High efficiency radio frequency power amplifier

Abstract

The utility model provides a high-efficiency radio frequency power amplifier, which is characterized in that a carrier power amplification unit comprises a first carrier power amplifier to an Nth carrier power amplifier, N is a natural number greater than or equal to 2, and the carrier power amplification unit receives an input signal, the signal amplified by the carrier power amplification unit is connected to an impedance combining point through an output 90-degree phase shifter, the peak power amplifier is connected to an input signal through the input 90-degree phase shifter, and the output is connected to the impedance combining point. The output matching network is configured between the impedance combining point and the output end of the high-efficiency radio frequency power amplifier, the first carrier power amplifier works in a class AB mode, and the second carrier power amplifier to the N carrier power amplifier and the peak power amplifier work in a class C mode.

Description

Technical Field

[0001] The utility model relates to the field of wireless communication, and more specifically, to a high-efficiency radio frequency power amplifier. Background Art

[0002] The power amplifier is an important component in modern communication. It is a device that provides energy from a power supply to an alternating current signal. The Doherty amplifier is a commonly used amplifier in wireless communication systems. Its efficiency optimization is achieved through the dynamic load modulation effect. It relies on two amplifiers operating in different states to cooperate with each other, causing the load of the amplifier to change, thereby optimizing the back-off efficiency of the amplifier. More specifically, the carrier power amplifier usually operates in class AB mode, while the peak power amplifier operates in class C mode. At low power, only the carrier power amplifier is turned on, and its load is at a higher position to maintain high efficiency. At high power, the peak power amplifier is turned on, and the load of the carrier power amplifier is modulated to a lower position to generate a high-power output. Compared with ordinary amplifiers, this improves the power back-off efficiency of the amplifier in wireless communication applications.

[0003] In mobile phone 5G communication, the power consumption problem caused by power increase is becoming increasingly obvious. At the same time, for non-constant envelope modulation methods, their peak-to-average power ratio (PAPR) is relatively high, and the power amplifier mostly operates in the back-off mode. Therefore, for the power amplifier, the back-off efficiency is even more important. Summary of the Utility Model

[0004] One aspect of the utility model provides a high-efficiency radio frequency power amplifier, including: a carrier power amplification unit, a peak power amplifier, an input 90-degree phase shifter, an output 90-degree phase shifter, and an output matching network, characterized in that: the carrier power amplification unit includes a first carrier power amplifier to an Nth carrier power amplifier, N is a natural number greater than or equal to 2, the carrier power amplification unit receives an input signal, and the signal amplified by the carrier power amplification unit is connected to an impedance combining point through the output 90-degree phase shifter, the peak power amplifier is connected to the input signal through the input 90-degree phase shifter, and the output is connected to the impedance combining point, the output matching network is configured between the impedance combining point and the output end of the high-efficiency radio frequency power amplifier, the first carrier power amplifier operates in class AB mode, and the second carrier power amplifier to the Nth carrier power amplifier and the peak power amplifier operate in class C mode.

[0005] One aspect of the utility model provides a high-efficiency radio frequency power amplifier, characterized in that the input 90-degree phase shifter and the output 90-degree phase shifter are configured as 1 / 4 wavelength lines.

[0006] One aspect of the present utility model provides a high-efficiency radio frequency power amplifier, characterized in that when N = 2, the high-efficiency radio frequency power amplifier further includes an input matching network, which is configured between the input signal and the input end of the second carrier power amplifier to compensate for the phase of the second carrier power amplifier.

[0007] One aspect of the present utility model provides a high-efficiency radio frequency power amplifier, characterized in that the input matching network is configured as an LC network circuit.

[0008] One aspect of the present utility model provides a high-efficiency radio frequency power amplifier, characterized in that when N is greater than 2, the high-efficiency radio frequency power amplifier further includes a first input matching network to an (N - 1)th input matching network, which are respectively configured at the input ends of the second carrier power amplifier to the Nth carrier power amplifier to compensate for the phases of the second carrier power amplifier to the Nth carrier power amplifier.

[0009] One aspect of the present utility model provides a high-efficiency radio frequency power amplifier, characterized in that the first input matching network to the (N - 1)th input matching network are configured as LC network circuits.

[0010] One aspect of the present utility model provides a high-efficiency radio frequency power amplifier, characterized in that the second carrier power amplifier to the Nth carrier power amplifier are configured to include different bias configurations.

[0011] One aspect of the present utility model provides a high-efficiency radio frequency power amplifier, characterized in that the carrier power amplification unit and the peak power amplifier include one of an HBT amplifier, a CMOS amplifier, a SiGe amplifier, a single-ended amplifier, a differential amplifier or a Cascode structure power amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic diagram showing a conventional Doherty power amplifier;

[0013] Figure 2 is a schematic diagram showing a high-efficiency Doherty power amplifier according to an embodiment of the present utility model; and

[0014] Figure 3 is a schematic diagram showing a high-efficiency Doherty power amplifier according to another embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] Before proceeding with the following detailed description, it may be advantageous to set forth definitions of certain words and phrases used throughout this document of the present utility model. The terms "coupled", "connected", and their derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with each other. The terms "transmit", "receive", and "communicate", and their derivatives cover both direct and indirect communication. The terms "comprise" and "include", and their derivatives mean including but not limited to. The term "or" is inclusive, meaning and / or. The phrase "associated with", and its derivatives, mean including, included within, interconnected, containing, contained within, connected or connected to, coupled or coupled to, communicating with, cooperating with, interlacing, juxtaposed, adjacent, bound or bound to, having, having the attribute of, having a relationship or having a relationship with, etc. The term "controller" refers to any device, system, or part thereof that controls at least one operation. Such a controller can be implemented in hardware, or in a combination of hardware and software and / or firmware. The functions associated with any particular controller can be centralized or distributed, whether local or remote. The phrase "at least one", when used in conjunction with a list of items, means that different combinations of one or more of the listed items can be used, and it may only be necessary to have one item in the list. For example, "at least one of A, B, C" includes any one of the following combinations: A, B, C, A and B, A and C, B and C, A and B and C.

[0016] Definitions of other specific words and phrases are provided throughout this document of the present utility model. Those of ordinary skill in the art should understand that in many cases, if not most cases, such definitions apply to the prior and future use of the words and phrases so defined.

[0017] In this document of the present utility model, the application combinations of circuit blocks and the division of sub-circuit blocks are only for illustration, and within the scope not departing from this disclosure, the application combinations of circuit blocks and the division of sub-circuit blocks can have different ways.

[0018] The following discussion Figures 1 to 3 and the various embodiments for describing the principles of this disclosure in this document of the present utility model are only for illustration and should not be construed in any way as limiting the scope of this disclosure. Those skilled in the art will understand that the principles of this disclosure can be implemented in any appropriately arranged system or device.

[0019] Currently, a conventional Doherty amplifier includes two amplifiers, a carrier power amplifier and a peak power amplifier. In a conventional Doherty amplifier, the carrier and peak power amplifiers are of the same size, and the input signals are of the same size with a 90-degree phase difference. Among them, a 1 / 4 wavelength line or its LC equivalent circuit is placed after the carrier power amplifier. When the peak power amplifier is not turned on, the output impedance is converted to a high impedance by the 1 / 4 wavelength line or its LC equivalent circuit to improve the back-off efficiency.

[0020] Figure 1 is a schematic diagram showing a conventional Doherty power amplifier.

[0021] As Figure 1 shown, the output matching network converts the 50 Ohm impedance of the load to an R impedance. When the peak power amplifier is not turned on, the load of the carrier power amplifier has its output impedance R converted to a high impedance 4*R by the 1 / 4 wavelength line or its LC equivalent circuit to improve the back-off efficiency. When the peak power amplifier is fully turned on, the loads of both the carrier power amplifier and the peak power amplifier are 2*R. That is, the load of the carrier power amplifier is converted from 4*R to 2*R, but the size of the carrier power amplifier remains unchanged. According to the amplifier principle, the load level is related to the amplifier size. Therefore, in a conventional Doherty amplifier, the carrier power amplifier cannot achieve the best output efficiency in both states simultaneously, thus affecting the overall performance of the Doherty amplifier.

[0022] According to an embodiment of the present invention, a high-efficiency Doherty power amplifier is provided. By introducing multiple carrier power amplifiers, the output efficiency of the carrier power amplifier path in the Doherty power amplifier is improved to enhance the overall performance of the Doherty power amplifier.

[0023] Figure 2 is a schematic diagram showing a high-efficiency Doherty power amplifier according to an embodiment of the present invention.

[0024] Referring to Figure 2 , the high-efficiency Doherty power amplifier according to the present invention includes: a first carrier power amplifier, a second carrier power amplifier, an input 90-degree phase shifter, a peak power amplifier, an output 90-degree phase shifter, and an output matching network.

[0025] The first carrier power amplifier and the second carrier power amplifier are configured to receive a first input signal, and the outputs of the first carrier power amplifier and the second carrier power amplifier are connected to an impedance combining point through the output 90-degree phase shifter.

[0026] The peak power amplifier is configured to receive the first input signal through the input 90-degree phase shifter and provide the signal amplified by the peak power amplifier to the impedance combining point.

[0027] An output matching network is configured between the impedance combining point and the output end of the high-efficiency radio frequency power amplifier to provide output impedance matching for the high-efficiency radio frequency power amplifier.

[0028] According to an embodiment of the present invention, the input 90-degree phase shifter and the output 90-degree phase shifter can be configured as 1 / 4 wavelength lines.

[0029] According to an embodiment of the present invention, the first carrier power amplifier and the second carrier power amplifier together constitute a carrier power amplification unit, and its total size is the same as that of the peak power amplifier. The first carrier power amplifier operates in Class A or Class AB mode, and the second carrier power amplifier and the peak power amplifier operate in Class C mode. In the low power state, the load of the carrier power amplification unit is converted from the output impedance R to a high impedance 4*R by a 1 / 4 wavelength line or its LC equivalent circuit, and at this time only the first carrier power amplifier operates, and the second carrier power amplifier and the peak power amplifier are not turned on. In the high power state, the load of the carrier power amplification unit is converted from 4*R to 2*R, and at the same time, the second carrier power amplifier and the peak power amplifier are turned on. In both states, the size of the carrier power amplification unit is adapted to its load, and the best output efficiency can be achieved simultaneously.

[0030] According to an embodiment of the present invention, to ensure that the path phases of the first carrier power amplifier and the second carrier power amplifier are consistent, an input matching network is added to the input end of the first carrier power amplifier. The input matching network is configured between the input first signal and the input end of the first carrier power amplifier to compensate for the phase of the second carrier power amplifier. According to an embodiment of the present invention, the output matching network is configured as an LC network circuit.

[0031] Figure 3 FIG. is a schematic diagram showing a high-efficiency Doherty power amplifier according to another embodiment of the present invention.

[0032] Reference Figure 3 , the high-efficiency Doherty power amplifier according to the present invention includes: a first carrier power amplifier to an Nth carrier power amplifier, a first input matching network to an (N-1)th input matching network, a peak power amplifier, an input 90-degree phase shifter, an output 90-degree phase shifter, and an output matching network.

[0033] The first carrier power amplifier to the Nth carrier power amplifier receive a first input signal, and the outputs of the first carrier power amplifier and the second carrier power amplifier are connected to the impedance combining point through the output 90-degree phase shifter.

[0034] The peak power amplifier is configured to receive a first input signal through an input 90-degree phase shifter and provide the signal amplified by the peak power amplifier to an impedance combining point.

[0035] The output matching network is configured between the impedance combining point and the output terminal of the high-efficiency RF power amplifier to provide output impedance matching for the high-efficiency RF power amplifier.

[0036] According to an embodiment of the present invention, the input 90-degree phase shifter and the output 90-degree phase shifter can be configured as 1 / 4 wavelength lines.

[0037] According to an embodiment of the present invention, to ensure the phase consistency of the first carrier power amplifier to the Nth carrier power amplifier, a first input matching network to the (N - 1)th input matching network are respectively added to the input terminals of the second carrier power amplifier to the Nth carrier power amplifier. The first input matching network to the (N - 1)th input matching network are respectively configured between the first signal and the input terminals of the second carrier power amplifier to the Nth carrier power amplifier to compensate for the phase of the second carrier power amplifier to the Nth carrier power amplifier.

[0038] According to an embodiment of the present invention, the second carrier power amplifier to the Nth carrier power amplifier can be implemented by more different biases and amplifier tubes to ensure that the efficiency is always in the best state during the process of the load impedance of the carrier amplifier converting from 4*R to 2*R. According to an embodiment of the present invention, the second carrier power amplifier to the Nth carrier power amplifier is configured to include different bias configurations to control the turn-on of the second carrier power amplifier to the Nth carrier power amplifier, so that the second carrier power amplifier to the Nth carrier power amplifier operating in class C mode has higher output efficiency.

[0039] The architecture of the present invention is applicable to Doherty power amplifiers implemented in various CMOS, HBT, and SiGe processes with differential, single-ended, or Cascode structures.

[0040] Although the present disclosure has been described with exemplary embodiments, various changes and modifications can be proposed to those skilled in the art. The present disclosure is intended to cover such changes and modifications that fall within the scope of the appended claims.

[0041] Any description in the present invention should not be construed as implying that any specific element, step, or function is an essential element that must be included within the scope of the claims. The scope of the inventive subject matter is defined only by the claims.

Claims

1. A high-efficiency radio frequency power amplifier, comprising: A carrier power amplification unit, a peak power amplifier, an input 90-degree phase shifter, an output 90-degree phase shifter, and an output matching network, characterized in that: The carrier power amplification unit includes a first carrier power amplifier to an Nth carrier power amplifier, where N is a natural number greater than or equal to 2. The carrier power amplification unit receives an input signal and connects the signal amplified by the carrier power amplification unit to an impedance combining point through the output 90-degree phase shifter. The peak power amplifier is connected to the input signal through the input 90-degree phase shifter and the output is connected to the impedance combining point. The output matching network is configured between the impedance combining point and the output end of the high-efficiency radio frequency power amplifier. The first carrier power amplifier operates in class A or class AB mode, and the second carrier power amplifier to the Nth carrier power amplifier and the peak power amplifier operate in class C mode.

2. The high-efficiency radio frequency power amplifier according to claim 1, wherein The input 90-degree phase shifter and the output 90-degree phase shifter are configured as 1 / 4 wavelength lines.

3. The high-efficiency radio frequency power amplifier according to claim 1, wherein, When N = 2, the high-efficiency radio frequency power amplifier further includes an input matching network. The input matching network is configured between the input signal and the input end of the second carrier power amplifier to compensate for the phase of the second carrier power amplifier.

4. The high-efficiency radio frequency power amplifier according to claim 3, wherein The input matching network is configured as an LC network circuit.

5. The high-efficiency radio frequency power amplifier according to claim 1, characterized in that When N is greater than 2, the high-efficiency radio frequency power amplifier further includes a first input matching network to an (N-1)th input matching network. The first input matching network to the (N-1)th input matching network are respectively configured at the input ends of the second carrier power amplifier to the Nth carrier power amplifier to compensate for the phases of the second carrier power amplifier to the Nth carrier power amplifier.

6. The high-efficiency radio frequency power amplifier according to claim 5, wherein The first input matching network to the (N-1)th input matching network are configured as LC network circuits.

7. The high-efficiency radio frequency power amplifier according to claim 6, wherein The second carrier power amplifier to the Nth carrier power amplifier are configured to include different bias configurations.

8. The high-efficiency radio frequency power amplifier according to claim 1, characterized in that, The carrier power amplification unit and the peak power amplifier include one of an HBT amplifier, a CMOS amplifier, a SiGe amplifier, a single-ended amplifier, a differential amplifier, or a Cascode structure power amplifier.

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