RF power amplifier, RF front-end module and communication terminal

Abstract

The present invention discloses a radio frequency power amplifier, a radio frequency front-end module and a communication terminal. The radio frequency power amplifier comprises a control unit, a power amplification unit, a detection unit and an input matching unit. In the radio frequency power amplifier, the detection unit detects the index parameter related to the output power of the power amplification unit in real time, and converts it into a voltage positively correlated with the index parameter, and outputs it to the input matching unit, so that the phase change of the radio frequency signal input to the power amplification unit is opposite to the phase change generated by the output signal of the power amplification unit, thereby effectively realizing the phase distortion compensation of the radio frequency signal output by the power amplification unit in different modes, and improving the linearity index of the radio frequency front-end module.

Description

Technical Field

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

[0002] With the advancement of technology, Wifi communication standards have gone through IEEE 802.11-1997, IEEE 802.11a, 802.11b, 802.11g, 802.11n and 802.11ac, and finally IEEE 802.11ax. Similarly, mobile communication technology has gone through 2G, 3G, and now the widespread application of 4G, as well as the active deployment of 5G in the future. The development of Wifi communication and mobile communication has put higher and higher requirements on the linearity of the RF front end. Therefore, manufacturers of communication equipment need to design high-linearity communication devices.

[0003] The RF front-end module is an important RF component that cannot be integrated into the transceiver in the current wireless communication terminal. In the RF front-end module, the modulated RF signal is amplified to a certain power value through the power amplifier, and then the amplified RF signal is sent out through the antenna.

[0004] However, in the process of amplifying the power of the RF signal by the power amplifier of the existing RF front-end module, as the output power continues to increase, the operating point of the power amplifier will be affected by the high power and change, causing the working state of the power amplifier to change, thereby causing the characteristics of the power amplifier to change, including the phase under different output power RF signals will change, thereby affecting the linearity index of the RF front-end module. Summary of the invention

[0005] The primary technical problem to be solved by the present invention is to provide a radio frequency power amplifier.

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

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] According to a first aspect of an embodiment of the present invention, there is provided a radio frequency 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;

[0009] The detection unit detects the index parameter related to the output power of the power amplification unit in real time, converts it into a voltage positively correlated with the size of the index parameter, and outputs it to the input matching unit, so that the phase change of the radio frequency signal input to the power amplification unit is opposite to the phase change generated by the output signal of the power amplification unit.

[0010] According to a second aspect of an embodiment of the present invention, there is provided a radio frequency power amplifier, comprising a power amplification unit, a detection unit and an input matching unit, wherein a bias 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;

[0011] The detection unit detects the index parameter related to the output power of the power amplification unit in real time, converts it into a voltage positively correlated with the size of the index parameter, and outputs it to the input matching unit, so that the phase change of the radio frequency signal input to the power amplification unit is opposite to the phase change generated by the output signal of the power amplification unit.

[0012] Preferably, the indicator parameter is the output power or operating current of the power amplification unit.

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

[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 end of a certain stage of the amplification circuit is connected to the input end of the power detection unit.

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

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

[0017] Preferably, the detection unit adopts a current acquisition circuit and a bias voltage generating circuit, the input end of the current acquisition circuit is connected to a bias circuit connected to a certain stage of an amplifier circuit, the output end of the current acquisition circuit is connected to the input end of the bias voltage generating circuit, and the output end of the bias voltage generating circuit is connected to the input end of the input matching unit.

[0018] Preferably, the input matching unit includes at least one first LC matching circuit, the input end of each first LC matching circuit is connected to the output end of the detection unit, and the output end of the last first LC matching circuit 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 end of each first LC matching circuit and each second LC matching circuit is respectively connected to the output end of the detection unit, and the output end of the last first LC matching circuit and the last second LC matching circuit is 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 inductor connected in parallel to the ground and a first voltage-controlled capacitor connected in series, the non-grounded end of the first voltage-controlled capacitor is connected to the output end of the detection unit, and the non-grounded end of the first voltage-controlled capacitor of the last first LC matching circuit is also connected to the input end of the power amplification unit.

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

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

[0024] According to a fourth aspect of an embodiment of the present invention, there is provided a communication terminal, comprising the above-mentioned radio frequency power amplifier.

[0025] The RF power amplifier provided by the present invention changes the functional relationship between the output power of the power amplifier unit and the output voltage of the detection unit according to different frequency bands and different power level modes through a control unit, and uses the detection unit to convert the detected output power or working current of the power amplifier unit into a corresponding voltage, which is then input into an input matching unit, so that the phase change of the RF signal input to the power amplifier unit is opposite to the phase change generated by the power amplifier unit, so that the phase of the RF signal finally output by the power amplifier unit remains unchanged, effectively realizing the compensation of the phase distortion of the RF signal output by the power amplifier unit in different modes, thereby improving the linearity index of the RF front-end module. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the structure of the radio frequency power amplifier provided by the present invention;

[0027] Figure 2 A flowchart showing the working principle of the radio frequency power amplifier provided by the present invention;

[0028] Figure 3 A schematic structural diagram of a first detection unit combined with a first input matching unit in the radio frequency power amplifier provided by the present invention;

[0029] Figure 4 A schematic structural diagram of a second detection unit combined with a second input matching unit in the radio frequency power amplifier provided by the present invention;

[0030] Figure 5 This is a schematic structural diagram of a third detection unit combined with a third input matching unit in the radio frequency power amplifier provided by the present invention;

[0031] Fig. 6A It is a schematic diagram of the variation curve of the output power of the power amplification unit and the phase of the radio frequency signal when the radio frequency power amplifier provided by the present invention is not used;

[0032] Figure 6B A schematic diagram of a curve showing a change in output power of a power amplification unit and a phase of a radio frequency signal when the radio frequency power amplifier provided by the present invention is used;

[0033] Figure 7 This is a structural schematic diagram of a second detection unit in the radio frequency power amplifier provided by the present invention;

[0034] Figure 8 A schematic diagram of a curve showing a change in the current collected by the second detection unit versus the output power of the power amplification unit in the radio frequency power amplifier provided by the present invention;

[0035] Fig. 9A schematic diagram showing a comparison of curves of ACPR versus output power when the RF power amplifier provided by the present invention is used and when it is not used;

[0036] Fig.10 A schematic diagram of the structure of the radio frequency front-end module provided by the present invention;

[0037] Fig.11 Another structural schematic diagram of the radio frequency front-end module provided by the present invention. DETAILED DESCRIPTION

[0038] The technical content of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0039] In order to solve the problem that the phase of the RF signal changes with the increase of its output power caused by the RF power amplifier, such as Figure 1 As shown, an embodiment of the present invention provides a newly designed RF power amplifier, including a control unit 100, a power amplifying 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 respectively connected to the input ends of the power amplifying unit 110 and the power supply unit 120, the output end or the bias end of the power amplifying 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 amplifying unit 110, and the power supply ends of the power amplifying unit 110 and the detection unit 130 are respectively connected to the output end of the power supply unit 120.

[0040] like Figure 2 As shown, the RF power amplifier detects the index parameter related to the output power of the power amplifying unit 110 in real time through the detection unit 130, and converts it into a voltage positively correlated with the index parameter, and then outputs it to the input matching unit 150 to adjust the phase of the RF signal input to the power amplifying unit 110. Among them, the detection unit 130 detects the index parameter related to the output power of the power amplifying unit 110 in real time, including the output power or working current of the power amplifying unit 110.

[0041] Therefore, the RF power amplifier can convert the output power of the power amplifier unit 110 detected in real time into a voltage positively correlated with the output power through the detection unit 130, and output it to the input matching unit 150, so that the phase change of the RF signal input to the power amplifier unit 110 is opposite to the phase change generated by the output signal of the power amplifier unit 110, thereby playing the role of offsetting the phase change, so that the phase of the RF signal finally output by the power amplifier unit 110 remains unchanged, thereby realizing compensation for the phase distortion of the RF signal output by the power amplifier unit 110 in different modes, and improving the linearity index of the RF front-end module.

[0042] Alternatively, the RF power amplifier converts the working current of the power amplifier unit 110 detected in real time into a voltage positively correlated with the working current through the detection unit 130, and inputs the voltage into the input matching unit 150, so that the phase change of the RF signal output to the power amplifier unit 110 is opposite to the phase change generated by the output signal of the power amplifier unit 110, thereby offsetting the phase change and making the phase of the RF signal finally output by the power amplifier unit 110 unchanged, thereby achieving compensation for the phase distortion of the RF signal output by the power amplifier unit 110 in different modes and improving the linearity index of the RF front-end module.

[0043] The control unit 100 can be implemented by a central processing unit in a communication terminal. The control unit 100 can not only control the working state of the power supply unit 120, and the magnitude of the power supply voltage and current generated and output during operation, but also change the functional relationship between the output power of the power amplifier unit 110 and the output voltage of the detection unit 130 according to different frequency bands and different power level modes.

[0044] The power amplifier unit 110 is used to amplify the modulated RF signal to a preset power value. The power amplifier unit 110 includes at least one stage of amplifier circuit, and each stage of amplifier circuit is connected to a bias circuit, wherein the output end of any one stage of amplifier circuit is connected to the input end of the power detection unit 130; if the power amplifier unit 110 has only one stage of amplifier circuit, the input end of the amplifier circuit of this stage is connected to the output end of the input matching unit 150, and the impedance of the amplifier circuit of this stage is matched with the external antenna through the output matching circuit; if the power amplifier unit 110 includes two or more stages of amplifier circuits, the amplifier circuits of each stage are connected through an inter-stage matching circuit, the input end of the first stage of amplifier circuit is connected to the output end of the input matching unit 150, and the impedance of the last stage of amplifier circuit is matched with the external antenna through the output matching circuit. Figure 3 As shown, taking the power amplification unit 110 including two-stage amplification circuit 1101 as an example, the first-stage amplification circuit and the second-stage amplification circuit are connected through an inter-stage matching circuit, the input end of the first-stage amplification circuit is connected to the output end of the input matching unit 150, and the second-stage amplification circuit is impedance matched with the external antenna through the output matching circuit. Among them, each stage of the amplification circuit 1101, the inter-stage matching circuit and the output matching circuit are existing conventional circuits, which will not be repeated here.

[0045] The bias circuit is used to provide bias voltage and operating current for the corresponding amplifier circuit. Figure 3As shown, taking a two-stage amplifier circuit as an example, the first-stage amplifier circuit and the second-stage amplifier circuit are respectively connected to a bias circuit 1103 . Each bias circuit 1103 includes a first transistor HBT1, a second transistor HBT2, a third transistor HBT3, a capacitor C1, a first resistor R1 and a second resistor R2; the connection relationship between the various parts of the bias circuit 1103 is as follows: the collector of the first transistor HBT1 is connected to the power supply voltage Vdd, the emitter of the first transistor HBT1 is connected to the bias end of the corresponding amplifier circuit through the first resistor R1, the base of the first transistor HBT1 is respectively connected to one end of the capacitor C1, the collector of the second transistor HBT2 and one end of the second resistor R2, the other end of the capacitor C1 is grounded, the collector of the second transistor HBT2 is connected to its base, the other end of the second resistor R2 is connected to the bias voltage Vreg, the emitter of the second transistor HBT2 is respectively connected to the base and collector of the third transistor HBT3, and the emitter of the third transistor HBT3 is grounded.

[0046] The power supply unit 120 is used to provide the required voltage and current for the power amplification unit 110 and the detection unit 130. The power supply unit 120 is implemented by a linear voltage-stabilized power supply.

[0047] like Figure 3 As shown, in one embodiment of the present invention, the detection unit 130 uses a power detection module 1301, the input end of the power detection module 1301 is connected to the output end of a certain stage of the amplifier circuit of the power amplification unit 110, and the output end of the power detection module 1301 is connected to the input end of the input matching unit 150. The output power of a certain stage of the amplifier circuit of 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 with the output power. The power detection module 1301 can be implemented by a detector, for example, a logarithmic detector, a mean detector, or a peak detector.

[0048] like Figure 3 to Figure 5 As shown, the input matching unit 150 is not only used for input matching of the power amplifying unit 110, but also used for offsetting the phase change generated by the power amplifying unit 110, so as to achieve the unchanged phase of the RF signal finally output by the power amplifying unit 110. The input matching unit 150 has various structural forms. Figure 3As shown, the first input matching unit 150 includes at least one first LC matching circuit, the input end of each first LC matching circuit is connected to the output end of the power detection module 1301, and the output end of the last first LC matching circuit is connected to the input end of the power amplification unit 110. Each first LC matching circuit is composed of a first inductor L1 connected in parallel to the ground and a first voltage-controlled capacitor C1 connected in series, and the non-grounded end of the first voltage-controlled capacitor C1 is connected to the output end of the power detection module 1301. In addition, the non-grounded end of the first voltage-controlled capacitor C1 of the last first LC matching circuit is also connected to the input end of the power amplification unit 110. The number of first LC matching circuits is adjusted according to the frequency and bandwidth of the RF signal.

[0049] like Figure 3 As shown, in order to facilitate the understanding of the embodiment of the present invention, taking the case where the frequency and bandwidth of the RF signal are relatively small as an example, the input matching unit 150 may include a first LC matching circuit, and the first LC matching circuit is composed of a first inductor L1 connected in parallel to the ground and a first voltage-controlled capacitor C1 connected in series. The first voltage-controlled capacitor C1 is implemented using a CMOS process, and its working characteristic is that the size of the capacitor changes according to the voltage difference between the two ends of the first voltage-controlled capacitor C1, thereby affecting the phase change of the RF signal passing through the input matching unit 150. The phase change of the RF signal is opposite to the phase change of the RF signal caused by the power amplification unit 110, so that the phase change generated by the power amplification unit 110 can be offset, so that the phase of the RF signal finally output by the power amplification unit 110 remains unchanged.

[0050] Specifically, as the output power of the power amplifying unit 110 gradually increases, the phase of the RF signal outputted by the power amplifying unit 110 will change. In one case, as the output power of the power amplifying unit 110 gradually increases, the phase of the RF signal outputted by the power amplifying unit 110 gradually increases, that is, the phase of the RF signal outputted by the power amplifying unit 110 changes in a positive direction with its output power. At this time, the first voltage-controlled capacitor C1 is adjusted to be positive polarity, so that the voltage difference across the first voltage-controlled capacitor C1 is positive, and the phase of the RF signal input to the matching unit 150 changes inversely with the voltage difference across the first voltage-controlled capacitor C1; therefore, as the output power of the power amplifying unit 110 gradually increases, the output voltage of the power detection module 1301 will gradually increase, and the output voltage controls the voltage at the positive terminal of the first voltage-controlled capacitor C1 in the input matching unit 150, while the voltage at the negative terminal of the first voltage-controlled capacitor C1 is zero (because the first inductor L1 is grounded). Combined with formula (1), it is not difficult to deduce that: at a fixed frequency of the RF signal, the voltage difference across the first voltage-controlled capacitor C1 changes with As the output power of the power amplifying unit 110 increases, the capacitance of the first voltage-controlled capacitor C1 increases as the output power of the power amplifying unit increases, and the phase of the RF signal input through the matching unit 150 decreases as the output power of the power amplifying unit increases, that is, the phase of the RF signal input through the matching unit 150 changes inversely with the output power of the power amplifying unit, and the change in the phase of the RF signal input through the matching unit 150 is opposite to the change in the phase of the RF signal caused by the power amplifying unit 110, which can offset the phase change caused by the power amplifying unit 110, thereby achieving the unchanged phase of the RF signal finally output by the power amplifying unit 110.

[0051]

[0052] Wherein, θ represents the phase of the radio frequency signal passing through the input matching unit 150, K represents the proportionality coefficient, C1 represents the first voltage-controlled capacitor, and f represents the frequency of the radio frequency signal.

[0053] Another situation, such as Fig. 6AAs shown, as the output power of the power amplifying unit 110 gradually increases, the phase of the RF signal outputted by it can gradually decrease, that is, the phase of the RF signal outputted by the power amplifying unit 110 changes inversely with its output power. At this time, the first voltage-controlled capacitor C1 is adjusted to be negative polarity, so that the voltage difference across the first voltage-controlled capacitor C1 is negative, and the phase of the RF signal input to the matching unit 150 changes positively with the voltage difference across the first voltage-controlled capacitor C1; similarly, as the output power of the power amplifying unit 110 gradually increases, the output voltage of the power detection module 1301 will gradually increase, and the output voltage controls the voltage at the negative terminal of the first voltage-controlled capacitor C1 in the input matching unit 150, while the voltage at the positive terminal of the first voltage-controlled capacitor C1 is zero (because the first inductor L1 is grounded), so the voltage difference across the first voltage-controlled capacitor C1 decreases as the output power of the power amplifying unit 110 increases, and the first voltage-controlled capacitor C1 The capacitance will decrease as the output power of the power amplifier unit increases, while the phase of the RF signal input to the matching unit 150 will increase as the output power of the power amplifier unit increases, that is, the phase of the RF signal input to the matching unit 150 changes in a positive direction with the output power of the power amplifier unit. The change in the phase of the RF signal input to the matching unit 150 is opposite to the change in the phase of the RF signal caused by the power amplifier unit 110, which can offset the phase change caused by the power amplifier unit 110, thereby achieving the phase of the RF signal finally output by the power amplifier unit 110 remains unchanged, such as Figure 6B As shown, when the RF signal is input to the RF power amplifier, the phase change of the RF signal output by the RF power amplifier approaches zero.

[0054] like Figure 4 As shown, the second input matching unit 150 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 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 is composed of a second inductor L2 connected in series and a second voltage-controlled capacitor C2 connected in parallel to the ground, and the non-grounded end of the second voltage-controlled capacitor C2 is connected to the output end of the power detection module 1301. In addition, the non-grounded end of the second voltage-controlled capacitor C2 of the last second LC matching circuit is also connected to the input end of the power amplification unit 110. The number of the second LC matching circuits is adjusted according to the frequency and bandwidth of the RF signal.

[0055] like Figure 4As shown, in order to facilitate the understanding of the embodiment of the present invention, taking the case where the frequency and bandwidth of the RF signal are relatively small as an example, the input matching unit 150 may include a second LC matching circuit, and the second LC matching circuit is composed of a second inductor L2 connected in series and a second voltage-controlled capacitor C2 connected in parallel to the ground. The second voltage-controlled capacitor C2 is also implemented using a CMOS process, and its working characteristics are that the size of the capacitor varies according to the voltage difference between the two ends of the second voltage-controlled capacitor C2, thereby affecting the phase change of the RF signal passing through the input matching unit 150. The phase change of the RF signal is opposite to the phase change of the RF signal caused by the power amplification unit 110, so the phase change generated by the power amplification unit 110 can be offset, thereby achieving the phase of the RF signal finally output by the power amplification unit 110 unchanged. Specifically, at a fixed frequency of the RF signal, as shown in formula (2), (1-K2*C2) is a positive value, so the second voltage-controlled capacitor C2 becomes larger, and the phase θ of the RF signal passing through the input matching unit 150 decreases. The specific process of the second input matching unit 150 to achieve the unchanged phase of the radio frequency signal finally output by the power amplifying unit 110 is the same as the first input matching unit 150, and will not be repeated here.

[0056]

[0057] Wherein, θ represents the phase of the radio frequency signal passing through the input matching unit, K1 and K2 represent proportional coefficients, and C2 represents the second voltage-controlled capacitor.

[0058] like Figure 5 As shown, the third input matching unit 150 includes at least one first LC matching circuit and a second LC matching circuit; the input end of each first LC matching circuit and each second LC matching circuit is respectively connected to the output end of the power detection module 1301, and the output end of the last first LC matching circuit and the last second LC matching circuit is respectively connected to the input end of the power amplification unit 110. Among them, the structures of the first LC matching circuit and the second LC matching circuit and the connection relationship with the power detection module 1301 and the power amplification unit 110 are the same as above, and the specific process of the third input matching unit realizing the phase invariance of the radio frequency signal finally output by the power amplification unit 110 through the first LC matching circuit and the second LC matching circuit is the same as the first input matching unit 150, which will not be repeated here.

[0059] like Figure 7As shown, in another embodiment of the present invention, the detection unit 130 uses a current acquisition circuit 1302 and a bias voltage generating circuit 1303; the input end of the current acquisition circuit 1302 is connected to the collector of the first transistor HBT1 of the bias circuit connected to a certain stage of the amplifier circuit, the output end of the current acquisition circuit 1302 is connected to the input end of the bias voltage generating circuit 1303, and the output end of the bias voltage generating circuit 1303 is connected to the input end of the input matching unit 150, that is, the output end of the bias voltage generating circuit 1303 is connected to the non-grounded end of the first voltage-controlled capacitor C1 and / or the second voltage-controlled capacitor C2 of the input matching unit 150. The working current of the power amplifier unit 110 is collected in real time by the current acquisition circuit 1302, and the working current is input to the bias voltage generating circuit 1303, and converted into a DC voltage positively correlated with the magnitude of the working current. Among them, the current detection circuit 1302 and the bias voltage generating circuit 1303 can be implemented with existing conventional circuits, which will not be described in detail here.

[0060] Specifically, the operating current of the first transistor HBT1 of the bias circuit connected to any one stage of the amplifier circuit in the power amplifier unit 110 will increase as the output power of the power amplifier unit 110 increases. Figure 8 As shown, the current detection circuit 1302 detects the working current on the first transistor HBT1, and converts it into a DC voltage that is positively correlated with the working current through the bias voltage generating circuit 1303. Therefore, as the output power of the power amplifier unit 110 increases, the DC voltage output by the bias voltage generating circuit 1303 will also increase. The output DC voltage is input to the input matching unit 150, so that the phase of the RF signal passing through the input matching unit 150 will change in a positive or negative direction with the output power of the power amplifier unit. By changing the polarity of the corresponding voltage-controlled capacitor, the change in the phase of the RF signal of the input matching unit 150 is opposite to the change in the phase of the RF signal caused by the power amplifier unit 110, which can offset the phase change caused by the power amplifier unit 110, thereby achieving the phase of the RF signal finally output by the power amplifier unit 110 remains unchanged, thereby ensuring the optimal linearity of the RF front-end module. Fig. 9 As shown, ACPR is an indicator that describes the linearity of the RF power amplifier. The smaller the ACPR, the better the linearity of the RF power amplifier. Fig. 9 In the figure, the thicker curve is after using the RF power amplifier, as the output power of the RF power amplifier increases, its linearity is significantly higher than the linearity of not using the RF power amplifier represented by the thinner curve. The specific process of the input matching unit 150 achieving the unchanged phase of the RF signal finally output by the power amplification unit 110 is the same as above, which will not be repeated here.

[0061] The RF power amplifier provided by the present invention changes the functional relationship between the output power of the power amplifier unit and the output voltage of the detection unit according to different frequency bands and different power level modes through a control unit, and uses the detection unit to convert the detected output power or working current of the power amplifier unit into a corresponding voltage, which is then input into an input matching unit, so that the phase change of the RF signal input to the power amplifier unit is opposite to the phase change generated by the power amplifier unit, so that the phase of the RF signal finally output by the power amplifier unit remains unchanged, thereby realizing compensation for the phase distortion of the RF signal output by the power amplifier unit in different modes and improving the linearity index of the RF front-end module.

[0062] The radio frequency power amplifier provided by the present invention can be applied in a radio frequency front-end module, which includes but is not limited to a Wifi radio frequency front-end module and a multi-mode multi-frequency radio frequency front-end module.

[0063] Among them, Fig.10 As shown, in addition to the RF power amplifier, the RF front-end module may also include a switch unit 140, which is respectively connected to the control unit 100, the power supply unit 120 and the power amplifier unit 110 of the RF power amplifier. The RF signal amplified by the RF power amplifier is transmitted to the antenna through the switch unit 140, and is sent to the base station through the antenna, so that the RF front-end module sends the RF signal to the base station. The switch unit 140 can be implemented by a single-pole multi-throw switch or a multi-pole multi-throw switch.

[0064] When it is necessary to realize bidirectional transmission of RF signals between the RF front-end module and the base station, such as Fig.11 As shown, a low noise amplifier 160 may also be provided in the RF front-end module, and the low noise amplifier 160 is connected to the switch unit 140; the RF signal transmitted from the base station is power amplified by the low noise amplifier 160 and then sent to the transceiver for demodulation.

[0065] The radio frequency front-end module provided by the present invention can be used in a radio frequency chip. The specific structure of the radio frequency power amplifier in the radio frequency chip will not be described in detail here.

[0066] In addition, the above-mentioned RF power amplifier / RF front-end module can also be used in communication terminals as an important component of RF circuits. The communication terminal mentioned here refers to a computer device that can be used in a mobile environment and supports multiple communication formats such as GSM, EDGE, TD_SCDMA, TDD_LTE, FDD_LTE, etc., including but not limited to mobile phones, laptops, tablet computers, car computers, etc. In addition, the RF power amplifier is also suitable for other communication technology application occasions, such as communication base stations compatible with multiple communication formats, etc., which will not be described in detail here.

[0067] The above is a detailed description of the RF power amplifier, RF front-end module and communication terminal provided by the present invention. For those skilled in the art, any obvious changes made to it without departing from the essence of the present invention will fall within the scope of protection of the patent right of the present invention.

Claims

1. A radio frequency power amplifier, characterized in that It includes a power amplification unit, a detection unit and an input matching unit, wherein the bias 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 power amplification unit includes at least one stage of amplification circuit, each stage of the amplification circuit is connected to a bias circuit, each stage of the amplification circuit is connected through an inter-stage matching circuit, and the output end of any stage of the amplification circuit is connected to the input end of the detection unit; wherein the input end of the first stage of the amplification circuit is connected to the output end of the input matching unit, and the last stage of the amplification circuit is impedance matched with the external antenna through the output matching circuit; The detection unit detects the index parameter related to the output power of the power amplification unit in real time, converts it into a voltage positively correlated with the size of the index parameter, and outputs it to the input matching unit, so that the phase change of the radio frequency signal input to the power amplification unit is opposite to the phase change generated by the output signal of the power amplification unit.

2. The radio frequency power amplifier according to claim 1, wherein: The indicator parameter is the output power or operating current of the power amplification unit.

3. The radio frequency power amplifier according to claim 1, characterized in that It also includes a control unit and a power supply unit, wherein the output end of the control unit is respectively connected to the input end of the power amplification unit and the power supply unit, and the output end of the power supply unit is respectively connected to the power amplification unit and the power supply end of the detection unit.

4. The radio frequency power amplifier according to claim 1, wherein: The detection unit adopts a power detection module, the input end of the power detection module is connected to the output end of any one stage of the amplification circuit in the power amplification unit, and the output end of the power detection module is connected to the input end of the input matching unit.

5. The radio frequency power amplifier according to claim 1, wherein: The detection unit adopts a current acquisition circuit and a bias voltage generating circuit, the input end of the current acquisition circuit is connected to the bias circuit connected to any one stage of the amplification circuit, the output end of the current acquisition circuit is connected to the input end of the bias voltage generating circuit, and the output end of the bias voltage generating circuit is connected to the input end of the input matching unit.

6. The radio frequency power amplifier according to claim 1, wherein: The input matching unit includes at least one first LC matching circuit, the input end of each first LC matching circuit is connected to the output end of the detection unit, and the output end of the last first LC matching circuit is connected to the input end of the power amplification unit.

7. The radio frequency power amplifier according to claim 1, wherein: 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.

8. The radio frequency power amplifier according to claim 1, wherein: The input matching unit includes at least one first LC matching circuit and a second LC matching circuit; the input end of each of the first LC matching circuit and each of the second LC matching circuits are respectively connected to the output end of the detection unit, and the output end 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.

9. The radio frequency power amplifier according to claim 6, characterized in that: Each of the first LC matching circuits is composed of a first inductor connected in parallel to the ground and a first voltage-controlled capacitor connected in series. The non-grounded end of the first voltage-controlled capacitor is connected to the output end of the detection unit. The non-grounded end of the first voltage-controlled capacitor of the last first LC matching circuit is also connected to the input end of the power amplification unit.

10. The radio frequency power amplifier according to claim 7, wherein: Each of the second LC matching circuits is composed of a second inductor connected in series and a second voltage-controlled capacitor connected in parallel to the ground. The non-grounded end of the second voltage-controlled capacitor is connected to the output end of the detection unit. The non-grounded end of the second voltage-controlled capacitor of the last second LC matching circuit is also connected to the input end of the power amplification unit.

11. A radio frequency front-end module, characterized in that The radio frequency front-end module includes the radio frequency power amplifier according to any one of claims 1 to 10.

12. A communication terminal, characterized in that The communication terminal includes the radio frequency power amplifier according to any one of claims 1 to 10.

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