes at least a first impedance device, and the second branch includes a second impedance device. The switching circuit is electrically connected to the first branch and the second branch. The switching circuit is used to switch the first branch to be electrically connected to the first isolation terminal or to switch the second branch to be electrically connected to the first isolation terminal.

17. The Dougherty power amplifier circuit according to claim 16, characterized in that, The first impedance device includes a capacitor, and the second impedance device includes an inductor.

18. The Dougherty power amplifier circuit according to claim 16, characterized in that, The first power amplifier unit and the second power amplifier unit are integrated on the radio frequency power amplifier chip. The first coupler, the first impedance device, and the second impedance device are disposed on the substrate. The first switch and the second switch are integrated on the control chip or the switch chip. The radio frequency power amplifier chip, the control chip, or the switch chip are disposed on the substrate.

19. The Dougherty power amplifier circuit according to any one of claims 1-8, characterized in that, The operating frequency band of the Doherty power amplifier circuit includes a first frequency band and a second frequency band. The first frequency band is the 4.8GHz-4.96GHz band, and the second frequency band is the 3.3GHz-4.2GHz band.

20. The Dougherty power amplifier circuit according to any one of claims 1-8, characterized in that, The operating frequency band of the Doherty power amplifier circuit includes a first frequency band and a second frequency band. The first frequency band is the 2.5GHz-2.7GHz band, and the second frequency band is the 2.3GHz-2.4GHz band.

21. The Dougherty power amplifier circuit according to claim 1, characterized in that, The operating frequency band of the Dougherty power amplifier circuit includes a third frequency band, and the center frequency of the first coupler is the same as the center frequency corresponding to the third frequency band. In the third frequency band, the first impedance circuit is set to open circuit or short circuit.

22. The Dougherty power amplifier circuit according to any one of claims 1-8, characterized in that, The Dougherty power amplifier circuit also includes: The third power amplifier unit is used to amplify the power of the input radio frequency signal; The second coupler includes at least a second input terminal, a second through terminal, and a second coupling terminal. The second input terminal is connected to the output terminal of the third power amplifier unit; the second through terminal is connected to the input terminal of the first power amplifier unit, and the second coupling terminal is connected to the input terminal of the second power amplifier unit; or the second through terminal is connected to the input terminal of the second power amplifier unit, and the second coupling terminal is connected to the input terminal of the first power amplifier unit.

23. The Dougherty power amplifier circuit according to any one of claims 1-8, characterized in that, The Dougherty power amplifier circuit also includes: A power divider, comprising an input terminal and two output terminals, wherein the power divider is used to split an input radio frequency signal into two radio frequency signals, and the two output terminals are used to output the two radio frequency signals; Phase shifter; One output terminal of the power divider is connected to the input terminal of the first power amplifier unit, and the other output terminal of the power divider is connected to the input terminal of the second power amplifier unit via the phase shifter; or One of the output terminals of the power divider is connected to the input terminal of the second power amplifier unit, and the other output terminal of the power divider is connected to the input terminal of the first power amplifier unit through the phase shifter.

24. A Dougherty power amplifier circuit, characterized in that, include: First power amplifier unit; Second power amplifier unit; A first coupler includes a first through terminal, a first coupling terminal, a first output terminal, and a first isolation terminal. The first through terminal is connected to the output terminal of the first power amplifier unit, the first coupling terminal is connected to the output terminal of the second power amplifier unit, and the first output terminal is used to output a radio frequency signal. as well as The first impedance circuit, wherein the first isolation terminal is electrically connected to the first impedance circuit; The operating frequency band of the Dougherty power amplifier circuit includes a first frequency band and a second frequency band, wherein the first frequency band and the second frequency band do not overlap or at least partially overlap; the resistance value of the first impedance circuit of the Dougherty power amplifier circuit in the first frequency band is different from the resistance value of the first impedance circuit of the Dougherty power amplifier circuit in the second frequency band.

25. The Dougherty power amplifier circuit according to claim 24, characterized in that, The first impedance circuit can be switched to a first state or a second state; When the operating frequency band of the Dougherty power amplifier circuit is the first frequency band, the first impedance circuit switches to the first state; when the operating frequency band of the Dougherty power amplifier circuit is the second frequency band, the first impedance circuit switches to the second state, and the resistance value of the first impedance circuit in the first state is different from the resistance value of the first impedance circuit in the second state; and / or, the capacitance value of the first impedance circuit in the first state is different from the capacitance value of the first impedance circuit in the second state; and / or the inductance value of the first impedance circuit in the first state is different from the inductance value of the first impedance circuit in the second state.

26. The Dougherty power amplifier circuit according to claim 25, characterized in that, The first power amplification unit is a peak amplifier, and the second power amplification unit is a carrier amplifier; at least a portion of the frequencies in the first frequency band are greater than the center frequency of the first coupler, and at least a portion of the frequencies in the second frequency band are less than the center frequency of the first coupler; in the first state, the first impedance circuit includes a grounded capacitor, and in the second state, the first impedance circuit includes a grounded inductor; or The first power amplification unit is a carrier amplifier, the second power amplification unit is a peak amplifier, at least a portion of the frequencies in the first frequency band are greater than the center frequency of the first coupler, and at least a portion of the frequencies in the second frequency band are less than the center frequency of the first coupler; in the first state, the first impedance circuit includes a grounded inductor, and in the second state, the first impedance circuit includes a grounded capacitor.

27. The Dougherty power amplifier circuit according to any one of claims 24-26, characterized in that, The first frequency band includes the 4.8GHz-4.96GHz band, and the second frequency band includes the 3.3GHz-4.2GHz band; in the first frequency band, the first impedance circuit includes a grounded capacitor, and in the second frequency band, the first impedance circuit includes a grounded inductor.

28. A radio frequency front-end module, characterized in that, include: First power amplifier unit and second power amplifier unit; The first power amplifier unit is configured as a peak amplifier, and the second power amplifier unit is configured as a carrier amplifier; or the first power amplifier unit is configured as a carrier amplifier, and the second power amplifier unit is configured as a peak amplifier. A first coupler includes a first through terminal, a first coupling terminal, a first output terminal, and a first isolation terminal. The first through terminal is connected to the output terminal of the first power amplifier unit, the first coupling terminal is connected to the output terminal of the second power amplifier unit, and the first output terminal is used to output a radio frequency signal. as well as The first impedance circuit, wherein the first isolation terminal is electrically connected to the first impedance circuit; The first impedance circuit includes at least a first branch and a second branch. The first end of the first branch and the first end of the second branch are both connected to the first isolation terminal, and the second end of the first branch and the second end of the second branch are both grounded.

29. The radio frequency front-end module according to claim 28, characterized in that, The radio frequency front-end module further includes a second impedance circuit, and the first output terminal is electrically connected to the second impedance circuit. The first power amplification unit is configured as a peak amplifier, and the second power amplification unit is configured as a carrier amplifier. In the operating frequency band of the RF front-end module, the resistance value of the first impedance circuit is R1, and the resistance value of the characteristic impedance of the first coupler is R0, wherein: This indicates the phase shift angle corresponding to the frequency in the operating frequency band. express The corresponding phase factor.

30. The radio frequency front-end module according to claim 28, characterized in that, The radio frequency front-end module further includes a second impedance circuit, and the first output terminal is electrically connected to the second impedance circuit. The first power amplification unit is configured as a carrier amplifier, and the second power amplification unit is configured as a peak amplifier. In the operating frequency band of the RF front-end module, the resistance value of the first impedance circuit is R1, and the resistance value of the characteristic impedance of the first coupler is R0, wherein: This indicates the phase shift angle corresponding to the frequency in the operating frequency band. express The corresponding phase factor.

31. The radio frequency front-end module according to any one of claims 28-30, characterized in that, The first branch includes at least a first impedance device and a first switch connected in series, and the second branch includes at least a second impedance device and a second switch connected in series; the first isolation terminal is grounded through the first impedance device and the first switch connected in series, and the first isolation terminal is grounded through the second impedance device and the second switch connected in series, and at most one of the first switch and the second switch is closed; or The first impedance circuit includes a first branch, a second branch, and a switching circuit. The first branch includes at least a first impedance device, and the second branch includes a second impedance device. The switching circuit is electrically connected to the first branch and the second branch. The switching circuit is used to switch the first branch to be electrically connected to the first isolation terminal or to switch the second branch to be electrically connected to the first isolation terminal.

32. The radio frequency front-end module according to any one of claims 28-30, characterized in that, The first impedance circuit can be switched to a first state or a second state; When the operating frequency band of the radio frequency front-end module is the first frequency band, the first impedance circuit switches to the first state. When the operating frequency band of the RF front-end module is the second frequency band, the first impedance circuit switches to the second state, and the resistance value of the first impedance circuit in the first state is different from the resistance value of the first impedance circuit in the second state; and / or, the capacitance value of the first impedance circuit in the first state is different from the capacitance value of the first impedance circuit in the second state; and / or the inductance value of the first impedance circuit in the first state is different from the inductance value of the first impedance circuit in the second state.

33. An electronic device, characterized in that, The electronic device includes the Dougherty power amplifier circuit as claimed in any one of claims 1 to 27, or includes the radio frequency front-end module as claimed in any one of claims 28 to 32.

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