Low noise amplifier and radio frequency front end module

Abstract

The application discloses a low-noise amplifier and a radio frequency front-end module. The low-noise amplifier comprises an amplifier circuit configured to receive a radio frequency input signal and output a radio frequency output signal, the amplifier circuit comprising a first transistor and a first adjusting branch. An input end of the first adjusting branch is used for receiving an externally input first bias voltage, and an output end of the first adjusting branch is connected with a controlled end of the first transistor. The first adjusting branch comprises a first voltage dividing unit, a second voltage dividing unit and a first switch unit. A first end of the first voltage dividing unit is connected with the input end of the first adjusting branch, a second end of the first voltage dividing unit is connected with the output end of the first adjusting branch, a first end of the second voltage dividing unit is connected with the first end of the first voltage dividing unit, a second end of the second voltage dividing unit is connected with a first end of the first switch unit, and a second end of the first switch unit is connected with the second end of the first voltage dividing unit. The low-noise amplifier provided by the application can realize fast gain switching.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a low-noise amplifier and a radio frequency front-end module. Background Technology

[0002] In radio frequency and microwave systems such as wireless communication and radar, low noise amplifiers (LNAs) are widely used in various transceiver links to amplify weak signals. In time-division communication systems, the receive and transmit modes need to be switched constantly, so the system requires the transceiver link to have a fast switching time. As a crucial active device in the transceiver link, the switching time of the amplifier directly determines the switching time of the transceiver link.

[0003] Typically, low-noise amplifiers (LNAs) are at the very front end of the RF receiver link, and their performance directly affects the overall receiver performance. For example, in 5G RF applications, LNAs are required to have automatic gain control (AGC) functionality, and to improve communication efficiency, they need to have a fast gain switching time. However, in existing technologies, the stable gain waveform of LNAs is slow to establish, resulting in a long gain level switching time.

[0004] Therefore, how to shorten the switching time of low-noise amplifier gain levels in order to accelerate the switching response speed of the circuit is a hot topic that is being studied by those skilled in the art. Summary of the Invention

[0005] Based on this, embodiments of this application provide a low-noise amplifier and an RF front-end module, which aim to shorten the switching time of the low-noise amplifier gain level, so as to achieve fast switching of the low-noise amplifier gain level.

[0006] In a first aspect, embodiments of this application provide a low-noise amplifier, including:

[0007] An amplifier circuit is configured to receive a radio frequency (RF) input signal and output an RF output signal. The amplifier circuit includes a first transistor, a second transistor, and a first adjustment branch. The first terminal of the first transistor and the second terminal of the second transistor are connected. The RF input signal is input to the amplifier circuit through the controlled terminal of the second transistor, and the RF output signal is output through the second terminal of the first transistor. The input terminal of the first adjustment branch is used to receive a first bias voltage from an external input, and the output terminal of the first adjustment branch is connected to the controlled terminal of the first transistor.

[0008] The first regulating branch includes a first voltage divider unit, a second voltage divider unit, and a first switching unit. The first end of the first voltage divider unit is connected to the input end of the first regulating branch, the second end of the first voltage divider unit is connected to the output end of the first regulating branch, the first end of the second voltage divider unit is connected to the first end of the first voltage divider unit, the second end of the second voltage divider unit is connected to the first end of the first switching unit, and the second end of the first switching unit is connected to the second end of the first voltage divider unit.

[0009] In some implementations, the second voltage divider unit is configured to adjust the overshoot height of the output pulse corresponding to the output terminal of the first regulating branch.

[0010] In some implementations, the resistance of the second voltage divider unit is adjustable, and the overshoot height of the output pulse of the first adjustment branch can be adjusted by adjusting the resistance of the second voltage divider unit.

[0011] In some implementations, the second voltage divider unit is configured to adjust the gain switching time of the amplifier circuit.

[0012] In some implementations, when the second voltage divider unit is connected to the first adjustment branch through the first switching unit, the gain switching time of the amplifier circuit is less than 1µs.

[0013] In some implementations, the first voltage divider unit includes a first resistor, and the second voltage divider unit includes a second resistor, wherein the resistance of the first resistor is greater than the resistance of the second resistor.

[0014] In some embodiments, the ratio of the resistance of the first resistor to the resistance of the second resistor is greater than 10; or, the ratio of the resistance of the first resistor to the resistance of the second resistor is greater than 10 and less than or equal to 100.

[0015] In some embodiments, the low-noise amplifier further includes a switching control circuit configured to provide at least a first switching control signal to the amplifier circuit and output the first switching control signal to a first switching unit to turn the first switching unit on or off.

[0016] In some embodiments, the first switching unit includes a transmission gate and / or a switching transistor.

[0017] In some implementations, the switching control circuit is equipped with a capacitor unit, and the capacitance value of the capacitor unit is adjustable.

[0018] The pulse width corresponding to the first switching control signal can be adjusted by adjusting the capacitance value of the capacitor unit.

[0019] In some implementations, the pulse width corresponding to the first switching control signal is 200ns-600ns.

[0020] In some implementations, the switching control circuit includes a first inverter, a first NAND flash and a first capacitor, wherein the output of the first inverter is connected to the first input of the first NAND flash and the first capacitor.

[0021] The enable signal is input to the first input terminal of the first NAND gate through the first inverter, and the enable signal is also input to the second input terminal of the first NAND gate; the first NAND gate generates a first switching control signal through the input signals from the first input terminal and the second input terminal.

[0022] In some implementations, the amplifier circuit further includes a second regulation branch, the input of which is used to receive a second bias voltage from an external input, and the output of which is connected to the controlled terminal of the second transistor.

[0023] In some embodiments, the second regulating branch includes a third voltage divider unit, a fourth voltage divider unit, and a second switching unit. The first end of the third voltage divider unit is connected to the input end of the second regulating branch, the second end of the third voltage divider unit is connected to the output end of the second regulating branch, the first end of the fourth voltage divider unit is connected to the first end of the third voltage divider unit, the second end of the fourth voltage divider unit is connected to the first end of the second switching unit, and the second end of the second switching unit is connected to the second end of the third voltage divider unit.

[0024] In some implementations, the fourth voltage divider unit is configured to adjust the overshoot height of the output pulse corresponding to the output terminal of the second adjustment branch.

[0025] In some implementations, the resistance of the fourth voltage divider unit is adjustable, and the overshoot height of the output pulse of the second regulating branch can be adjusted by adjusting the resistance of the fourth voltage divider unit.

[0026] Secondly, embodiments of this application provide a low-noise amplifier, including:

[0027] An amplifier circuit is configured to receive a radio frequency (RF) input signal and output a radio frequency (RF) output signal. The amplifier circuit includes a first transistor and a first adjustment branch. The RF input signal is input to the amplifier circuit through the controlled terminal of the first transistor, and the RF output signal is output through the second terminal of the first transistor. The input terminal of the first adjustment branch is used to receive a first bias voltage from an external input, and the output terminal of the first adjustment branch is connected to the controlled terminal of the first transistor.

[0028] The first regulating branch includes a first voltage divider unit, a second voltage divider unit, and a first switching unit. The first end of the first voltage divider unit is connected to the input end of the first regulating branch, the second end of the first voltage divider unit is connected to the output end of the first regulating branch, the first end of the second voltage divider unit is connected to the first end of the first voltage divider unit, the second end of the second voltage divider unit is connected to the first end of the first switching unit, and the second end of the first switching unit is connected to the second end of the first voltage divider unit.

[0029] Thirdly, embodiments of this application provide a radio frequency front-end module, which includes at least the aforementioned low-noise amplifier.

[0030] This application provides a low-noise amplifier and a radio frequency front-end module. The amplifier circuit of the low-noise amplifier is provided with a first adjustment branch. The first adjustment branch is used to receive external control signals and use the control signals to control the first switching unit of the first adjustment branch to switch between the on state and the off state, thereby realizing the gain switching of the low-noise amplifier.

[0031] During the switching process of the first switching unit in the on or off state, since the first regulating branch is equipped with a second voltage divider unit, the first switching unit connects the second voltage divider unit and the first voltage divider unit in parallel when the first switching unit is in the on state, so that the first bias voltage input through the first regulating branch can be charged and discharged quickly, and the first bias voltage can be quickly stabilized at the preset voltage value, thereby realizing the rapid switching of the gain level of the low noise amplifier.

[0032] Furthermore, since the first adjustment branch is equipped with a second voltage divider unit, when the first switching unit connects the second voltage divider unit and the first voltage divider unit in parallel while the first switching unit is in the conducting state, the change amplitude of the equivalent resistance of the first adjustment branch can be effectively reduced, thereby effectively reducing the instantaneous overshoot formed at the controlled end of the transistor, enabling the amplifier circuit to quickly establish the gain waveform, effectively shortening the switching time of the low-noise amplifier gain level, and ultimately realizing the rapid switching of the low-noise amplifier gain level.

[0033] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1This is a structural block diagram of a low-noise amplifier provided in an embodiment of this application;

[0036] Figure 2 This is a schematic diagram of the circuit structure of a specific embodiment of the low-noise amplifier provided in this application.

[0037] Figure 3 This is a schematic diagram of the circuit structure of a modified low-noise amplifier provided in an embodiment of this application;

[0038] Figure 4 This is a circuit structure diagram of a specific implementation of a low-noise amplifier in related technologies;

[0039] Figure 5 This is a comparative schematic diagram of the bias voltage variation of the first transistor in the low-noise amplifier provided in this application and the bias voltage variation of the first transistor in the low-noise amplifier in related technologies.

[0040] Figure 6 This is a structural block diagram of another low-noise amplifier provided in the embodiments of this application;

[0041] Figure 7 This is a schematic diagram of the circuit structure of one specific implementation of the switching control circuit of a low-noise amplifier.

[0042] Figure 8 This is a schematic diagram of the circuit structure of another specific implementation of the switching control circuit of a low-noise amplifier.

[0043] Figure 9A This is a structural block diagram of another low-noise amplifier provided in the embodiments of this application;

[0044] Figure 9B This is a circuit structure diagram of another specific embodiment of a low-noise amplifier provided in this application;

[0045] Figure 10 This is a schematic diagram of a circuit structure of a modified low-noise amplifier provided in an embodiment of this application. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] It should be noted that the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0048] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, and they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0049] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0050] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0051] Please see Figure 1 , Figure 1 This is a schematic block diagram of a low-noise amplifier provided for an embodiment of this application.

[0052] like Figure 1 As shown, the low noise amplifier 100a includes an amplifier circuit 10, which is configured to receive a radio frequency input signal and output a radio frequency output signal. The low noise amplifier 100a can also receive an external switching control signal and adjust the gain of the amplifier circuit 10 through the switching control signal, thereby adjusting the radio frequency output signal output by the low noise amplifier 100a.

[0053] Please see Figure 2In some embodiments, the switching control signal includes at least a first switching control signal, and the amplifier circuit 10 includes a first adjustment branch 11 and a signal amplification unit 12. The input terminal of the first adjustment branch 11 is used to receive an externally input first bias voltage Vb1, and the output terminal of the first adjustment branch 11 is connected to the input terminal of the signal amplification unit 12. The first adjustment branch 11 is configured to receive the external first switching control signal, adjust the magnitude of the first bias voltage Vb1 received at the output terminal of the first adjustment branch 11 according to the first switching control signal, and output the adjusted first bias voltage Vb1 to the signal amplification unit 12, thereby adjusting the gain of the signal amplification unit 12 and realizing the gain adjustment of the amplifier circuit 10.

[0054] In some embodiments, the signal amplification unit 12 includes a first transistor 121, the first terminal of the first transistor 121 is grounded, the second terminal of the transistor 121 is connected to the pull-up power supply VDD, the controlled terminal of the first transistor 121 is connected to the output terminal of the first adjustment branch 11, and the radio frequency input signal RFIN is input to the amplification unit 12 of the amplifier circuit 10 through the controlled terminal of the first transistor 121. After being amplified by the amplification unit 12, the radio frequency output signal RFOUT is generated, and then the amplification unit 12 outputs the radio frequency output signal RFOUT through the second terminal of the first transistor 121.

[0055] The first transistor 121 can be either a MOSFET or a BJT, and there is no limitation on this.

[0056] like Figure 2 As shown, optionally, the signal amplification unit 12 further includes a first capacitor C1. The controlled terminal of the first transistor 121 is connected to the first capacitor C1 and grounded through the first capacitor C1. The first capacitor C1 and the first adjustment branch 11 work together to perform filtering. At the same time, grounding the first capacitor C1 can improve the stability of the bias potential of the first transistor 121.

[0057] like Figure 2 As shown, optionally, the signal amplification unit 12 further includes a first inductor L1 and a second inductor L2. The first terminal of the first transistor 121 is connected to the first inductor L1 and grounded through the first inductor L1. The second terminal of the first transistor 121 is connected to the second inductor L2 and connected to the pull-up power supply VDD through the second inductor L2. By setting the second inductor L2, the output matching of the low-noise amplifier 100a can be improved. At the same time, grounding through the first inductor L1 can effectively improve the stability and noise performance of the low-noise amplifier 100a. In addition, the signal amplification unit 12 also includes a third inductor Lg (not shown in the figure) connected between RFIN and the first transistor 121. The third inductor Lg is configured to achieve 50 ohms impedance matching at the input of the low-noise amplifier 100a.

[0058] like Figure 2 As shown, in some embodiments, the first regulating branch 11 includes a first voltage divider unit 111, a second voltage divider unit 112, and a first switching unit 113. The first end of the first voltage divider unit 111 is connected to the input end of the first regulating branch 11, and the second end of the first voltage divider unit 111 is connected to the output end of the first regulating branch 11. The first end of the second voltage divider unit 112 is connected to the first end of the first voltage divider unit 111, and the second end of the second voltage divider unit 112 is connected to the first end of the first switching unit 113. The second end of the first switching unit 113 is connected to the second end of the first voltage divider unit 111.

[0059] The first switching unit 113 has an on state and an off state, and can switch between the on state and the off state. For example, the first switching unit 113 can receive an external first switching control signal and switch between the on state and the off state in response to the first switching control signal. Furthermore, when the first switching unit 113 is in the on state, the first voltage divider unit 111 and the second voltage divider unit 112 are connected in parallel, and the equivalent resistance of the first regulating branch 11 is Rx. When the first switching unit 113 is in the off state, the second voltage divider unit 112 is disconnected from the parallel connection with the first voltage divider unit 111. At this time, the equivalent resistance of the first regulating branch 11 is Ry, and Ry > Rx.

[0060] It is understood that the first switching unit 113 includes a transmission gate or a switching transistor. The transmission gate or switch is used to respond to the received corresponding switching control signal, thereby enabling the first switching unit 113 to switch between the on state and the off state.

[0061] like Figure 2 The first switching unit 113 shown includes a switching transistor. For example... Figure 3 The first switching unit 113 shown includes a transmission gate. When the first switching unit 113 includes a transmission gate, the transmission gate can be a CMOS transmission gate or a TTL transmission gate. When the first switching unit 113 includes a switching transistor, the switching transistor can be a MOSFET or a BJT, and there is no limitation herein.

[0062] During the switching process of the first switching unit 113 in the on state or the off state, since the first regulating branch 11 is provided with the second voltage divider unit 112, the first switching unit 113 connects the second voltage divider unit 112 and the first voltage divider unit 111 in parallel when it is in the on state, thereby establishing a low resistance channel to enable the rapid charging and discharging of the first bias voltage Vb1 input through the first regulating branch 11, and to enable the bias voltage output by the first regulating branch 11 to be quickly stabilized at the preset voltage value, thereby realizing the rapid adjustment of the gain of the low noise amplifier 100a.

[0063] Furthermore, at the instant the first switching unit 113 is turned on, due to the change in the equivalent resistance of the first adjustment branch 11, the pulse signal corresponding to the bias voltage output by the output terminal of the first adjustment branch 11 may generate an overshoot pulse. The height and width of the overshoot pulse may affect the time taken for the waveform of the pulse signal to stabilize quickly, and ultimately affect the rapid adjustment of the gain of the low noise amplifier 100a.

[0064] Furthermore, the second voltage divider unit 112 is also configured to adjust the overshoot height of the output pulse corresponding to the output terminal of the first adjustment branch 11. By adjusting the overshoot height of the output pulse corresponding to the output terminal of the first adjustment branch 11, the waveform of the pulse signal of the bias voltage output by the output terminal of the first adjustment branch 11 is quickly stabilized, so that the bias voltage output by the first adjustment branch 11 can be quickly stabilized at the preset voltage value, thereby realizing the rapid adjustment of the gain of the low noise amplifier 100a.

[0065] That is, since the time required for gain adjustment is related to the time required for the waveform of the bias voltage pulse signal output by the first adjustment branch 11 to stabilize, the second voltage divider unit 112 is configured to adjust the overshoot height of the output pulse corresponding to the output of the first adjustment branch 11. It can also be understood that the second voltage divider unit 112 is configured to adjust the gain switching time of the amplifier circuit 10. In other words, the second voltage divider unit 112 is configured to adjust the length of time required for gain adjustment of the amplifier circuit 10.

[0066] Preferably, when the second voltage divider unit 112 is connected in parallel with the first voltage divider unit 111 through the first switching unit 113 and thus connected to the first adjustment branch 11, the gain switching time of the amplifier circuit 10 is less than 1µs.

[0067] Optionally, the resistance of the second voltage divider unit 112 is adjustable, and the overshoot height of the output pulse corresponding to the bias voltage output by the first adjustment branch 11 can be adjusted by adjusting the resistance of the second voltage divider unit 112.

[0068] By adjusting the resistance of the second voltage divider unit 112, the overshoot height of the output pulse corresponding to the bias voltage output by the first adjustment branch 11 is within a preset range. This not only enables the switching of the amplifier circuit 10's state (e.g., switching the amplifier circuit 10 from the on state to the off state, or switching the amplifier circuit 10 from the off state to the on state), but also allows the waveform of the pulse signal of the bias voltage output by the first adjustment branch 11 to stabilize quickly. Consequently, the bias voltage output by the first adjustment branch 11 can be quickly stabilized at a preset voltage value, ultimately achieving rapid adjustment or switching of the gain of the low-noise amplifier 100a.

[0069] Please see Figure 4 In related technologies, when the first regulating branch 11 is not provided with the second voltage divider unit 112, the first end of the first voltage divider unit 111 is connected to the input end of the first regulating branch 11, the second end of the first voltage divider unit 111 is connected to the output end of the first regulating branch 11, and the first switch unit 113 is connected in parallel with the first voltage divider unit 111.

[0070] When the first switching unit 113 is in the ON state, the first voltage divider unit 111 is short-circuited, and the first bias voltage Vb1 input through the first adjustment branch 11 charges and discharges rapidly. Since the equivalent resistance of the first adjustment branch 11 changes significantly during the switching process between the ON and OFF states of the first switching unit 113, it can be approximated that the equivalent resistance of the first adjustment branch 11 changes from the resistance of the first voltage divider unit 111 to zero. This abrupt change in the equivalent resistance of the first adjustment branch 11 causes an overshoot spike in the output pulse corresponding to the output terminal of the first adjustment branch 11, thus affecting the gain adjustment time of the amplifier circuit 12.

[0071] In related technologies, the low-noise amplifier may also be without the first adjustment branch 11. However, without the first adjustment branch 11, the time required for the low-noise amplifier to reach the first bias voltage Vb1 is longer, which affects the gain adjustment time of the amplifier circuit 12.

[0072] like Figure 5 As shown, in Figure 5 Curve A is a graph showing the bias voltage variation of the first transistor in the low-noise amplifier provided in this application, and curve B is... Figure 4 The graph shows the bias voltage variation of the first transistor in a low-noise amplifier of the related technology. Curve C is the bias voltage variation curve of the first transistor in a low-noise amplifier of the related technology without a first adjustment branch. From Figure 5 It can be clearly seen that without the first adjustment branch, the bias voltage of the first transistor takes a long time to reach the preset value, thus affecting the gain adjustment time of the amplifier circuit.

[0073] use Figure 4 In related technologies, the bias voltage corresponding to the first transistor of a low-noise amplifier generates a large overshoot spike, and the bias voltage takes a long time to stabilize to a preset value, thus affecting the gain adjustment time of the amplifier circuit. Furthermore, the overshoot voltage corresponding to the overshoot spike has a certain impact on components, affecting their lifespan. By using the low-noise amplifier provided in this application, the time required for the bias voltage of the first transistor to reach the preset value can be shortened, and the impact of the overshoot spike can be reduced or even eliminated, thereby reducing the gain adjustment time in the amplifier circuit.

[0074] like Figure 2As shown, in some embodiments, the first voltage divider unit 111 includes a first resistor R1, and the second voltage divider unit 112 includes a second resistor R2, wherein the resistance value of the first resistor R1 is greater than the resistance value of the second resistor R2.

[0075] It is understood that the first voltage divider unit 111 includes at least two resistors, and the connection between the at least two resistors can be a series connection or a parallel connection, which is not limited here.

[0076] In some embodiments, the ratio of the resistance of the first resistor R1 to the resistance of the second resistor R2 is greater than 10, that is, R1 / R2 > 10. Preferably, the ratio of the resistance of the first resistor R1 to the resistance of the second resistor R2 is greater than 10 and less than or equal to 100, that is, 100 ≥ R1 / R2 > 10.

[0077] Please see Figure 6 In some embodiments, the low-noise amplifier 100a further includes a switching control circuit 200 configured to provide at least a switching control signal to the amplifier circuit 10 and output the switching control signal to the first switching unit 113 to turn the first switching unit 113 on or off. For example, the switching control signal includes at least a first switching control signal. When the switching control circuit 200 is triggered, it outputs the first switching control signal to at least the first switching unit 113 of the amplifier circuit 10 to cause the first switching unit 113 to perform a switching operation from an on state to an off state, or to perform a switching operation from an off state to an on state.

[0078] In some embodiments, when the first switching unit 113 includes a transmission gate, the switching control circuit 200 is provided with a capacitor unit 203, and the capacitance value of the capacitor unit 203 is adjustable; wherein, by adjusting the capacitance value of the capacitor unit 203, the pulse width corresponding to the first switching control signal output by the switching control circuit 200 can be adjusted. Preferably, the pulse width corresponding to the first switching control signal is 200ns-600ns.

[0079] At the instant the first switching unit 113 is turned on, the equivalent resistance of the first adjustment branch 11 changes, which may cause an overshoot pulse in the pulse signal corresponding to the bias voltage output by the first adjustment branch 11. The width of the overshoot pulse is related to the pulse width of the first switching control signal. By adjusting the capacitance of the capacitor unit 203, the pulse width corresponding to the first switching control signal output by the switching control circuit 200 is adjusted, so that the waveform of the pulse signal of the bias voltage output by the first adjustment branch 11 can be quickly stabilized, and the bias voltage output by the first adjustment branch 11 can be quickly stabilized at the preset voltage value, thus achieving rapid adjustment of the gain of the low-noise amplifier 100a.

[0080] like Figure 7 As shown, in some embodiments, the switching control circuit 200 includes a first inverter 201, a first NAND flash 202, and a capacitor unit 203, wherein the capacitance of the capacitor unit 203 is adjustable. The output terminal of the first inverter 201 is connected to the first input terminal of the first NAND flash 202 and the capacitor unit 203; wherein an enable signal is input to the first input terminal of the first NAND flash 202 through the first inverter 201, and the enable signal is also input to the second input terminal of the first NAND flash 202; the first NAND flash 202 generates a first switching control signal through the input signals at the first and second input terminals.

[0081] like Figure 8 As shown, in some embodiments, the switching control circuit 200 includes a first inverter 201, a second inverter 205, a third inverter 206, a fourth inverter 207, a capacitor unit 203, a resistor unit 208, and a NOR gate 204. The capacitance of the capacitor unit 203 is adjustable. The output terminal of the first inverter 201 is connected to the first input terminal of the NOR gate 204, the second input terminal of the NOR gate 204 is connected to the first terminal of the capacitor unit 203, the second terminal of the capacitor unit 203 is grounded, and the first input terminal of the NOR gate 204 is connected to the first terminal of the resistor unit 208, and the second input terminal of the NOR gate 204 is connected to the second terminal of the resistor unit 208; the output terminal of the NOR gate 204 is connected to the input terminal of the second inverter 205, the output terminal of the second inverter 205 is connected to the input terminal of the third inverter 206, and the output terminal of the third inverter 206 is connected to the input terminal of the fourth inverter 207.

[0082] The enable signal is input to the switching control circuit 200 through the output terminal of the first inverter 201. After being processed by the switching control circuit 200, the first switching control signal is output through the output terminal of the fourth inverter 207.

[0083] Optionally, the output terminal of at least one of the second inverter 205, the third inverter 206, and the fourth inverter 207 is grounded through a capacitor unit, and the capacitance value of the capacitor unit is adjustable. By adjusting the capacitance value of the capacitor unit, the pulse width corresponding to the first switching control signal output by the switching control circuit 200 can be adjusted.

[0084] Please see Figure 9A and Figure 9B This application also provides another low-noise amplifier.

[0085] like Figure 9AAs shown, the low noise amplifier 100b includes an amplifier circuit 20, which is configured to receive a radio frequency input signal and output a radio frequency output signal. The low noise amplifier 100b can also receive an external switching control signal and control the amplifier circuit 20 to perform gain switching (also known as gain adjustment) through the switching control signal, thereby adjusting the radio frequency output signal output by the low noise amplifier 100b.

[0086] like Figure 9B As shown, in some embodiments, the amplifier circuit 20 includes a first adjustment branch 21 and a signal amplification unit 22. The first adjustment branch 21 has the same structure and function as the aforementioned first adjustment branch 11.

[0087] That is, the input terminal of the first adjustment branch 21 is used to receive the first bias voltage Vb1 input from the outside, the output terminal of the first adjustment branch 21 is connected to the input terminal of the signal amplification unit 22, and the first adjustment branch 21 is configured to receive the first switching control signal from the outside, and adjust the magnitude of the first bias voltage Vb1 received by the output terminal of the first adjustment branch 21 according to the first switching control signal, and output the adjusted first bias voltage Vb1 to the signal amplification unit 22, thereby adjusting the gain of the signal amplification unit 22 and realizing the gain switching of the amplifier circuit 20.

[0088] Furthermore, the first regulating branch 21 includes a first voltage divider unit 211, a second voltage divider unit 212, and a first switching unit 213. The first end of the first voltage divider unit 211 is connected to the input end of the first regulating branch 21, and the second end of the first voltage divider unit 211 is connected to the output end of the first regulating branch 21. The first end of the second voltage divider unit 212 is connected to the first end of the first voltage divider unit 211, and the second end of the second voltage divider unit 212 is connected to the first end of the first switching unit 213. The second end of the first switching unit 213 is connected to the second end of the first voltage divider unit 211. For further details regarding the circuit structure and function of the first regulating branch 21, please refer to the aforementioned descriptions related to the first regulating branch 11, which will not be repeated here.

[0089] like Figure 9B As shown, the signal amplification unit 22 includes a first transistor 221 and a second transistor 222. The first terminal of the first transistor 221 and the second terminal of the second transistor 222 are connected. The second terminal of the first transistor 221 is connected to the pull-up power supply VDD, and the controlled terminal of the first transistor 221 is connected to the output terminal of the first adjustment branch 21.

[0090] The first terminal of the second transistor 222 is grounded. The RF input signal RFIN is input to the amplification unit 22 of the amplifier circuit 20 through the controlled terminal of the second transistor 222. After amplification by the amplification unit 22, the RF output signal RFOUT is generated. Then, the amplification unit 22 outputs the RF output signal RFOUT through the second terminal of the first transistor 221. Both the first transistor 221 and the second transistor 222 can be MOSFETs or BJTs; no specific limitation is made here.

[0091] like Figure 9B As shown, optionally, the signal amplification unit 22 further includes a first capacitor C1, the controlled terminal of the first transistor 221 is connected to the first capacitor C1, and is grounded through the first capacitor C1.

[0092] like Figure 9B As shown, optionally, the signal amplification unit 22 further includes a first inductor L1 and a second inductor L2. The second terminal of the first transistor 121 is connected to the second inductor L2 and is connected to the pull-up power supply VDD through the second inductor L2. The first terminal of the second transistor 222 is connected to the first inductor L1 and is grounded through the first inductor L1.

[0093] Please see Figure 10 In some embodiments, the amplifier circuit 20 further includes a second adjustment branch 23, the input of which is used to receive a second bias voltage Vb2 from an external input, and the output of which is connected to the controlled terminal of the second transistor 222.

[0094] Optionally, the magnitudes of the first bias voltage Vb1 and the second bias voltage Vb2 can be set as needed, such as the first bias voltage Vb1 being less than the second bias voltage Vb2, the first bias voltage Vb1 being equal to the second bias voltage Vb2, or the first bias voltage Vb1 being greater than the second bias voltage Vb2.

[0095] like Figure 10 As shown, in some embodiments, the second regulating branch 23 includes a third voltage divider unit 231, a fourth voltage divider unit 232, and a second switching unit 233. The first end of the third voltage divider unit 231 is connected to the input end of the second regulating branch 23, and the second end of the third voltage divider unit 231 is connected to the output end of the second regulating branch 23. The first end of the fourth voltage divider unit 232 is connected to the first end of the third voltage divider unit 231, and the second end of the fourth voltage divider unit 232 is connected to the first end of the second switching unit 233. The second end of the second switching unit 233 is connected to the second end of the third voltage divider unit 231.

[0096] The second switching unit 233 has an on state and an off state, and can switch between the on state and the off state. For example, the second switching unit 233 can receive an external second switching control signal and switch between the on state and the off state in response to the second switching control signal. Furthermore, when the second switching unit 233 is in the on state, the third voltage divider unit 231 and the fourth voltage divider unit 232 are connected in parallel, and the equivalent resistance of the second regulating branch 23 is Rn. When the second switching unit 233 is in the off state, the third voltage divider unit 231 is disconnected from the parallel connection with the fourth voltage divider unit 232. At this time, the equivalent resistance of the second regulating branch 23 is Rm, and Rm > Rn.

[0097] Optionally, the second switching control signal is output through the aforementioned switching control circuit 200.

[0098] It is understood that the second switching unit 233 includes a transmission gate or a switching transistor. The transmission gate or switch is used to respond to the received corresponding switching control signal, thereby enabling the second switching unit 233 to switch between the on state and the off state.

[0099] During the switching process of the second switching unit 233 in the on or off state, since the second regulating branch 23 is equipped with the fourth voltage divider unit 232, the second switching unit 233 connects the fourth voltage divider unit 232 and the third voltage divider unit 231 in parallel when in the on state, thereby establishing a low resistance channel to enable the rapid charging and discharging of the second bias voltage Vb2 input through the second regulating branch 23, and to enable the bias voltage output by the second regulating branch 23 to be quickly stabilized at the preset voltage value, thereby realizing the rapid switching of the gain level of the low noise amplifier 100a.

[0100] Furthermore, at the instant the second switching unit 233 is turned on, due to the change in the equivalent resistance of the second adjustment branch 23, the pulse signal corresponding to the bias voltage output by the output terminal of the second adjustment branch 23 may generate an overshoot pulse. The height and width of the overshoot pulse may affect the time taken for the waveform of the pulse signal to stabilize quickly, and ultimately affect the rapid adjustment of the gain of the low noise amplifier 100a.

[0101] Furthermore, the fourth voltage divider unit 232 is also configured to adjust the overshoot height of the output pulse corresponding to the output terminal of the second adjustment branch 23. By adjusting the overshoot height of the output pulse corresponding to the output terminal of the second adjustment branch 23, the waveform of the pulse signal of the bias voltage output by the output terminal of the second adjustment branch 23 is quickly stabilized, so that the bias voltage output by the second adjustment branch 23 can be quickly stabilized at the preset voltage value, thereby realizing the rapid adjustment of the gain of the low noise amplifier 100a.

[0102] That is, since the gain switching time is related to the time required for the waveform of the bias voltage pulse signal output by the output terminal of the second adjustment branch 23 to stabilize, the fourth voltage divider unit 232 is configured to adjust the overshoot height of the output pulse corresponding to the output terminal of the second adjustment branch 23, which can be understood as the fourth voltage divider unit 232 being configured to adjust the gain switching time of the amplifier circuit 10.

[0103] Preferably, when the fourth voltage divider unit 232 is connected in parallel with the third voltage divider unit 231 through the second switching unit 233 and thus connected to the second adjustment branch 23, the gain switching time of the amplifier circuit 20 is less than 1µs.

[0104] Optionally, the resistance of the fourth voltage divider unit 232 is adjustable, and the overshoot height of the output pulse corresponding to the bias voltage output by the second adjustment branch 23 can be adjusted by adjusting the resistance of the fourth voltage divider unit 232.

[0105] By adjusting the resistance of the fourth voltage divider unit 232, the overshoot height of the output pulse corresponding to the bias voltage output by the second adjustment branch 23 is within a preset range. This allows the waveform of the pulse signal of the bias voltage output by the second adjustment branch 23 to stabilize quickly, thereby allowing the bias voltage output by the second adjustment branch 23 to stabilize quickly at the preset voltage value. Ultimately, this achieves rapid adjustment of the gain of the low-noise amplifier 100a.

[0106] like Figure 10 As shown, in some embodiments, the third voltage divider unit 231 includes a third resistor R3, and the fourth voltage divider unit 232 includes a fourth resistor R4, wherein the resistance value of the third resistor R3 is greater than the resistance value of the fourth resistor R4.

[0107] It is understood that the third voltage divider unit 231 includes at least two resistors, and the connection between the at least two resistors can be a series connection or a parallel connection, which is not limited here.

[0108] Optionally, the ratio of the resistance of the third resistor R3 to the resistance of the fourth resistor R4 is greater than 10, that is, R3 / R4 > 10. Preferably, the ratio of the resistance of the third resistor R3 to the resistance of the fourth resistor R4 is greater than 10 and less than or equal to 100, that is, 100 ≥ R3 / R4 > 10.

[0109] This application also provides a radio frequency (RF) front-end module, which includes the low-noise amplifier described in any embodiment of this application. The specific structure and function of the low-noise amplifier are described in the foregoing embodiments and will not be repeated here.

[0110] Understandably, RF front-end modules can be used in 5G sub-6GHz RF front-end products (including but not limited to smartphones). However, when existing RF front-end modules are used in RF front-end products, the long gain switching time severely affects the circuit response speed, thus impacting the communication efficiency of the RF front-end products.

[0111] The low-noise amplifier and / or RF front-end module provided in this application embodiment can realize the rapid gain establishment waveform of the amplifier circuit, effectively shorten the switching time of the low-noise amplifier gain level, and ultimately realize the rapid adjustment of the low-noise amplifier gain.

[0112] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0113] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A low-noise amplifier, characterized in that, include: An amplifier circuit is configured to receive a radio frequency (RF) input signal and output a radio frequency (RF) output signal. The amplifier circuit includes a first transistor, a second transistor, and a first adjustment branch. A first terminal of the first transistor and a second terminal of the second transistor are connected. The RF input signal is input to the amplifier circuit through the controlled terminal of the second transistor, and the RF output signal is output through the second terminal of the first transistor. The input terminal of the first regulating branch is used to receive the first bias voltage from an external input, and the output terminal of the first regulating branch is connected to the controlled terminal of the first transistor. The first regulating branch includes a first voltage divider unit, a second voltage divider unit, and a first switching unit. The first end of the first voltage divider unit is connected to the input end of the first regulating branch, the second end of the first voltage divider unit is connected to the output end of the first regulating branch, the first end of the second voltage divider unit is connected to the first end of the first voltage divider unit, the second end of the second voltage divider unit is connected to the first end of the first switching unit, and the second end of the first switching unit is connected to the second end of the first voltage divider unit. Furthermore, the resistance of the second voltage divider unit is adjustable, and the overshoot height of the output pulse of the first adjustment branch can be adjusted by adjusting the resistance of the second voltage divider unit.

2. A low-noise amplifier, characterized in that, include: An amplifier circuit is configured to receive a radio frequency (RF) input signal and output a radio frequency (RF) output signal. The amplifier circuit includes a first transistor, a second transistor, and a first adjustment branch. A first terminal of the first transistor and a second terminal of the second transistor are connected. The RF input signal is input to the amplifier circuit through the controlled terminal of the second transistor, and the RF output signal is output through the second terminal of the first transistor. The input terminal of the first regulating branch is used to receive the first bias voltage from an external input, and the output terminal of the first regulating branch is connected to the controlled terminal of the first transistor. The first regulating branch includes a first voltage divider unit, a second voltage divider unit, and a first switching unit. The first end of the first voltage divider unit is connected to the input end of the first regulating branch, the second end of the first voltage divider unit is connected to the output end of the first regulating branch, the first end of the second voltage divider unit is connected to the first end of the first voltage divider unit, the second end of the second voltage divider unit is connected to the first end of the first switching unit, and the second end of the first switching unit is connected to the second end of the first voltage divider unit. The low-noise amplifier further includes a switching control circuit, which is configured to provide at least a first switching control signal to the amplifier circuit and output the first switching control signal to the first switching unit so that the first switching unit is turned on or off. Furthermore, when the first switching unit includes a transmission gate, the switching control circuit also includes a capacitor unit, and the capacitance value of the capacitor unit is adjustable. The pulse width corresponding to the first switching control signal can be adjusted by adjusting the capacitance value of the capacitor unit.

3. The low-noise amplifier according to any one of claims 1-2, characterized in that, When the second voltage divider unit is connected to the first adjustment branch through the first switching unit, the gain switching time of the amplifier circuit is less than 1µs.

4. The low-noise amplifier according to any one of claims 1-2, characterized in that, The first voltage divider unit includes a first resistor, and the second voltage divider unit includes a second resistor, wherein the resistance value of the first resistor is greater than the resistance value of the second resistor.

5. The low-noise amplifier according to claim 4, characterized in that, The ratio of the resistance of the first resistor to the resistance of the second resistor is greater than 10; Alternatively, the ratio of the resistance of the first resistor to the resistance of the second resistor is greater than 10 and less than or equal to 100.

6. The low-noise amplifier according to claim 2, characterized in that, The pulse width corresponding to the first switching control signal is 200ns-600ns.

7. The low-noise amplifier according to claim 2, characterized in that, The switching control circuit further includes a first inverter and a first NAND, wherein the output terminal of the first inverter is connected to the first input terminal of the first NAND and the capacitor unit. The enable signal is input to the first input terminal of the first NAND gate through the first inverter, and the enable signal is also input to the second input terminal of the first NAND gate; the first NAND gate generates the first switching control signal through the input signals of the first input terminal and the second input terminal.

8. The low-noise amplifier according to any one of claims 1-2, characterized in that, The amplifier circuit further includes a second adjustment branch, the input terminal of which is used to receive a second bias voltage from an external input, and the output terminal of which is connected to the controlled terminal of the second transistor.

9. The low-noise amplifier according to claim 8, characterized in that, The second regulating branch includes a third voltage divider unit, a fourth voltage divider unit, and a second switching unit. The first end of the third voltage divider unit is connected to the input end of the second regulating branch, and the second end of the third voltage divider unit is connected to the output end of the second regulating branch. The first end of the fourth voltage divider unit is connected to the first end of the third voltage divider unit, and the second end of the fourth voltage divider unit is connected to the first end of the second switching unit. The second end of the second switching unit is connected to the second end of the third voltage divider unit.

10. The low-noise amplifier according to claim 9, characterized in that, The fourth voltage divider unit is configured to adjust the overshoot height of the output pulse corresponding to the output terminal of the second adjustment branch.

11. The low-noise amplifier according to claim 10, characterized in that, The resistance of the fourth voltage divider unit is adjustable, and the overshoot height of the output pulse of the second adjustment branch can be adjusted by adjusting the resistance of the fourth voltage divider unit.

12. A low-noise amplifier, characterized in that, include: An amplifier circuit is configured to receive a radio frequency input signal and output a radio frequency output signal, the amplifier circuit including a first transistor and a first adjustment branch; The radio frequency input signal is input to the amplifier circuit through the controlled terminal of the first transistor, and the radio frequency output signal is output through the second terminal of the first transistor; the input terminal of the first adjustment branch is used to receive the first bias voltage input from the outside, and the output terminal of the first adjustment branch is connected to the controlled terminal of the first transistor. The first regulating branch includes a first voltage divider unit, a second voltage divider unit, and a first switching unit. The first end of the first voltage divider unit is connected to the input end of the first regulating branch, the second end of the first voltage divider unit is connected to the output end of the first regulating branch, the first end of the second voltage divider unit is connected to the first end of the first voltage divider unit, the second end of the second voltage divider unit is connected to the first end of the first switching unit, and the second end of the first switching unit is connected to the second end of the first voltage divider unit. The low-noise amplifier further includes a switching control circuit, which is configured to provide at least a first switching control signal to the amplifier circuit and output the first switching control signal to the first switching unit so that the first switching unit is turned on or off. Furthermore, when the first switching unit includes a transmission gate, the switching control circuit also includes a capacitor unit, and the capacitance value of the capacitor unit is adjustable. The pulse width corresponding to the first switching control signal can be adjusted by adjusting the capacitance value of the capacitor unit.

13. A radio frequency front-end module, characterized in that, The radio frequency front-end module includes at least the low-noise amplifier as described in any one of claims 1-12.

Images