High frequency power amplifier, high frequency front-end module and communication terminal

Abstract

The present invention discloses an RF power amplifier, an RF front-end module, and a communication terminal, in which the RF power amplifier includes a control unit, a power amplification unit, a detection unit, and an input matching unit. In the RF power amplifier, the detection unit detects an index parameter related to the output power of the power amplification unit in real time, converts the index parameter into a voltage positively correlated with the magnitude of the index parameter so that the phase change of the RF signal input to the power amplification unit is inverse to the phase change generated by the output signal of the power amplification unit, and outputs the voltage to the input matching unit. This effectively compensates for phase distortion of the RF signal output from the power amplification unit in different modes, and improves the linearity index of the RF front-end module.

Description

[Technical Field]

[0001] The present invention relates to an RF power amplifier belonging to the field of wireless communication technology, and also to an RF front-end module including the RF power amplifier and a corresponding communication terminal. [Background technology]

[0002] With the advancement of science and technology, Wi-Fi communication standards have evolved from IEEE 802.11-1997, through IEEE 802.11a, 802.11b, 802.11g, 802.11n, and 802.11ac, to IEEE 802.11ax. Similarly, mobile communication technology has evolved from 2G and 3G to the widespread use of 4G today and the aggressive deployment of 5G in the future. The development of Wi-Fi and mobile communication has led to increasingly higher requirements for RF front-end linearity. Therefore, communication equipment manufacturers are being required to design communication devices with high linearity.

[0003] The RF front-end module is a key RF component that cannot be integrated into the transceiver of current wireless communication terminals. The RF front-end module amplifies the modulated RF signal through a power amplifier to a certain power level and then transmits the amplified RF signal through an antenna.

[0004] However, in the process of amplifying the power of an RF signal, the power amplifier in a conventional RF front-end module changes its operating point due to the influence of high power as the output power increases, causing changes in the operating state of the power amplifier, which in turn changes the characteristics of the power amplifier, including phase changes in RF signals with different output powers, which affects the linearity index of the RF front-end module. Summary of the Invention [Problem to be solved by the invention]

[0005] The main technical problem that the present invention aims to solve is to provide an RF power amplifier.

[0006] Another technical problem to be solved by the present invention is to provide an RF front-end module including the above RF power amplifier and a corresponding communication terminal.

[0007] To achieve the above objectives, the present invention adopts the following technical solutions.

[0008] According to a first aspect of an embodiment of the present invention, there is provided an RF power amplifier comprising a power amplification unit, a detection unit, and an input matching unit, wherein an output end of the power amplification unit is connected to an input end of the detection unit, an output end of the detection unit is connected to an input end of the input matching unit, and an output end of the input matching unit is connected to an input end of the power amplification unit.

[0009] The detection unit detects the output voltage of the power amplification unit. Power Real-time detection a power detection module for converting the output power into a voltage proportional to the magnitude of the output power and outputting the voltage to the input matching unit, the input matching unit including a voltage control capacitor, and controlling the voltage control capacitor with the voltage output by the power detection module. , so that the phase change of the RF signal input to the power amplifier unit is opposite to the phase change produced by the output signal of the power amplifier unit. Consists of , When an increase in the output power of the power amplifier unit causes an increase in the phase of the output signal, the voltage-controlled capacitor is adjusted to a positive polarity, and as a result of this adjustment, the phase of the RF signal passing through the input matching unit decreases as the output power increases, and when an increase in the output power of the power amplifier unit causes a decrease in the phase of the output signal, the voltage-controlled capacitor is adjusted to a negative polarity, and as a result, the phase of the RF signal passing through the input matching unit increases as the output power increases. do.

[0013] Preferably, the RF power amplifier further includes a control unit and a power supply unit, the output terminal of the control unit is connected to the input terminals of the power amplification unit and the power supply unit respectively, and the output terminal of the power supply unit is connected to the power supply terminals of the power amplification unit and the detection unit respectively.

[0014] Preferably, the power amplification unit includes at least one stage of amplification circuit, each stage of the amplification circuit is connected to a bias circuit, and the output terminal of the amplification circuit of a specific stage is connected to the input terminal of the power detection unit.

[0015] Preferably, when the power amplification unit includes two or more stages of amplification circuits, the amplification circuits of each stage are connected via an inter-stage matching circuit, the input terminal of the first stage amplification circuit is connected to the output terminal of the input matching unit, and the amplification circuit of the last stage is impedance-matched with an external antenna via an output matching circuit.

[0016] Preferably, the detection unit uses a power detection module, the input terminal of the power detection module is connected to the output terminal of a specific stage of the amplifier circuit of the power amplification unit, and the output terminal of the power detection module is connected to the input terminal of the input matching unit.

[0018] Preferably, the input matching unit includes at least one first LC matching circuit, the input end of each of the first LC matching circuits is connected to the output end of the detection unit, and the output end of the last of the first LC matching circuits is connected to the input end of the power amplification unit.

[0019] Preferably, the input matching unit includes at least one second LC matching circuit, the input end of each second LC matching circuit is connected to the output end of the detection unit, and the output end of the last second LC matching circuit is connected to the input end of the power amplification unit.

[0020] Preferably, the input matching unit includes at least one first LC matching circuit and a second LC matching circuit, the input ends of each of the first LC matching circuit and each of the second LC matching circuit are respectively connected to the output end of the detection unit, and the output ends of the last of the first LC matching circuit and the last of the second LC matching circuit are respectively connected to the input end of the power amplification unit.

[0021] Preferably, each of the first LC matching circuits is composed of a first inductance connected in parallel to ground and a first voltage-controlled capacitor connected in series, the ungrounded end of the first voltage-controlled capacitor is connected to the output end of the detection unit, and the ungrounded end of the first voltage-controlled capacitor in the last first LC matching circuit is further connected to the input end of the power amplification unit.

[0022] Preferably, each of the second LC matching circuits is composed of a second inductance connected in series and a second voltage-controlled capacitor connected in parallel to ground, the ungrounded end of the second voltage-controlled capacitor is connected to the output end of the detection unit, and the ungrounded end of the second voltage-controlled capacitor in the last second LC matching circuit is further connected to the input end of the power amplification unit.

[0023] According to a third aspect of an embodiment of the present invention, there is provided an RF front-end module comprising the RF power amplifier.

[0024] According to a fourth aspect of the embodiment of the present invention, there is provided a communication terminal including the RF power amplifier. [Effects of the Invention]

[0025] The RF power amplifier provided by the present invention changes the functional relationship between the output power of the power amplification unit and the output voltage of the detection unit through the control unit according to different frequency bands and different power level modes, and converts the output power or operating current of the power amplification unit detected by the detection unit into a corresponding voltage, which is then input to the input matching unit, so that the phase change of the RF signal input to the power amplification unit is opposite to the phase change generated by the power amplification unit, thereby maintaining the phase of the RF signal finally output from the power amplification unit constant, effectively compensating for the phase distortion of the RF signal output from the power amplification unit in different modes and improving the linearity index of the RF front-end module. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a schematic diagram showing the structure of an RF power amplifier provided by the present invention; [Figure 2] FIG. 2 is a flow diagram illustrating the operation principle of the RF power amplifier provided by the present invention. [Figure 3] FIG. 2 is a schematic diagram showing a combined structure of a first detection unit and a first input matching unit in an RF power amplifier provided by the present invention; [Figure 4] FIG. 10 is a schematic diagram showing a combined structure of a second detection unit and a second input matching unit in the RF power amplifier provided by the present invention; [Figure 5] FIG. 10 is a schematic diagram showing a combined structure of a third detection unit and a third input matching unit in the RF power amplifier provided by the present invention; [Figure 6A] 1 is a schematic diagram showing the change curves of the output power of the power amplification unit and the phase of the RF signal when the RF power amplifier provided by the present invention is not used; [Figure 6B] 2 is a schematic diagram showing the change curve of the output power of the power amplification unit and the phase of the RF signal when the RF power amplifier provided by the present invention is used; FIG. [Figure 7] FIG. 2 is a schematic diagram showing the structure of a second detection unit in the RF power amplifier provided by the present invention; [Figure 8] 4 is a schematic diagram showing the change curve of the current collected by the second detection unit versus the output power of the power amplification unit in the RF power amplifier provided by the present invention; FIG. [Figure 9] FIG. 10 is a comparative diagram of ACPR change curves with respect to output power when the RF power amplifier provided by the present invention is used and when it is not used. [Figure 10] 1 is a schematic diagram showing the structure of an RF front-end module provided by the present invention; [Figure 11] FIG. 2 is a schematic diagram showing another structure of an RF front-end module provided by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] The technical contents of the present invention will be described in more detail below with reference to the accompanying drawings and specific embodiments.

[0028] 1 , in order to solve the problem that the phase of the RF signal generated by the RF power amplifier changes as the output power of the RF power amplifier increases, an embodiment of the present invention provides a newly designed RF power amplifier, which includes a control unit 100, a power amplification unit 110, a power supply unit 120, a detection unit 130, and an input matching unit 150. The output end of the control unit 100 is connected to the input ends of the power amplification unit 110 and the power supply unit 120, respectively, the output end or bias end of the power amplification unit 110 is connected to the input end of the detection unit 130, the output end of the detection unit 130 is connected to the input end of the input matching unit 150, the output end of the input matching unit 150 is connected to the input end of the power amplification unit 110, and the power supply ends of the power amplification unit 110 and the detection unit 130 are connected to the output end of the power supply unit 120, respectively.

[0029] 2, this RF power amplifier detects an index parameter related to the output power of the power amplification unit 110 in real time via the detection unit 130, converts the index parameter into a voltage positively correlated with the magnitude of the index parameter, and outputs the voltage to the input matching unit 150 in order to adjust the phase of the RF signal input to the power amplification unit 110. Here, the detection unit 130 detects the index parameter related to the output power of the power amplification unit 110 in real time, including the output power or operating current of the power amplification unit 110.

[0030] Therefore, this RF power amplifier converts the output power of the power amplification unit 110, detected in real time via the detection unit 130, into a voltage that is positively correlated with the magnitude of the output power, and outputs it to the input matching unit 150, so that the phase change of the RF signal input to the power amplification unit 110 is opposite to the phase change generated by the output signal of the power amplification unit 110, thereby canceling out the phase change. Thus, by keeping the phase of the RF signal finally output from the power amplification unit 110 constant, the phase distortion of the RF signal output from the power amplification unit 110 is compensated for in different modes, and the linearity index of the RF front-end module is improved.

[0031] Alternatively, this RF power amplifier converts the operating current of the power amplification unit 110 detected in real time via the detection unit 130 into a voltage that is positively correlated to the magnitude of the operating current, and inputs this voltage to the input matching unit 150, so that the phase change of the RF signal output to the power amplification unit 110 is opposite to the phase change generated by the output signal of the power amplification unit 110, thereby canceling out the phase change. Thus, by keeping the phase of the RF signal finally output from the power amplification unit 110 constant, the phase distortion of the RF signal output from the power amplification unit 110 is compensated for in different modes, and the linearity index of the RF front-end module is improved.

[0032] Here, the control unit 100 can be realized using a central processing unit in a communication terminal. The control unit 100 not only controls the operating state of the power supply unit 120 and the magnitude of the power supply voltage and current generated and output when it is operating, but also changes the functional relationship between the output power of the power amplification unit 110 and the output voltage of the detection unit 130 based on different frequency bands and different power level modes.

[0033] The power amplifier unit 110 is used to amplify the modulated RF signal to a predetermined power value. The power amplifier unit 110 includes at least one amplifier circuit, each connected to a first bias circuit. The output terminal of any particular amplifier circuit is connected to the input terminal of the power detection unit 130. If the power amplifier unit 110 includes only one amplifier circuit, the input terminal of that amplifier circuit is connected to the output terminal of the input matching unit 150, and the amplifier circuit of that stage is impedance-matched to an external antenna via an output matching circuit. If the power amplifier unit 110 includes two or more amplifier circuits, the amplifier circuits of each stage are connected to each other via inter-stage matching circuits, the input terminal of the first amplifier circuit is connected to the output terminal of the input matching unit 150, and the amplifier circuit of the final stage is impedance-matched to an external antenna via an output matching circuit. 3, taking the case where power amplification unit 110 includes two-stage amplification circuits 1101 as an example, the first-stage amplification circuit and the second-stage amplification circuit are connected via an inter-stage matching circuit, the input terminal of the first-stage amplification circuit is connected to the output terminal of input matching unit 150, and the second-stage amplification circuit is impedance-matched with an external antenna via an output matching circuit. Here, each stage of amplification circuit 1101, the inter-stage matching circuit, and the output matching circuit are conventional ordinary circuits, and will not be described in detail here.

[0034] A bias circuit is used to supply a bias voltage and an operating current to a corresponding amplifier circuit. As shown in FIG. 3, in a two-stage amplifier circuit, the first and second stage amplifier circuits are each connected to one bias circuit 1103. Each bias circuit 1103 includes a first crystal triode HBT1, a second crystal triode HBT2, a third crystal triode HBT3, a capacitor C1, a first resistor R1, and a second resistor R2. The connections between the components of the bias circuit 1103 are as follows: The collector electrode of the first crystal triode HBT1 is connected to a power supply voltage Vdd, the emitter of the first crystal triode HBT1 is connected to a bias terminal of a corresponding amplifier circuit via a first resistor R1, the base of the first crystal triode HBT1 is connected to one end of a capacitor C1, the collector electrode of the second crystal triode HBT2, and one end of a second resistor R2, the other end of the capacitor C1 is grounded, the collector electrode of the second crystal triode HBT2 is connected to its base, the other end of the second resistor R2 is connected to a bias voltage Vreg, the emitter of the second crystal triode HBT2 is connected to the base and collector electrodes of a third crystal triode HBT3, the emitter of the third crystal triode HBT3 is grounded.

[0035] The power supply unit 120 provides the voltage and current required by the power amplification unit 110 and the detection unit 130. The power supply unit 120 is implemented using a linear stable voltage power supply.

[0036] 3, in one embodiment of the present invention, the detection unit 130 uses a power detection module 1301, the input terminal of which is connected to the output terminal of a specific stage of an amplifier circuit in the power amplification unit 110, and the output terminal of the power detection module 1301 is connected to the input terminal of the input matching unit 150. The output power of the specific stage of the amplifier circuit in the power amplification unit 110 is collected in real time by the power detection module 1301 and converted into a DC voltage that is positively correlated to the magnitude of the output power. The power detection module 1301 can be implemented using a detector such as a logarithmic detector, an average detector, or a peak detector.

[0037] As shown in FIGS. 3 to 5, the input matching unit 150 not only performs input matching for the power amplifier unit 110 but also cancels out phase changes generated by the power amplifier unit 110, thereby maintaining a constant phase for the RF signal finally output from the power amplifier unit 110. The input matching unit 150 may have various structural forms. Specifically, referring to FIG. 3, the first input matching unit 150 includes at least one first LC matching circuit, the input terminal of each first LC matching circuit being connected to the output terminal of the power detection module 1301, and the output terminal of the last first LC matching circuit being connected to the input terminal of the power amplifier unit 110. Each first LC matching circuit includes a first inductance L1 connected in parallel to ground and a first voltage-controlled capacitor C1 connected in series, the ungrounded terminal of the first voltage-controlled capacitor C1 being connected to the output terminal of the power detection module 1301. In addition, the ungrounded end of the first voltage-controlled capacitor C1 in the last first LC matching circuit is further connected to the input end of the power amplification unit 110. The number of first LC matching circuits is adjusted based on the frequency and bandwidth of the RF signal.

[0038] 3, for ease of understanding of the embodiment of the present invention, taking the case where the frequency and bandwidth of the RF signal are small as an example, the input matching unit 150 may include a first LC matching circuit composed of a first inductance L1 connected in parallel to ground and a first voltage-controlled capacitor C1 connected in series. Here, the first voltage-controlled capacitor C1 is implemented using a CMOS process, and its operating characteristic is that the capacitance changes based on the voltage difference between both ends of the first voltage-controlled capacitor C1, thereby affecting the phase change of the RF signal passing through the input matching unit 150. Since the phase change of the RF signal is opposite to the phase change of the RF signal caused by the power amplification unit 110, the phase change caused by the power amplification unit 110 can be canceled out, and the phase of the RF signal finally output from the power amplification unit 110 can be kept constant.

[0039] Specifically, as the output power of the power amplifier unit 110 gradually increases, the phase of the RF signal output therefrom changes. For example, as the output power of the power amplifier unit 110 increases, the phase of the RF signal output therefrom gradually increases. That is, the phase of the RF signal output from the power amplifier unit 110 changes in a forward direction relative to the output power. At this time, the first voltage-controlled capacitor C1 is adjusted to a positive polarity so that the voltage difference between both ends of the first voltage-controlled capacitor C1 becomes positive, and the phase of the RF signal passing through the input matching unit 150 changes in a reverse direction relative to the voltage difference between both ends of the first voltage-controlled capacitor C1. Therefore, as the output power of the power amplifier unit 110 gradually increases, the output voltage of the power detection module 1301 gradually increases, and the voltage at the positive terminal of the first voltage-controlled capacitor C1 in the input matching unit 150 is controlled by the output voltage, and the voltage at the negative terminal of the first voltage-controlled capacitor C1 becomes zero (because the first inductance L1 is grounded). By combining this with equation (1), it can be easily concluded that when the frequency of the RF signal is constant, as the output power of the power amplifier unit 110 increases, the voltage difference across the first voltage-controlled capacitor C1 increases, and as the output power of the power amplifier unit increases, the capacitance of the first voltage-controlled capacitor C1 increases. However, as the output power of the power amplifier unit increases, the phase of the RF signal passing through the input matching unit 150 decreases. That is, the phase of the RF signal passing through the input matching unit 150 changes in the opposite direction to the output power of the power amplifier unit, and the phase change of the RF signal passing through the input matching unit 150 is opposite to the phase change of the RF signal caused by the power amplifier unit 110, so that it can cancel out the phase change caused by the power amplifier unit 110. Therefore, the phase of the RF signal finally output from the power amplifier unit 110 can be kept constant.

number

[0040] In equation (1), θ represents the phase of the RF signal passing through the input matching unit 150, K represents a proportionality coefficient, C1 represents the capacitance of the first voltage-controlled capacitor, and f represents the frequency of the RF signal.

[0041] 6A, as the output power of the power amplifier unit 110 gradually increases, the phase of the RF signal output thereby gradually decreases. That is, the phase of the RF signal output from the power amplifier unit 110 changes in the opposite direction to the output power. At this time, by adjusting the first voltage-controlled capacitor C1 to a negative polarity, the voltage difference between both ends of the first voltage-controlled capacitor C1 becomes negative, and the phase of the RF signal passing through the input matching unit 150 changes in the forward direction relative to the voltage difference between both ends of the first voltage-controlled capacitor C1. Similarly, as the output power of the power amplifier unit 110 gradually increases, the output voltage of the power detection module 1301 gradually increases, and the voltage at the negative terminal of the first voltage-controlled capacitor C1 in the input matching unit 150 is controlled by the output voltage, and the voltage at the positive terminal of the first voltage-controlled capacitor C1 becomes zero (because the first inductance L1 is grounded). Therefore, as the output power of the power amplifier unit 110 increases, the voltage difference across the first voltage-controlled capacitor C1 decreases, and as the output power of the power amplifier unit increases, the capacitance of the first voltage-controlled capacitor C1 decreases. However, as the output power of the power amplifier unit increases, the phase of the RF signal passing through the input matching unit 150 increases. That is, the phase of the RF signal passing through the input matching unit 150 changes in the forward direction relative to the output power of the power amplifier unit, and the phase change of the RF signal passing through the input matching unit 150 is opposite to the phase change of the RF signal caused by the power amplifier unit 110, thereby canceling out the phase change caused by the power amplifier unit 110. Therefore, the phase of the RF signal finally output from the power amplifier unit 110 remains constant. As shown in FIG. 6B , when an RF signal is input to this RF power amplifier, the phase change of the RF signal output from the RF power amplifier output tends to be zero.

[0042] 4, the second input matching unit 150 includes at least one second LC matching circuit, the input end of which is connected to the output end of the power detection module 1301, and the output end of the last second LC matching circuit is connected to the input end of the power amplification unit 110. Each second LC matching circuit includes a second inductance L2 connected in series with a second voltage-controlled capacitor C2 connected in parallel to ground, and the ungrounded end of the second voltage-controlled capacitor C2 is connected to the output end of the power detection module 1301. The ungrounded end of the second voltage-controlled capacitor C2 in the last second LC matching circuit is also connected to the input end of the power amplification unit 110. The number of second LC matching circuits is adjusted based on the frequency and bandwidth of the RF signal.

[0043] As shown in FIG. 4 , for ease of understanding the embodiment of the present invention, taking the case where the frequency and bandwidth of the RF signal are small as an example, the input matching unit 150 can include a second LC matching circuit composed of a second inductance L2 connected in series and a second voltage-controlled capacitor C2 connected in parallel to ground. Here, the second voltage-controlled capacitor C2 is also implemented using a CMOS process, and its operational feature is that the capacitance changes based on the voltage difference between both ends of the second voltage-controlled capacitor C2, thereby affecting the phase change of the RF signal passing through the input matching unit 150. This phase change of the RF signal is opposite to the phase change of the RF signal caused by the power amplification unit 110, and can cancel out the phase change caused by the power amplification unit 110. Therefore, the phase of the RF signal finally output from the power amplification unit 110 can be kept constant. Specifically, when the frequency of the RF signal is constant, (1−K2*C2) is a positive value as shown in equation (2), so the capacitance of the second voltage-controlled capacitor C2 increases, and the phase θ of the RF signal passing through the input matching unit 150 decreases. The specific process of making the phase of the RF signal finally output from the power amplification unit 110 constant by the second input matching unit 150 is the same as that of the first input matching unit 150 described above, and will not be described in detail here.

number

[0044] In equation (2), θ represents the phase of the RF signal passing through the input matching unit, K1 and K2 represent proportionality coefficients, and C2 represents the capacitance of the second voltage-controlled capacitor.

[0045] 5, the third input matching unit 150 includes at least one first LC matching circuit and one second LC matching circuit. The input terminals of each first LC matching circuit and each second LC matching circuit are connected to the output terminal of the power detection module 1301, respectively, and the output terminals of the last first LC matching circuit and the last second LC matching circuit are connected to the input terminal of the power amplification unit 110, respectively. Here, the structures of the first LC matching circuit and the second LC matching circuit and the connection relationship between the power detection module 1301 and the power amplification unit 110 are the same as those described above. The specific process by which the third input matching unit maintains the phase of the RF signal finally output from the power amplification unit 110 constant through the first LC matching circuit and the second LC matching circuit is the same as that of the first input matching unit 150 described above, and will not be described in detail here.

[0046] 7, in another embodiment of the present invention, the detection unit 130 uses a current collecting circuit 1302 and a bias voltage generating circuit 1303. The input terminal of the current collecting circuit 1302 is connected to the collector electrode of a first HBT triode in a bias circuit connected to a specific stage of the amplifier circuit. The output terminal of the current collecting circuit 1302 is connected to the input terminal of the bias voltage generating circuit 1303, and the output terminal of the bias voltage generating circuit 1303 is connected to the input terminal of the input matching unit 150. That is, the output terminal of the bias voltage generating circuit 1303 is connected to the ungrounded terminal of the first voltage-controlled capacitor C1 and / or the second voltage-controlled capacitor C2 in the input matching unit 150. The operating current of the power amplifier unit 110 is collected in real time by the current collecting circuit 1302 and input to the bias voltage generating circuit 1303 for conversion into a DC voltage that is positively correlated with the magnitude of the operating current. Here, the current detection circuit 1302 and the bias voltage generation circuit 1303 can be realized by conventional ordinary circuits, and will not be described in detail here.

[0047] Specifically, the operating current flowing through the first HBT1 crystal triode in the bias circuit, which is connected to any stage of the amplifier circuit in the power amplifier unit 110, increases as the output power of the power amplifier unit 110 increases. As shown in FIG. 8 , the current detection circuit 1302 detects the operating current flowing through the first HBT1 crystal triode and converts it into a DC voltage positively correlated with the magnitude of the operating current using the bias voltage generation circuit 1303. Therefore, as the output power of the power amplifier unit 110 increases, the DC voltage output from the bias voltage generation circuit 1303 also increases. When this DC voltage is input to the input matching unit 150, the phase of the RF signal passing through the input matching unit 150 changes in the forward or reverse direction relative to the output power of the power amplifier unit. By changing the polarity of the corresponding voltage-controlled capacitor, the phase change of the RF signal in the input matching unit 150 becomes opposite to the phase change of the RF signal caused by the power amplifier unit 110, thereby canceling out the phase change caused by the power amplifier unit 110. Therefore, by maintaining a constant phase of the RF signal finally output from the power amplifier unit 110, optimal linearity of this RF front-end module is ensured. As shown in FIG. 9, ACPR is an index representing the linearity of an RF power amplifier, and the smaller the ACPR, the better the linearity of the RF power amplifier. In FIG. 9, the thick curve indicates that when this RF power amplifier is used, the linearity is significantly improved as the output power of the RF power amplifier increases, compared to the linearity when this RF power amplifier is not used, represented by the thin curve. Here, the specific process of maintaining a constant phase of the RF signal finally output from the power amplifier unit 110 using the input matching unit 150 is the same as described above, and will not be described in detail here.

[0048] The RF power amplifier provided by the present invention changes the functional relationship between the output power of the power amplification unit and the output voltage of the detection unit through the control unit according to different frequency bands and different power level modes, converts the output power or operating current of the power amplification unit detected by the detection unit into a corresponding voltage, and then inputs it into the input matching unit, so that the phase change of the RF signal input to the power amplification unit is opposite to the phase change generated by the power amplification unit, thereby maintaining a constant phase of the RF signal finally output from the power amplification unit, effectively compensating for the phase distortion of the RF signal output from the power amplification unit in different modes and improving the linearity index of the RF front-end module.

[0049] The RF power amplifier provided by the present invention can be applied to RF front-end modules, including but not limited to Wifi RF front-end modules and multi-mode multi-frequency RF front-end modules.

[0050] 10, the RF front-end module may include, in addition to the RF power amplifier, a switch unit 140 connected to the RF power amplifier control unit 100, power supply unit 120, and power amplification unit 110. The RF signal amplified by the RF power amplifier is transmitted to an antenna via the switch unit 140 and then to the base station via the antenna, thereby achieving transmission of the RF signal to the base station by the RF front-end module. The switch unit 140 can be implemented using a single-pole, multi-throw switch (SP4T) or a multi-pole, multi-throw switch.

[0051] If RF signals need to be transmitted bidirectionally between the RF front-end module and the base station, the RF front-end module may also be provided with a low-noise amplifier 160 connected to the switch unit 140, as shown in Figure 11. The RF signals transmitted from the base station are power-amplified by the low-noise amplifier 160, and then transmitted to the transceiver for demodulation.

[0052] The RF front-end module provided by the present invention can be used in an RF chip, the specific structure of the RF power amplifier in the RF chip will not be described in detail here.

[0053] The RF power amplifier / RF front-end module may also be used in a communication terminal as a key component of an RF circuit. The communication terminal referred to here refers to a computing device that can be used in a mobile environment and supports various communication standards such as GSM, EDGE, TD_SCDMA, TDD_LTE, and FDD_LTE, including, but not limited to, a mobile phone, a laptop, a tablet PC, and an in-vehicle computer. The RF power amplifier may also be used in cases where other communication technologies are applied, such as a communication base station that supports multiple communication standards, but this will not be described in detail here.

[0054] The RF power amplifier, RF front-end module and communication terminal provided by the present invention have been described in detail above. Any obvious modifications made to the present invention by those skilled in the art without departing from the essential content of the present invention will fall within the scope of patent protection of the present invention.

Claims

1. 1. An RF power amplifier comprising: a power amplification unit, a detection unit, and an input matching unit, wherein the output end of the power amplification unit is connected to the input end of the detection unit, the output end of the detection unit is connected to the input end of the input matching unit, and the output end of the input matching unit is connected to the input end of the power amplification unit; the detection unit has a power detection module for detecting the output power of the power amplification unit in real time, converting the output power into a voltage proportional to its magnitude, and outputting the voltage to the input matching unit; the input matching unit includes a voltage-controlled capacitor, and is configured to control the voltage-controlled capacitor with the voltage output by the power detection module so that a phase change of the RF signal input to the power amplification unit is opposite to a phase change generated by an output signal of the power amplification unit; When an increase in the output power of the power amplification unit causes an increase in the phase of the output signal, the voltage-controlled capacitor is adjusted to a positive polarity, and by this adjustment, the phase of the RF signal passing through the input matching unit decreases as the output power increases; an RF power amplifier, characterized in that when an increase in output power of the power amplification unit causes a decrease in the phase of the output signal, the voltage-controlled capacitor is adjusted to a negative polarity, and by this adjustment, the phase of the RF signal passing through the input matching unit increases as the output power increases.

2. 2. The RF power amplifier according to claim 1, further comprising: a control unit and a power supply unit, wherein an output terminal of the control unit is connected to an input terminal of the power amplification unit and an input terminal of the power supply unit, respectively, and an output terminal of the power supply unit is connected to a power supply terminal of the power amplification unit and an input terminal of the detection unit, respectively.

3. 2. The RF power amplifier according to claim 1, wherein the power amplification unit comprises at least one amplifier circuit, each amplifier circuit of the at least one stage is connected to a bias circuit, and an output terminal of the at least one amplifier circuit of a specific stage is connected to an input terminal of the detection unit.

4. 4. The RF power amplifier according to claim 3, wherein when the power amplification unit includes two or more stages of amplifier circuits, the amplifier circuits of the two or more stages are connected via an inter-stage matching circuit, an input terminal of a first stage amplifier circuit of the two or more stages of amplifier circuits is connected to an output terminal of the input matching unit, and a final stage amplifier circuit is impedance-matched with an external antenna via an output matching circuit.

5. An RF power amplifier as described in claim 3, characterized in that the input terminal of the power detection module is connected to the output terminal of an amplifier circuit of a specific stage of the power amplification unit, and the output terminal of the power detection module is connected to the input terminal of the input matching unit.

6. 2. The RF power amplifier according to claim 1, wherein the input matching unit comprises at least one first LC matching circuit, an input end of each of the at least one first LC matching circuits being connected to the output end of the detection unit, and an output end of a last-position first LC matching circuit being connected to the input end of the power amplification unit.

7. 2. The RF power amplifier according to claim 1, wherein the input matching unit comprises at least one second LC matching circuit, an input end of each second LC matching circuit of the at least one second LC matching circuit is connected to the output end of the detection unit, and an output end of a last-position second LC matching circuit is connected to the input end of the power amplification unit.

8. 2. The RF power amplifier according to claim 1, wherein the input matching unit comprises at least one first LC matching circuit and a second LC matching circuit, an input end of each of the first LC matching circuit and the second LC matching circuit of the at least one second LC matching circuit is connected to the output end of the detection unit, and an output end of a last-positioned first LC matching circuit and a last-positioned second LC matching circuit is connected to the input end of the power amplification unit.

9. 9. The RF power amplifier according to claim 6, wherein each of the first LC matching circuits is composed of a first inductance connected in parallel to ground and a first voltage-controlled capacitor connected in series, the ungrounded end of the first voltage-controlled capacitor is connected to the output terminal of the detection unit, and the ungrounded end of the first voltage-controlled capacitor in the first LC matching circuit located last is further connected to the input terminal of the power amplification unit.

10. 9. The RF power amplifier according to claim 7, wherein each of the second LC matching circuits is composed of a second inductance connected in series and a second voltage-controlled capacitor connected in parallel to ground, the ungrounded end of the second voltage-controlled capacitor is connected to the output end of the detection unit, and the ungrounded end of the second voltage-controlled capacitor in the second LC matching circuit located last is further connected to the input end of the power amplification unit.

11. An RF front-end module comprising an RF power amplifier according to any one of claims 1 to 10.

12. A communication terminal comprising the RF power amplifier according to any one of claims 1 to 10.

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