Power Amplifier and Method for Achieving High-Efficiency Amplification in Deep Back-Off Region

Abstract

The present invention provides a power amplifier, comprising: a first power amplification unit, a second power amplification unit, a third power amplification unit, a fourth power amplification unit, a first transformer, a second transformer, a first power supply, a second power supply, and a switch unit. The present invention also provides a method for realizing high-efficiency amplification in a deep back-off zone based on a power amplifier. The present application controls the switching state of the switch unit and the power output state of the first to fourth power amplification units, and through the coordinated operation of the switch unit and the first to fourth power amplification units, can achieve high-efficiency peaks at power back-off of 6dB, 12dB, and 18dB, thereby improving the high-efficiency power back-off depth of the power amplifier and the average efficiency of its back-off zone, thereby improving the working efficiency of the power amplifier.

Description

Technical Field

[0001] The present application relates to the technical field of radio frequency power amplifiers, and in particular to a power amplifier and a method for achieving high-efficiency amplification in a deep back-off region. Background Art

[0002] Currently, advanced communication standards around the world use OFDM (Orthogonal Frequency Division Multiplexing) modulation. This modulation results in a high peak-to-average ratio in the output power of power amplifiers, often operating in a deeper power back-off region, far from the maximum efficiency saturation power output. This results in lower average power amplifier efficiency. Therefore, it is necessary to improve the efficiency of power amplifiers in this deeper power back-off region.

[0003] Doherty architecture power amplifiers can form an efficiency peak when the power is backed off by 6dB, thereby improving the efficiency within the 6dB back-off region and thus improving the average efficiency. However, the efficiency of Doherty architecture power amplifiers in deeper back-off regions, where the modulation scheme's peak-to-average ratio is much greater than 6dB, decreases significantly as the back-off depth increases, and the average efficiency in deeper back-off regions is lower. Therefore, a power amplifier architecture that only forms an efficiency peak at 6dB and improves the average efficiency within the 6dB back-off range does not meet the efficiency requirements of advanced communication standards for high peak-to-average ratio modulation technologies with deep power back-off regions. Summary of the Invention

[0004] The present application provides a power amplifier, which can solve the problem of low average efficiency of the power amplifier in a deeper back-off range where the power back-off is greater than 6 dB.

[0005] On the one hand, an embodiment of the present application provides a power amplifier, comprising: a first power amplification unit, a second power amplification unit, a third power amplification unit, a fourth power amplification unit, a first transformer, a second transformer, a first power supply, a second power supply, and a switch unit;

[0006] The two input ends of the primary side of the first transformer are respectively connected to the output end of the first power amplifier unit and the output end of the second power amplifier unit, the two input ends of the primary side of the second transformer are respectively connected to the output end of the third power amplifier unit and the output end of the fourth power amplifier unit, the switch unit is connected in series between the output end of the second power amplifier unit and the output end of the third power amplifier unit, an output end of the secondary side of the first transformer is connected in series with an output end of the secondary side of the second transformer, the other output end of the secondary side of the first transformer is connected in series with a subsequent load and grounded, the other output end of the secondary side of the second transformer is grounded, the first power amplifier unit is powered by the first power supply or the second power supply, and the second power amplifier unit, the third power amplifier unit and the fourth power amplifier unit are all powered by the second power supply.

[0007] Optionally, in the power amplifier, the voltage value of the second power supply is twice the voltage value of the first power supply.

[0008] Optionally, in the power amplifier, the power amplifier also includes: a control unit, which receives an external phase input signal, an amplitude signal and a clock signal, and outputs first, second, third and fourth power control signals to the first to fourth power amplification units to control the working mode and output power of the first to fourth power amplification units, and outputs a switch control signal to the switch unit to control the conduction and disconnection of the switch unit.

[0009] Optionally, in the power amplifier, the first power amplification unit, the second power amplification unit, the third power amplification unit and the fourth power amplification unit are all switched capacitor power amplifier units, and each includes: multiple groups of inverting amplifier units and capacitor units connected in series with the inverting amplifier units, and each group of the inverting amplifier units is connected in series with the capacitor units and then connected in parallel with each other.

[0010] The inverting amplifier subunit of the first power amplifier unit includes: a first branch and a second branch; the inverting amplifier subunits of the second to fourth power amplifier units include: a second branch, wherein the first branch includes two PMOS tubes and two NMOS tubes connected in series, and the second branch includes one NMOS tube and one PMOS tube connected in series.

[0011] Optionally, in the power amplifier, the switch unit includes: a plurality of MOS tubes connected in series.

[0012] On the other hand, an embodiment of the present application also provides a method for implementing high-efficiency amplification in a deep back-off zone. According to the switch control signal output by the control unit, the switch unit switches the switch state, and according to the first to fourth power control signals output by the control unit, the first power amplification unit to the fourth power amplification unit respectively adjust their respective operating modes and output powers to achieve efficiency peaks at power back-off depths of 6dB, 12dB and 18dB, thereby improving the average efficiency within a deeper back-off power depth.

[0013] Optionally, in the method for implementing high-efficiency amplification in the deep back-off zone, the switch unit is disconnected according to the switch control signal output by the control unit; according to the first to fourth power control signals output by the control unit, the first power amplification unit, the second power amplification unit, the third power amplification unit and the fourth power amplification unit are all powered by the second power supply and all operate in a saturated output power mode to achieve power saturation output and maximum efficiency output of the power amplifier.

[0014] Optionally, in the method for implementing high-efficiency amplification in the deep back-off zone, the switch unit is disconnected according to the switch control signal output by the control unit; according to the first to fourth power control signals output by the control unit, the first to fourth power amplification units are all powered by the second power supply, the first power amplification unit and the fourth power amplification unit operate in a saturated output power mode, the second power amplification unit and the third power amplification unit operate in a dynamically adjusted output power following amplification mode, the first power amplification unit and the second power amplification unit, and the third power amplification unit and the fourth power amplification unit respectively constitute a Doherty power amplifier architecture mode to achieve power back-off and efficiency improvement of the power amplifier in the range of 0dB to 6dB.

[0015] Optionally, in the method for implementing high-efficiency amplification in the deep back-off zone, the switch unit is turned on according to the switch control signal output by the control unit; according to the first to fourth power control signals output by the control unit, the first power amplification unit and the fourth power amplification unit are both powered by the second power supply and the first power amplification unit and the fourth power amplification unit both operate in a saturated output power mode, and the second power amplification unit and the third power amplification unit are turned off, so that the power amplifier operates in a saturated output power mode at a 6dB power back-off point to achieve a first high-efficiency peak.

[0016] Optionally, in the method for implementing high-efficiency amplification in the deep back-off zone, the switch unit is turned on according to the switch control signal output by the control unit; according to the first to fourth power control signals output by the control unit, the first power amplifier unit and the fourth power amplifier unit are both powered by the second power supply and the first power amplifier unit operates in a saturated output power mode, the fourth power amplifier unit operates in a dynamically adjusted output power following amplification mode, the second power amplifier unit and the third power amplifier unit are turned off, and the first power amplifier unit and the fourth power amplifier unit constitute a Doherty power amplifier architecture mode to achieve power back-off and efficiency improvement of the power amplifier in the range of 6dB to 12dB.

[0017] Optionally, in the method for implementing high-efficiency amplification in the deep back-off zone, the switch unit is turned on according to the switch control signal output by the control unit; according to the first to fourth power control signals output by the control unit, the first power amplifier unit is powered by the second power supply and the first power amplifier unit operates in a saturated output power mode, and the second power amplifier unit, the third power amplifier unit and the fourth power amplifier unit are turned off, so that the power amplifier operates in a saturated output power mode at a 12dB power back-off point to achieve a second high-efficiency peak.

[0018] Optionally, in the method for implementing high-efficiency amplification in the deep backoff zone, the switch unit is turned on according to the switch control signal output by the control unit; according to the first to fourth power control signals output by the control unit, the first power amplifier unit is powered by the second power supply and operates in a dynamically adjusted output power following amplification mode, and the second power amplifier unit, the third power amplifier unit and the fourth power amplifier unit are turned off to achieve power backoff and efficiency improvement of the power amplifier in the range of 12dB to 18dB.

[0019] Optionally, in the method for implementing high-efficiency amplification in the deep back-off zone, the switch unit is turned on according to the switch control signal output by the control unit; according to the first to fourth power control signals output by the control unit, the first power amplifier unit is powered by the first power supply and operates in a saturated output power mode, and the second power amplifier unit, the third power amplifier unit and the fourth power amplifier unit are turned off, so that the power amplifier operates in a saturated output power mode at the 18dB power back-off point to achieve a third high-efficiency peak.

[0020] Optionally, in the method for implementing high-efficiency amplification in the deep back-off zone, the switch unit is turned on according to the switch control signal output by the control unit; according to the first to fourth power control signals output by the control unit, the first power amplifier unit is powered by the first power supply and operates in a dynamically adjusted output power following amplification mode, and the second power amplifier unit, the third power amplifier unit and the fourth power amplifier unit are turned off to achieve power back-off and efficiency improvement of the power amplifier in a range greater than 18dB.

[0021] The technical solution of this application has at least the following advantages:

[0022] In the present application, through the switching unit, multiple power amplifier unit branches can work in parallel or in series, and control the working power supply, working mode and power output status of the first to fourth power amplifier units. According to the input and output power, in the output power back-off range of 0db to 18dB, three, two or a single power amplifier unit is controlled to work in a high-efficiency saturated output power mode, so that as many power amplifier units as possible can work in the maximum efficiency saturated output power mode close to full load, and efficiency peaks are achieved when the power is backed off by 6dB, 12dB and 18dB, thereby improving the total efficiency and average efficiency of the power amplifier in the 18dB power back-off area (the power back-off range greater than 6dB), that is, the high-efficiency working back-off depth of the power amplifier is increased to 18db.

[0023] In addition, when the output power can no longer be reduced by a single power amplifier (the first power amplification unit), the present application switches the second power supply to the first power supply, that is, reduces the supply voltage of the single power amplifier, and can further maintain the power amplifier in a relatively efficient working state when the power back-off range is greater than and equal to 18dB. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] Figure 1 is a schematic structural diagram of a power amplifier according to an embodiment of the present invention;

[0026] Figure 2 is an overall schematic diagram of a power amplifier structure including a control unit according to an embodiment of the present invention;

[0027] Figure 3 1 is a schematic diagram of the circuit structure of the first to fourth power amplifying units according to an embodiment of the present invention;

[0028] Figure 4 1 is a schematic diagram of the circuit structure of a switch unit according to an embodiment of the present invention;

[0029] Figure 5 1 is a schematic diagram of the structure of a power amplifier for achieving power saturation output according to an embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of the structure of a power amplifier that implements power back-off in the range of 0dB to 6dB according to an embodiment of the present invention;

[0031] Figure 7 Schematic diagram of a power amplifier structure for achieving 6dB power back-off according to an embodiment of the present invention;

[0032] Figure 8 This is a schematic diagram of the structure of a power amplifier that implements power back-off in the range of 6dB to 12dB according to an embodiment of the present invention;

[0033] Figure 9 1 is a schematic diagram of the structure of a power amplifier for achieving 12dB power back-off according to an embodiment of the present invention;

[0034] Figure 10 This is a schematic diagram of the structure of a power amplifier that implements power back-off in the range of 12dB to 18dB according to an embodiment of the present invention;

[0035] Figure 11 2 is a schematic diagram of a power amplifier structure for achieving 18dB power back-off according to an embodiment of the present invention;

[0036] Figure 12 This is a schematic diagram of the structure of a power amplifier that achieves a power back-off greater than 18 dB according to an embodiment of the present invention;

[0037] Figure 13 It is a schematic diagram of a comparison curve of the efficiency of the power amplifier of the present invention, the traditional Doherty power amplifier, and the class B power amplifier in the power back-off range. DETAILED DESCRIPTION

[0038] The following is a clear and complete description of the technical solutions in this application in conjunction with the accompanying drawings. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0039] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal connections between two components; they can refer to wireless connections or wired connections. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0041] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0042] On the one hand, the embodiment of the present application provides a power amplifier, please refer to Figure 1The power amplifier includes: a first power amplification unit PA1, a second power amplification unit PA2, a third power amplification unit PA3, a fourth power amplification unit PA4, a first transformer T1, a second transformer T2, a first power supply VDD1, a second power supply VDD2 and a switch unit SW1. Specifically, the two input ends of the primary side of the first transformer T1 are respectively connected to the output end of the first power amplifier unit PA1 and the output end of the second power amplifier unit PA2, the two input ends of the primary side of the second transformer T2 are respectively connected to the output end of the third power amplifier unit PA3 and the output end of the fourth power amplifier unit PA4, the switch unit SW1 is connected in series between the output end of the second power amplifier unit PA2 and the output end of the third power amplifier unit PA3, an output end of the secondary side of the first transformer T1 is connected in series with an output end of the secondary side of the second transformer T2, the other output end of the secondary side of the first transformer T1 is connected in series with the subsequent load RL and grounded GND, the other output end of the secondary side of the second transformer T2 is grounded GND, the first power amplifier unit PA1 is powered by the first power supply VDD1 or the second power supply VDD2, and the second power amplifier unit PA2, the third power amplifier unit PA3 and the fourth power amplifier unit PA4 are all powered by the second power supply VDD2.

[0043] In this embodiment, the voltage value of the second power supply VDD2 is twice the voltage value of the first power supply VDD1.

[0044] Better, reference Figure 2 , Figure 21 is an overall schematic diagram of a power amplifier structure including a control unit according to an embodiment of the present invention. The power amplifier further includes: a control unit 10, which can be used for decoding, non-overlapping clock driving, and signal selection. The control unit 10 receives an external phase input signal Phase Input, an N-bit amplitude signal Amplitude Input, and a clock signal Clock, and outputs a first power control signal to the input terminal IN1 of the first power amplifier unit PA1, a second power control signal to the input terminal IN2 of the second power amplifier unit PA2, a third power control signal to the input terminal IN3 of the third power amplifier unit PA3, and a fourth power control signal to the input terminal IN4 of the fourth power amplifier unit PA4, so as to control the operating modes of the first power amplifier unit PA1, the second power amplifier unit PA2, the third power amplifier unit PA3, and the fourth power amplifier unit PA3, and outputs a switch control signal to the switch unit SW1 to control the conduction and disconnection of the switch unit SW1. In the present application, through the switching unit SW1, multiple power amplifier unit branches can work in parallel or in series, and the working power supply, working mode and power output status of the first to fourth power amplifier units are controlled according to the input and output power. In the output power back-off range of 0db~18dB, three, two or a single power amplifier unit are controlled to work in a high-efficiency saturated output power mode, so that as many power amplifier units as possible can work in the maximum efficiency saturated output power mode close to full load, and efficiency peaks are achieved when the power is backed off by 6dB, 12dB and 18dB (three power back-off points), thereby improving the efficiency and average efficiency of the power amplifier in the 18dB power back-off area (the power back-off range greater than 6dB), that is, the high-efficiency working back-off depth of the power amplifier is increased to 18db.

[0045] Please refer to Figure 3 , Figure 3This is a schematic diagram of the circuit structure of the first to fourth power amplifier units according to an embodiment of the present invention. In this embodiment, the first, second, third, and fourth power amplifier units PA1, PA2, PA3, and PA4 are all switched capacitor power amplifier units. Each of the first to fourth power amplifier units PA1-PA4 may include multiple groups of inverting amplifier units S1 and capacitor units C1 connected in series with the inverting amplifier units S1. Each group of inverting amplifier units S1 and capacitor units C1 is connected in series and then in parallel. The inverting amplifier unit S1 of the first power amplifier unit PA1 includes a first branch and a second branch. The inverting amplifier unit S1 of the second to fourth power amplifier units PA2-PA4 includes a second branch. The first branch includes two PMOS transistors and two NMOS transistors connected in series, and the second branch includes one NMOS transistor and one PMOS transistor connected in series. The selection of the second power supply VDD2 and the first power supply VDD1 can be achieved using the above-described circuit. The present invention does not impose any limitation on the specific circuit structure of the inverting amplifier unit S1.

[0046] Please refer to Figure 4 , Figure 4 Figure 2 is a schematic diagram of the circuit structure of a switch unit according to an embodiment of the present invention. The switch unit SW1 comprises: multiple MOS transistors N1 connected in series. A capacitor C2 may be connected in series at each end of the series MOS transistors N1 to suppress interference. The switch unit SW1 may also include multiple drive resistors R1, each connected in series between the gates of two adjacent MOS transistors N1. The switch unit SW1 utilizes positive power supply drive technology, and the number of transistor stages is determined by the voltage VG / VSD across the switch.

[0047] On the other hand, the embodiment of the present application also provides a method for realizing high-efficiency amplification in the deep backoff region based on the power amplifier. According to the switch control signal output by the control unit 10, the switch unit SW1 switches the switch state, and according to the first to fourth power control signals output by the control unit 10, the first power amplifier unit to the fourth power amplifier unit PA1-PA4 respectively adjust their respective working modes and output powers to achieve efficiency peaks at 6dB, 12dB and 18dB power backoff depths, thereby improving the average efficiency within a deeper backoff power depth. For details, please refer to Figure 5-Figure 12 , Figure 5-Figure 12 The high-efficiency amplification implementation method (operation method) corresponding to the power amplifier in the deep back-off range is illustrated.

[0048] Please refer to Figure 5 , Figure 51 is a schematic diagram of a power amplifier structure for achieving power saturation output according to an embodiment of the present invention. According to the switch control signal output by the control unit 10, the switch unit SW1 is disconnected. When the switch unit SW1 is disconnected, the first power amplifier unit PA1 and the second power amplifier unit PA2 operate in series, and the third power amplifier unit PA3 and the fourth power amplifier unit PA4 operate in series. The branch containing the first power amplifier unit PA1 and the second power amplifier unit PA2 is not electrically connected to the branch containing the third power amplifier unit PA3 and the fourth power amplifier unit PA4. According to the first to fourth power control signals output by the control unit 10, the first power amplifier unit PA1, the second power amplifier unit PA2, the third power amplifier unit PA3, and the fourth power amplifier unit PA4 are all powered by the second power supply VDD2 and operate in a saturated output power mode, thereby achieving power saturation output and maximum efficiency output of the power amplifier.

[0049] Please refer to Figure 6 , Figure 6 This is a schematic diagram of the power amplifier structure for achieving power back-off in the range of 0dB to 6dB according to an embodiment of the present invention. According to the switch control signal output by the control unit 10, the switch unit SW1 is disconnected; according to the first to fourth power control signals output by the control unit 10, the first power amplifier unit PA1, the second power amplifier unit PA2, the third power amplifier unit PA3 and the fourth power amplifier unit PA4 are all powered by the second power supply VDD2, the first power amplifier unit PA1 and the fourth power amplifier unit PA4 operate in a saturated output power mode, and the second power amplifier unit PA2 and the third power amplifier unit PA3 operate in a follower amplification mode that dynamically adjusts the output power according to the input power control signal; the first power amplifier unit PA1 and the second power amplifier unit PA2 constitute a Doherty power amplifier architecture mode, and the third power amplifier unit PA3 and the fourth power amplifier unit PA4 also constitute a Doherty power amplifier architecture mode, so as to achieve power back-off and efficiency improvement of the power amplifier in the range of 0dB to 6dB.

[0050] Please refer to Figure 7 , Figure 7It is a schematic diagram of the power amplifier structure for achieving 6dB power back-off in an embodiment of the present invention. According to the switch control signal output by the control unit 10, the switch unit SW1 is turned on. When the switch unit SW1 is turned on, the first power amplifier unit PA1 and the fourth power amplifier unit PA4 work in series, and the second power amplifier unit PA2 and the third power amplifier unit PA3 are short-circuited; according to the first to fourth power control signals output by the control unit 10, the first power amplifier unit PA1 and the fourth power amplifier unit PA4 are both powered by the second power supply VDD2 and both work at saturated output power, and the second power amplifier unit PA2 and the third power amplifier unit PA2 are turned off and do not participate in the work, so that the power amplifier power works at the saturated output power mode at the 6dB power back-off point to achieve the first high-efficiency peak.

[0051] Please refer to Figure 8 , Figure 8 This is a schematic diagram of the power amplifier structure for achieving power back-off in the range of 6dB to 12dB according to an embodiment of the present invention. According to the switch control signal output by the control unit 10, the switch unit SW1 is turned on; according to the first to fourth power control signals output by the control unit 10, the first power amplifier unit PA1 and the fourth power amplifier unit PA4 are both powered by the second power supply VDD2, the first power amplifier unit PA1 operates in a saturated output power mode, the fourth power amplifier unit PA4 operates in a dynamically adjusted output power following amplification mode according to the input power control signal, the second power amplifier unit PA2 and the third power amplifier unit PA3 are turned off, and the first power amplifier unit PA1 and the fourth power amplifier unit PA4 form a Doherty power amplifier architecture mode to achieve power back-off and efficiency improvement of the power amplifier in the range of 6dB to 12dB. In the power backoff range of 6dB to 12dB, the second power amplifier unit PA2 and the third power amplifier unit PA3 still have no output, and the corresponding branches are in the off state; the first power amplifier unit PA1 is fully loaded and saturated; the fourth power amplifier unit PA4 has not reached the full load state, and its output power still has a margin from the full load. The specific output amount is determined according to the front-end input and output, that is, the output power is adjusted according to the input power.

[0052] Please refer to Figure 9 , Figure 9This is a schematic diagram of the power amplifier structure for achieving 12dB power back-off in an embodiment of the present invention. According to the switch control signal output by the control unit 10, the switch unit SW1 is turned on; according to the first to fourth power control signals output by the control unit 10, the first power amplifier unit PA1 is powered by the second power supply VDD2 and operates in a saturated output power mode, and the second power amplifier unit PA2, the third power amplifier unit PA3, and the fourth power amplifier unit PA4 are turned off, so that the power amplifier operates in a saturated output power mode at a 12dB power back-off point to achieve a second high efficiency peak. It can be seen that at the power back-off point of 12dB, only the first power amplifier unit PA1 is operating. At this power back-off point, the first power amplifier unit PA1 operates in a full-load saturated output mode, and a second efficiency peak appears at this time.

[0053] Please refer to Figure 10 , Figure 10 This is a schematic diagram of the power amplifier structure for achieving power backoff in the range of 12dB to 18dB according to an embodiment of the present invention. According to the switch control signal output by the control unit 10, the switch unit SW1 is turned on; according to the first to fourth power control signals output by the control unit 10, the first power amplifier unit PA1 is powered by the second power supply VDD2 and works in a follow-up amplification mode that dynamically adjusts the output power according to the input power control signal, and the second power amplifier unit PA2, the third power amplifier unit PA3 and the fourth power amplifier unit PA4 are turned off to achieve power backoff and efficiency improvement of the power amplifier in the range of 12dB to 18dB. In the power backoff range of 12dB to 18dB, only the first power amplifier unit PA1 is outputting power, and the output power of the first power amplifier unit PA1 is dynamically adjusted with the input power, but it never reaches the full load saturation power.

[0054] Please refer to Figure 11 , Figure 11This is a schematic diagram of the structure of a power amplifier that achieves 18dB power back-off according to an embodiment of the present invention. Based on the switch control signal output by the control unit 10, the switch unit SW1 is turned on. Based on the first to fourth power control signals output by the control unit 10, the first power amplifier unit PA1 is powered by the first power supply VDD1 and operates in a saturated output power mode. The second power amplifier unit PA2, the third power amplifier unit PA3, and the fourth power amplifier unit PA4 are turned off, so that the power amplifier operates in a saturated output power mode at the 18dB power back-off point and achieves the third highest efficiency peak. At the 18dB power back-off point, since the output power has been reduced to the minimum by relying solely on the first power amplifier unit PA1, the power supply voltage of the power amplifier can only be further reduced to reduce the output power. The power supply of the first power amplifier unit PA1 is switched to the first power supply VDD1, which has a voltage value half that of the second power supply VDD2, to reduce the output power. At this time, the third efficiency peak appears.

[0055] Please refer to Figure 12 , Figure 12 This is a schematic diagram of the structure of a power amplifier that achieves power backoff in a range greater than 18dB according to an embodiment of the present invention. According to the switch control signal output by the control unit 10, the switch unit SW1 is turned on; according to the first to fourth power control signals output by the control unit 10, the first power amplifier unit PA1 is powered by the first power supply VDD1 and operates in a follow-up amplification mode that dynamically adjusts the output power according to the input power control signal, and the second power amplifier unit PA2, the third power amplifier unit PA3, and the fourth power amplifier unit PA3 are turned off, so that the power amplifier achieves power backoff in a range greater than 18dB and improves efficiency. In the power backoff range greater than 18dB, after the first power amplifier unit PA1 is switched to be powered by the first power supply VDD1, the output power is further adjusted and reduced with the input power. In this application, when the output power cannot be reduced by only a single power amplifier (the first power amplifier unit PA1), by switching the second power supply VDD2 to the first power supply VDD1, that is, reducing the supply voltage of the single power amplifier, the power amplifier can be further maintained in a relatively efficient working state when the power backoff range is greater than or equal to 18dB.

[0056] For further information, please refer to Figure 13 , Figure 13 Schematic diagram of the comparison curve of the efficiency of the power amplifier of the present invention, the traditional Doherty power amplifier and the traditional Class B power amplifier in the power back-off range. Figure 13It can be seen that the power of the traditional Class B power amplifier gradually decreases during power back-off, and the traditional Doherty power amplifier only has an efficiency peak when the power is backed off by 6dB. The power amplifier provided by the present invention uses the amplification method provided by the present invention to have high efficiency peaks when the power is backed off by 6dB, 12dB and 18dB, thereby improving the total efficiency and average efficiency of the power amplifier in the 0dB to 18dB power back-off region (the power back-off range greater than 6dB), so that the high-efficiency working back-off power depth of the power amplifier of the present invention is increased to 18dB.

[0057] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of this application.

Claims

1. A power amplifier, characterized in that: include: A first power amplifying unit, a second power amplifying unit, a third power amplifying unit, a fourth power amplifying unit, a first transformer, a second transformer, a first power supply, a second power supply and a switching unit; Wherein, the two input ends of the primary side of the first transformer are respectively connected to the output end of the first power amplification unit and the output end of the second power amplification unit, the two input ends of the primary side of the second transformer are respectively connected to the output end of the third power amplification unit and the output end of the fourth power amplification unit, the switch unit is connected in series between the output end of the second power amplification unit and the output end of the third power amplification unit, an output end of the secondary side of the first transformer is connected in series with an output end of the secondary side of the second transformer, the other output end of the secondary side of the first transformer is connected in series with a subsequent load and grounded, the other output end of the secondary side of the second transformer is grounded, the first power amplification unit is powered by the first power supply or the second power supply, and the second power amplification unit, the third power amplification unit and the fourth power amplification unit are all powered by the second power supply; In which, the power amplifier also includes: a control unit, which receives an external phase input signal, amplitude signal and clock signal, and outputs first, second, third and fourth power control signals to the first to fourth power amplification units to control the working mode and output power of the first to fourth power amplification units, and outputs a switch control signal to the switch unit to control the conduction and disconnection of the switch unit.

2. The power amplifier according to claim 1, wherein: The voltage value of the second power supply is twice the voltage value of the first power supply.

3. The power amplifier according to claim 1, wherein: The first power amplifying unit, the second power amplifying unit, the third power amplifying unit and the fourth power amplifying unit are all switched capacitor power amplifier units, and each includes: multiple groups of inverting amplifier units and capacitor units connected in series with the inverting amplifier units, and each group of the inverting amplifier units is connected in series with the capacitor units and then connected in parallel with each other.

4. The power amplifier according to claim 3, wherein: The inverting amplifier subunit of the first power amplifier unit includes: a first branch and a second branch; the inverting amplifier subunits of the second to fourth power amplifier units include: a second branch, wherein the first branch includes two PMOS tubes and two NMOS tubes connected in series, and the second branch includes one NMOS tube and one PMOS tube connected in series.

5. The power amplifier according to claim 1, wherein: The switch unit includes: a plurality of MOS tubes connected in series.

6. A method for realizing high-efficiency amplification in a deep back-off region based on the power amplifier according to claim 1, characterized in that: According to the switch control signal output by the control unit, the switch unit switches the switch state, and according to the first to fourth power control signals output by the control unit, the first power amplification unit to the fourth power amplification unit respectively adjust their respective operating modes and output powers to achieve efficiency peaks at power back-off depths of 6dB, 12dB and 18dB, thereby improving the average efficiency within a deeper back-off power depth.

7. The method for realizing high-efficiency amplification in a deep back-off region according to claim 6, characterized in that: According to the switch control signal output by the control unit, the switch unit is disconnected; according to the first to fourth power control signals output by the control unit, the first power amplification unit, the second power amplification unit, the third power amplification unit and the fourth power amplification unit are all powered by the second power supply and all operate in a saturated output power mode to achieve power saturation output and maximum efficiency output of the power amplifier.

8. The method for realizing high-efficiency amplification in a deep back-off region according to claim 6, characterized in that: According to the switch control signal output by the control unit, the switch unit is disconnected; according to the first to fourth power control signals output by the control unit, the first to fourth power amplification units are all powered by the second power supply, the first power amplification unit and the fourth power amplification unit operate in a saturated output power mode, the second power amplification unit and the third power amplification unit operate in a dynamically adjusted output power following amplification mode, the first power amplification unit and the second power amplification unit, and the third power amplification unit and the fourth power amplification unit respectively constitute a Doherty power amplifier architecture mode to achieve power backoff and efficiency improvement of the power amplifier in the range of 0dB to 6dB.

9. The method for realizing high-efficiency amplification in a deep back-off region according to claim 6, characterized in that: According to the switch control signal output by the control unit, the switch unit is turned on; according to the first to fourth power control signals output by the control unit, the first power amplification unit and the fourth power amplification unit are both powered by the second power supply and the first power amplification unit and the fourth power amplification unit both operate in a saturated output power mode, and the second power amplification unit and the third power amplification unit are turned off, so that the power amplifier operates in a saturated output power mode at a 6dB power back-off point to achieve a first high-efficiency peak.

10. The method for realizing high-efficiency amplification in a deep back-off region according to claim 6, characterized in that: According to the switch control signal output by the control unit, the switch unit is turned on; according to the first to fourth power control signals output by the control unit, the first power amplifier unit and the fourth power amplifier unit are both powered by the second power supply and the first power amplifier unit operates in a saturated output power mode, the fourth power amplifier unit operates in a dynamically adjusted output power following amplification mode, the second power amplifier unit and the third power amplifier unit are turned off, and the first power amplifier unit and the fourth power amplifier unit constitute a Doherty power amplifier architecture mode to achieve power back-off and efficiency improvement of the power amplifier in the range of 6dB to 12dB.

11. The method for realizing high-efficiency amplification in a deep back-off region according to claim 6, characterized in that: According to the switch control signal output by the control unit, the switch unit is turned on; according to the first to fourth power control signals output by the control unit, the first power amplifier unit is powered by the second power supply and the first power amplifier unit operates in a saturated output power mode, and the second power amplifier unit, the third power amplifier unit and the fourth power amplifier unit are turned off, so that the power amplifier operates in a saturated output power mode at a 12dB power back-off point to achieve a second high efficiency peak.

12. The method for realizing high-efficiency amplification in a deep back-off region according to claim 6, characterized in that: According to the switch control signal output by the control unit, the switch unit is turned on; according to the first to fourth power control signals output by the control unit, the first power amplifier unit is powered by the second power supply and operates in a dynamically adjusted output power following amplification mode, and the second power amplifier unit, the third power amplifier unit and the fourth power amplifier unit are turned off to achieve power backoff and efficiency improvement of the power amplifier in the range of 12dB to 18dB.

13. The method for realizing high-efficiency amplification in a deep back-off region according to claim 6, characterized in that: According to the switch control signal output by the control unit, the switch unit is turned on; according to the first to fourth power control signals output by the control unit, the first power amplifier unit is powered by the first power supply and operates in a saturated output power mode, and the second power amplifier unit, the third power amplifier unit and the fourth power amplifier unit are turned off, so that the power amplifier operates in a saturated output power mode at an 18dB power back-off point to achieve a third high efficiency peak.

14. The method for realizing high-efficiency amplification in a deep back-off region according to claim 6, characterized in that: According to the switch control signal output by the control unit, the switch unit is turned on; according to the first to fourth power control signals output by the control unit, the first power amplifier unit is powered by the first power supply and operates in a dynamically adjusted output power following amplification mode, and the second power amplifier unit, the third power amplifier unit and the fourth power amplifier unit are turned off to achieve power backoff and efficiency improvement of the power amplifier in a range greater than 18dB.

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