Power amplifier

Abstract

The embodiment of the invention provides a power amplifier. The power amplifier comprises a main path amplifying circuit, an auxiliary path amplifying circuit and a combiner circuit, the main path amplifying circuit comprises a main path amplifier; the auxiliary amplifying circuit comprises an auxiliary amplifier; the combiner circuit is used for combining the main amplification circuit and the auxiliary amplification circuit; the main amplification circuit and / or the auxiliary amplification circuit also comprises a first matching circuit; the first matching circuit is connected between the main amplifier or the auxiliary amplifier and the combiner circuit; the first matching circuit comprises an impedance conversion circuit and a first filter inductor, and the first filter inductor is connected with a capacitor in the impedance conversion circuit, so that the capacitor is grounded through the first filter inductor, and a first resonance circuit is formed.

Description

Technical Field

[0001] The present disclosure relates to the field of electronic technology, and relates to but is not limited to a power amplifier. Background Art

[0002] In mobile communication systems, the peak to average power ratio (PAPR) continues to increase, which requires the transmission system to maintain high linearity within a large dynamic range. In order to meet the system linearity requirements, the power amplifier (PA) needs to work in a power back-off state. However, after high power back-off, the power amplifier has problems such as low efficiency, narrow bandwidth, and high insertion loss. Summary of the invention

[0003] In view of this, an embodiment of the present disclosure provides a power amplifier, including a main amplifier circuit, an auxiliary amplifier circuit and a combiner circuit;

[0004] The main path amplification circuit comprises a main path amplifier;

[0005] The auxiliary path amplification circuit comprises an auxiliary path amplifier;

[0006] The combiner circuit is used to combine the main amplifier circuit and the auxiliary amplifier circuit;

[0007] The main amplifier circuit and / or the auxiliary amplifier circuit also includes a first matching circuit, which is connected between the main amplifier or the auxiliary amplifier and the combiner circuit; the first matching circuit includes an impedance conversion circuit and a first filter inductor, and the first filter inductor is connected to a capacitor in the impedance conversion circuit so that the capacitor is grounded through the first filter inductor to form a first resonant circuit.

[0008] In some embodiments, the first matching circuit includes a plurality of the first filter inductors, and the plurality of the first filter inductors are used to form a plurality of resonance points to suppress different harmonics.

[0009] In some embodiments, the first filter inductor is connected to different capacitors in the impedance conversion circuit through switches to suppress different harmonics.

[0010] In some embodiments, the impedance conversion circuit has two-stage conversion circuits, each stage of the conversion circuit includes a grounded capacitor, and at least one of the capacitors is grounded through the first filter inductor.

[0011] In some embodiments, the two-stage conversion circuit includes a first inductor, a first capacitor, a second inductor and a second capacitor; wherein,

[0012] The output end of the main amplifier or the auxiliary amplifier is connected to the first end of the first inductor, the second end of the first inductor is connected to the first end of the first capacitor and the first end of the second inductor, and the second end of the second inductor and the first end of the second capacitor are connected to the input end of the combiner circuit;

[0013] The second end of the first capacitor is grounded through the first filter inductor; and / or the second end of the second capacitor is grounded through the first filter inductor.

[0014] In some embodiments, the first matching circuit also includes a third capacitor; the first end of the third capacitor is connected to the output end of the auxiliary amplifier or the main amplifier, and the second end is grounded; the third capacitor is used to make the auxiliary amplifier or the main amplifier operate in Class E.

[0015] In some embodiments, the first matching circuit further includes a second filtering inductor, and the third capacitor is grounded through the second filtering inductor to form a second resonant circuit.

[0016] In some embodiments, the impedance conversion circuit is further used for phase shifting to shift the phase of the output signal of the main amplifier or the auxiliary amplifier.

[0017] In some embodiments, the main amplifier circuit and / or the auxiliary amplifier circuit further includes a second matching circuit, and the second matching circuit is connected between the main amplifier or the auxiliary amplifier and the combiner circuit;

[0018] The second matching circuit includes a fourth capacitor and a third filtering inductor;

[0019] The output end of the main amplifier or the auxiliary amplifier is connected to the first end of the fourth capacitor, the first end of the third filter inductor is connected to the second end of the fourth capacitor, and the second end of the third filter inductor is grounded.

[0020] In some embodiments, the fourth capacitor is further used to enable the main amplifier and / or the auxiliary amplifier to operate in class E, inverse class E or class AB.

[0021] In some embodiments, the filter inductor is an inductor with adjustable inductance.

[0022] In some embodiments, the main amplifier circuit includes a second matching circuit, and the auxiliary amplifier circuit includes a first matching circuit; or,

[0023] The main amplifier circuit includes a first matching circuit, and the auxiliary amplifier circuit includes a second matching circuit.

[0024] In some embodiments, the main amplifier circuit further includes:

[0025] A third matching circuit is connected between the power divider circuit and the main amplifier;

[0026] The auxiliary amplifier circuit also includes:

[0027] A fourth matching circuit is connected between the power divider circuit and the auxiliary amplifier; a phase difference between an output signal of the third matching circuit and an output signal of the fourth matching circuit is 90 degrees.

[0028] In some embodiments, the combiner circuit includes a balun.

[0029] In some embodiments, the balun is further configured to adjust the combined impedance to the transmission impedance.

[0030] In some embodiments, the power amplifier further includes a power supply, which is connected to the balun and feeds the main amplifier circuit and the auxiliary amplifier circuit through the balun.

[0031] In the disclosed embodiment, the first filter inductor is connected to the capacitor in the impedance conversion circuit so that the capacitor is grounded through the first filter inductor to form a first resonant circuit, and the combiner circuit is used to combine the main amplifier circuit and the auxiliary amplifier circuit by voltage. In this way, on the one hand, the Doherty architecture can make the amplifier still have high efficiency under deep power back-off; on the other hand, the first resonant circuit can realize the function of harmonic suppression, thereby reducing harmonic power and loss, and improving the efficiency of the power amplifier; on the other hand, the combiner circuit increases the output impedance and combined impedance by voltage combining, thereby increasing the bandwidth and reducing the sensitivity of low-impedance combining and mass production fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of a power amplifier provided by the present disclosure;

[0033] Figure 2 A schematic diagram of a first matching circuit in a power amplifier provided by the present disclosure;

[0034] Figure 3 A circuit diagram of a first matching circuit in a power amplifier provided by the present disclosure;

[0035] Figure 4 A circuit diagram of a second resonant circuit in a power amplifier provided by the present disclosure;

[0036] Figure 5 A circuit diagram of a second matching circuit in a power amplifier provided by the present disclosure;

[0037] Figure 6 A schematic diagram of a balun in a power amplifier provided by the present disclosure;

[0038] Figure 7 A circuit diagram of a power amplifier provided by the present disclosure;

[0039] Figure 8 A circuit diagram of another power amplifier provided by the present disclosure. DETAILED DESCRIPTION

[0040] In order to facilitate the understanding of the present disclosure, the exemplary embodiments of the present disclosure will be described in more detail below with reference to the relevant drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the specific embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0041] In the following description, a large number of specific details are given to provide a more thorough understanding of the present disclosure. However, it is obvious to those skilled in the art that the present disclosure can be implemented without one or more of these details. In some embodiments, in order to avoid confusion with the present disclosure, some technical features known in the art are not described; that is, all features of the actual embodiment may not be described here, and well-known functions and structures may not be described in detail.

[0042] Generally, terms can be understood at least in part from their use in context. For example, depending at least in part on the context, the term "one or more" as used herein can be used to describe any feature, structure or characteristic in a singular sense, or can be used to describe a combination of features, structures or characteristics in a plural sense. Similarly, terms such as "one" or "the" can also be understood to convey singular usage or to convey plural usage, depending at least in part on the context. In addition, the term "based on" can be understood to not necessarily be intended to convey an exclusive set of factors, and can alternatively allow for the presence of additional factors that are not necessarily explicitly described, which also depends at least in part on the context.

[0043] Unless otherwise defined, the purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present disclosure. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates another way. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0044] In order to thoroughly understand the present disclosure, detailed steps and detailed structures will be presented in the following description to illustrate the technical solution of the present disclosure. The preferred embodiments of the present disclosure are described in detail below, but in addition to these detailed descriptions, the present disclosure may also have other implementations. It should be understood that in order to make each structure clearly shown in the drawings, the size ratio relationship of each structure may not be consistent with the actual structure.

[0045] The impedance of the combining node of a conventional Doherty power amplifier is low, which will introduce more sensitivity problems and increase the bandwidth and insertion loss requirements of the main matching circuit and impedance transformation circuit.

[0046] like Figure 1 As shown, an embodiment of the present disclosure provides a power amplifier 100, including a main amplifier circuit 110, an auxiliary amplifier circuit 120 and a combiner circuit 130; the main amplifier circuit 110 includes a main amplifier 111; the auxiliary amplifier circuit 120 includes an auxiliary amplifier 121; the combiner circuit 130 is used to combine the main amplifier circuit 110 and the auxiliary amplifier circuit 120; the main amplifier circuit 110 and / or the auxiliary amplifier circuit 120 also include a first matching circuit 112, the first matching circuit 112 is connected between the main amplifier 111 or the auxiliary amplifier 121 and the combiner circuit 130; the first matching circuit 112 includes an impedance conversion circuit and a first filter inductor, the first filter inductor is connected to the capacitor in the impedance conversion circuit so that the capacitor is grounded through the first filter inductor to form a first resonant circuit 113.

[0047] The first matching circuit of the present application can not only perform impedance matching through an impedance conversion circuit, but also reuse the capacitor in the impedance conversion circuit and the first filter inductor to form a resonant circuit, thereby reducing harmonic power and loss, improving the efficiency of the power amplifier 100, and improving the performance of the amplifier.

[0048] In some embodiments, the power amplifier 100 can be configured as a 2-way, 3-way or more Doherty power amplifier according to actual needs. Here, a 2-way Doherty power amplifier is used as an example for explanation. The power amplifier also includes a power divider circuit ( Figure 1 The power divider circuit divides the input signal into two paths. In other embodiments, the power divider circuit may be omitted, and the input signal is distributed through other circuits.

[0049] In some embodiments, reference Figure 2 The first matching circuit 112 includes an impedance conversion circuit 115 and a first filter inductor L11, and the capacitor in the impedance conversion circuit 115 is grounded through the first filter inductor L11, thereby forming a first resonant circuit 113. The impedance conversion circuit includes one or more conversion circuits, and each conversion circuit can be L-type, π-type or T-type, which is not limited in this application.

[0050] In some embodiments, the first resonant circuit 113 is used to suppress odd waves and / or even waves. For example, the first resonant circuit is used to suppress the second harmonic or the third harmonic. For another example, the first resonant circuit is used to suppress the second harmonic and the third harmonic. For another example, the first resonant circuit is used to suppress at least one of the second harmonic, the third harmonic, and other higher harmonics.

[0051] The first resonant circuit 113 can effectively suppress harmonics in the power amplifier 100 , thereby reducing harmonic power and loss, and further improving the efficiency of the power amplifier 100 .

[0052] In some embodiments, the first resonant circuit is used to suppress different harmonics. In this case, the first harmonic inductor may be one or more, and the first inductor cooperates with the capacitor in the impedance conversion circuit to suppress different harmonics.

[0053] In some embodiments, there are multiple first filter inductors, and each first filter inductor L11 is respectively connected to a capacitor in a primary conversion circuit so that the capacitor is grounded through the first filter inductor to form a multi-stage first resonant circuit 113, which is used to suppress different harmonics.

[0054] In some embodiments, the first filter inductor is one, through the switch ( Figure 2 The first and second impedance converters (not shown) are respectively connected to different capacitors in the impedance conversion circuit to suppress different harmonics.

[0055] In some embodiments, the first filter inductor is a variable inductor, so that it can be adjusted as needed.

[0056] In some embodiments, Figure 3As shown, the first matching circuit 112 includes a two-stage conversion circuit. In the two-stage conversion circuit, the first inductor L1 and the first capacitor C1 constitute a first-stage conversion circuit, and the second inductor L2 and the second capacitor C2 constitute a second-stage conversion circuit.

[0057] In some embodiments, reference Figure 2 The first matching circuit 112 includes an n-stage conversion circuit (n is a positive integer), including m first filter inductors L11 (m is a positive integer), wherein each first filter inductor L11 is respectively connected to a capacitor in a first-stage conversion circuit, so that the capacitor is grounded through the first filter inductor L11 to form a first resonant circuit. The first filter inductor and the corresponding capacitor in the first matching circuit 112 constitute a first resonant circuit 113.

[0058] In some embodiments, the impedance conversion circuit has multiple stages, and only one stage or part of the stages in the conversion circuit are grounded through the first filter inductor, and it is not necessary for each stage to be connected to the first filter inductor accordingly.

[0059] In some embodiments, Figure 3 As shown, the impedance conversion circuit 115 has a two-stage conversion circuit, each stage of the conversion circuit includes a grounded capacitor, wherein at least one capacitor is grounded through a first filter inductor. Exemplarily, the capacitor of one of the two-stage conversion circuits is grounded through the first filter inductor, or both capacitors of the two-stage conversion circuits are grounded through the first filter inductor.

[0060] In some embodiments, Figure 3 As shown, the first capacitor C1 and the second capacitor C2 are grounded through a first filter inductor L11 respectively. In other embodiments, the first filter inductor connected to the second capacitor C2 may be omitted, and the first capacitor C1 is grounded through the first filter inductor L11; the first filter inductor L11 connected to the first capacitor C1 may be omitted, and the second capacitor C2 is grounded through the first filter inductor L11.

[0061] In some embodiments, Figure 3 As shown, the output end of the main amplifier 111 or the auxiliary amplifier 121 is connected to the first end of the first inductor L1, the second end of the first inductor L1 is connected to the first end of the first capacitor C1 and the first end of the second inductor L2, the second end of the second inductor L2 and the first end of the second capacitor C2 are connected to the input end of the combiner circuit; the second end of the first capacitor C1 is grounded through the first filter inductor L11; and / or the second end of the second capacitor C2 is grounded through the first filter inductor L11.

[0062] In some embodiments, Figure 4As shown, the first matching circuit 112 also includes a third capacitor C3; the first end of the third capacitor C3 is connected to the output end of the auxiliary amplifier 121 or the main amplifier 111, and the second end is grounded; the third capacitor C3 is used to make the auxiliary amplifier 121 or the main amplifier 111 work in Class E.

[0063] In some embodiments, the third capacitor C3 is used to present a large capacitance at the baseband to serve as a charging and discharging capacitor of the auxiliary amplifier 121 or the main amplifier 111, so that the auxiliary amplifier 121 or the main amplifier 111 operates in Class E to improve the efficiency of the amplifier.

[0064] In some embodiments, the third capacitor C3 may be one or more, or the third capacitor C3 is a variable capacitor. When there are multiple third capacitors C3, multiple third capacitors C3 are connected in parallel; when the third capacitor C3 is a variable capacitor, it can be selected according to the frequency band, power, mode, etc. of the input signal.

[0065] In some embodiments, Figure 4 As shown, the first matching circuit 112 further includes a second filtering inductor L12, and the third capacitor C3 is grounded through the second filtering inductor L12 to form a second resonant circuit 123 to further suppress harmonics.

[0066] In some embodiments, the second resonant circuit 123 is used to suppress odd waves and / or even waves. For example, the second resonant circuit is used to suppress the second harmonic or the third harmonic. For another example, the second resonant circuit is used to suppress the second harmonic and the third harmonic. For another example, the second resonant circuit is used to suppress at least one of the second harmonic, the third harmonic, and other higher harmonics.

[0067] It should be noted that the related configurations of the second filter inductor and the third capacitor are the same as those of the first filter inductor in various embodiments. For example, the second filter inductor is a variable inductor, which will not be described in detail here.

[0068] In some embodiments, Figure 3 or Figure 4 As shown, the impedance conversion circuit 115 is also used for phase shifting to shift the output signal of the main amplifier 111 or the auxiliary amplifier 121 .

[0069] In some embodiments, the first stage conversion circuit composed of the first inductor L1 and the first capacitor C1 is used to shift the phase by 45 degrees, and the second stage conversion circuit composed of the second inductor L2 and the second capacitor C2 is used to shift the phase by 45 degrees, thereby adjusting the phase by 90 degrees in total. It should be noted that the phase adjusted by each stage conversion circuit of the impedance conversion circuit 115 in the present disclosure is not limited to 45 degrees, and can be flexibly designed according to actual needs. For example, the first stage conversion circuit shifts the phase by 60 degrees, and the second stage conversion circuit shifts the phase by 30 degrees.

[0070] In some embodiments, the impedance conversion circuit 115 cooperates with the main input matching circuit or the auxiliary input matching circuit (such as the third matching circuit or the fourth matching circuit described below) to shift the phase of the output signal of the main amplifier circuit or the auxiliary amplifier circuit by 90 degrees. For example, the impedance conversion circuit 115 shifts the phase by 45 degrees, and the main input matching circuit or the auxiliary input matching circuit shifts the phase by 45 degrees; for another example, the impedance conversion circuit 115 shifts the phase by 60 degrees, and the main input matching circuit or the auxiliary input matching circuit shifts the phase by 30 degrees; for another example, the impedance conversion circuit 115 shifts the phase by 30 degrees, and the main input matching circuit or the auxiliary input matching circuit shifts the phase by 60 degrees.

[0071] In some embodiments, Figure 4 As shown, the third capacitor C3 can also cooperate with the subsequent two-stage conversion circuit (i.e., the two-stage conversion circuit composed of the first inductor L1, the first capacitor C1, the second inductor L2 and the second capacitor C2) for phase adjustment. At this time, the first capacitor C1 and the second capacitor C2 can have smaller capacitance values.

[0072] In some embodiments, the third capacitor C3 may utilize the parasitic capacitance of the main amplifier 111 or the auxiliary amplifier 121 , thereby reducing the area of ​​the third capacitor C3 .

[0073] In some embodiments, Figure 4 As shown, the first matching circuit 112 may further include a third inductor L3, a first end of the third inductor L3 is connected to the output end of the main amplifier 111 or the auxiliary amplifier 121, and a second end of the third inductor L3 is connected to the power supply Vcc. In this way, the third inductor L3 is used for impedance matching and isolating RF signals.

[0074] In some embodiments, Figure 5 As shown, the main amplifier circuit and / or the auxiliary amplifier circuit also includes a second matching circuit 122, which is connected between the main amplifier 111 or the auxiliary amplifier 121 and the combiner circuit 130; the second matching circuit 122 includes a fourth capacitor C4 and a third filter inductor L13, and the fourth capacitor C4 and the third filter inductor L13 form a resonant circuit to suppress the harmonics of the output signal of the main amplifier 111 or the auxiliary amplifier 121.

[0075] In some embodiments, the output end of the main amplifier 111 or the auxiliary amplifier 121 is connected to the first end of the fourth capacitor C4, the first end of the third filter inductor L13 is connected to the second end of the fourth capacitor C4, and the second end of the third filter inductor L13 is grounded.

[0076] Similar to the first matching circuit, the second matching circuit 122 may be the same as the above-mentioned embodiments. For example, the third filter inductor is a variable inductor; for another example, in some embodiments, the second matching circuit 122 may include one or more stages of conversion circuits, and one or more third filter inductors, wherein each third filter inductor may be respectively connected to a capacitor in a stage of conversion circuit, so that the capacitor is grounded through the third filter inductor to form a resonant circuit. It should be noted that the third filter inductor may not correspond one-to-one to each stage of conversion circuit. For another example, in some embodiments, part of the conversion circuit may not be grounded through the third filter inductor, that is, harmonics are not processed. For another example, in some other embodiments, part of the conversion circuit may be grounded through multiple third filter inductors connected in series. It will not be repeated here, and reference may be made to the relevant content of the first matching circuit in the above-mentioned embodiments.

[0077] In some embodiments, Figure 5 As shown, the fourth capacitor C4 is also used to make the main amplifier 111 and / or the auxiliary amplifier 121 operate in class E, inverse class E or class AB.

[0078] In some embodiments, a portion of the fourth capacitor C4 forms a resonant circuit with the third filter inductor L13, and the other portion presents a large capacitance at the base frequency to serve as a charging and discharging capacitor for the main amplifier 111 and / or the auxiliary amplifier 121, thereby making the main amplifier 111 and / or the auxiliary amplifier 121 operate in Class E.

[0079] The fourth capacitor C4 can also be used only to form a resonant circuit with the third filter inductor L13, that is, not as a charging and discharging capacitor of the main amplifier 111. In this case, the main amplifier 111 and / or the auxiliary amplifier 121 work in class AB. Since the fourth capacitor C4 is only used to form a resonant circuit and not as a charging and discharging capacitor, the fourth capacitor C4 can have a smaller area.

[0080] In some embodiments, the fourth capacitor C4 can also enable the main amplifier 111 and / or the auxiliary amplifier 121 to operate in inverse class E. The inverse class E amplifier is a dual form of the class E amplifier and can also improve efficiency, which will not be elaborated here.

[0081] In some embodiments, Figure 5 As shown, the second matching circuit 122 may further include a fourth inductor L4, a first end of the fourth inductor L4 is connected to the output end of the main amplifier 111 or the auxiliary amplifier 121, and a second end of the fourth inductor L4 is connected to the power supply Vcc. In this way, the fourth inductor L4 is used for impedance matching and isolating RF signals.

[0082] In some embodiments, the main amplifier circuit includes a second matching circuit, and the auxiliary amplifier circuit includes a first matching circuit; or, the main amplifier circuit includes a first matching circuit, and the auxiliary amplifier circuit includes a second matching circuit.

[0083] Exemplarily, the main amplifier circuit includes a second matching circuit as a main output matching circuit of the main amplifier, and the auxiliary amplifier circuit includes a first matching circuit as an auxiliary output matching circuit of the auxiliary amplifier; or, the main amplifier circuit includes a first matching circuit as a main output matching circuit of the main amplifier, and the auxiliary amplifier circuit includes a second matching circuit as an auxiliary output matching circuit of the auxiliary amplifier.

[0084] In other embodiments, the main amplifier circuit may include a first matching circuit and a second matching circuit connected in series at the same time, so as to serve as a main output matching circuit of the main amplifier; and / or, the auxiliary amplifier circuit may include a first matching circuit and a second matching circuit connected in series at the same time, so as to serve as an auxiliary output matching circuit of the auxiliary amplifier. In addition, the main amplifier circuit may include at least one of the first matching circuit and the second matching circuit, and the auxiliary amplifier circuit may include at least one of the first matching circuit and the second matching circuit, and the specific connection method is not repeated here.

[0085] In some embodiments, the combiner circuit 130 directly combines the voltages of the main amplifier circuit 110 and the auxiliary amplifier circuit 120 .

[0086] In some embodiments, Figure 6 As shown, combiner circuit 130 includes a balun.

[0087] In some embodiments, the combiner circuit 130 includes a balun, and the balun includes a primary coil, a secondary coil, and a capacitor. Since the combiner circuit 130 uses a balun to achieve impedance transformation, the system bandwidth is further improved.

[0088] In some embodiments, the balun is also used to adjust the combined impedance to the transmission impedance.

[0089] In some embodiments, the balun adjusts the combined impedance of the main amplifier circuit 110 and the auxiliary amplifier circuit 120 to the transmission impedance. Exemplarily, the transmission impedance is 50 ohms, and the combined impedance is 4 to 10 ohms, for example, 8 ohms, 9 ohms, 5 ohms, and 6 ohms. In this embodiment, the combined impedance of the two paths is directly raised to the transmission impedance through the balun, and only one impedance change is required, which can not only simplify the design, but also reduce insertion loss and improve bandwidth.

[0090] In some embodiments, Figure 6As shown, the balun includes a primary coil Lpc, a secondary coil Lsc, a fifth capacitor C5 and / or a sixth capacitor C6; wherein, the first end of the primary coil Lpc is connected to the output end of the main amplifier circuit 110, the second end of the primary coil Lpc is connected to the output end of the auxiliary amplifier circuit 120, the first end of the secondary coil Lsc is connected to the load 140, the fifth capacitor C5 is connected between the first end of the primary coil Lpc and the second end of the primary coil Lpc, and the sixth capacitor C6 is connected between the second end of the secondary coil Lsc and the ground end.

[0091] In some embodiments, the impedance transformation ratio of the balun is 1:4 to 1:8, for example, 1:5, 1:6, 1:7, etc. The fifth capacitor C5 and the sixth capacitor C6 are used for impedance tuning. The first end and the second end of the primary coil Lpc are connected to the output ends of the main amplifier circuit 110 and the auxiliary amplifier circuit 120, respectively.

[0092] In some embodiments, the fifth capacitor C5 and / or the sixth capacitor C6 can be set as variable capacitors, so that they can adjust the impedance transformation according to different radio frequency signals, for example, adjusting the impedance transformation of signals in different frequency bands; or adjusting different modes.

[0093] By performing voltage combining and impedance transformation through the balun, the loss can be reduced and the bandwidth can be further improved. Moreover, the power amplifier 100 still has a high efficiency after high power back-off.

[0094] In some embodiments, Figure 6 As shown, the power amplifier 100 further includes a power supply Vcc, which is connected to a balun and feeds power to the main amplifier circuit 110 and the auxiliary amplifier circuit 120 through the balun.

[0095] In some embodiments, the power supply Vcc is connected to the primary coil Lpc of the balun, and feeds power to the main amplifier circuit 110 and the auxiliary amplifier circuit 120 through the primary coil Lpc. Among them, the power supply Vcc divides the primary coil Lpc into two parts, and the two parts of the coil are used as the choke inductor of the main amplifier and the choke inductor of the auxiliary amplifier, that is, the inductance in the balun is reused, which is used as both a combiner and a choke inductor to avoid interference of the radio frequency signal to the power supply Vcc. It should be noted that the inductance values ​​of the two parts of the coil can be the same or different. In some embodiments, the primary coil can be set with multiple connection points, and each connection point makes the two choke inductors have different inductance values, so that the power supply can be connected to one of the connection points as needed. In addition, the power supply Vcc can also reuse other inductors in the balun except the primary coil Lpc, and the present disclosure does not limit this.

[0096] In some embodiments, Figure 7As shown, the power amplifier 100 also includes a power divider circuit 150, which is used to divide the input signal into two paths, and the two signals are transmitted to the main amplifier circuit 110 and the auxiliary amplifier circuit 120 respectively. Among them, there is a phase difference between the two input signals output by the power divider circuit 150, such as the phase difference between the two input signals can be 90 degrees, 45 degrees, 270 degrees, 180 degrees, etc. It should be noted that the phase of the input signal transmitted to the main amplifier circuit through the power divider circuit 150 can be changed or remain unchanged; similarly, the phase of the input signal transmitted to the auxiliary amplifier circuit can be changed or remain unchanged, and this application does not limit it. For example, the phase of the main input signal remains unchanged, and the phase of the auxiliary input signal is 90 degrees; for another example, the phase of the main input signal is 45 degrees, and the phase of the auxiliary input signal is -45 degrees; for another example, the phase of the main input signal is 90 degrees, and the auxiliary remains unchanged.

[0097] In some embodiments, the phase difference between the output signal of the main amplifier circuit 110 and the output signal of the auxiliary amplifier circuit 120 is 180 degrees.

[0098] In some embodiments, Figure 7 As shown, the main amplifier circuit 110 also includes: a third matching circuit 114, connected between the power divider circuit 150 and the main amplifier 111; the auxiliary amplifier circuit 120 also includes: a fourth matching circuit 124, connected between the power divider circuit 150 and the auxiliary amplifier 121; the phase difference between the output signal of the third matching circuit 114 and the output signal of the fourth matching circuit 124 is 90 degrees.

[0099] In some embodiments, the phase of the output signal of the main amplifier circuit 110 is adjusted by any one of the power divider circuit, the first matching circuit 112, the second matching circuit, and the third matching circuit in the path, or multiple circuits; the phase of the output signal of the auxiliary amplifier circuit 120 is adjusted by any one of the power divider circuit, the first matching circuit 112, the second matching circuit, and the fourth matching circuit in the path, or multiple circuits, so that the phase difference between the output signal of the main amplifier circuit 110 and the output signal of the auxiliary amplifier circuit 120 is 180 degrees, so that the combiner circuit 130 can directly perform voltage combining and differential impedance transformation.

[0100] In some embodiments, any one of the third matching circuit 114 and the fourth matching circuit 124 includes one or more impedance matching circuits, and each impedance matching circuit may be L-type, π-type, or T-type. Figure 7 As shown, the third matching circuit 114 and the fourth matching circuit 124 both include a first-stage T-type matching circuit.

[0101] In some embodiments, the third matching circuit 114 and the fourth matching circuit 124 keep the input phase unchanged. In other embodiments, the third matching circuit 114 and the fourth matching circuit 124 can also change the phase of the signal. For example, when the phase of the two signals output by the power divider circuit 150 remains unchanged (i.e., the phase difference between the two input signals is 0), the third matching circuit 114 shifts the phase by -45 degrees and the fourth matching circuit 124 shifts the phase by 45 degrees; or, the third matching circuit 114 shifts the phase by -30 degrees and the fourth matching circuit 124 shifts the phase by 60 degrees. When the phase difference between the two signals output by the power divider circuit 150 is 30 degrees (such as 30 degrees for the auxiliary path and the main path does not change the phase), the third matching circuit 114 shifts the phase by 30 degrees and the fourth matching circuit 124 shifts the phase by 90 degrees.

[0102] It should be noted that the reference Figure 7 The power divider circuit 150, the first matching circuit 112, the second matching circuit 122, the third matching circuit 114 and the fourth matching circuit 124 cooperate with each other to make the phase difference between the output signal of the main amplifier circuit 110 and the output signal of the auxiliary amplifier circuit 120 be 180 degrees, wherein the phase shift adjustment of each circuit can be flexibly designed according to actual needs, and the present disclosure does not impose too many restrictions. For example, the phase difference between the two signals output by the power divider circuit 150 is 90 degrees (45 degrees for the auxiliary path and -45 degrees for the main path), the second matching circuit 122 and the third matching circuit 114 do not change the phase, the first matching circuit 112 shifts the phase by 45 degrees, and the fourth matching circuit 124 shifts the phase by 45 degrees; for another example, the phase difference between the two signals output by the power divider circuit 150 is 90 degrees (90 degrees for the auxiliary path and 0 degrees for the main path), the second matching circuit 122 shifts the phase by 45 degrees, the third matching circuit 114 shifts the phase by 45 degrees, the first matching circuit 112 shifts the phase by 90 degrees, and the fourth matching circuit 124 shifts the phase by 90 degrees; for another example, the phase difference between the two signals output by the power divider circuit 150 is 0, the second matching circuit 122 shifts the phase by -45 degrees, the third matching circuit 114 shifts the phase by -45 degrees, the first matching circuit 112 shifts the phase by 45 degrees, and the fourth matching circuit 124 shifts the phase by 45 degrees.

[0103] Figure 7 and Figure 8 Two exemplary specific circuit diagrams of the power amplifier 100 are provided for the present disclosure.

[0104] in, Figure 7 The second filter inductor L12 and the third capacitor C3 of the first matching circuit 112 form a resonant circuit; Figure 8The first filter inductor L11 and the first capacitor C1 of the first matching circuit 112 form a resonant circuit. At this time, the first inductor L1 can be reused, that is, the first inductor L1 is used for both impedance matching and harmonic suppression. It can be understood that the present disclosure can form a resonant circuit by setting one or more filter inductors at different positions, and flexibly configure the harmonic suppression point to simultaneously suppress the second harmonic, the third harmonic, etc. In addition, Figure 7 The power source Vcc feeds the main amplifier 111 and the auxiliary amplifier 121 through the fourth inductor L4 and the third inductor L3 respectively. The fourth inductor L4 and the third inductor L3 are used for impedance matching and also as choke inductors. Figure 8 The power supply Vcc is fed to the main amplifier 111 and the auxiliary amplifier 121 through the primary coil Lpc of the balun, that is, the primary coil Lpc of the balun is reused and used as a choke inductor to avoid interference of the RF signal on the power supply Vcc, thereby eliminating the need for additional choke inductors and reducing the circuit area.

[0105] In some embodiments, reference Figure 7 , the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4 and the fifth capacitor C5 can be integrated on the chip; the third inductor L3, the fourth inductor L4, the third filter inductor L13, the second filter inductor L12, the primary coil Lpc and the secondary coil Lsc in the balun are formed on the substrate by winding, and finally there is only the sixth capacitor C6, a surface mount (Surface Mount Device, SMD) capacitor, on the substrate, which effectively reduces the chip area and material cost.

[0106] The present disclosure also provides an electronic device, including any power amplifier in the above embodiments. The electronic device includes but is not limited to a mobile phone, a tablet computer, a smart wearable device, etc.

[0107] It should be noted that the features disclosed in several method or device embodiments provided in the present disclosure can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0108] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A power amplifier, characterized in that: It includes a main amplifier circuit, an auxiliary amplifier circuit and a combiner circuit; The main path amplification circuit comprises a main path amplifier; The auxiliary path amplification circuit comprises an auxiliary path amplifier; The combiner circuit is used to combine the main amplifier circuit and the auxiliary amplifier circuit; The main amplifier circuit and / or the auxiliary amplifier circuit also includes a first matching circuit, which is connected between the main amplifier or the auxiliary amplifier and the combiner circuit; the first matching circuit includes an impedance conversion circuit and a first filter inductor, and the first filter inductor is connected to a capacitor in the impedance conversion circuit so that the capacitor is grounded through the first filter inductor to form a first resonant circuit.

2. The power amplifier according to claim 1, characterized in that: The first matching circuit includes a plurality of the first filter inductors, and the plurality of the first filter inductors are used to form a plurality of resonance points to suppress different harmonics.

3. The power amplifier according to claim 1, characterized in that: The first filter inductor is connected to different capacitors in the impedance conversion circuit through switches to suppress different harmonics.

4. The power amplifier according to claim 1, characterized in that: The impedance conversion circuit has two-stage conversion circuits, each stage of the conversion circuit includes a grounded capacitor, wherein at least one of the capacitors is grounded through the first filter inductor.

5. The power amplifier according to claim 4, characterized in that: The two-stage conversion circuit includes a first inductor, a first capacitor, a second inductor and a second capacitor; wherein, The output end of the main amplifier or the auxiliary amplifier is connected to the first end of the first inductor, the second end of the first inductor is connected to the first end of the first capacitor and the first end of the second inductor, and the second end of the second inductor and the first end of the second capacitor are connected to the input end of the combiner circuit; The second end of the first capacitor is grounded through the first filter inductor; and / or the second end of the second capacitor is grounded through the first filter inductor.

6. The power amplifier according to claim 1, characterized in that: The first matching circuit also includes a third capacitor; a first end of the third capacitor is connected to the output end of the auxiliary amplifier or the main amplifier, and a second end is grounded; the third capacitor is used to make the auxiliary amplifier or the main amplifier operate in Class E.

7. The power amplifier according to claim 6, characterized in that: The first matching circuit also includes a second filtering inductor, and the third capacitor is grounded through the second filtering inductor to form a second resonant circuit.

8. The power amplifier according to claim 1, characterized in that: The impedance conversion circuit is also used for phase shifting to shift the output signal of the main amplifier or the auxiliary amplifier.

9. The power amplifier according to claim 1, characterized in that: The main amplifier circuit and / or the auxiliary amplifier circuit further comprises a second matching circuit, wherein the second matching circuit is connected between the main amplifier or the auxiliary amplifier and the combiner circuit; The second matching circuit includes a fourth capacitor and a third filtering inductor; The output end of the main amplifier or the auxiliary amplifier is connected to the first end of the fourth capacitor, the first end of the third filter inductor is connected to the second end of the fourth capacitor, and the second end of the third filter inductor is grounded.

10. The power amplifier according to claim 9, characterized in that: The fourth capacitor is further used to enable the main amplifier and / or the auxiliary amplifier to operate in class E, inverse class E or class AB.

11. The power amplifier according to claim 7 or 9, characterized in that: The filter inductor is an inductor with adjustable inductance.

12. The power amplifier according to claim 9, characterized in that: The main amplifier circuit includes a second matching circuit, and the auxiliary amplifier circuit includes a first matching circuit; or, The main amplifier circuit includes a first matching circuit, and the auxiliary amplifier circuit includes a second matching circuit.

13. The power amplifier according to claim 1, characterized in that: The main amplifier circuit also includes: A third matching circuit is connected between the power divider circuit and the main amplifier; The auxiliary amplifier circuit also includes: A fourth matching circuit is connected between the power divider circuit and the auxiliary amplifier; a phase difference between an output signal of the third matching circuit and an output signal of the fourth matching circuit is 90 degrees.

14. The power amplifier according to claim 1, characterized in that: The combiner circuit includes a balun, which is further used to adjust the combining impedance to the transmission impedance.

15. The power amplifier according to claim 14, characterized in that: The power amplifier also includes a power supply, which is connected to the balun and feeds the main amplifier circuit and the auxiliary amplifier circuit through the balun.

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