Patent Application
20240364270
Embodiments of the present disclosure relate to the technical field of electronics, and in particular, to a power amplifier circuit, a base station, a signal transceiver device, and a power amplifier apparatus.
Facing the increasingly fierce market competition, the performance of base station products is the main focus of competition in the industry. As an important part of the base station, the power amplifier unit is directly related to the quality of transmitted signals and the communication effect.
Conventional Doherty power amplifier is one of the most widely used power amplifier architecture at present, which includes a main power amplifier and an auxiliary power amplifier. To achieve effective load pulling and power combining, phases of two links where the main power amplifier and the auxiliary power amplifier are respectively located need to be aligned. In related technologies, phase alignment is implemented by adjusting the lengths of microstrip lines on two branches based on the center frequency of the power amplifier. However, because the electrical length of the microstrip line changes with the frequency, when the Doherty power amplifier is used in a broadband case, phase deviation occurs in operating bands far away from the center frequency point, affecting the efficiency and operating bandwidth of the power amplifier. In addition, because the main and auxiliary power amplifiers in conventional power amplifiers are of different types, e.g., a main driver-stage power amplifier, a main output-stage power amplifier, and an auxiliary driver-stage power amplifier are Class-AB power amplifiers, and an auxiliary output-stage power amplifier is a Class-C power amplifier, the phases of the main and auxiliary power amplifiers are not aligned at different power levels, affecting the operating efficiency at different power levels to a certain extent. At different power levels and different frequencies, the main and auxiliary power amplifiers have different gains. Such gain difference affects the performance of the power amplifier circuit. However, conventional phase compensation methods using microstrip lines cannot compensate for the phase difference and the gain difference.
The following is a summary of the subject matter set forth in the description. This summary is not intended to limit the scope of protection of the claims.
An embodiment of the present disclosure provides a power amplifier circuit to solve the problem of phase misalignment of conventional power amplifiers. The power amplifier circuit may include:
a main amplifier circuit and an auxiliary amplifier circuit, where the main amplifier circuit and the auxiliary amplifier circuit are connected in parallel between a signal input end of the power amplifier circuit and a signal output end of the power amplifier circuit;
the main amplifier circuit includes a first power amplifier and a second power amplifier connected in series, where the first power amplifier is a class-C power amplifier, and the second power amplifier is a class-AB power amplifier; and
the auxiliary amplifier circuit includes a third power amplifier and a fourth power amplifier connected in series, where the third power amplifier is a class-AB power amplifier, and the fourth power amplifier is a class-C power amplifier.
An embodiment of the present disclosure provides a base station, which may include the power amplifier circuit described in the above embodiment.
An embodiment of the present disclosure provides a signal transceiver device, which may include the power amplifier circuit described in the above embodiment.
An embodiment of the present disclosure provides a power amplifier apparatus, which may include the power amplifier circuit described in the above embodiment.
Additional features and advantages of the present disclosure will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the present disclosure. The objects and other advantages of the present disclosure can be realized and obtained by the structures particularly pointed out in the description, claims and drawings.
The drawings are provided for a further understanding of the technical schemes of the present disclosure, and constitute a part of the description. The drawings and the embodiments of the present disclosure are used to illustrate the technical schemes of the present disclosure, and do not constitute a limitation to the technical schemes of the present disclosure.
To make the objectives, technical schemes, and advantages of the present disclosure clear, the present disclosure is described in further detail in conjunction with accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely used for illustrating the present disclosure, and are not intended to limit the present disclosure.
It should be understood that in the description of the embodiments of the present disclosure, the term “a plurality of” (or multiple) means at least two, the terms such as “greater than”, “less than”, “exceed” and the like should be understood to not include the following number. The terms such as “above”, “below”, “within” and the like should be understood to include the following number. If used herein, the terms such as “first”, “second” and the like are merely used for distinguishing technical features, and are not intended to indicate or imply relative importance, or implicitly point out the number of the indicated technical features, or implicitly point out the order of the indicated technical features.
Facing the increasingly fierce market competition, the performance of base station products is the main focus of competition in the industry. As an important part of the base station, the power amplifier unit is directly related to the quality of transmitted signals and the communication effect.
Doherty power amplifier is one of the most widely used power amplifier architecture at present, which includes a main power amplifier and an auxiliary power amplifier. To achieve effective load pulling and power combining, phases of the main power amplifier and the auxiliary power amplifier need to be aligned.
Accordingly, embodiments of the present disclosure provide a power amplifier circuit and a power amplifier apparatus to solve the problem of phase misalignment of conventional power amplifiers.
In an embodiment, the main amplifier circuit further includes a first compensation microstrip line, a first input matching network, and a first output matching network. The first compensation microstrip line and the first input matching network are connected in series between the first power amplifier and the second power amplifier. The first output matching network is connected between the second power amplifier and the signal output end. The auxiliary amplifier circuit further includes a second compensation microstrip line, a second input matching network, and a second output matching network. The second input matching network is connected between the third power amplifier and the fourth power amplifier. The second output matching network and the second compensation microstrip line are connected in series between the fourth power amplifier and the signal output end. In this embodiment, a driver-stage power amplifier for driving the main circuit is a Class-C power amplifier, and a driver-stage power amplifier for driving the auxiliary circuit is a Class-AB power amplifier, which can compensate for the phase difference at the output stage at different power levels caused by inconsistent working modes, thereby achieving phase alignment at different power levels and improving the efficiency of the power amplifier circuit.
I In an embodiment, as shown in
It should be noted that the specific operating process of the power amplifier circuit provided in the embodiment of the present disclosure is as follows. A signal is input through the signal input end to the power amplifier circuit provided in the embodiment of the present disclosure. Then, the signal flows to the main amplifier circuit and the auxiliary amplifier circuit, respectively. In the main amplifier circuit, the signal passes through the first power amplifier, the first compensation microstrip line, the first input matching network, the second power amplifier, and the first output matching network in sequence and is then output through the signal output end. In the auxiliary amplifier circuit, the signal passes through the third power amplifier, the second input matching network, the fourth power amplifier, the second output matching network, and the second compensation microstrip line in sequence and is then output through the signal output end.
In the power amplifier circuit provided in the embodiment of the present disclosure, the types of power amplifiers in the main circuit and the auxiliary circuit are changed to allow the types of power amplifiers in the main circuit to be symmetrical to those in the auxiliary circuit. It should be noted that for the structure of conventional Doherty power amplifier circuits, the method of changing the types of power amplifiers in the main circuit and the auxiliary circuit in the embodiment of the present disclosure is feasible, while other different combinations of amplifier types will cause other problems. For example, in the embodiment of the present disclosure, a driver-stage power amplifier in the main power amplifier circuit is a Class-C power amplifier and an output-stage power amplifier in the main power amplifier circuit is a Class-AB power amplifier, while a driver-stage power amplifier in the auxiliary power amplifier circuit is a Class-AB power amplifier and an output-stage power amplifier in the auxiliary power amplifier circuit is a Class-C power amplifier. Correspondingly, if the driver-stage power amplifier in the main power amplifier circuit is a Class-AB power amplifier and the output-stage power amplifier in the main power amplifier circuit is a Class-C power amplifier, while the driver-stage power amplifier in the auxiliary power amplifier circuit is a Class-AB power amplifier, and the output-stage power amplifier in the auxiliary power amplifier circuit is a Class-C power amplifier, problems such as unstable amplification current or amplification voltage occur in the conventional Doherty power amplifier circuit architecture, which is caused by the conventional Doherty power amplifier circuit architecture. Therefore, in the embodiment of the present disclosure, the driver-stage power amplifier in the main power amplifier circuit is a Class-C power amplifier and the output-stage power amplifier in the main power amplifier circuit is a Class-AB power amplifier, while the driver-stage power amplifier in the auxiliary power amplifier circuit is a Class-AB power amplifier and the output-stage power amplifier in the auxiliary power amplifier circuit is a Class-C power amplifier. Based on the conventional Doherty power amplifier circuit architecture, such a combination can effectively solve the problems of phase misalignment and amplitude difference in the power amplifier circuit, thereby improving the performance of the power amplifier circuit.
The input signal may be a radio frequency signal or other electrical signals, i.e., the power amplifier circuit provided in the embodiment of the present disclosure can be applied to all electrical signals that can be processed and amplified by a conventional Doherty power amplifier circuit, including radio frequency signals.
The signal processing procedure of this embodiment is as follows. An input signal is input from the signal input end into the power amplifier circuit provided in this embodiment. After being input into the power amplifier circuit provided in this embodiment, the input signal is divided into two paths. One of the paths enters the main power amplifier circuit and the other path enters the auxiliary power amplifier circuit. In the main power amplifier circuit, the input signal first passes through the first signal amplifier, then passes through the first compensation microstrip line, the first input matching network, the second power amplifier, and the first output matching network in sequence, and is then output through the signal output end. In the auxiliary power amplifier circuit, the input signal first passes through the third signal amplifier, then passes through the second input matching network, the fourth power amplifier, the second output matching network, and the second compensation microstrip line in sequence, and is then output through the signal output end. In this embodiment, the first power amplifier in the main amplifier circuit in the conventional power amplifier circuit is changed from the original Class-AB to Class C, to compensate for the phase difference at the output stage of the power amplifier circuit at different power levels caused by inconsistent operating modes, thereby achieving phase alignment at different power levels and improving the efficiency of the power amplifier circuit.
In an embodiment, as shown in
In an embodiment, the phase compensation module includes a band-pass filter and a phase modulation module. The band-pass filter and the phase modulation module are connected in series, the band-pass filter is connected to the signal input end, and the phase modulation module is connected in series with the first power amplifier. The phase compensation module is implemented in the form of a band-pass filter. Band-pass filters of different orders may be used to implement different degrees of phase compensation, to solve the frequency offset problem caused by compensation using microstrip lines in the conventional Doherty power amplifier circuit architecture. The phase modulation module implemented in the form of a four-port bridge circuit to achieve precise signal phase adjustment. The phase compensation module is composed of a band-pass filter and a phase modulation module. The band-pass filter and the phase modulation module are arranged in series in the power amplifier circuit provided in the embodiment of the present disclosure. In the main power amplifier circuit, the band-pass filter is connected in series between the signal input end and the phase modulation module, and the phase modulation module is connected in series between the band-pass filter and the first power amplifier. In the auxiliary power amplifier circuit, a band-pass filter is connected in series between the signal input end and a phase modulation module, and the phase modulation module is connected in series between the band-pass filter and the third power amplifier. It should be noted that the band-pass filter and the phase modulation module in the phase compensation module in the power amplifier circuit provided in the embodiment of the present disclosure have different functions. The band-pass filter needs to perform preliminary phase compensation on the input signal, to make phases of the input signal substantially consistent. Then, the processed input signal enters the phase modulation module. The phase modulation module performs a more accurate adjustment on the input signal. Compared with conventional power amplifier circuits, the power amplifier circuit provided in the embodiment of the present disclosure includes the phase compensation module additionally provided to effectively perform phase compensation on the signal, making the phases of the signal remain consistent and the frequencies of the signal remain aligned.
In an embodiment, as shown in
The operating process of the band-pass filter provided in this embodiment is as follows. The input signal is input from the signal input end into the band-pass filter and enters the cross-shaped stub band-pass filter shown in
In an embodiment, as shown in
In the phase modulation module provided in this embodiment, the phase of the branch where the phase compensation module is located can be changed by adjusting parameters of the first tunable variable capacitance diode and the second tunable variable capacitance diode, thereby achieving more accurate phase compensation.
In an embodiment, as shown in
The operating process of the amplitude compensation module provided in this embodiment is as follows. The input signal is input from the signal input end into the amplitude compensation module provided in the embodiment of the present disclosure. After being input from the input end of the amplitude compensation module, the input signal is divided into two paths. One of the paths is input to the envelope extraction module and then output through the gain attenuation bridge, and the other path is input to the envelope extraction module and then output. In this embodiment, the amplitude compensation module is mainly composed of the envelope extraction module and the gain attenuation bridge, a corresponding signal envelope is obtained through the envelope extraction module, and the output of the amplitude compensation module is controlled according to the extracted envelope, to implement gain compensation at different power levels.
The operating process of the power amplifier circuit provided in the present disclosure is as follows. The input signal is input from the signal input end into the power amplifier circuit provided in the above embodiment of the present disclosure. The input signal is divided into two paths which respectively flow into the main circuit of the power amplifier circuit and the auxiliary circuit of the power amplifier circuit. In the main circuit of the power amplifier circuit, the signal first passes through the phase compensation module, and then passes through the first power amplifier, the first compensation microstrip line, the first input matching network, the second power amplifier, and the first output matching network in sequence. In the auxiliary circuit of the power amplifier circuit, the signal first passes through the phase compensation module, and then passes through the third power amplifier, the second input matching network, the fourth power amplifier, the second output matching network, and the second compensation microstrip line in sequence. The function of the phase compensation module is to perform phase compensation on the input signal, to solve the frequency offset problem caused by compensation using microstrip lines in conventional amplifier circuits. The first power amplifier and the third power amplifier serve as driver-stage power amplifiers to drive the power amplifier circuit to operate. The compensation microstrip line serves to compensate for the signal frequency in a conventional manner. The second power amplifier and the fourth power amplifier serve to amplify the current, voltage, power, etc., of the signal, to realize functions of a power amplifier. The power amplifier circuit provided in this embodiment can achieve phase alignment at different powers while amplifying the input signal, thereby improving the performance of the power amplifier circuit. In this embodiment, the phase compensation module and the amplitude compensation module are respectively additionally provided between the first power amplifier and the signal input end and between the third power amplifier and the signal input end to implement signal phase compensation, thereby solving the frequency offset problem caused by compensation using microstrip lines in the conventional Doherty power amplifier circuit architecture. Auxiliary-circuit gain compensation at different frequencies can be implemented according to a slope of the amplitude-frequency curve of the transmission parameter in the pass band of the band-pass filter, thereby achieving better load pulling.
In an embodiment, the present disclosure further provides a base station, including the power amplifier circuit in the above embodiment.
In an embodiment, the present disclosure further provides a signal transceiver device, including the power amplifier circuit in the above embodiment.
In an embodiment, the present disclosure further provides a power amplifier apparatus, including the power amplifier circuit in the above embodiment.
Beneficial effects of the embodiments of the present disclosure are as follows. The main amplifier circuit and the auxiliary amplifier circuit are connected in parallel between the signal input end of the power amplifier circuit and the signal output end of the power amplifier circuit. To be specific, the main amplifier circuit includes a first power amplifier and a second power amplifier connected in series. The first power amplifier is a class-C power amplifier, and the second power amplifier is a class-AB power amplifier. The auxiliary amplifier circuit includes a third power amplifier and a fourth power amplifier connected in series. The third power amplifier is a class-AB power amplifier, and the fourth power amplifier is a class-C power amplifier. The above circuit structure changes the operating mode of the power amplifier, and effectively solves the problem of phase misalignment in conventional power amplifier circuits.
Those having ordinary skills in the art can understand that all or some of the steps in the methods disclosed above and the functional modules/units in the system and the apparatus can be implemented as software, firmware, hardware, and appropriate combinations thereof. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit.
Although some embodiments of the present disclosure have been described above, the present disclosure is not limited to the implementations described above. Those having ordinary skills in the art can make various equivalent modifications or replacements without departing from the essence of the present disclosure. Such equivalent modifications or replacements fall within the scope defined by the claims of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202110891779.0 | Aug 2021 | CN | national |
This application is a national stage filing under 35 U.S.C. § 371 of international application number PCT/CN2022/105763, filed Jul. 14, 2022, which claims priority to Chinese patent application No. 202110891779.0 filed Aug. 4, 2021. The contents of these applications are incorporated herein by reference in their entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2022/105763 | 7/14/2022 | WO |
