Doherty power amplifier and electronic device including the same

Abstract

A Doherty power amplifier of a wireless communication system is provided. The Doherty power amplifier may include: a first stage including a first power amplifier and a second power amplifier; the second stage comprises a third power amplifier and a fourth power amplifier; a coupler between the first stage and the second stage; and a load impedance connected to the second stage. The bias of the first power amplifier can be applied differently than the bias of the second power amplifier. The bias of the third power amplifier can be applied to be the same as the bias of the fourth power amplifier.

Description

Technical Field

[0001] The present disclosure relates to a wireless communication system, for example, to a Doherty power amplifier in the wireless communication system and an electronic device including the Doherty power amplifier. Background Art

[0002] In 5G systems, electronic devices can use modulation methods with high peak-to-average power ratio (PAPR) in order to handle large amounts of data capacity. In order to linearly amplify a modulated signal with a high PAPR, the power amplifier operates in a back-off region that is backed off by a certain value from the maximum output, rather than in an area with maximum output. In this case, the efficiency of the power amplifier operating in the back-off region decreases and power consumption increases. In order to improve the amplifier efficiency in the back-off region, a Doherty power amplifier configured with two power amplifiers can be used. However, since the Doherty power amplifier has a limited back-off region in which efficiency is improved, the efficiency improvement capability may be limited. Summary of the invention

[0003] According to various example embodiments, a Doherty power amplifier of a wireless communication system is provided. The Doherty power amplifier may include a first stage, wherein the first stage includes a first power amplifier and a second power amplifier. The Doherty power amplifier may include a second stage, wherein the second stage includes a third power amplifier and a fourth power amplifier. The Doherty power amplifier may include a coupler between the first stage and the second stage. The Doherty power amplifier may include a load impedance connected to the second stage. The bias of the first power amplifier may be applied differently from the bias of the second power amplifier. The bias of the third power amplifier may be applied in the same manner as the bias of the fourth power amplifier.

[0004] According to various example embodiments, an electronic device of a wireless communication system is provided. The electronic device may include at least one processor. The electronic device may include a plurality of radio frequency (RF) chains connected to the at least one processor. The electronic device may include a plurality of antenna elements connected to the plurality of RF chains. An RF chain among the plurality of RF chains may include a Doherty power amplifier. The Doherty power amplifier may include a first stage, wherein the first stage includes a first power amplifier and a second power amplifier. The Doherty power amplifier may include a second stage, wherein the second stage includes a third power amplifier and a fourth power amplifier. The Doherty power amplifier may include a coupler between the first stage and the second stage. The Doherty power amplifier may include a load impedance connected to the second stage. The bias of the first power amplifier may be applied differently from the bias of the second power amplifier. The bias of the third power amplifier may be applied in the same manner as the bias of the fourth power amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent through the following detailed description in conjunction with the accompanying drawings, in which:

[0006] Figure 1 is a diagram illustrating an example wireless communication system in accordance with various embodiments;

[0007] Figure 2A is a diagram showing an example of a power amplifier according to various embodiments;

[0008] Figure 2B is a diagram showing an example of a 2-stage Doherty power amplifier according to various embodiments;

[0009] Figure 3A is a graph showing a phase difference between output currents of amplifiers of a main stage according to input voltages according to various embodiments;

[0010] Figure 3B is a graph showing an output current of an amplifier of a main stage according to an input voltage according to various embodiments;

[0011] Figure 3C is a graph showing an output voltage of an amplifier of a main stage according to an input voltage according to various embodiments;

[0012] Figure 4 is a diagram showing an example of a 2-stage Doherty power amplifier according to various embodiments;

[0013] Figure 5 is a diagram illustrating an example of a combiner according to various embodiments;

[0014] Figure 6 is a diagram showing an example of a coupler according to various embodiments;

[0015] Figure 7 is a diagram showing an example of a 2-stage Doherty power amplifier including a hybrid coupler according to various embodiments;

[0016] Fig. 8A is a graph showing a phase difference between output currents of amplifiers of a main stage according to input voltages according to various embodiments;

[0017] Figure 8B is a graph showing an output current and an output voltage of an amplifier of a main stage according to an input voltage according to various embodiments;

[0018] Figure 8C is a graph showing a change in load impedance of a main amplifier of a main stage according to output power according to various embodiments;

[0019] Fig.8D is a graph showing power efficiency of a 2-stage Doherty power amplifier according to output power according to various embodiments; and

[0020] Fig. 9 is a diagram showing an example configuration of an electronic device according to various embodiments.

[0021] Regarding the description of the drawings, the same or similar reference numerals may be used for the same or similar components. DETAILED DESCRIPTION

[0022] The terms used in this disclosure are used to describe various example embodiments, and are not intended to limit the scope of any embodiment. Singular expressions may include plural expressions unless they are clearly expressed differently in the context. The terms used herein (including technical or scientific terms) may have the same meaning as the meanings commonly understood by personnel with ordinary knowledge in the technical field described in this disclosure. The terms defined in the general dictionary among the terms used in this disclosure may be interpreted with the same or similar meanings as the contextual meanings of the relevant technology, and unless clearly defined in this disclosure, the terms should not be interpreted with ideal or overly formal meanings. In some cases, even the terms defined in this disclosure cannot be interpreted as excluding embodiments of the present disclosure.

[0023] In various embodiments of the present disclosure described below, a hardware method is described as an example. However, since various embodiments of the present disclosure include techniques using both hardware and software, various embodiments of the present disclosure do not exclude software-based methods.

[0024] For ease of description, the terms used in the following description indicating components of the device (divider or splitter, power divider or power splitter, line, transmission line, feeder, power amplifier, main stage, driver stage, Doherty power amplifier, carrier amplifier, main power amplifier, main amplifier, peak amplifier, auxiliary power amplifier, auxiliary power amplifier, auxiliary amplifier, phase shift, modulation impedance, network, combiner, coupler, etc.), the terms indicating the configuration of the components of the device (port, terminal, end, input end, output end, node), etc. are shown. Therefore, the present disclosure is not limited to the terms described below, and another term with equivalent technical meaning may be used. In addition, terms such as "...component", "...device", "...material", "...body", etc. used below may indicate at least one shape structure, or may indicate a unit of processing function.

[0025] In addition, in the present disclosure, in order to determine whether a specific condition is met or fulfilled, the expression of greater than or less than can be used, but this is merely a description for expressing an example, and does not exclude the description of greater than or equal to or less than or equal to. The condition described as "greater than or equal to" can be replaced with "greater than", the condition described as "less than or equal to" can be replaced with "less than", and the condition described as "greater than or equal to and less than" can be replaced with "greater than and less than or equal to". In addition, hereinafter, "A" to "B" can indicate at least one element from A (including A) to B (including B).

[0026] Figure 1 is a diagram illustrating an example wireless communication system in accordance with various embodiments. Figure 1 A base station 110, a terminal 120, and a terminal 130 are shown as a part of nodes using a wireless channel in a wireless communication system. Figure 1 A shows one base station, but may further include another base station that is the same as or similar to the base station 110 .

[0027] The base station 110 is a network infrastructure that provides wireless access to the terminal 120 and the terminal 130. The base station 110 has a coverage range defined as a specific geographical area based on the distance at which a signal can be transmitted. In addition to a base station, the base station 110 may also be referred to as an "access point (AP)", "eNodeB (eNB)", "fifth generation node (5G node)", "radio point", "transmission / reception point (TRP)" or another term with equivalent technical meaning.

[0028] Each of the terminal 120 and the terminal 130 is a device used by a user and communicates with the base station 110 through a wireless channel. In some cases, at least one of the terminal 120 and the terminal 130 may be operated without user participation. In other words, at least one of the terminal 120 and the terminal 130 is a device that performs machine type communication (MTC) and may not be carried by the user. In addition to the terminal, each of the terminal 120 and the terminal 130 may also be referred to as a "user equipment (UE)", "mobile station", "subscriber station", "customer terminal equipment (CPE)", "remote terminal", "wireless terminal", "electronic device" or "user device" or another term with equivalent technical meaning.

[0029] Base station 110, terminal 120 and terminal 130 can send and receive wireless signals in millimeter wave band (for example, 28GHz, 30GHz, 38GHz, 60GHz or 60GHz or higher). At this time, in order to improve channel gain, base station 110, terminal 120 and terminal 130 can perform beamforming. Beamforming may include transmit beamforming and receive beamforming. In other words, base station 110, terminal 120 and terminal 130 can assign directivity to transmit signals or receive signals. To this end, base station 110 and terminals 120 and 130 can select service beams 112, 113, 121 and 131 through beam search or beam management process. After service beams 112, 113, 121 and 131 are selected, subsequent communications can be performed through resources having a quasi-co-location (QCL) relationship with resources that transmit service beams 112, 113, 121 and 131.

[0030] The base station 110 or the terminal 120 and the terminal 130 may include an antenna array. Each antenna included in the antenna array may be referred to as an array element or an antenna element. The antenna array may be configured in various forms, such as a two-dimensional planar array, a linear array, or a multi-layer array. The antenna array may be referred to as a large-scale antenna array. In addition, the antenna array may also have a plurality of sub-arrays including a plurality of antenna elements.

[0031] Figure 2A is a diagram showing an example of a power amplifier for describing various embodiments.

[0032] Figure 2A 201 is an example of a power amplifier 200, which is simplified for ease of description. The power amplifier 200 can amplify the power of a signal input through the input terminal 201 and output the amplified power to the output terminal 202. In the following, it is assumed that the power amplifier of the present disclosure is an amplifier matched with a voltage-controlled current source (ID), and the impedance of the input terminal 201 is Z inIn other words, the current source ID connected to the output terminal can be linearly operated according to the voltage of the input terminal 201. The power amplifier 200 applies a class C bias, and at a low power (LP) point, the power amplifier 200 can be in an off state.

[0033] Figure 2B 1 is a diagram showing an example of a 2-stage Doherty power amplifier for describing a power amplifier for describing various embodiments. The Doherty power amplifier may be a power amplifier configured with two power amplifiers. Therefore, the 2-stage Doherty power amplifier is a Doherty power amplifier including two stages, and the stage for driving may be referred to as a driver stage, and the stage for output may be referred to as a main stage.

[0034] refer to Figure 2B , a 2-stage Doherty power amplifier (DPA) 210 may include a driver stage 220 , a main stage 230 , a transmission line 240 for phase delay, a combiner 250 , and a power splitter 270 .

[0035] The driver stage 220 may include two power amplifiers. For example, the driver stage 220 may include a first power amplifier 221 and a second power amplifier 222. In this case, the first power amplifier 221 and the second power amplifier 222 may be amplifiers to which the same bias is applied. For example, the value of the bias current (or voltage) of the first power amplifier 221 may be the same as the value of the bias current (or voltage) of the second power amplifier 222. The bias of the first power amplifier 221 may be applied in the same manner as the bias of the second power amplifier 222. For example, the first power amplifier 221 may be an amplifier biased in class AB, and the second power amplifier 222 may also be an amplifier biased in class AB. This is merely an example, and the first power amplifier 221 and the second power amplifier 222 may be configured as amplifiers biased in class A, class B, and class C.

[0036] The main stage 230 may include two power amplifiers. For example, the main stage 230 may include a third power amplifier 231 and a fourth power amplifier 232. In this case, the third power amplifier 231 and the fourth power amplifier 232 may be amplifiers to which different biases are applied. For example, the value of the bias current (or voltage) of the third power amplifier 231 may be different from the value of the bias current (or voltage) of the fourth power amplifier 232. The bias of the third power amplifier 231 may be applied differently from the bias of the fourth power amplifier 232. For example, the third power amplifier 231 may be an amplifier with class AB bias, and the fourth power amplifier 232 may be an amplifier with class C bias. This is merely an example, and the third power amplifier 231 may be an amplifier with class A or class B bias. The fourth power amplifier 232 may be configured with an amplifier with class AB, class B, or class C bias. The third power amplifier 231 may be referred to as a carrier amplifier, a main power amplifier, and a main amplifier. The fourth power amplifier 232 may be referred to as a peak amplifier, an auxiliary power amplifier, or an auxiliary amplifier.

[0037] The transmission line 240 may be connected between the driver stage 220 and the main stage 230. For example, the transmission line 240 may connect the output end of the first power amplifier 221 to the input end of the third power amplifier 231. The transmission line 240 may form a phase difference between the signals applied to the main stage 230. In other words, the transmission line 240 may be a structure for forming a phase difference between a signal (signal 1) input to the third power amplifier 231 as a main amplifier and a signal (signal 2) input to the fourth power amplifier 232 as a peak amplifier. Here, the phase difference through the transmission line 240 may be θ D .

[0038] The combiner 250 is a structure for impedance modulation and may be connected to the third power amplifier 231, the fourth power amplifier 232, and the load impedance 260. The combiner 250 may include a first modulation structure 251 connected to the third power amplifier 231 and a second modulation structure 252 connected to the fourth power amplifier 232. For example, the first modulation structure 251 and the second modulation structure 252 may have a structure including at least one of a lumped element, a transmission line, or a transformer. Details thereof are described in detail in Figure 5 For example, the first modulation structure 251 may be configured with a characteristic impedance R 0 and an impedance having an electrical length of 90°, and the second modulation structure 252 may be configured with a characteristic impedance R 0 and an impedance having an electrical length of 180°. The signal (Signal 3 ) passing through the first modulation structure 251 and the signal (Signal 4 ) passing through the second modulation structure 252 may be combined and applied to the load impedance 260 .

[0039] The power splitter 270 may divide an input signal applied to the 2-stage Doherty power amplifier 210 and apply the signal to a power amplifier of the driver stage 220 .

[0040] refer to Figure 2B , the current of the signal 3 passing through the third power amplifier 231 may have a magnitude of I 0 and phase θ a , and the current of the signal 4 through the fourth power amplifier 232 may have a magnitude of I 0 and phase θ b In this case, θ b -θ a can be defined as Δθ.

[0041] Figure 3A is a graph showing a phase difference between output currents of an amplifier of a main stage according to an input voltage for describing various embodiments. Here, the main stage may indicate, for example, Figure 2B The main stage 230, and the amplifier of the main stage can be Figure 2B The third power amplifier 231 and the fourth power amplifier 232. In addition, the phase difference Δθ may indicate a signal ( Figure 2B The signal 3) output from the fourth power amplifier 232 is Figure 2B The phase difference between the signals 4).

[0042] Figure 3A The graph 300 of FIG. 310 shows a line 310, wherein the line 310 shows a phase difference Δθ according to a normalized input voltage. In the graph 300, the horizontal axis may indicate the amplitude of the normalized input voltage, and the vertical axis may indicate the phase difference (unit: °). Here, the normalized input voltage may be a voltage obtained by normalizing the amplitude of the input voltage of the 2-stage Doherty power amplifier to a value between 0 and 1. Referring to the line 310, even when the amplitude of the input voltage of the 2-stage Doherty power amplifier is changed, the phase difference Δθ at the input to the main stage power amplifier (e.g., Figure 2B The phase difference between the signals (signal 1, signal 2) before the third power amplifier 231 and the fourth power amplifier 232) or between the output signals (signal 3, signal 4) can also always be kept constant. In other words, even when the amplitude of the input voltage of the 2-stage Doherty power amplifier changes, the phase difference between the signals input to the main stage of the 2-stage Doherty power amplifier may not change.

[0043] Figure 3B is a graph showing an output current of an amplifier of a main stage according to an input voltage for describing various embodiments. Here, the main stage may indicate, for example, Figure 2B The main stage 230, and the amplifier of the main stage can be Figure 2B The third power amplifier 231 and the fourth power amplifier 232 are configured as follows.

[0044] Figure 3B The graph 320 shows a first line 325 and a second line 330, wherein the first line 325 shows the output current of the auxiliary amplifier of the main stage according to the normalized input voltage, and the second line 330 shows the output current of the main amplifier of the main stage according to the normalized input voltage. The horizontal axis of the graph 320 may indicate the amplitude of the normalized input voltage, and the vertical axis may indicate the current (unit: [A]). Here, the normalized input voltage may be a voltage obtained by normalizing the amplitude of the input voltage of the 2-stage Doherty power amplifier to a value between 0 and 1. For ease of description, the graph 320 shows a case where k is 2 as an example. Here, k may indicate, for example, a modulation ratio of impedance, and here, the impedance may be the impedance when viewed from the output end of the main amplifier of the main stage in the direction of the load impedance. In addition, the modulation ratio may indicate the impedance R in a state where the output power of the power amplifier is high (high power, HP). HP The impedance R at low output power LP The modulation ratio can be defined as R LP / R HP In this case, the threshold for distinguishing the state of high or low output power can be determined based on the power point at which the auxiliary amplifier is turned on. In the example of graph 320, the auxiliary amplifier can be turned on when the amplitude of the normalized input voltage is greater than 0.5. Therefore, the threshold can be determined based on the output power of the power amplifier at an input voltage amplitude of 0.5.

[0045] Referring to the first line 325, when the amplitude of the input voltage of the 2-stage Doherty power amplifier is 0.5 or less, the auxiliary amplifier of the main stage may not output current. In other words, the current of the auxiliary amplifier may be 0. However, in the case where the amplitude of the input voltage exceeds 0.5, the auxiliary amplifier increases linearly until the amplitude of the current reaches a maximum value I max In this case, the slope of the first line 325 may be 2I max On the other hand, referring to the second line 330, the current of the main amplifier of the main stage may increase linearly until it reaches a maximum value, regardless of the magnitude of the input voltage of the 2-stage Doherty power amplifier. In this case, the slope of the second line 330 may be I max According to the above, the ratio between the main amplifier and the auxiliary amplifier output current can be varied depending on the input voltage of the 2-stage Doherty power amplifier (or the input voltage of the driver stage).

[0046] Figure 3C is a graph showing an output voltage of an amplifier of a main stage according to an input voltage for describing various embodiments. Here, the main stage represents Figure 2B The main stage 230, and the amplifier of the main stage can be Figure 2B The third power amplifier 231 and the fourth power amplifier 232 are configured as follows.

[0047] Figure 3C The graph 340 shows a first line 345 and a second line 350, wherein the first line 345 shows the output voltage of the auxiliary amplifier of the main amplifier according to the normalized input voltage, and the second line 350 shows the output voltage of the main amplifier according to the normalized input voltage. The horizontal axis of the graph 340 may indicate the amplitude of the normalized input voltage, and the vertical axis may indicate the voltage (unit: [V]). Here, the normalized input voltage may be a voltage obtained by normalizing the amplitude of the input voltage of the 2-stage Doherty power amplifier to a value between 0 and 1. For ease of description, the graph 340 shows a case where k is 2 as an example. Here, k may indicate a modulation ratio of impedance, and here, impedance may be an impedance when viewed from the output end of the main amplifier of the main stage in the direction of the load impedance. In addition, the modulation ratio may indicate an impedance R in a state where the output power of the power amplifier is high (high power, HP). HP The impedance R at low output power LP The modulation ratio can be R LP / R HP In this case, the threshold for distinguishing the state of high or low output power can be determined based on the power point at which the auxiliary amplifier is turned on. In the example of graph 320, the auxiliary amplifier can be turned on when the amplitude of the normalized input voltage is greater than 0.5. Therefore, the threshold can be determined based on the output power of the power amplifier at an input voltage amplitude of 0.5.

[0048] Referring to the first line 345, the voltage of the auxiliary amplifier of the main stage can be linearly increased in proportion to the input voltage of the 2-stage Doherty power amplifier until a maximum value V max In this case, the slope of the first line 345 may be V max On the other hand, referring to the second line 350, when the amplitude of the input voltage of the 2-stage Doherty power amplifier is 0.5 or less, the voltage of the main amplifier of the main stage may increase linearly until it reaches a maximum value. In this case, the slope of the second line 350 may be 2V max In the case where the amplitude of the input voltage of the 2-stage Doherty power amplifier exceeds 0.5, in other words, in the case where the auxiliary amplifier is turned on, the output voltage of the main amplifier can be maintained at the maximum value.

[0049] refer to Figure 2A , Figure 2B , Figure 3A , Figure 3B and Figure 3C , a wireless communication system may use a modulation method with a high PAPR to process a large amount of data. In this case, in order to linearly amplify a modulated signal with a high PAPR, the power amplifier may operate in a back-off region rather than a maximum output region. However, since the efficiency of the back-off region may be reduced compared to the maximum output region, the power consumption of the electronic device including the power amplifier may increase and the battery use may increase. In order to extend such a back-off region, a Doherty power amplifier may be used. In particular, a 2-stage Doherty power amplifier may include a driver stage and a main stage, wherein the driver stage is configured with an amplifier having two identical biases, and the main stage is configured with an amplifier having two different biases. Since the power gain of the auxiliary amplifier at the main stage varies depending on the amplitude of the input power of the 2-stage Doherty power amplifier, and the amplitude ratio between the output current of the main amplifier and the auxiliary amplifier varies depending on the input power, load modulation may be generated. In this case, the phase difference between the output currents of the main amplifier and the auxiliary amplifier may be kept constant, and the ratio of the amplitude to the amplitude in the output signals of the main amplifier and the auxiliary amplifier may be changed. In other words, in a 2-stage Doherty power amplifier, only amplitude modulation may be generated. Furthermore, since the auxiliary amplifier uses a class C bias amplifier, the auxiliary amplifier is turned off at low output power, so there is a disadvantage that the gain of the main stage is reduced by half.

[0050] Therefore, hereinafter, the present disclosure proposes a 2-stage Doherty power amplifier (hereinafter referred to as a phase modulation mode Doherty power amplifier) ​​capable of phase modulation and improving power efficiency. The phase modulation mode Doherty power amplifier according to various embodiments of the present disclosure may include an amplifier of a driver stage with different biases and an amplifier of a main stage with the same bias. In addition, the phase modulation mode Doherty power amplifier according to an embodiment of the present disclosure may include a coupler between the driver stage and the main stage. In the phase modulation mode Doherty power amplifier according to an embodiment of the present disclosure, as the magnitude of the input power changes, the phase difference between the amplifiers of the main stage changes, and the ratio of the amplitude magnitudes can be kept constant. In other words, the phase modulation mode Doherty power amplifier according to various embodiments of the present disclosure can perform phase modulation, and since all amplifiers of the main stage remain in a conducting state, the efficiency of the output power (or the gain of the power amplifier of the main stage) can be improved. In addition, an electronic device including a phase modulation mode Doherty power amplifier according to an embodiment of the present disclosure can minimize and / or reduce power consumption and heat generation, and can extend the life of the battery. The phase modulation mode Doherty power amplifier according to various embodiments of the present disclosure may be configured with minimal structural changes compared to existing structures and may be used in a miniaturized design such as an integrated circuit.

[0051] Figure 4 2 is a diagram showing an example of a 2-stage Doherty power amplifier according to various embodiments. Here, the Doherty power amplifier may be a power amplifier configured with two power amplifiers. Therefore, the 2-stage Doherty power amplifier is a Doherty power amplifier including two stages, and the stage for driving may be referred to as a driver stage, and the stage for output may be referred to as a main stage.

[0052] refer to Figure 4 , a 2-stage Doherty power amplifier (DPA) 400 may include a driver stage 410, a main stage 420, a transmission line 430 for phase delay, a coupler 440, a combiner 450, and a power splitter 470. According to an embodiment, the 2-stage Doherty power amplifier 400 may be configured by connecting in the following order: a power splitter 470 for distributing an input signal, a driver stage 410 receiving a signal from the power splitter 470, a coupler 440 for connecting the driver stage 410 and the main stage 420, a transmission line 430 connected to one output end of the coupler 440, a main stage 420 receiving a signal from the coupler 440, and a combiner 450 for combining the signals of the amplifiers of the main stage 420. Load impedance 460R LIt can be connected to the output of a 2-stage Doherty power amplifier 400 .

[0053] According to an embodiment, the driver stage 410 may include two power amplifiers. For example, the driver stage 410 may include a first power amplifier 411 and a second power amplifier 412. In this case, the first power amplifier 411 and the second power amplifier 412 may be amplifiers to which different biases are applied. For example, the value of the bias current (or voltage) of the first power amplifier 411 may be different from the value of the bias current (or voltage) of the second power amplifier 412. The bias of the first power amplifier 411 may be applied differently from the bias of the second power amplifier 412. For example, the first power amplifier 411 may be an amplifier biased in class A, class AB, or class B. The second power amplifier 412 may be an amplifier biased in class AB, class B, or class C. In this case, in the case where the first power amplifier 411 is an amplifier biased in class AB, the second power amplifier 412 may be an amplifier biased in class B or class C. Hereinafter, in the present disclosure, the case where the first power amplifier 411 is a class AB biased amplifier and the second power amplifier 412 is a class C biased amplifier will be described as an example. However, the present disclosure is not limited thereto, and all cases where the first power amplifier 411 and the second power amplifier 412 have different biases and the second power amplifier 412 is configured with a power amplifier having a higher power efficiency bias than the first power amplifier 411 may be applied.

[0054] According to an embodiment, the main stage 420 may include two power amplifiers. For example, the main stage 420 may include a third power amplifier 421 and a fourth power amplifier 422. In this case, the third power amplifier 421 and the fourth power amplifier 422 may be amplifiers to which the same bias is applied. For example, the value of the bias current (or voltage) of the third power amplifier 421 may be the same as the value of the bias current (or voltage) of the fourth power amplifier 422. The bias of the third power amplifier 421 may be applied in the same manner as the bias of the fourth power amplifier 422. For example, the third power amplifier 421 and the fourth power amplifier 422 may be configured as class A, class B, or class AB biased amplifiers. The third power amplifier 421 may be referred to as a carrier amplifier, a main power amplifier, and a main amplifier. The fourth power amplifier 422 may be referred to as a peak amplifier, an auxiliary power amplifier, and an auxiliary amplifier. In Figure 4 In the example of FIG. 1 , the current of the signal (signal 3) passing through the third power amplifier 421 may have a magnitude of I 0 and phase θ a , and the current of the signal (signal 4) passing through the fourth power amplifier 422 may have a magnitude of I 0 and phase θ b In this case, θb -θ a It can be defined as Δθ.

[0055] According to an embodiment, the transmission line 430 may be connected between the driver stage 410 and the main stage 420. For example, the transmission line 430 may connect the output end of the first power amplifier 411 and the input end of the third power amplifier 421. In this case, the transmission line 430 may be connected to the output end of the first power amplifier 411 through the coupler 440. The transmission line 430 may form a phase difference between the signals applied to the main stage 420. In other words, the transmission line 430 may have a structure for forming a phase difference between a signal (signal 1) input to the third power amplifier 421 as a main amplifier and a signal (signal 2) input to the fourth power amplifier 422 as a peak amplifier. Here, the phase difference through the transmission line 430 may be θ D θ D The size of Δθ(=θ b -θ a ) are the same size.

[0056] According to an embodiment, the coupler 440 may be disposed between the driver stage 410 and the main stage 420. For example, the coupler 440 may be connected to the first power amplifier 411 and the second power amplifier 412 of the driver stage 410. The coupler 440 may be connected to the third power amplifier 421 of the main stage 420 through the transmission line 430. The coupler 440 may be connected to the fourth power amplifier 422 of the main stage 420. According to an embodiment, the coupler 440 may be configured as a 4-port coupler. For example, the coupler 440 may be connected to the first power amplifier 411 through the first port, to the transmission line 430 through the second port, to the fourth power amplifier 422 through the third port, and to the second power amplifier 412 through the fourth port. Here, the first port may be referred to as an input terminal. The first port may indicate, for example, a terminal connected to the output terminal of an RF component such as a power amplifier. The second port may be referred to as a through terminal. The second port may indicate, for example, a terminal through which a signal (e.g., an RF signal) input from the output terminal of an RF component such as a power amplifier passes through the coupler 440 and is output. The third port may be referred to as a coupling terminal or other output terminal. The third port may indicate, for example, a terminal that outputs a portion of a signal input to the first port using the coupler 440. The fourth port may be referred to as an isolation terminal. The fourth port may indicate, for example, a terminal that is not actually used for input / output but is used for stabilizing power. However, the position of each port of the coupler 440 may not be limited to Figure 4Rather, it is not the position of the port of the coupler 440 shown in the figure, but can be determined by the position of the port connected to the output end of other components (e.g., a power amplifier) ​​connected to the coupler 440. In addition, in the present disclosure, a port may be referred to as a term with similar or equivalent technical meanings, such as a terminal or an end, etc.

[0057] According to an embodiment, the combiner 450 has a structure for impedance modulation and may be connected to the third power amplifier 421, the fourth power amplifier 422, and the load impedance 460. The combiner 450 may include a port a connected to the third power amplifier 421, a port b connected to the fourth power amplifier 422, and a port c connected to the load impedance 460. For example, the combiner 450 may have a structure including at least one of a lumped element, a transmission line, or a transformer. Details thereof are described in detail in Figure 5 Described in.

[0058] According to an embodiment, the power splitter 470 may distribute an input signal applied to the 2-stage Doherty power amplifier 400 to apply the signal to the power amplifiers 411 and 412 of the driver stage 410. Each of the input signals distributed by the power splitter 470 may be amplified and output by the first power amplifier 411, and amplified and output by the second power amplifier 412. The signals output from the first power amplifier 411 and the second power amplifier 412 may be transmitted to the main stage 420 through the coupler 440. The signals passing through the main stage 420 may be combined by the combiner 450 and transmitted to the load impedance 460.

[0059] Referring to the above, the signal input to the 2-stage Doherty power amplifier 400 is divided by the power separator 470 and can be respectively input to the first power amplifier 411 and the second power amplifier 412. When the 2-stage Doherty power amplifier 400 is in the HP state, the first power amplifier 411 and the second power amplifier 412 can respectively output a constant current. When the 2-stage Doherty power amplifier 400 is in the LP state, the second power amplifier 412 can be turned off. Therefore, as the amplitude of the input power changes, the current I output by the first power amplifier 411 is 1 ∠θ 1 The current I output by the second power amplifier 412 2 ∠θ 2 In this case, the ratio of the current of the first power amplifier 411 to the current of the second power amplifier 412 may be defined as in the following equation.

[0060] [Equation 1]

[0061]

[0062] β indicates the ratio between the current of the first power amplifier 411 and the current of the second power amplifier 412, I 1 Indicates the magnitude of the current of the first power amplifier 411, I 2 Indicates the magnitude of the current of the second power amplifier 412, θ 1 Indicates the phase of the current of the first power amplifier 411, θ 2 Indicates the phase of the current of the second power amplifier 412. According to an embodiment, since the phases of the currents distributed by the power splitter 470 are the same, β may be a net real number. In other words, it may be calculated as β=I 2 / I 1 .

[0063] The signals amplified by the driver stage 410 may be transmitted to the main stage 420 through the coupler 440, respectively. In this case, the transmission line 430 may be connected between the coupler 440 and the third power amplifier 421 so as to form a phase difference between the signal (signal 1) input to the third power amplifier 421 of the main stage 420 and the signal (signal 2) input to the fourth power amplifier 422. The signal (signal 1) input to the third power amplifier 421 by the transmission line 430 may be delayed in phase by θ compared to the signal (signal 2) input to the fourth power amplifier 422. D . Thereafter, the signals (signal 1 and signal 2) input to the main stage 420 may be applied to the third power amplifier 421 and the fourth power amplifier 422, respectively, and may be amplified and output. The phase difference between the signal (signal 3) amplified and output by the third power amplifier 421 and the signal (signal 4) amplified and output by the fourth power amplifier 422 may be the same as the phase difference between the signal (signal 1) input to the third power amplifier 421 by the transmission line 430 and the signal (signal 2) input to the fourth power amplifier 422. In other words, the phase difference between the signals before being input to the main stage 420 may be maintained even after being output from the main stage 420. For example, as the current I of the signal (signal 3) 0 ∠θ a The current I of the signal (signal 4) 0 ∠θ b The phase difference between b -θ a ) can be related to θ D The relationship between Δθ and β, which is the ratio between the input currents of the driver stage 410 , is as shown in the following equation.

[0064] [Equation 2]

[0065]

[0066] β indicates the ratio between the current of the first power amplifier 411 and the current of the second power amplifier 412, and Δθ indicates the difference between the current phase of the signal (signal 3) output from the third power amplifier 421 and the current phase of the signal (signal 4) output from the fourth power amplifier 422. As described above, the phase difference of the signal output from the main stage 420 may be changed according to the ratio of the current output from the driver stage 410. In the present disclosure, it is assumed that the phases of the signals distributed by the power separator 470 are the same and the phase of the signal amplified by the driver stage 410 does not change either. Therefore, the phase difference of the signal output from the main stage 420 may be changed according to the amplitude ratio of the current output from the driver stage 410. The signals amplified by the main stage 420 may be combined by the combiner 450, and the combined signal may be applied to the load impedance 460.

[0067] According to an embodiment, the load impedance Z observed from the output terminal of the third power amplifier 421 is 1 The current I of the signal (signal 3) output by the third power amplifier 421 may be 0 ∠θ a The current I of the signal (signal 4) output by the fourth power amplifier 422 0 ∠θ b Here, the load impedance Z 1 The modulation ratio of may represent a ratio of an impedance observed from the output end of the third power amplifier 421 in the HP state to an impedance observed from the output end of the third power amplifier 421 in the LP state.

[0068] In summary, the ratio β of the currents output from the driver stage 410 may vary depending on the magnitude of the power of the input signal of the 2-stage Doherty power amplifier 400. In addition, the phase difference Δθ of the signal output from the main stage 420 may vary according to the ratio β of the output currents. The load impedance Z observed from the output end of the third power amplifier 421 1 The modulation can be performed by the phase difference Δθ of the signal output from the main stage 420. In other words, the load impedance Z observed from the output of the third power amplifier 421 depends on the amplitude of the power of the input signal of the 2-stage Doherty power amplifier 400. 1 Can be modulated. The specific equation expression related to this is as follows.

[0069] [Equation 3]

[0070]

[0071] β indicates a ratio between a current of the first power amplifier 411 and a current of the second power amplifier 412, Δθ indicates a difference between a current phase of a signal (Signal 3) output from the third power amplifier 421 and a current phase of a signal (Signal 4) output from the fourth power amplifier 422, and k indicates a ratio R of an impedance observed from an output terminal of the third power amplifier 421 in an HP state by the 2-stage Doherty power amplifier 400 to an impedance observed from an output terminal of the third power amplifier 421 in an LP state. LP / R HP .

[0072] In addition, according to the transmission line theory, the range of the back-off region of the power amplifier can be changed according to the load impedance modulation ratio k of the main amplifier of the main stage. The specific equation expression related to this is as follows.

[0073] [Equation 4]

[0074] P backoff =20logk

[0075] P backoff indicates the back-off power of the two-stage Doherty power amplifier, and k indicates the ratio R of the impedance observed from the output terminal of the third power amplifier 421 by the 2-stage Doherty power amplifier 400 in the HP state to the impedance observed from the output terminal of the third power amplifier 421 in the LP state. LP / R HP .

[0076] As described above, by adjusting the power amplitude of the signal input to the 2-stage Doherty power amplifier, the modulation ratio of the impedance observed from the main amplifier of the main stage can be changed. In addition, as the modulation ratio of the impedance changes, the back-off power (e.g., back-off area) of the 2-stage Doherty power amplifier may change. Therefore, the phase modulation mode Doherty power amplifier according to various embodiments of the present disclosure can change the back-off area by adjusting the input signal, and therefore, the performance of the power amplifier can be improved. In addition, an electronic device including a phase modulation mode Doherty power amplifier according to an embodiment of the present disclosure can minimize and / or reduce power consumption and heat generation, and can extend the life of the battery. The phase modulation mode Doherty power amplifier according to various embodiments of the present disclosure can be configured with minimal structural changes compared to existing structures, and can be used in miniaturized designs such as integrated circuits.

[0077] Figure 5 is a diagram illustrating an example of a combiner according to various embodiments.

[0078] Figure 5The combiners 510, 520, 530 and 540 show Figure 4 4. According to an embodiment, each of the combiners 510, 520, 530, and 540 may include at least one of a lumped element, a transmission line, or a transformer.

[0079] According to an embodiment, the combiner 510 may include a lumped element. The combiner 510 may be configured with a capacitor connected to ground at port a, an inductor between port a and port c, an inductor connected to ground at port b, and a capacitor between port b and port c.

[0080] According to an embodiment, the combiner 520 may include a lumped element and a transmission line. The combiner 520 may be configured with a capacitor connected to the ground at port a, a transmission line between port a and port c, an inductor connected to the ground at port b, and a connection of a transmission line between port b and port c. In this case, the transmission line between port a and port c and the transmission line between port b and port c may be the same. For example, the transmission line may be formed to have a characteristic impedance R 0 And the electrical length is 90°. This is just an example, and the present disclosure is not limited thereto.

[0081] According to an embodiment, the combiner 530 may include a transmission line. The combiner 530 may be configured with a connection of a transmission line between port a and port c and a transmission line between port b and port c. In this case, the transmission line between port a and port c and the transmission line between port b and port c may have the same characteristic impedance and different phases. For example, the transmission line between port a and port c and the transmission line between port b and port c may be formed to have the same characteristic impedance R 0 However, the electrical length of the transmission line between port a and port c can be configured with 90° + θ ph , and the electrical length of the transmission line between port b and port c can be configured with a 90°-θ ph In this case, the phase between the transmission lines may be formed to lag or lead the same value based on 90°. This is merely an example for convenience of explanation of 8, and the present disclosure is not limited thereto. It may be formed to lag or lead the same value based on a value other than 90°.

[0082] According to an embodiment, the combiner 540 may include a lumped element and a transformer. The combiner 540 may be configured with a capacitor connected to ground at port a, an inductor connected to ground at port b, and connections of the transformer between ports a, b, and c.

[0083] As mentioned above, the combiner can be formed based on various electrical components. Figure 5In FIG. 4 , an example of four combiners is shown, but the embodiments of the present disclosure are not limited thereto. The embodiments of the present disclosure can be applied to both circuits or structures having the same electrical function (combination of signals).

[0084] Figure 6 is a diagram illustrating an example of a coupler according to various embodiments. Figure 6 Shown for Figure 4 The various couplers 610, 620, 630 and 640 of the coupler 440. However, the couplers of the phase modulation mode Doherty power amplifier according to various embodiments of the present disclosure will not be limited to Figure 6 The coupler shown in .

[0085] Figure 6 A coupled-line coupler 610, a lange coupler 620, a hybrid coupler 630, and a ring hybrid coupler 640 are shown.

[0086] The coupled line coupler 610 may indicate a coupler in which two lines are arranged in an adjacent state. In this case, the coupling amount may be adjusted by the distance and length of the two lines arranged in an adjacent state. Figure 4 Each port (first to fourth ports) of the coupled line coupler 610 can be understood in the same way as each port of the coupler 440. In other words, the first port of the coupled line coupler 610 can indicate an input terminal, the second port can indicate a through terminal, the third port can indicate a coupled terminal or other output terminal, and the fourth port can indicate an isolated terminal.

[0087] The lange coupler 620 may indicate a coupler formed in a form in which a line is bent. Therefore, compared with other couplers, the lange coupler 620 may be formed to have a relatively small size. Figure 4 Each port (first to fourth port) of the Lange coupler 620 can be understood in the same way as each port of the coupler 440. In other words, the first port of the Lange coupler 620 can indicate an input terminal, the second port can indicate a through terminal, the third port can indicate a coupled terminal or other output terminal, and the fourth port can indicate an isolated terminal.

[0088] The hybrid coupler 630 may indicate a coupler that directly couples by connecting branch lines (e.g., Z1 and Z3) of lines arranged in parallel. Therefore, the hybrid coupler 630 may be referred to as a branch line coupler. Each port (first to fourth ports) of the hybrid coupler 630 may be understood as being connected to Figure 4In other words, the first port of the hybrid coupler 630 may indicate an input terminal, the second port may indicate a through terminal, the third port may indicate a coupled terminal or other output terminal, and the fourth port may indicate an isolated terminal.

[0089] The annular hybrid coupler 640 may indicate a coupler in which a circular line and four ports are provided. Each port (first to fourth ports) of the annular hybrid coupler 640 may be understood as Figure 4 In other words, the first port of the ring hybrid coupler 640 may indicate an input terminal, the second port may indicate a through terminal, the third port may indicate a coupled terminal or other output terminal, and the fourth port may indicate an isolated terminal.

[0090] Figure 7 is a diagram showing an example of a 2-stage Doherty power amplifier including a hybrid coupler according to various embodiments. Here, the Doherty power amplifier may be a power amplifier configured with two power amplifiers. Therefore, the 2-stage Doherty power amplifier is a Doherty power amplifier including two stages, and the stage for driving may be referred to as a driver stage, and the stage for output may be referred to as a main stage.

[0091] refer to Figure 7 , shows a 2-stage Doherty power amplifier 700, which is Figure 4 Specific example of the 2-stage Doherty power amplifier 400. For example, the 2-stage Doherty power amplifier 700 may include a hybrid coupler and a combiner including a transmission line.

[0092] refer to Figure 7 , a 2-stage Doherty power amplifier (DPA) 700 may include a driver stage 710, a main stage 720, a transmission line 730 for phase delay, a coupler 740, a combiner 750, and a power splitter 770. According to an embodiment, the 2-stage Doherty power amplifier 700 may be configured by connecting in the following order: a power splitter 770 for distributing an input signal, a driver stage 710 receiving a signal from the power splitter 770, a coupler 740 for connecting the driver stage 710 and the main stage 720, a transmission line 730 connected to one output end of the coupler 740, a main stage 720 receiving a signal from the coupler 740, and a combiner 750 for combining the signals of the amplifiers of the main stage 720. Load impedance 760R L Can be connected to the output of a 2-stage Doherty power amplifier 700 .

[0093] According to an embodiment, the driver stage 710 may include two power amplifiers. For example, the driver stage 710 may include a first power amplifier 711 and a second power amplifier 712. In this case, the first power amplifier 711 and the second power amplifier 712 may be amplifiers to which different biases are applied. For example, the value of the bias current (or voltage) of the first power amplifier 711 may be different from the value of the bias current (or voltage) of the second power amplifier 712. The bias of the first power amplifier 711 may be applied differently from the bias of the second power amplifier 712. For example, the first power amplifier 711 may be a class A, class AB, or class B biased amplifier. The second power amplifier 712 may be a class AB, class B, or class C biased amplifier. In this case, in the case where the first power amplifier 711 is a class AB biased amplifier, the second power amplifier 712 may be a class B or class C biased amplifier. Hereinafter, in the present disclosure, the case where the first power amplifier 711 is a class AB biased amplifier and the second power amplifier 712 is a class C biased amplifier will be described as an example. However, the present disclosure is not limited thereto, and all of the following situations may apply: the first power amplifier 711 and the second power amplifier 712 have different biases, and the second power amplifier 712 is configured as a power amplifier with a lower power efficiency bias than the first power amplifier 711. According to an embodiment, the main stage 720 may include two power amplifiers. For example, the main stage 720 may include a third power amplifier 721 and a fourth power amplifier 722. In this case, the third power amplifier 721 and the fourth power amplifier 722 may be amplifiers to which the same bias is applied. For example, the value of the bias current (or voltage) of the third power amplifier 721 may be the same as the value of the bias current (or voltage) of the fourth power amplifier 722. The bias of the third power amplifier 721 may be applied in the same manner as the bias of the fourth power amplifier 722. For example, the third power amplifier 721 and the fourth power amplifier 722 may be configured as class A, class B, or class AB biased amplifiers. The third power amplifier 721 may be referred to as a carrier amplifier, a main power amplifier, and a main amplifier. The fourth power amplifier 722 may be referred to as a peak amplifier, an auxiliary power amplifier, and an auxiliary amplifier. In Figure 4 In the example of FIG. 1 , the current of the signal (signal 3) passing through the third power amplifier 721 may have a magnitude of I 0 and phase θ a , and the current of the signal (signal 4) passing through the fourth power amplifier 722 may have a magnitude of I 0 and phase θ b In this case, θ b -θ a It can be defined as Δθ.

[0094] According to an embodiment, the transmission line 730 may be connected between the driver stage 710 and the main stage 720. For example, the transmission line 730 may connect the output end of the first power amplifier 711 and the input end of the third power amplifier 721. In this case, the transmission line 730 may be connected to the output end of the first power amplifier 711 through the coupler 740. The transmission line 730 may form a phase difference between signals applied to the main stage 720. In other words, the transmission line 730 may have a structure for forming a phase difference between a signal (signal 1) input to the third power amplifier 721 as a main amplifier and a signal (signal 2) input to the fourth power amplifier 722 as a peak amplifier. For example, the transmission line 730 may be formed to have a characteristic impedance R 0 and electrical length θ D °. In this case, the phase difference through the transmission line 730 may be θ D θ D The size of Δθ(=θ b -θ a ) are the same size.

[0095] According to an embodiment, the coupler 740 may be configured as a 4-port coupler. For example, the coupler 740 may be a hybrid coupler. In other words, the coupler 740 may be understood as Figure 6 The coupler 740 may include a hybrid coupler 630 in which the electrical characteristics between the first port and the second port have a characteristic impedance R 1 The coupler 740 may include an element having an electrical length of 90°. The electrical characteristic between the second port and the third port has a characteristic impedance R 2 The coupler 740 may include a device in which the electrical characteristic between the third port and the fourth port has a characteristic impedance R 1 The coupler 740 may include a device in which the electrical characteristic between the fourth port and the first port has a characteristic impedance R 2 and an element with an electrical length of 90°. Here, the first port may be referred to as an input port. The first port may indicate a terminal connected to an output port of an RF component such as a power amplifier. The second port may be referred to as a through port. The second port may indicate a terminal through which a signal (e.g., an RF signal) input from an output port of an RF component such as a power amplifier passes through the coupler 740 and is output. The third port may be referred to as a coupling port or other output port. The third port may indicate a terminal that outputs a portion of a signal input to the first port using the coupler 740. The fourth port may be referred to as an isolation port. The fourth port may indicate a terminal that is not actually used for input / output but for stabilizing power. However, the position of each port of the coupler 740 may not be limited to Figure 4Rather, it is not the position of the port of the coupler 740 shown in , but can be determined by the position of the port connected to the output end of other components (e.g., a power amplifier) ​​connected to the coupler 740. In addition, in the present disclosure, a port may be referred to as a term with similar or equivalent technical meanings, such as a terminal or an end, etc.

[0096] According to an embodiment, the coupler 740 may be arranged between the driver stage 710 and the main stage 720. For example, the coupler 740 may be connected to the first power amplifier 711 and the second power amplifier 712 of the driver stage 710. The coupler 740 may be connected to the third power amplifier 721 of the main stage 720 through the transmission line 730. The coupler 740 may be connected to the fourth power amplifier 722 of the main stage 720. The coupler 740 may be connected to the first power amplifier 711 through the first port, to the transmission line 730 through the second port, to the fourth power amplifier 722 through the third port, and to the second power amplifier 712 through the fourth port.

[0097] According to an embodiment, the combiner 750 has a structure for impedance modulation and may be connected to the third power amplifier 721, the fourth power amplifier 722, and the load impedance 760. The combiner 750 may include a port a connected to the third power amplifier 721, a port b connected to the fourth power amplifier 722, and a port c connected to the load impedance 760.

[0098] According to an embodiment, the combiner 750 may include a first transmission line 751 and a second transmission line 752. For example, the first transmission line 751 may be formed to have a characteristic impedance R 0 and electrical length 90°+θ ph The second transmission line 752 may be formed to have a characteristic impedance R 0 and electrical length 90°-θ ph . Figure 7 The combiner 750 can be understood as Figure 5 An example of a combiner 530 is shown.

[0099] According to an embodiment, the power splitter 770 may distribute an input signal applied to the 2-stage Doherty power amplifier 700 to apply the signal to the power amplifiers 711 and 712 of the driver stage 710. Each of the input signals distributed by the power splitter 770 may be amplified and output by the first power amplifier 711, and amplified and output by the second power amplifier 712. The signals output from the first power amplifier 711 and the second power amplifier 712 may be transmitted to the main stage 720 through the coupler 740. The signals passing through the main stage 720 may be combined by the combiner 750 and transmitted to the load impedance 760.

[0100] As described above, by adjusting the power amplitude of the signal input to the 2-stage Doherty power amplifier, the modulation ratio of the impedance observed from the main amplifier of the main stage can be changed. In addition, as the modulation ratio of the impedance changes, the back-off power (e.g., back-off area) of the 2-stage Doherty power amplifier may change. Therefore, the phase modulation mode Doherty power amplifier according to various embodiments of the present disclosure can change the back-off area by adjusting the input signal, and therefore, the performance of the power amplifier can be improved. In addition, an electronic device including a phase modulation mode Doherty power amplifier according to an embodiment of the present disclosure can minimize and / or reduce power consumption and heat generation, and can extend the life of the battery. The phase modulation mode Doherty power amplifier according to various embodiments of the present disclosure can be configured with minimal structural changes compared to existing structures, and can be used in miniaturized designs such as integrated circuits.

[0101] Fig. 8A is a graph showing the phase difference between the output currents of the amplifier of the main stage according to the input voltage according to the embodiment. Here, the main stage may indicate Figure 4 The main stage 420, and the amplifier of the main stage can be Figure 4 The third power amplifier 421 and the fourth power amplifier 422. In addition, the phase difference Δθ may indicate a signal ( Figure 4 The current of the signal 3) is the same as the signal ( Figure 4 4) The phase difference between the currents of the signal.

[0102] Fig. 8A The graph 800 shows a first line 801, a second line 802 and a third line 803, wherein the first line 801 shows the phase difference of the amplifier of the main stage according to the normalized input voltage when k is 2, the second line 802 shows the phase difference of the amplifier of the main stage according to the normalized input voltage when k is 4, and the third line 803 shows the phase difference of the amplifier of the main stage according to the normalized input voltage when k is 6. The horizontal axis of the graph 800 indicates the amplitude of the normalized input voltage, and the vertical axis indicates the phase difference (unit: °). Here, the normalized input voltage may be a voltage obtained by normalizing the magnitude of the input voltage of the 2-stage Doherty power amplifier to a value between 0 and 1. Here, k may indicate a modulation ratio of impedance, and here, impedance may be an impedance when viewed from the output end of the main amplifier of the main stage in the direction of the load impedance. In addition, the modulation ratio may indicate an impedance R in a state where the output power of the power amplifier is high (high power, HP). HP The impedance R at low output power LP The modulation ratio can be defined as RLP / R HP In this case, it is possible to use an amplifier (e.g., a bias amplifier with high power efficiency in the driver stage) to Figure 4 In the case of k=2, the power point at which the second power amplifier 412 is turned on determines the threshold for distinguishing the state of high or low output power. In the example of the graph 800, in the case of k=2, and when the amplitude of the normalized input voltage is 0.5, the amplifier can be turned on. In the case of k=4, when the amplitude of the normalized input voltage is 0.25, the amplifier can be turned on. In the case of k=6, when the amplitude of the normalized input voltage is approximately 0.16, the amplifier can be turned on.

[0103] Referring to the first line 801, even when the input voltage of the 2-stage Doherty power amplifier changes, the phase difference between the signals input to the main stage of the 2-stage Doherty power amplifier may not change until the biased amplifier with high power efficiency of the driver stage is turned on. However, when the input voltage of the 2-stage Doherty power amplifier changes after the biased amplifier with high power efficiency of the driver stage is turned on, the phase difference between the signals input to the main stage of the 2-stage Doherty power amplifier may change. Considering the second line 802 and the third line 803, only the phase difference with the first line 801 and the amplitude of the input voltage at which the amplifier is turned on may change, and the second line 802 and the third line 803 may be understood similarly to the first line 801. In other words, in the phase modulation mode Doherty power amplifier according to an embodiment of the present disclosure, when the voltage (or power) amplitude of the input signal changes, the phase difference of the signal output from the amplifier of the main stage may change. In other words, as the impedance modulation ratio k of the main amplifier of the main stage changes, the phase difference of the signal output from the amplifier of the main stage may change.

[0104] Figure 8B is a graph showing an output current and an output voltage of an amplifier of a main stage according to an input voltage according to various embodiments. Here, the main stage indicates Figure 4 The main stage 420, and the amplifier of the main stage can be Figure 4 The third power amplifier 421 and the fourth power amplifier 422. In addition, the phase difference Δθ may indicate a signal ( Figure 4 The current of the signal 3) is the same as the signal ( Figure 4 4) The phase difference between the currents of the signal.

[0105] Figure 8BThe graph 810 of FIG. 810 shows a first line 831, a second line 832, a third line 833, and a fourth line 820, wherein the first line 831 shows the main amplifier of the main stage (eg, Figure 7 The graph 800 shows the output voltage of the third power amplifier 721 of the main stage according to the normalized input voltage when k is 4, the second line 832 shows the output voltage of the main amplifier of the main stage according to the normalized input voltage when k is 6, and the fourth line 820 shows the output current of the main amplifier of the main stage according to the normalized input voltage when k is 2, 4 and 6. The horizontal axis of the graph 800 indicates the amplitude of the normalized input voltage, and the vertical axis indicates the voltage (unit: [V]) of the first line 831, the second line 832 and the third line 833, and the current (unit: [A]) of the fourth line 820. Here, the normalized input voltage may be a voltage obtained by normalizing the amplitude of the input voltage of the 2-stage Doherty power amplifier to a value between 0 and 1. Here, k may indicate the modulation ratio of the impedance, and here, the impedance may be the impedance when viewed from the output end of the main amplifier of the main stage in the direction of the load impedance. In addition, the modulation ratio may indicate the impedance R in a state where the output power of the power amplifier is high (high power, HP). HP The impedance R at low output power LP The modulation ratio can be referred to as R LP / R HP In this case, it is possible to use an amplifier (e.g., a bias amplifier with high power efficiency in the driver stage) to Figure 4 In the case of k=2, the power point at which the second power amplifier 412 is turned on determines the threshold for distinguishing the state of high or low output power. In the example of the graph 810, in the case of k=2, and when the amplitude of the normalized input voltage is 0.5, the amplifier can be turned on. In the case of k=4, when the amplitude of the normalized input voltage is 0.25, the amplifier can be turned on. In the case of k=6, when the amplitude of the normalized input voltage is approximately 0.16, the amplifier can be turned on.

[0106] Referring to the fourth line 820, regardless of the load impedance modulation ratio k, the output current of the 2-stage Doherty power amplifier can increase linearly when the amplitude of the normalized input voltage increases. For example, in the case of k = 2, 4 or 6, the amplitude of the current can be 0 when the normalized input voltage is 0, and the amplitude of the current can be maximum (I-max) when the normalized input voltage is maximum (1). In the case of the output current, the slope of the output current according to the input voltage can be constant regardless of the load impedance modulation ratio.

[0107] On the other hand, in the case where the load impedance modulation ratio is changed, the output voltage of the 2-stage Doherty power amplifier according to the input voltage may be changed. Here, the output voltage may indicate the output voltage of the main amplifier of the main stage. Referring to the first line 831, when the amplitude of the input voltage is the largest (1), the output voltage of the 2-stage Doherty power amplifier may be the maximum value (V max ). In addition, when the amplitude of the input voltage is 0.5, the output voltage may be a maximum value. In other words, in the case of the first line 831, the back-off region of the 2-stage Doherty power amplifier may be within a range from 0.5 to 1.0 based on the amplitude of the normalized input voltage. Referring to the second line 832, as with the first line 831, when the amplitude of the input voltage is maximum (1), the output voltage of the 2-stage Doherty power amplifier may be a maximum value (V max ). However, unlike the first line 831, when the amplitude of the input voltage is 0.25, the output voltage can be a maximum value. In other words, in the case of the second line 832, the back-off region of the 2-stage Doherty power amplifier can be in the range from 0.25 to 1.0 based on the amplitude of the normalized input voltage, and can have a wider back-off region than the back-off region of the first line 831. In addition, referring to the third line 833, the output voltage of the 2-stage Doherty power amplifier can be a maximum value (V ) when the amplitude of the input voltage is maximum (1), like the first line 831. max ). However, unlike the first line 831, when the amplitude of the input voltage is approximately 0.16, the output voltage can be a maximum value. In other words, in the case of the third line 833, the back-off region of the 2-stage Doherty power amplifier can be in the range of approximately 0.16 to 1.0 based on the amplitude of the normalized input voltage, and can have a wider back-off region than the back-off regions of the first line 831 and the second line 832.

[0108] As described above, when the modulation ratio of the load impedance is changed, the output voltage of the phase modulation mode Doherty power amplifier according to the embodiment of the present disclosure can vary depending on the amplitude of the input voltage. In addition, since the output voltage is changed, the back-off region of the phase modulation mode Doherty power amplifier according to various embodiments of the present disclosure can be changed.

[0109] Figure 8C is a graph showing changes in load impedance of a main amplifier of a main stage according to output power according to various embodiments. Here, the main stage indicates Figure 4 The main stage 420, and the amplifier of the main stage can be Figure 4 The third power amplifier 421 and the fourth power amplifier 422. In addition, the phase difference Δθ may indicate a signal ( Figure 4The current of the signal 3) is the same as the signal ( Figure 4 4) The phase difference between the currents of the signal.

[0110] Graph 840 shows the load impedance at the output stage of the main amplifier of the main stage according to the output power in the phase modulation mode Doherty power amplifier according to various embodiments of the present disclosure. Graph 840 shows a first line 841, a second line 842, and a third line 843, wherein the first line 841 shows the change of the load impedance according to the output power when the modulation ratio k of the load impedance is 2, the second line 842 shows the change of the load impedance according to the output power when k is 4, and the third line 843 shows the change of the load impedance according to the output power when k is 6. Here, R opt is the optimum load impedance observed from the output end of the main amplifier of the main stage when the phase modulation mode Doherty power amplifier according to various embodiments of the present disclosure has a maximum output power.

[0111] Referring to the first line 841, when the output amplitude of the phase modulation mode Doherty power amplifier changes from low output power to high output power, the amplitude of the load impedance may change from 2Ropt to Ropt. Referring to the second line 842, when the output amplitude of the phase modulation mode Doherty power amplifier changes from low output power to high output power, the amplitude of the load impedance may change from 4Ropt to Ropt. Referring to the third line 843, when the output amplitude of the phase modulation mode Doherty power amplifier changes from low output power to high output power, the amplitude of the load impedance may change from 6Ropt to Ropt. As described above, in the phase modulation mode Doherty power amplifier according to various embodiments of the present disclosure, as the output power increases, the amplitude of the load impedance observed from the output end of the main amplifier of the main stage may decrease to Ropt. In addition, regardless of the load impedance modulation ratio, the phase modulation mode Doherty power amplifier according to various embodiments of the present disclosure may have a load impedance Ropt when the output power is maximum. However, in the phase modulation mode Doherty power amplifier according to the embodiment of the present disclosure, when the output power decreases, the magnitude of the load impedance observed from the output end of the main amplifier of the main stage may increase to kRopt.

[0112] Fig.8D is a graph showing the power efficiency of a 2-stage Doherty power amplifier according to output power according to various embodiments. Here, the 2-stage Doherty power amplifier may refer to a phase modulation mode Doherty power amplifier according to an embodiment of the present disclosure. Fig.8DIn the figure, for the convenience of description, it is assumed that the main amplifier of the main stage is a class B biased amplifier.

[0113] The graph 850 shows a first line 871, a second line 872, a third line 873, and a fourth line 860, wherein the first line 871 shows the PAE according to the output power when the load impedance modulation ratio (k) of the phase modulation mode Doherty power amplifier is 2, the second line 872 shows the PAE according to the output power when the k of the phase modulation mode Doherty power amplifier is 4, the third line 873 shows the PAE according to the output power when the k of the phase modulation mode Doherty power amplifier is 6, and the fourth line 860 shows the power added efficiency (PAE) according to the output power of the power amplifier of the general AB class bias. The horizontal axis of the graph 850 may indicate the magnitude of the normalized output power (unit: dB), and the vertical axis may refer to the power added efficiency (PAE) (unit: %).

[0114] Referring to the first line 871, in the case where the output power is a maximum value (0), the PAE of the phase modulation mode Doherty power amplifier may be a maximum efficiency (78.5%). In addition, in the case where the output power is approximately -3dB, the PAE of the phase modulation mode Doherty power amplifier may be a maximum efficiency (78.5%). In this case, the portion of the output power approximately -3dB may indicate a low output power point compared to the maximum output power, and an amplifier with low power efficiency of the driver stage (e.g., Figure 4 Referring to the second line 872, in the case where the output power is at a maximum value (0), the PAE of the phase modulation mode Doherty power amplifier may be the maximum efficiency (78.5%). In addition, in the case where the output power is approximately -6 dB, the PAE of the phase modulation mode Doherty power amplifier may be the maximum efficiency (78.5%). In this case, the portion of the output power approximately -6 dB may indicate a low output power point compared to the maximum output power, and an amplifier with low power efficiency at the driver stage (e.g., Figure 4 Referring to the third line 873, in the case where the output power is at a maximum value (0), the PAE of the phase modulation mode Doherty power amplifier may be the maximum efficiency (78.5%). In addition, in the case where the output power is approximately -8 dB, the PAE of the phase modulation mode Doherty power amplifier may be the maximum efficiency (78.5%). In this case, the portion of the output power approximately -8 dB may indicate a low output power point compared to the maximum output power, and an amplifier with low power efficiency at the driver stage (e.g., Figure 4Comparing the first line 871 with the third line 873, the amplifier with low power efficiency (e.g., Figure 4 The power point (e.g., low output power point) at which the first power amplifier 411 is turned on can change with the load impedance modulation ratio k. In other words, the back-off region of the phase modulation mode Doherty power amplifier can change with the change of k value. When the k value increases, the back-off region can be extended.

[0115] Referring to the fourth line 860 showing the efficiency of a general class AB biased power amplifier, the PAE of the phase modulation mode Doherty power amplifier may be the maximum efficiency (78.5%) when the output power is at a maximum value (0). However, as the output power decreases, the PAE may decrease. Therefore, a general class AB power amplifier may have a narrow back-off region.

[0116] As described above, in the case of the phase modulation mode Doherty power amplifier according to various embodiments of the present disclosure, as the modulation ratio of the load impedance of the main amplifier of the main stage is adjusted, the back-off region can be extended. Therefore, the performance of the phase modulation mode Doherty power amplifier of the present disclosure can be improved because the efficient back-off region is extended compared to the general power amplifier.

[0117] refer to Figures 1 to 8D , a phase modulation mode Doherty power amplifier according to an embodiment of the present disclosure may include an amplifier having a driver stage with different biases and an amplifier having a main stage with the same bias. In addition, a phase modulation mode Doherty power amplifier according to an embodiment of the present disclosure may include a coupler between the driver stage and the main stage. Compared with a general power amplifier, the phase modulation mode Doherty power amplifier having the structure described above has an extended high-efficiency back-off region, so the performance of the power amplifier can be improved. In addition, the phase modulation mode Doherty power amplifier can minimize and / or reduce power consumption and heat generation, and can extend the life of the battery. The phase modulation mode Doherty power amplifier can be configured with minimal structural changes compared to existing structures, and can be used in miniaturized designs such as integrated circuits.

[0118] Fig. 9 910 is a diagram showing an example configuration of an electronic device according to various embodiments. The electronic device 910 may be one of a base station or a terminal. According to an embodiment, the electronic device 910 may be an MMU or a millimeter wave device. Figures 1 to 8DThe mentioned phase modulation mode Doherty power amplifier itself, as well as the structure of a radio frequency (RF) chain including the phase modulation mode Doherty power amplifier and an electronic device including the phase modulation mode Doherty power amplifier are also included in the embodiments of the present disclosure.

[0119] refer to Fig. 9 , shows an example configuration of an electronic device 910. The electronic device 910 may include an antenna unit (e.g., including at least one antenna) 911, a filter unit (e.g., including a filter) 912, a radio frequency (RF) processing unit (e.g., including an RF processing circuit) 913, and a control unit (e.g., including a processing / control circuit) 914.

[0120] The antenna unit 911 may include multiple antennas. The antenna performs a function for sending and receiving signals through a wireless channel. The antenna may include a conductor formed on a substrate (e.g., an antenna PCB, an antenna board) or a radiator formed by a conductive pattern. The antenna may radiate an up-converted signal on a wireless channel, or may obtain a signal radiated by another device. Each antenna may be referred to as an antenna element. In various embodiments, the antenna unit 911 may include an antenna array (e.g., a subarray), wherein a plurality of antenna elements form an array. The antenna unit 911 may be electrically connected to the filter unit 912 via an RF signal line. The antenna unit 911 may be mounted on a PCB including a plurality of antenna elements. The PCB may include a plurality of RF signal lines connecting each antenna element and a filter of the filter unit 912. These RF signal lines may be referred to as a feed network. The antenna unit 911 may provide a received signal to the filter unit 912, or may radiate a signal provided from the filter unit 912 into the air.

[0121] The antenna unit 911 according to various embodiments may include at least one antenna module having a dual-polarized antenna. The dual-polarized antenna may be, for example, a cross-pole (x-pole) antenna. The dual-polarized antenna may include two antenna elements corresponding to different polarizations. For example, the dual-polarized antenna may include a first antenna element having a +45° polarization and a second antenna element having a -45° polarization. It goes without saying that the polarization mode may be formed by other orthogonal polarizations other than ±45°. Each antenna element may be connected to a feeder line and electrically connected to a filter unit 912, an RF processing unit 913, and a control unit 914 to be described later.

[0122] The dual-polarized antenna can be a patch antenna (or microstrip antenna). By having the form of a patch antenna, the dual-polarized antenna can be easily implemented and integrated into an array antenna. Two signals with different polarizations can be input to each antenna port. Each antenna port corresponds to an antenna element. For high efficiency, it is necessary to optimize the relationship between the co-polarization characteristics and the cross-polarization characteristics between the two signals with different polarizations. In a dual-polarized antenna, the co-polarization characteristics represent the characteristics of a specific polarization component, and the cross-polarization characteristics represent the characteristics of a polarization component different from the specific polarization component.

[0123] The filter unit 912 may include a filter and perform filtering to send a signal of a desired frequency. The filter unit 912 may perform a function of selectively identifying a frequency by forming a resonance. In various embodiments, the filter unit 912 may form a resonance by structurally including a cavity of a dielectric. In addition, in various embodiments, the filter unit 912 may form a resonance by forming an element of an inductor or capacitor. In addition, in various embodiments, the filter unit 912 may include an elastic filter, such as a bulk acoustic wave (BAW) filter or a surface acoustic wave (SAW) filter. The filter unit 912 may include at least one of a bandpass filter, a low-pass filter, a high-pass filter, and a bandstop filter. In other words, the filter unit 912 may include an RF circuit for obtaining a signal of a frequency band for transmission or a frequency band for reception. The filter unit 912 according to various embodiments may electrically connect the antenna unit 911 and the RF processing unit 913.

[0124] The RF processing unit 913 may include various circuits and multiple RF paths. The RF path may be a unit of a path through which a signal received by an antenna or a signal radiated by an antenna passes. At least one RF path may be referred to as an RF chain. The RF chain may include multiple RF elements. The RF elements may include amplifiers, mixers, oscillators, DACs, ADCs, etc. For example, the RF processing unit 913 may include an up-converter that up-converts a baseband digital transmission signal to a transmission frequency, and a digital-to-analog converter (DAC) that converts the up-converted digital transmission signal into an analog RF transmission signal. The up-converter and the DAC form a part of the transmission path. The transmission path may also include a power amplifier (PA) or a coupler (or a combiner). In addition, for example, the RF processing unit 913 may include an analog-to-digital converter (ADC) that converts an analog RF receive signal into a digital receive signal and a down-converter that converts a digital receive signal into a baseband digital receive signal. The ADC and the down-converter form a part of the receiving path. The receiving path may also include a low noise amplifier (LNA) or a coupler (or a divider). The RF components of the RF processing unit may be implemented on a PCB. The electronic device 910 may include a structure stacked in the order of an antenna unit 911-filter unit 912-and an RF processing unit 913. The antenna and RF components of the RF processing unit may be implemented on a PCB, and the filter may be repeatedly fastened between the PCB and the PCB to form a plurality of layers. A phase modulation mode Doherty power amplifier according to an embodiment of the present disclosure may be included in the RF processing unit 913.

[0125] The control unit 914 may include various processing / control circuits and control the overall operation of the electronic device 910. The control unit 914 may include various modules for performing communication. The control unit 914 may include at least one processor such as a modem. The control unit 914 may include a module for digital signal processing. For example, the control unit 914 may include a modem. When sending data, the control unit 914 generates complex symbols by encoding and modulating the transmission bit string. In addition, for example, when receiving data, the control unit 914 recovers the received bit string by demodulating and decoding the baseband signal. The control unit 914 may perform the functions of the protocol stack required by the communication standard.

[0126] exist Fig. 9 In the embodiment, the functional configuration of the electronic device 910 is described as a device that can utilize the Doherty power amplifier of the present disclosure. However, Fig. 9 The examples shown in the example are merely Figures 1 to 8D The structure of the power amplifier according to the embodiment of the present disclosure and the example configuration of the electronic device including the power amplifier are described, and the various embodiments of the present disclosure are not limited to Fig. 9Therefore, a communication device including a phase modulation mode Doherty power amplifier structure according to an embodiment of the present disclosure and a configuration of a communication device including the phase modulation mode Doherty power amplifier structure can also be understood as an embodiment of the present disclosure.

[0127] As described above, a Doherty power amplifier (400) in a wireless communication system according to various exemplary embodiments includes a first stage (410), wherein the first stage (410) includes a first power amplifier (411) and a second power amplifier (412). The Doherty power amplifier (400) includes a second stage (420), wherein the second stage (420) includes a third power amplifier (421) and a fourth power amplifier (422). The Doherty power amplifier (400) includes a coupler (440) between the first stage (410) and the second stage (420). The Doherty power amplifier (400) includes a load impedance (460) connected to the second stage (420). The bias of the first power amplifier (411) is different from the bias of the second power amplifier (412). The bias of the third power amplifier (421) corresponds to the bias of the fourth power amplifier (422).

[0128] According to an example embodiment, the first power amplifier (411) and the second power amplifier (412) include power amplifiers biased as class AB. The third power amplifier (421) includes a power amplifier biased as class A or class AB. The fourth power amplifier (422) includes a power amplifier biased as class C.

[0129] According to an example embodiment, the coupler (440) includes a first port connected to the output of the first power amplifier (411), a second port connected to the output of the second power amplifier (412), a third port connected to the input of the third power amplifier (421), and a fourth port connected to the input of the fourth power amplifier (422).

[0130] According to an example embodiment, the coupler (440) includes at least one of a coupled-line coupler, a lange coupler, a hybrid coupler, or a ring hybrid coupler.

[0131] According to an example embodiment, the Doherty power amplifier (400) further includes a transmission line (430) configured for phase delay. An input terminal of the third power amplifier (421) is connected to the coupler (440) through the transmission line (430).

[0132] According to an example embodiment, the Doherty power amplifier (400) further comprises a combiner (450). The combiner (450) is connected to an output terminal of the third power amplifier (421), an output terminal of the fourth power amplifier (422) and a load impedance (460).

[0133] According to example embodiments, the combiner (450) includes a lumped element, a lumped element and a transmission line, a transmission line, or a lumped element and a transformer.

[0134] According to an example embodiment, the amplitude of the first signal input to the input terminal of the third power amplifier (421) corresponds to the amplitude of the second signal input to the input terminal of the fourth power amplifier (422).

[0135] According to an example embodiment, the Doherty power amplifier (400) further comprises a power splitter (470). The power splitter (470) is connected to an input terminal of the first power amplifier (411) and an input terminal of the second power amplifier (412).

[0136] According to an example embodiment, based on the Doherty power amplifier (400) being in a first state, the output signal of the first power amplifier (411) is branched through a coupler (440). Based on the Doherty power amplifier (400) being in a second state, the output signal of the first power amplifier (411) is applied to a third power amplifier (421) through a coupler (440), and the output signal of the second power amplifier (412) is applied to a fourth power amplifier (422) through a coupler. The first state is a state in which the output power of the Doherty power amplifier (400) is greater than or equal to a threshold value. The second state is a state in which the output power is less than a threshold value.

[0137] As described above, according to various exemplary embodiments, an electronic device (910) in a wireless communication system includes at least one processor (914). The electronic device (910) includes a plurality of radio frequency (RF) chains (913) connected to the at least one processor (914). The electronic device (910) includes a plurality of antenna elements (911) connected to the plurality of RF chains (913). An RF chain in the plurality of RF chains (913) includes a Doherty power amplifier (400). The Doherty power amplifier (400) includes a first stage (410), wherein the first stage (410) includes a first power amplifier (411) and a second power amplifier (412). The Doherty power amplifier (400) includes a second stage (420), wherein the second stage (420) includes a third power amplifier (421) and a fourth power amplifier (422). The Doherty power amplifier (400) includes a coupler (440) between the first stage (410) and the second stage (420). The Doherty power amplifier (400) includes a load impedance (460) connected to the second stage (420). The bias of the first power amplifier (411) is different from the bias of the second power amplifier (412). The bias of the third power amplifier (421) corresponds to the bias of the fourth power amplifier (422).

[0138] According to an example embodiment, the first power amplifier (411) and the second power amplifier (412) include power amplifiers biased as class AB. The third power amplifier (421) includes a power amplifier biased as class A or class AB. The fourth power amplifier (422) includes a power amplifier biased as class C.

[0139] According to an example embodiment, the coupler (440) includes a first port connected to the output of the first power amplifier (411), a second port connected to the output of the second power amplifier (412), a third port connected to the input of the third power amplifier (421), and a fourth port connected to the input of the fourth power amplifier (422).

[0140] According to an example embodiment, the coupler (440) includes at least one of a coupled-line coupler, a lange coupler, a hybrid coupler, or a ring hybrid coupler.

[0141] According to an example embodiment, the Doherty power amplifier (400) further includes a transmission line (430) configured for phase delay. An input terminal of the third power amplifier (421) is connected to the coupler (440) through the transmission line (430).

[0142] According to an example embodiment, the Doherty power amplifier (400) further comprises a combiner (450). The combiner (450) is connected to an output terminal of the third power amplifier (421), an output terminal of the fourth power amplifier (422) and a load impedance (460).

[0143] According to example embodiments, the combiner (450) includes a lumped element, a lumped element and a transmission line, a transmission line, or a lumped element and a transformer.

[0144] According to an example embodiment, the amplitude of the first signal input to the input terminal of the third power amplifier (421) corresponds to the amplitude of the second signal input to the input terminal of the fourth power amplifier (422).

[0145] According to an example embodiment, the Doherty power amplifier (400) further comprises a power splitter (470). The power splitter (470) is connected to an input terminal of the first power amplifier (411) and an input terminal of the second power amplifier (412).

[0146] According to an example embodiment, based on the Doherty power amplifier (400) being in a first state, the output signal of the first power amplifier (411) is branched through a coupler (440). Based on the Doherty power amplifier (400) being in a second state, the output signal of the first power amplifier (411) is applied to a third power amplifier (421) through a coupler (440), and the output signal of the second power amplifier (412) is applied to a fourth power amplifier (422) through a coupler (440). The first state is a state in which the output power of the Doherty power amplifier (400) is greater than or equal to a threshold value. The second state is a state in which the output power is less than a threshold value.

[0147] The methods according to various exemplary embodiments described in the claims or the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0148] When implemented as software, a non-transitory computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium are configured to be executed by one or more processors in an electronic device. One or more programs include instructions that cause the electronic device to perform the method according to the embodiments described in the present disclosure.

[0149] Such a program (software module, software) may be stored in a random access memory, a non-volatile memory including flash memory, a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic disk storage device, a compact disk-ROM (CD-ROM), a digital versatile disk (DVD) or other form of optical storage, a magnetic tape cartridge. Alternatively, it may be stored in a memory configured with some or all combinations thereof. Furthermore, each configured memory may include multiple.

[0150] In addition, the program may be stored in an attachable storage device that can be accessed through a communication network (such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), or a storage area network (SAN), or a combination thereof). Such a storage device may be connected to a device that performs an embodiment of the present disclosure through an external port. In addition, a separate storage device on a communication network may access a device that performs an embodiment of the present disclosure.

[0151] In the example embodiments described above of the present disclosure, the components included in the present disclosure are expressed in the singular or plural, depending on the specific embodiment presented. However, for ease of explanation, the singular or plural expression is appropriately selected for the presented situation, and the present disclosure is not limited to singular or plural components, and even if the component is expressed in the plural, it can also be configured in the singular, or even if it is expressed in the singular, it can also be configured in the plural.

[0152] Although the present disclosure has been shown and described with reference to various exemplary embodiments, it will be understood that the various exemplary embodiments are intended to be illustrative rather than restrictive. It will be further understood by those skilled in the art that various changes may be made in form and detail without departing from the true spirit and full scope of the present disclosure, including the appended claims and their equivalents. It will also be understood that any embodiment (or multiples) described herein may be used in combination with any other embodiment (or multiples) described herein.

Claims

1. A Doherty power amplifier (400) in a wireless communication system, include: A first stage (410) comprising a first power amplifier (411) and a second power amplifier (412); a second stage (420) comprising a third power amplifier (421) and a fourth power amplifier (422); a coupler (440) between the first stage (410) and the second stage (420); and A load impedance (460), connected to the second stage (420), wherein the bias of the first power amplifier (411) is different from the bias of the second power amplifier (412), and The bias of the third power amplifier (421) corresponds to the bias of the fourth power amplifier (422).

2. The Doherty power amplifier (400) according to claim 1, in, The first power amplifier (411) and the second power amplifier (412) include power amplifiers biased as class AB, wherein the third power amplifier (421) comprises a power amplifier biased as class A or class AB, and The fourth power amplifier (422) comprises a power amplifier biased as class C.

3. The Doherty power amplifier (400) according to claim 1, in, The coupler (440) includes a first port connected to the output of the first power amplifier (411), a second port connected to the output of the second power amplifier (412), a third port connected to the input of the third power amplifier (421), and a fourth port connected to the input of the fourth power amplifier (422).

4. The Doherty power amplifier (400) according to claim 1, in, The coupler (440) includes at least one of a coupled-line coupler, a lange coupler, a hybrid coupler, or a ring hybrid coupler.

5. The Doherty power amplifier (400) according to claim 1, in, The Doherty power amplifier (400) further comprises a transmission line (430) configured for phase delay, Wherein, the input end of the third power amplifier (421) is connected to the coupler (440) through the transmission line (430).

6. The Doherty power amplifier (400) according to claim 1, in, The Doherty power amplifier (400) further comprises a combiner (450), The combiner (450) is connected to the output end of the third power amplifier (421), the output end of the fourth power amplifier (422) and the load impedance (460).

7. The Doherty power amplifier (400) according to claim 6, in, The combiner (450) includes at least one of the following: Lumped elements, Lumped elements and transmission lines, Transmission line, or Lumped elements and transformers.

8. The Doherty power amplifier (400) according to claim 1, in, The amplitude of the first signal input to the input terminal of the third power amplifier (421) corresponds to the amplitude of the second signal input to the input terminal of the fourth power amplifier (422).

9. The Doherty power amplifier (400) according to claim 1, in, The Doherty power amplifier (400) further comprises a power splitter (470), The power separator (470) is connected to an input end of the first power amplifier (411) and an input end of the second power amplifier (412).

10. The Doherty power amplifier (400) according to claim 1, Based on the Doherty power amplifier (400) being in the first state, the output signal of the first power amplifier (411) is branched through the coupler (440), Based on the Doherty power amplifier (400) being in the second state, the output signal of the first power amplifier (411) is applied to the third power amplifier (421) through the coupler (440), and the output signal of the second power amplifier (412) is applied to the fourth power amplifier (422) through the coupler, in, The first state is a state in which the output power of the Doherty power amplifier (400) is greater than or equal to a threshold value, The second state is a state in which the output power of the Doherty power amplifier is less than the threshold.

11. An electronic device (910) in a wireless communication system, include: at least one processor (914); A plurality of radio frequency (RF) chains (913) connected to the at least one processor (914); as well as a plurality of antenna elements (911) connected to the plurality of RF chains (913), wherein an RF chain in the plurality of RF chains (913) comprises a Doherty power amplifier (400), Wherein, the Doherty power amplifier (400) comprises: A first stage (410) comprising a first power amplifier (411) and a second power amplifier (412); a second stage (420) comprising a third power amplifier (421) and a fourth power amplifier (422); a coupler (440) between the first stage (410) and the second stage (420); and A load impedance (460), connected to the second stage (420), wherein the bias of the first power amplifier (411) is different from the bias of the second power amplifier (412), and The bias of the third power amplifier (421) corresponds to the bias of the fourth power amplifier (422).

12. The electronic device (910) according to claim 11, in, The first power amplifier (411) and the second power amplifier (412) include power amplifiers biased as class AB, wherein the third power amplifier (421) comprises a power amplifier biased as class A or class AB, and The fourth power amplifier (422) comprises a power amplifier biased as class C.

13. The electronic device (910) according to claim 11, in, The coupler (440) includes a first port connected to the output of the first power amplifier (411), a second port connected to the output of the second power amplifier (412), a third port connected to the input of the third power amplifier (421), and a fourth port connected to the input of the fourth power amplifier (422).

14. The electronic device (910) according to claim 11, in, The coupler (440) includes at least one of a coupled-line coupler, a lange coupler, a hybrid coupler, or a ring hybrid coupler.

15. The electronic device (910) according to claim 11, in, The Doherty power amplifier (400) further comprises a transmission line (430) configured for phase delay, Wherein, the input end of the third power amplifier (421) is connected to the coupler (440) through the transmission line (430).

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