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 communications terminal. The RF power amplifier includes a control unit, a power amplification unit, a detection and comparison unit, and a gain adjustment unit. The control unit adjusts the functional relationship between the adjustment current generated by the gain adjustment unit and the bias current of the power amplification unit based on the functional relationship between the gain of the power amplification unit and its output power in different frequency bands and different power level modes, and then compares the bias current of the power amplification unit detected in real time by the detection and comparison unit with a reference current. Based on the comparison result, the control unit controls whether the gain adjustment unit generates and outputs the adjustment current to the power amplification unit, thereby flexibly and effectively compensating for the gain of the power amplification unit in different modes and improving 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, as the output power of a conventional RF front-end module increases, its gain gradually decreases, affecting its linearity. To address this issue, linearization bias technology is typically used in the bias circuit of the power amplifier. However, in wideband RF front-end modules, it is difficult to adapt this adaptive bias circuit to the wideband frequency requirements. At the same time, the gain adjustment at different power levels is also inflexible, making it difficult to successfully optimize the linearity of the RF front-end module at different power levels. 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 including a control unit, a power amplification unit, a detection and comparison unit, and a gain adjustment unit, wherein the output end of the control unit is connected to the input ends of the detection and comparison unit and the gain adjustment unit, the detection end of the power amplification unit is connected to the input end of the detection and comparison unit, the output end of the detection and comparison unit is connected to the input end of the control unit, and the output end of the gain adjustment unit is connected to the bias end of the power amplification unit.

[0009] The control unit detects the bias current of the power amplifier unit in real time by the detection and comparison unit. generated by the detection and comparison unit Based on the comparison with the reference current, different output electric power level In order to ensure that the gain of the power amplification unit operating at a constant voltage does not change, the gain adjustment unit controls whether to generate and output an adjustment current to the power amplification unit. The control unit also controls the reference current generated by the detection and comparison unit so that it becomes large when the power amplifier unit outputs a large power and becomes small when the power amplifier unit outputs a small power.

[0010] Preferably, when the bias current of the power amplifier unit is greater than the reference current, the control unit output electric power level The gain adjustment unit generates an adjustment current to ensure that the gain of the power amplification unit operating at a constant current does not change. , and its adjustment current is The power amplifier unit is controlled to output the power.

[0011] When the bias current of the power amplifier unit is smaller than the reference current, the control unit controls the gain adjustment unit to stop outputting the adjustment current to the power amplifier unit.

[0012] Preferably, the power amplification unit includes at least one stage of amplification circuit, each stage of amplification circuit is connected to one first bias circuit, the first bias circuit of any one of the stages of amplification circuit is connected to the input terminal of the detection and comparison unit, and the output terminal of the detection and comparison unit is connected to the bias terminal of any one stage of amplification circuit adjacent to the any one stage of amplification circuit via the gain adjustment unit controlled by the control unit.

[0013] 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 final stage is impedance-matched with an external antenna via an output matching circuit.

[0014] Preferably, the detection and comparison unit comprises a current collection circuit, a current size comparison circuit and a reference current generation circuit, the input terminal of the current collection circuit is connected to the bias circuit of any one stage of amplifier circuit, the output terminals of the current collection circuit and the reference current generation circuit are connected to the input terminal of the current size comparison circuit, the output terminal of the current size comparison circuit is connected to the input terminal of the control unit, and the output terminal of the control unit is connected to the input terminal of the reference current generation circuit.

[0015] Preferably, the gain adjustment unit includes a bias current generating circuit.

[0016] When the power amplifier unit includes a single-stage amplifier circuit, the input terminal of the bias current generating circuit is connected to the control unit, and the output terminal of the bias current generating circuit is The bias currentIt is connected to the bias terminal of the amplifier circuit to be detected.

[0017] When the power amplification unit has two or more stages of amplification circuits, the input terminal of the bias current generation circuit is connected to the control unit, and the output terminal of the bias current generation circuit is connected to the bias terminal of any one stage of amplification circuit adjacent to the amplification circuit to be detected.

[0018] Preferably, the gain adjustment unit includes a bias current generating circuit and a second bias circuit.

[0019] When the power amplification unit includes a single stage amplifier circuit, the input terminal of the bias current generating circuit is connected to the control unit, the output terminal of the bias current generating circuit is connected to the input terminal of the second bias circuit, and the output terminal of the second bias circuit is connected to the bias terminal of the amplifier circuit of this stage.

[0020] When the power amplification unit has two or more stages of amplification circuits, the input terminal of the bias current generation circuit is connected to the control unit, the output terminal of the bias current generation circuit is connected to the input terminal of the second bias circuit, and the output terminal of the second bias circuit is connected to the bias terminal of any one-stage amplification circuit adjacent to the amplification circuit to be detected.

[0021] Preferably, the gain adjustment unit includes a bias current generating circuit and a third resistor.

[0022] When the power amplification unit has a single stage of amplification circuit, the input terminal of the bias current generating circuit is connected to the control unit, the output terminal of the bias current generating circuit is connected to one terminal of the third resistor, and the other terminal of the third resistor is connected to the bias terminal of the amplification circuit of this stage.

[0023] When the power amplification unit has two or more stages of amplification circuits, the input terminal of the bias current generation circuit is connected to the control unit, the output terminal of the bias current generation circuit is connected to one terminal of the third resistor, and the other terminal of the third resistor is connected to the bias terminal of any one-stage amplification circuit adjacent to the amplification circuit to be detected.

[0024] Preferably, the RF power amplifier further comprises a power supply unit, the input terminal of the power supply unit is connected to the output terminal of the control unit, and the output terminal of the power supply unit is connected to the power supply terminal of the power amplification unit.

[0025] According to a second aspect of an embodiment of the present invention, there is provided an RF front-end module comprising the RF power amplifier.

[0026] According to a third aspect of an embodiment of the present invention, there is provided a communication terminal including the RF power amplifier. [Effects of the Invention]

[0027] In the RF power amplifier provided by the present invention, the control unit adjusts the functional relationship between the adjustment current generated by the gain adjustment unit and the bias current of the power amplification unit based on the functional relationship between the gain of the power amplification unit and its output power in different frequency bands and different power level modes, and then compares the bias current of the power amplification unit detected in real time by the detection and comparison unit with a reference current.The control unit controls whether the gain adjustment unit generates and outputs an adjustment current to the power amplification unit based on the comparison result, thereby flexibly and effectively achieving gain compensation of the power amplification unit in different modes and improving the linearity index of the RF front-end module. [Brief explanation of the drawings]

[0028] [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] 1 is a schematic diagram showing a combined structure of a first gain adjustment unit, a power amplification unit, and a detection and comparison unit in an RF power amplifier provided by the present invention; [Figure 4] 1 is a schematic diagram showing a combined structure of a second gain adjustment unit, a power amplification unit, and a detection and comparison unit in an RF power amplifier provided by the present invention; [Figure 5] 10 is a schematic diagram showing a configuration in which a third gain adjustment unit, a power amplification unit, and a detection and comparison unit are combined in an RF power amplifier provided by the present invention. FIG. [Figure 6] 2 is a schematic diagram showing the curve of the adjustment current changing according to the output power of the power amplification unit in the RF power amplifier provided by the present invention; FIG. [Figure 7] 2 is a schematic diagram showing a curve of the bias current of the power amplifier varying with the output power in the RF power amplifier provided by the present invention; FIG. [Figure 8] 3 is a schematic diagram showing the curves of the gain of a power amplification unit changing with output power when the RF power amplifier provided by the present invention is used and when it is not used; FIG. [Figure 9] FIG. 10 is a comparative diagram showing curves of ACPR change according to output power when an 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; DETAILED DESCRIPTION OF THE INVENTION

[0029] The technical contents of the present invention will be described in more detail below with reference to the accompanying drawings and specific embodiments.

[0030] 1 , to solve the problem that the linearity of an RF front-end module cannot be properly optimized due to the inflexible gain adjustment of the RF power amplifier at different power levels, 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 and comparison unit 130, and a gain adjustment unit 140. The output terminal of the control unit 100 is connected to the input terminals of the detection and comparison unit 130, the gain adjustment unit 140, and the power supply unit 120, respectively. The detection terminal of the power amplification unit 110 is connected to the input terminal of the detection and comparison unit 130, the output terminal of the detection and comparison unit 130 is connected to the input terminal of the control unit 100, the output terminal of the gain adjustment unit 140 is connected to the bias terminal of the power amplification unit 110, and the power supply terminal of the power amplification unit 110 is connected to the output terminal of the power supply unit 120.

[0031] The control unit 100 controls whether the gain adjustment unit 140 generates and outputs an adjustment current to the power amplification unit 110 based on the comparison result between the bias current of the power amplification unit 110 detected in real time by the detection and comparison unit 130 and the reference current, thereby ensuring optimal linearity of the RF front-end module. Specifically, as shown in FIG. 2 , when the bias current of the power amplification unit 110 detected in real time by the detection and comparison unit 130 is greater than the reference current, the control unit 100 controls the gain adjustment unit 140 to generate and output an adjustment current to the power amplification unit 110, thereby ensuring that the gain of the power amplification unit 110 operating at different power levels does not change. When the bias current of the power amplification unit 110 detected in real time by the detection and comparison unit 130 is smaller than the reference current, the control unit 100 controls the gain adjustment unit 140 to stop outputting the adjustment current to the power amplification unit 110.

[0032] Here, the control unit 100 can be realized using a central processing unit in a communication terminal. The control unit 100 can control not only the operating state of the power supply unit 120 but also the magnitude of the power supply voltage and current generated and output during operation. As an application, the control unit 100 can control the functional relationship between the adjustment current generated by the gain adjustment unit 140 and the bias current of the power amplification unit 110 based on the functional relationship in which the gain of the power amplification unit 110 decreases as its output power increases.

[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 of which is connected to a first bias circuit. The first bias circuit of any one amplifier circuit is connected to the input terminal of the detection and comparison unit 130. The output terminal of the detection and comparison unit 130 is connected via the gain adjustment unit 140 to the bias terminal of any one amplifier circuit adjacent to the amplifier circuit of that stage, and the bias terminal of the amplifier circuit of that stage is used as the detection terminal of the power amplifier unit 110.

[0034] When the power amplifier unit 110 has only one amplifier circuit, the amplifier circuit of this stage is impedance-matched with an external antenna via an output matching circuit. The first bias circuit of the amplifier circuit of this stage is connected to the input terminal of the detection and comparison unit 130, and the output terminal of the detection and comparison unit 130 is connected to the bias terminal of the amplifier circuit of this stage via the gain adjustment unit 140. Similarly, the bias terminal of the amplifier circuit of this stage is used as the detection terminal of the power amplifier unit 110.

[0035] When the power amplifier unit 110 includes two or more stages of amplifier circuits (including two stages, the same applies below), the amplifier circuits of each stage are connected via inter-stage matching circuits, and the amplifier circuit of the final stage is impedance-matched with an external antenna via an output matching circuit. Here, the first bias circuit of any one amplifier stage is connected to the input terminal of the detection and comparison unit 130, and the output terminal of the detection and comparison unit 130 is connected via the gain adjustment unit 140 to the bias terminal of any one amplifier stage adjacent to the amplifier circuit of that stage.

[0036] 3, for example, when the power amplifier unit 110 includes a two-stage amplifier circuit 1101, the first-stage amplifier circuit and the second-stage amplifier circuit are connected via an inter-stage matching circuit, and the second-stage amplifier circuit is impedance-matched with an external antenna via an output matching circuit. Here, the amplifier circuits 1101 of each stage, the inter-stage matching circuit, and the output matching circuit are conventional ordinary circuits, and will not be described in detail here.

[0037] The first bias circuit is used to supply a bias voltage and a bias current to the corresponding amplifier circuit. As shown in FIG. 3, in a two-stage amplifier circuit, one first bias circuit 1103 is connected to each of the first and second stage amplifier circuits. Each first 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 first 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, and the emitter of the third crystal triode HBT3 is grounded.

[0038] The power supply unit 120 provides the necessary bias voltage and operating current for the power amplifier unit 110. The power supply unit 120 is realized using a linear stable voltage power supply.

[0039] 3, the detection and comparison unit 130 includes a current collection circuit 1301, a current size comparison circuit 1302, and a reference current generation circuit 1304. The input terminal of the current collection circuit 1301 is connected to the bias circuit of any one stage of the amplifier circuit, the output terminals of the current collection circuit 1301 and the reference current generation circuit 1304 are connected to the input terminal of the current size comparison circuit 1302, the output terminal of the current size comparison circuit 1302 is connected to the input terminal of the control unit 100, and the output terminal of the control unit 100 is connected to the input terminal of the reference current generation circuit 1304. Here, the current collection circuit 1301, the current size comparison circuit 1302, and the reference current generation circuit 1304 are conventional ordinary circuits, and the results of each circuit will not be described in detail.

[0040] The operation principle of the detection and comparison unit 130 is as follows. First, the control unit 100 controls the magnitude of the reference current generated by the reference current generation circuit 1304 based on the actual application scenario. For example, the reference current is large when high power is applied, and small when low power is applied. This reference current is output to the current size comparison circuit 1302. Then, the current collection circuit 1301 outputs the bias current of a specific stage of the amplifier circuit in the power amplifier unit 110, detected in real time, to the current size comparison circuit 1302. The current collection circuit 1301 compares the bias current of the power amplifier unit 110 with the reference current and feeds back the comparison result to the control unit 100. Based on the comparison result, the control unit 100 further controls whether the gain adjustment unit 140 generates and outputs an adjustment current to the power amplifier unit 110, thereby ensuring that the gain of the power amplifier unit 110 operating at different power levels does not change, thereby ensuring optimal linearity of the RF front-end module.

[0041] 3, in the embodiment of the present invention, the gain adjustment unit 140 includes a bias current generation circuit 1401. An input terminal of the bias current generation circuit 1401 is connected to the control unit 100, and an output terminal of the bias current generation circuit 1401 is connected to a bias terminal of any one stage of an amplifier circuit adjacent to the amplifier circuit to be detected. Alternatively, the output terminal of the bias current generation circuit 1401 is connected to the bias terminal of the amplifier circuit to be detected (when there is only one amplifier circuit).

[0042] Specifically, when the bias current of the power amplification unit 110 detected in real time by the detection and comparison unit 130 is greater than the reference current, the control unit 100 controls the bias current generation circuit 1401 to operate and generate an adjustment current (as shown in the latter half of FIG. 6 ). This adjustment current is output to the corresponding amplifier circuit to increase the gain of the power amplification unit 110, thereby compensating for the problem of the gain of the power amplification unit 110 decreasing as the output power of the power amplification unit 110 increases and ensuring that the gain of the power amplification unit 110 does not change when operating at different power levels, thereby achieving the purpose of optimizing the linearity of the RF front-end module.

[0043] If the bias current of the power amplifier unit 110 detected in real time by the detection and comparison unit 130 is smaller than the reference current, it indicates that the gain of the power amplifier unit 110 meets the requirement, and the control unit 100 controls the bias current generation circuit 1401 to stop operating, i.e., to stop outputting the adjustment current to the power amplifier unit 110 (so that there is no adjustment current output in the first half of Figure 6).

[0044] A detailed description will be given below of a case where the bias current of the power amplifier unit 110 detected in real time by the detection and comparison unit 130 is greater than the reference current.

[0045] 3, the power amplifier unit 110 includes a two-stage amplifier circuit 1101, and the current collector circuit 1301 detects the bias current of the second-stage amplifier circuit. When the current collector circuit 1301 detects in real time that the bias current of the first crystal triode HBT1 corresponding to the second-stage amplifier circuit is greater than the reference current, the control unit 100 controls the bias current generator circuit 1401 to operate and generate an adjustment current to be output to the first-stage amplifier circuit in order to increase the gain of the power amplifier unit 110.

[0046] Specifically, the current collecting circuit 1301 detects in real time the bias current of the first HBT1 crystal triode corresponding to the second-stage amplifier circuit, which increases as the input power or output power of the power amplifier unit 110 increases. For example, as shown in FIG. 7, the bias current of the second-stage amplifier circuit increases as the input power of the power amplifier unit 110 increases, but the gain of the power amplifier unit 110 decreases as its output power increases. Therefore, the bias current generating circuit 1401 generates an adjustment current to be output to the first-stage amplifier circuit, and the adjustment current generated by the bias current generating circuit 1401 is supplied to the first-stage amplifier circuit by utilizing the positive correlation between the magnitude of the adjustment current generated by the bias current generating circuit 1401 and the bias current of the first HBT1 crystal triode in the second-stage amplifier circuit. This increases the gain of the power amplifier unit 110, compensates for the problem of the gain of the power amplifier unit 110 decreasing as the output power of the power amplifier unit 110 increases, and ensures that the gain of the power amplifier unit 110 does not change when operating at different power levels, thereby achieving the purpose of optimizing the linearity of the RF front-end module.

[0047] The thin curve in Figure 8 indicates that after using this RF power amplifier, the gain of the power amplifier remains unchanged as the output power of the RF power amplifier increases, thereby ensuring optimal linearity of the RF front-end module. As shown in Figure 9, ACPR is an indicator of the linearity of an RF power amplifier; the smaller the ACPR, the better the linearity of the RF power amplifier. The thin curve in Figure 9 indicates that after using this RF power amplifier, as the output power of the RF power amplifier increases, its linearity is significantly higher than that of the unused RF power amplifier, as shown by the thick curve.

[0048] As shown in FIG. 4 , in another embodiment of the present invention, the gain adjustment unit 140 includes a bias current generation circuit 1401 and a second bias circuit 1402. The input terminal of the bias current generation circuit 1401 is connected to the control unit 100, the output terminal of the bias current generation circuit 1401 is connected to the input terminal of the second bias circuit 1402, and the output terminal of the second bias circuit 1402 is connected to the bias terminal of any one stage of an amplifier circuit adjacent to the amplifier circuit to be detected. Alternatively, the output terminal of the second bias circuit 1402 is connected to the bias terminal of the amplifier circuit to be detected (when there is only one amplifier circuit). Here, the second bias circuit 1402 has the same structure as the first bias circuit, and the other terminal of the second resistor of the second bias circuit 1402 is used as the input terminal of the second bias circuit 1402, and the other terminal of the first resistor of the second bias circuit 1402 is used as the output terminal of the second bias circuit 1402.

[0049] Specifically, when the bias current of the power amplification unit 110 detected in real time by the detection and comparison unit 130 is greater than the reference current, the control unit 100 controls the bias current generation circuit 1401 to operate and generate an adjusted current (as shown in the latter half of FIG. 6 ). This adjusted current is output to the second bias circuit 1402 to supply bias power to the second bias circuit 1402, which then controls the second bias circuit 1402 to generate a bias current and supply it to the corresponding amplifier circuit. This increases the gain of the power amplification unit 110, compensates for the problem of the gain of the power amplification unit 110 decreasing as the output power of the power amplification unit 110 increases, and ensures that the gain of the power amplification unit 110 does not change when operating at different power levels, thereby achieving the goal of optimizing the linearity of the RF front-end module.

[0050] If the bias current of the power amplifier unit 110 detected in real time by the detection and comparison unit 130 is smaller than the reference current, it indicates that the gain of the power amplifier unit 110 meets the requirement, and the control unit 100 controls the bias current generation circuit 1401 to stop operating, i.e., to stop outputting the adjustment current to the power amplifier unit 110 (so that there is no adjustment current output in the first half of Figure 6).

[0051] A detailed description will be given below of the case where the bias current of the power amplifier unit 110 detected in real time by the detection and comparison unit 130 is greater than the reference current.

[0052] 4, the power amplifier unit 110 includes a two-stage amplifier circuit 1101, and the current collector circuit 1301 detects the bias current of the second-stage amplifier circuit. When the current collector circuit 1301 detects in real time that the bias current of the first HBT1 crystal triode corresponding to the second-stage amplifier circuit is greater than the reference current, the control unit 100 controls the bias current generator circuit 1401 to operate and generate an adjusted current that is output to the second bias circuit 1402 and used to supply bias power to the second bias circuit 1402. This controls the second bias circuit 1402 to generate a bias current and supply it to the first-stage amplifier circuit, thereby increasing the gain of the power amplifier unit 110.

[0053] Specifically, the current collecting circuit 1301 detects in real time the bias current of the first HBT1 crystal triode corresponding to the second-stage amplifier circuit, which increases as the input power or output power of the power amplifier unit 110 increases. For example, as shown in FIG. 7, the bias current of the second-stage amplifier circuit increases as the input power of the power amplifier unit 110 increases, but the gain of the power amplifier unit 110 decreases as the output power thereof increases. Therefore, the bias current generating circuit 1401 generates an adjustment current to be output to the second bias circuit 1402, and the bias current generated by the second bias circuit 1402 can be supplied to the first-stage amplifier circuit by utilizing the positive correlation between the magnitude of the adjustment current generated by the bias current generating circuit 1401 and the bias current of the first HBT1 crystal triode in the second-stage amplifier circuit. This increases the gain of the power amplification unit 110, compensates for the problem of the gain of the power amplification unit 110 decreasing as the output power of the power amplification unit 110 increases, and ensures that the gain of the power amplification unit 110 does not change when operating at different power levels, thereby achieving the purpose of optimizing the linearity of the RF front-end module.

[0054] 5, in a further embodiment of the present invention, the gain adjustment unit 140 includes a bias current generating circuit 1401 and a third resistor R3. The input terminal of the bias current generating circuit 1401 is connected to the control unit 100, the output terminal of the bias current generating circuit 1401 is connected to one terminal of the third resistor R3, and the other terminal of the third resistor R3 is connected to the bias terminal of any one stage of an amplifier circuit adjacent to the amplifier circuit to be detected. Alternatively, the other terminal of the third resistor R3 is connected to the bias terminal of the amplifier circuit to be detected (when there is only one amplifier circuit).

[0055] Specifically, when the bias current of the power amplifier unit 110 detected in real time by the detection and comparison unit 130 is greater than the reference current, the control unit 100 controls the bias current generation circuit 1401 to generate an adjustment current (as shown in the latter half of FIG. 6). This adjustment current is output to the first-stage amplifier circuit via the third resistor R3, increasing the gain of the power amplifier unit 110. This compensates for the problem of the gain of the power amplifier unit 110 decreasing as the output power of the power amplifier unit 110 increases, and ensures that the gain of the power amplifier unit 110 does not change when operating at different power levels, thereby achieving the goal of optimizing the linearity of the RF front-end module. Here, the third resistor R3 performs a voltage division function to control the bias voltage input to the first amplifier circuit, further ensuring that the gain of the power amplifier unit 110 increases within a predetermined range.

[0056] If the bias current of the power amplifier unit 110 detected in real time by the detection and comparison unit 130 is smaller than the reference current, it indicates that the gain of the power amplifier unit 110 meets the requirement, and the control unit 100 controls the bias current generation circuit 1401 to stop operating, i.e., to stop outputting the adjustment current to the power amplifier unit 110 (so that there is no adjustment current output in the first half of Figure 6).

[0057] A detailed description will be given below of a case where the bias current of the power amplifier unit 110 detected in real time by the detection and comparison unit 130 is greater than the reference current.

[0058] 5, for example, the power amplifier unit 110 includes a two-stage amplifier circuit 1101, and the current collector circuit 1301 detects the bias current of the second-stage amplifier circuit. When the current collector circuit 1301 detects in real time that the bias current of the first crystal triode HBT1 corresponding to the second-stage amplifier circuit is greater than the reference current, the control unit 100 controls the operation of the bias current generator circuit 1401 to generate an adjusted current that is output to the first-stage amplifier circuit through the third resistor R3 to increase the gain of the power amplifier unit 110.

[0059] Specifically, the current collecting circuit 1301 detects in real time the bias current of the first crystal triode HBT1 corresponding to the second-stage amplifier circuit, which increases with an increase in the input power or output power of the power amplifier unit 110. For example, as shown in Fig. 7, the bias current of the second-stage amplifier circuit increases with an increase in the input power of the power amplifier unit 110, but the gain of the power amplifier unit 110 decreases with an increase in its output power. Therefore, the bias current generating circuit 1401 can generate an adjustment current that is output to the first-stage amplifier circuit via the third resistor R3. By utilizing the positive correlation between the magnitude of the adjustment current generated by the bias current generating circuit 1401 and the bias current of the first crystal triode HBT1 in the second-stage amplifier circuit, the gain of the power amplifier unit 110 is increased, thereby compensating for the problem of the gain of the power amplifier unit 110 decreasing as the output power of the power amplifier unit 110 increases, and ensuring that the gain of the power amplifier unit 110 operating at different power levels does not change, thereby achieving the purpose of optimizing the linearity of the RF front-end module.

[0060] In the RF power amplifier provided by the present invention, the control unit adjusts the functional relationship between the adjustment current generated by the gain adjustment unit and the bias current of the power amplification unit based on the functional relationship between the gain of the power amplification unit and its output power under different RF band and different power level modes, and then compares the bias current of the power amplification unit detected in real time by the detection and comparison unit with a reference current.The control unit controls whether the gain adjustment unit generates and outputs the adjustment current to the power amplification unit based on the comparison result, thereby flexibly and effectively achieving gain compensation of the power amplification unit in different modes and improving the linearity index of the RF front-end module.

[0061] 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.

[0062] Here, as shown in FIG. 10 , in addition to the RF power amplifier, the RF front-end module may also include a control unit 100 for the RF power amplifier, a power supply unit 120, and a switch unit 150 connected to the power amplification unit 110. The RF signal amplified by the RF power amplifier is transmitted to an antenna via the switch unit 150 and then transmitted to a base station via the antenna, thereby enabling the RF front-end module to transmit the RF signal to the base station. The switch unit 150 can be implemented using a single-pole multi-throw switch or a multi-pole multi-throw switch. The operation mode of the switch unit 150 and the switch state of the output port are controlled by the control unit 100.

[0063] If RF signals need to be transmitted bidirectionally between the RF front-end module and the base station, a low-noise amplifier can be installed in the RF front-end module and connected to the switch unit. The RF signals transmitted from the base station are power-amplified by the low-noise amplifier, then sent to the transceiver for demodulation.

[0064] 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.

[0065] 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 can also be used in communication base stations that support multiple communication standards, and other communication technologies are not described in detail here.

[0066] 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: The power amplifier includes a control unit, a power amplifier unit, a detection and comparison unit, and a gain adjustment unit, wherein the output terminal of the control unit is connected to the input terminals of the detection and comparison unit and the gain adjustment unit, respectively, the detection terminal of the power amplifier unit is connected to the input terminal of the detection and comparison unit, the output terminal of the detection and comparison unit is connected to the input terminal of the control unit, and the output terminal of the gain adjustment unit is connected to the bias terminal of the power amplifier unit; the control unit controls whether the gain adjustment unit generates and outputs an adjustment current to the power amplification unit based on a comparison result between the reference current generated by the detection and comparison unit and the bias current of the power amplification unit detected in real time by the detection and comparison unit, so as to ensure that the gain of the power amplification unit operating at different output power levels does not change; the control unit controls the reference current generated by the detection and comparison unit so that the reference current is large when the power amplification unit outputs a large power and is small when the power amplification unit outputs a small power; When the bias current of the power amplification unit is greater than the reference current, the control unit controls the gain adjustment unit to generate the adjustment current and output the adjustment current to the power amplification unit through the bias terminal, so as to ensure that the gain of the power amplification unit operating at different output power levels does not change; When the bias current of the power amplification unit is smaller than the reference current, the control unit controls the gain adjustment unit to stop outputting the adjustment current to the power amplification unit.

2. 2. The RF power amplifier according to claim 1, wherein the power amplification unit includes at least one amplifier circuit, each of the at least one amplifier circuit stages is connected to a first bias circuit, the first bias circuit connected to an arbitrary one of the amplifier circuits stages is connected to an input terminal of the detection and comparison unit, and the output terminal of the detection and comparison unit is connected to a bias terminal of an arbitrary one amplifier circuit stage adjacent to the arbitrary one amplifier circuit stage via the gain adjustment unit controlled by the control unit.

3. 3. The RF power amplifier according to claim 2, 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 gain adjustment unit, and a final stage amplifier circuit is impedance-matched with an external antenna via an output matching circuit.

4. 4. The RF power amplifier according to claim 3, wherein the detection and comparison unit comprises a current collection circuit, a current size comparison circuit, and a reference current generation circuit that generates the reference current, an input terminal of the current collection circuit is connected to a first bias circuit of the any one-stage amplification circuit, output terminals of the current collection circuit and the reference current generation circuit are connected to an input terminal of the current size comparison circuit, an output terminal of the current size comparison circuit is connected to an input terminal of the control unit, and an output terminal of the control unit is connected to the input terminal of the reference current generation circuit.

5. the gain adjustment unit includes a bias current generating circuit; When the power amplification unit includes a single-stage amplifier circuit, an input terminal of the bias current generation circuit is connected to the control unit, and an output terminal of the bias current generation circuit is connected to a bias terminal of the single-stage amplifier circuit that is the detection target of the bias current, 5. The RF power amplifier according to claim 4, wherein, when the power amplification unit includes two or more stages of amplification circuits, an input terminal of the bias current generation circuit is connected to the control unit, and an output terminal of the bias current generation circuit is connected to a bias terminal of any one stage of amplification circuit adjacent to the amplification circuit to be detected.

6. the gain adjustment unit includes a bias current generating circuit and a second bias circuit; When the power amplification unit includes a single-stage amplifier circuit, an input terminal of the bias current generation circuit is connected to the control unit, an output terminal of the bias current generation circuit is connected to an input terminal of the second bias circuit, and an output terminal of the second bias circuit is connected to a bias terminal of the single-stage amplifier circuit; 5. The RF power amplifier according to claim 4, wherein, when the power amplification unit includes two or more stages of amplification circuits, an input terminal of the bias current generation circuit is connected to the control unit, an output terminal of the bias current generation circuit is connected to an input terminal of the second bias circuit, and an output terminal of the second bias circuit is connected to a bias terminal of an arbitrary one-stage amplification circuit adjacent to the amplification circuit whose bias current is to be detected.

7. the gain adjustment unit includes a bias current generating circuit and a third resistor; when the power amplification unit includes a single-stage amplification circuit, an input terminal of the bias current generation circuit is connected to the control unit, an output terminal of the bias current generation circuit is connected to one terminal of the third resistor, and the other terminal of the third resistor is connected to a bias terminal of the single-stage amplification circuit; 5. The RF power amplifier according to claim 4, wherein, when the power amplification unit includes two or more stages of amplification circuits, an input terminal of the bias current generation circuit is connected to the control unit, an output terminal of the bias current generation circuit is connected to one terminal of the third resistor, and the other terminal of the third resistor is connected to a bias terminal of an arbitrary one-stage amplification circuit adjacent to the amplification circuit whose bias current is to be detected.

8. 2. The RF power amplifier according to claim 1, further comprising a power supply unit, an input terminal of the power supply unit being connected to an output terminal of the control unit, and an output terminal of the power supply unit being connected to a power supply terminal of the power amplification unit.

9. An RF front-end module comprising an RF power amplifier according to any one of claims 1 to 8.

10. A communication terminal comprising the RF power amplifier according to any one of claims 1 to 8.

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