Low-noise amplifier and radio frequency front-end module

Abstract

The present application discloses a low-noise amplifier and a radio frequency front-end module. The low-noise amplifier includes a radio frequency input end, a radio frequency output end, a bias module, and an amplification module. The amplification module includes an amplification circuit and a bypass circuit. The bias module includes a bias circuit and at least one pull-down switch, and the pull-down switch is used to conduct when receiving a first control voltage. The bypass circuit is connected between the radio frequency input end and the radio frequency output end and includes at least one bypass switch, and the bypass switch is used to conduct when receiving a second control voltage. Wherein, the value of the second control voltage is greater than the value of the first control voltage. In the above low-noise amplifier, the switches in the bias module and the amplification module have different control voltages, so that the switches in the amplification module have a faster response speed, more excellent switching performance, and reduce the leakage of the switches in the bias module, thereby improving the overall performance of the low-noise amplifier.

Description

Technical Field

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

[0002] In a wireless communication system, a low-noise amplification circuit is usually provided to perform low-noise amplification on a radio frequency signal received from an antenna terminal. However, with the rapid development of wireless communication technology, the industry's demand for the performance of wireless communication systems is getting higher and higher.

[0003] How to improve the performance of the low-noise amplifier is an urgent problem to be solved at present. Summary of the Invention

[0004] The present application provides a low-noise amplifier and a radio frequency front-end module, which can improve the performance of the low-noise amplifier.

[0005] In a first aspect, an embodiment of the present application provides a low-noise amplifier, including a radio frequency input terminal and a radio frequency output terminal. The low-noise amplifier further includes a bias module and an amplification module. The amplification module includes an amplification circuit and a bypass circuit.

[0006] The bias module includes a bias circuit and at least one pull-down switch. The output terminal of the bias circuit is connected to the amplification circuit. One end of the pull-down switch is connected to the output terminal of the bias circuit, and the other end is grounded. The pull-down switch is configured to conduct when receiving a first control voltage.

[0007] The amplification circuit is connected between the radio frequency input terminal and the radio frequency output terminal, and is configured to amplify a first radio frequency signal input from the radio frequency input terminal to obtain a second radio frequency signal.

[0008] The bypass circuit is connected between the radio frequency input terminal and the radio frequency output terminal, and includes at least one bypass switch. The bypass switch is configured to conduct when receiving a second control voltage.

[0009] Wherein, the value of the second control voltage is greater than the value of the first control voltage.

[0010] In a second aspect, an embodiment of the present application provides a low-noise amplifier, a bias module and an amplification module. The bias module and the amplification module each include at least one switch. Among them, at least one switch in the bias module conducts when receiving a first control voltage, and at least one switch in the amplification module conducts when receiving a second control voltage. The value of the second control voltage is greater than the value of the first control voltage.

[0011] In a third aspect, an embodiment of the present application provides a radio frequency front-end module, including a substrate and a first chip disposed on the substrate. The first chip is provided with a low-noise amplifier as described in the first aspect or the second aspect.

[0012] In the embodiment of the present application, different control voltages are provided for the switches in the bias module 13 and the switches in the amplification module 14, so that the conduction control voltage (i.e., the second control voltage) of at least one switch in the amplification module 14 is greater than the conduction control voltage (i.e., the first control voltage) of at least one switch in the bias module 13, thereby enabling the switches in the amplification module 14 to have a faster response speed and superior switching performance. In addition, making the first control voltage less than the second control voltage can reduce the leakage of the switches in the bias module 13 on the premise of meeting the performance requirements of the switches in the bias module 13. Therefore, the embodiment of the present application can improve the overall performance of the low-noise amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0014] Figure 1 FIG. shows a schematic diagram of a low-noise amplifier provided by an embodiment of the present application.

[0015] Figure 2 FIG. shows a schematic diagram of a low-noise amplifier provided by another embodiment of the present application.

[0016] Figure 3 FIG. shows a schematic diagram of an amplification module in a low-noise amplifier provided by an embodiment of the present application.

[0017] Figure 4 FIG. shows a schematic diagram of an amplification module in a low-noise amplifier provided by another embodiment of the present application.

[0018] Figure 5 FIG. shows a schematic diagram of an amplification module in a low-noise amplifier provided by yet another embodiment of the present application.

[0019] Figure 6 FIG. shows a schematic diagram of a low-noise amplifier provided by yet another embodiment of the present application.

[0020] Figure 7 FIG. shows a schematic diagram of a low-noise amplifier provided by yet another embodiment of the present application.

[0021] Figure 8Shows a schematic diagram of a low-noise amplifier provided by another embodiment of the present application.

[0022] Figure 9 Shows a schematic diagram of a bias module in a low-noise amplifier provided by an embodiment of the present application.

[0023] Figure 10 Shows a schematic diagram of a bias module in a low-noise amplifier provided by another embodiment of the present application.

[0024] Figure 11 Shows a schematic diagram of a radio frequency front-end module provided by an embodiment of the present application.

[0025] Figure 12 Shows a schematic diagram of a radio frequency front-end module provided by another embodiment of the present application. Detailed implementation manners

[0026] In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0027] The terms "first", "second", etc. in the present application are used to distinguish different objects, rather than to describe a specific order. The term "plurality" means two or more. The term "and / or" refers to at least one of the listed plurality of objects. For example, "A and / or B" can be any one of the following three situations: including A but not including B, including B but not including A, and including both A and B at the same time.

[0028] In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or devices.

[0029] Referring to "embodiment" in this article means that the specific features, structures or characteristics described in combination with the embodiment can be included in at least one embodiment of the present application. The phrase appears in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0030] An embodiment of the present application provides a low-noise amplifier 10 and a radio frequency front-end module 20 including the low-noise amplifier 10.

[0031] Please refer to Figure 1 , Figure 1 which shows a circuit schematic diagram of a low-noise amplifier provided by an embodiment of the present application. As Figure 1 shown, the low-noise amplifier 10 includes a radio frequency input end 11, a radio frequency output end 12, a bias module 13, and an amplification module 14. The amplification module 14 is connected between the radio frequency input end 11 and the radio frequency output end 12 and is configured to amplify a first radio frequency signal RF_1 input from the radio frequency input end 11 in an amplification mode to obtain a second radio frequency signal RF_2 and output the second radio frequency signal RF_2 from the radio frequency output end 12. The output end of the bias module 13 is connected to the amplification module 14 and is configured to provide a bias signal for the amplification module 14.

[0032] In an embodiment of the present application, the bias module 13 and the amplification module 14 each include at least one switch. At least one switch in the bias module 13 conducts when receiving a first control voltage, and at least one switch in the amplification module 14 conducts when receiving a second control voltage. Moreover, the value of the second control voltage is greater than the value of the first control voltage.

[0033] It can be understood that each of the above switches may include one or more switching tubes. The switching tubes may be unipolar transistors (such as field effect transistors) or bipolar transistors. Optionally, the PN junction of the switching tube may be a homojunction or a heterojunction.

[0034] Taking the unipolar transistor as an example, it may be a field effect transistor (FET) based on a silicon substrate, such as a MOS transistor (metal oxide semiconductor field effect transistor); it may also be a transistor based on silicon on insulator (SOI) technology; or it may be a unipolar transistor with a heterojunction, such as a high electron mobility transistor (HEMT) or a pseudomorphic high electron mobility transistor (PHEMT).

[0035] Taking the bipolar transistor as an example, it may be a homojunction bipolar transistor or a heterojunction bipolar transistor (HBT), etc.

[0036] Optionally, the types of the switches in the bias module 13 and the switches in the amplification module 14 may be the same. For example, the switches in the bias module 13 and the switches in the amplification module 14 may both be PHEMTs. PHEMT has a double heterojunction structure, which can improve the temperature stability of the threshold voltage and improve the output volt-ampere characteristics. Compared with other unipolar transistors, PHEMT has a larger output resistance, a higher transconductance, a larger current handling capacity, a higher operating frequency, and lower noise, which helps to improve the performance such as the gain and noise of the low-noise amplifier. Another example is that the switches in the bias module 13 and the switches in the amplification module 14 may both be SOI transistors. SOI transistors have the characteristics of small parasitic capacitance and small leakage, which can improve the switching speed and reduce the insertion loss of the switch.

[0037] Optionally, the types of the switches in the bias module 13 and the switches in the amplification module 14 may also be different. For example, the switch in the amplification module 14 may be a PHEMT, while the switch in the bias module 13 may be other types of transistors, such as MOS transistors.

[0038] It can be understood that a switch has a control terminal and two connection terminals, and can conduct or cut off the path between the two connection terminals according to the control signal received by the control terminal. For a unipolar transistor, the control terminal is the gate, and the two connection terminals are the source and the drain respectively; for a bipolar transistor, the control terminal is the base, and the two connection terminals are the collector and the emitter respectively. For the convenience of description, the two connection terminals of each switch will be respectively referred to as the first terminal and the second terminal below, and the control terminal will be referred to as the third terminal. Among them, the above first control voltage and second control voltage are both voltages applied to the control terminal (i.e., the third terminal) of the corresponding switch.

[0039] Optionally, the above switch may conduct at a high level and cut off at a low level; or, the above switch may also conduct at a low level and cut off at a high level.

[0040] In the embodiment of the present application, at least one switch in the bias module 13 conducts under the first control voltage, at least one switch in the amplification module 14 conducts under the second control voltage, and the value of the second control voltage is greater than the value of the first control voltage. It can be understood that the values of the first control voltage and the second control voltage refer to the absolute values and have nothing to do with the direction of the control voltage.

[0041] Exemplarily, when the switches in the bias module 13 and the switches in the amplification module 14 both conduct at a high level, the first control voltage and the second control voltage are both positive voltages, and the value of the second control voltage is greater than the value of the first control voltage. For example, the second control voltage is 5V and the first control voltage is 1.8V.

[0042] Exemplarily, when the switches in the bias module 13 and the switches in the amplification module 14 are both turned on at a low level, both the first control voltage and the second control voltage are reverse voltages, and the value of the second control voltage is greater than the value of the first control voltage. For example, the second control voltage is -5V and the first control voltage is -1.8V. Here, the "-" indicates that the first control voltage and the second control voltage are reverse voltages, and the value of the second control voltage (5V) is greater than the value of the first control voltage (1.8V).

[0043] Optionally, when the bias module 13 includes multiple switches, the control voltages used to control the conduction of these multiple switches can be the same or different.

[0044] Optionally, when the amplification module 14 includes multiple switches, the control voltages used to control the conduction of these multiple switches can be the same or different.

[0045] Exemplarily, when the bias module 13 includes multiple switches, the control voltages used to control the conduction of the multiple switches in the bias module 13 are the same, all being the first control voltage. When the amplification module 14 includes multiple switches, the control voltages used to control the conduction of the multiple switches in the amplification module 14 are the same, all being the second control voltage. In this way, the number of control voltages required for the low-noise amplifier can be reduced, and the control circuit of the low-noise amplifier can be simplified.

[0046] In the embodiments of the present application, different control voltages are provided for the switches in the bias module 13 and the switches in the amplification module 14, so that the conduction control voltage (i.e., the second control voltage) of at least one switch in the amplification module 14 is greater than the conduction control voltage (i.e., the first control voltage) of at least one switch in the bias module 13, thereby enabling the switches in the amplification module 14 to have a faster response speed and more excellent switching performance. In addition, making the first control voltage less than the second control voltage can reduce the leakage of the switches in the bias module 13 on the premise of meeting the performance requirements of the switches in the bias module 13. Therefore, the embodiments of the present application can improve the overall performance of the low-noise amplifier.

[0047] In some embodiments, at least one switch in the bias module 13 can be used to switch whether to output a bias signal to the amplification module.

[0048] As an implementation manner, one end of at least one switch in the bias module 13 is connected to the output end of the bias module 13, and the other end is grounded. When this switch is turned on, the voltage at the output end of the bias module 13 is pulled down to the reference potential (such as zero potential), thereby stopping the output of the bias signal to the amplification module 14 to reduce power consumption. When this switch is turned off, the output end of the bias module 13 can output a bias signal, thereby normally providing a bias signal for the amplification module 14.

[0049] As an implementation manner, at least one switch in the bias module 13 is connected in series between the output end of the bias module 13 and the amplification module 14. When this switch is turned on, the bias module 13 can normally provide a bias signal for the amplification module 14. When this switch is turned off, the path between the output end of the bias module 13 and the amplification module 14 is disconnected, so as to stop outputting the bias signal to the amplification module 14 to reduce power consumption.

[0050] As an implementation manner, one end of at least one switch in the bias module 13 is connected to the output end of the bias module 13, and the other end is grounded. Moreover, at least one other switch in the bias module 13 is connected in series between the output end of the bias module 13 and the amplification module 14. The working principles of these two types of switches can refer to the foregoing implementation manner and will not be elaborated here.

[0051] In some embodiments, the low-noise amplifier 10 can operate in an amplification mode or a bypass mode, and at least one switch in the bias module 13 can be controlled to be turned on or off according to the operating state of the low-noise amplifier 10. Exemplarily, when one end of at least one switch in the bias module 13 is connected to the output end of the bias module 13 and the other end is grounded, this switch is configured to be turned off when the low-noise amplifier 10 is in the amplification mode and turned on when the low-noise amplifier 10 is in the bypass mode or not working. Exemplarily, when one end of at least one switch in the bias module 13 is connected to the output end of the bias module 13 and the other end is grounded, this switch is configured to be turned on when the low-noise amplifier 10 is in the amplification mode and turned off when the low-noise amplifier 10 is in the bypass mode or not working.

[0052] Correspondingly, at least one switch in the amplification module 14 is used to switch the operating mode of the low-noise amplifier 10. Please refer to Figure 2 , Figure 2 which shows a circuit schematic diagram of a low-noise amplifier provided by another embodiment of the present application. As Figure 2 shown, the low-noise amplifier 10 of this embodiment includes a radio frequency input end 11 and a radio frequency output end 12, and further includes a bias module 13 and an amplification module 14, wherein the amplification module 14 includes an amplification circuit 141 and a bypass circuit 142.

[0053] The bias module 13 includes a bias circuit 131 and at least one pull-down switch S1. Among them, the output end of the bias circuit 131 is connected to the amplification circuit 14; one end of the pull-down switch S1 is connected to the output end of the bias circuit 131, and the other end is grounded. The pull-down switch S1 is used to be turned on when receiving a first control voltage.

[0054] The amplification circuit 14 is connected between the radio frequency input end 11 and the radio frequency output end 12, and is used to amplify the first radio frequency signal RF_1 input from the radio frequency input end 11 to obtain a second radio frequency signal RF_2.

[0055] The bypass circuit 142 is connected between the RF input terminal 11 and the RF output terminal 12, and includes at least one bypass switch, which is used to conduct when receiving a second control voltage; wherein the value of the second control voltage is greater than the value of the first control voltage.

[0056] In the embodiment of the present application, when the low-noise amplifier 10 operates in the amplification mode, the pull-down switch S1 is turned off, and the voltage output by the bias circuit 131 can provide bias for the amplification circuit 14, so that the amplification circuit 14 can operate normally. In the amplification mode, the amplification circuit 14 amplifies the first RF signal RF_1 input from the RF input terminal 11 to form a second RF signal RF_2, and outputs the second RF signal RF_2 from the RF output terminal 12.

[0057] When the low-noise amplifier 10 operates in the bypass mode, the pull-down switch S1 is turned on, pulling down the output voltage of the bias circuit 131 to the reference potential (such as zero potential), stopping providing bias for the amplification circuit 14, thereby reducing the power consumption of the low-noise amplifier 10. In the bypass mode, the bypass switch in the bypass circuit 142 is turned on, so that the first RF signal RF_1 input from the RF input terminal 11 can be transmitted to the RF output terminal 12 through the bypass circuit 142.

[0058] As an implementation manner, when the received first RF signal RF_1 is weak, the low-noise amplifier 10 operates in the amplification mode, so as to perform gain amplification on the first RF signal RF_1, so that the subsequent circuit can recognize the signal output by the low-noise amplifier 10. When the received first RF signal RF_1 is large, the low-noise amplifier 10 operates in the bypass mode, bypassing the first RF signal RF_1 without amplification, avoiding exceeding the range that the subsequent circuit can recognize, and at this time the amplification circuit 14 does not work, which can reduce the power consumption.

[0059] It can be understood that the pull-down switch S1 and the bypass switch can each include one or more switching tubes.

[0060] Optionally, the types of switching tubes in the pull-down switch S1 and the bypass switch can be different. For example, the switching tube in the bypass switch can be a PHEMT, while the switching tube in the pull-down switch S1 can be other types of transistors.

[0061] Optionally, the types of switching tubes in the pull-down switch S1 and the bypass switch can be the same. For example, the switching tubes in both the pull-down switch S1 and the bypass switch are PHEMTs. Another example is that the switching tubes in both the pull-down switch S1 and the bypass switch are SOI transistors.

[0062] Optionally, the pull - down switch S1 and the bypass switch can conduct at a high level and turn off at a low level; alternatively, the pull - down switch S1 and the bypass switch can also conduct at a low level and turn off at a high level.

[0063] In the embodiments of the present application, the pull - down switch S1 conducts under a first control voltage, and the bypass switch conducts under a second control voltage, and the value of the second control voltage is greater than the value of the first control voltage. It can be understood that the values of the first control voltage and the second control voltage refer to absolute values.

[0064] Exemplarily, when both the pull - down switch S1 and the bypass switch conduct at a high level, both the first control voltage and the second control voltage are positive voltages, and the value of the second control voltage is greater than the value of the first control voltage. For example, the second control voltage is 5V and the first control voltage is 1.8V.

[0065] Exemplarily, when both the pull - down switch S1 and the bypass switch conduct at a low level, both the first control voltage and the second control voltage are negative voltages, and the value of the second control voltage is greater than the value of the first control voltage. For example, the second control voltage is - 5V and the first control voltage is - 1.8V. Here, the "-" indicates that the first control voltage and the second control voltage are negative voltages, and the value of the second control voltage (5V) is greater than the value of the first control voltage (1.8V).

[0066] In the embodiments of the present application, different control voltages are provided for the pull - down switch S1 and the bypass switch, so that the conduction control voltage of the bypass switch (i.e., the second control voltage) is greater than the conduction control voltage of the pull - down switch S1 (i.e., the first control voltage), thereby enabling the bypass switch to have a faster conduction speed and more excellent switching performance, and further improving the switching speed when the low - noise amplifier switches between the amplification state and the bypass state. In addition, making the first control voltage of the pull - down switch S1 less than the second control voltage of the bypass switch can reduce the leakage current of the pull - down switch S1 on the premise of meeting the performance requirements of the bias module for the switch. Therefore, the embodiments of the present application can improve the overall performance of the low - noise amplifier.

[0067] In some embodiments, as Figure 2 shown, at least one bypass switch includes a third switch S3. The first end of the third switch S3 is connected to the RF input terminal 11, the second end of the third switch S3 is used to connect to the RF output terminal 12, and the third switch S3 conducts when receiving the second control voltage at the third end.

[0068] As an implementation manner, the third switch S3 conducts at a high level, and its second control voltage is 5V. The third switch S3 selects a PHEMT transistor with a relatively high breakdown voltage, so that it can conduct quickly and safely under the first control voltage of 5V. Among them, the switching transistor in the pull-down switch S1 can also be a PHEMT transistor, or other types of switching transistors, and this application does not limit this.

[0069] As an implementation manner, when the low-noise amplifier 10 operates in the bypass mode, the third switch S3 conducts, so that the first radio frequency signal RF_1 input from the radio frequency input terminal 11 is transmitted to the radio frequency output terminal 12 through the third switch S3, without being amplified by the amplifier circuit 141. At this time, the pull-down switch S1 in the bias module 13 can be closed, so that the bias circuit 131 stops providing bias for the amplifier circuit 141, and the amplifier circuit 141 stops working.

[0070] When the low-noise amplifier 10 operates in the amplification mode, the third switch S3 is turned off to avoid affecting the operation of the amplifier circuit 141.

[0071] When the low-noise amplifier 10 does not work, the third switch S3 is turned off to avoid the interference signal radiated to the radio frequency input terminal 11 from being transmitted to the radio frequency output terminal 12 through the third switch S3, thereby improving the isolation between the radio frequency input terminal 11 and the radio frequency output terminal 12.

[0072] In some embodiments, as Figure 3 shown, the bypass circuit 142 further includes a second resistor R2 and a fourth switch S4. The second resistor R2 and the fourth switch S4 are sequentially connected in series between the second end of the third switch S3 and the radio frequency output terminal 12. Among them, the fourth switch S4 and the third switch S3 can be switching transistors of the same type and conduct under the same control voltage, and both the third switch S3 and the fourth switch S4 conduct when the low-noise amplifier 10 operates in the bypass mode. For the specific description of the third switch S3, reference can be made to the previous text, and details are not repeated here.

[0073] In this embodiment, the bypass circuit 142 includes a plurality of switches connected in series with each other and the second resistor R2. When the low-noise amplifier 10 operates in the bypass mode, it can attenuate the passing first radio frequency signal RF_1 to a certain extent to avoid the output signal being too large and exceeding the recognizable range of the subsequent circuit. In addition, increasing the number of series bypass switches can improve the isolation between the radio frequency input terminal 11 and the radio frequency output terminal 12 when the low-noise amplifier does not work.

[0074] As an implementation manner, as Figure 4As shown, the bypass circuit 142 further includes a fifth switch S5. The first end of the fifth switch S5 is connected to the connection node of the second resistor R2 and the fourth switch S4, and the second end of the fifth switch S5 is grounded. The fifth switch S5 is used to conduct when a third control voltage is received at the third end, where the third control voltage is greater than or equal to the first control voltage. Optionally, the third control voltage and the second control voltage may be the same or different, and the present application does not limit this. Exemplarily, the third control voltage is the same as the second control voltage, for example, both are 5V. In this way, the sixth switch S6 and the third switch S3 can both have good switching performance, and the number of control voltages required for the low-noise amplifier can be reduced, simplifying the design of the control circuit of the low-noise amplifier.

[0075] Among them, when the third switch S3 and the fourth switch S4 are conducting, the fifth switch S5 is turned off to avoid affecting the operation of the bypass circuit 142. When the third switch S3 and the fourth switch S4 are turned off, the fifth switch S5 is conducting to further improve the isolation between the RF input terminal 11 and the RF output terminal 12.

[0076] As an implementation, as Figure 5 shown, the bypass circuit 142 further includes a third capacitor C3. The third capacitor C3 is connected in series between the RF input terminal 11 and the bypass switch. Among them, when there are multiple bypass switches connected in series in the bypass circuit 142, the third capacitor C3 is connected in series between the RF input terminal 11 and the first bypass switch. The first bypass switch refers to the bypass switch closest to the RF input terminal 11 in the series order, such as Figure 3 or Figure 4 the third switch S3 in

[0077] In some embodiments, as Figure 6 shown, the amplifying circuit 141 includes an amplifying unit 1411 and a sixth switch S6. The sixth switch S6 is connected in series between the output terminal of the amplifying unit and the RF output terminal 12. The sixth switch S6 is used to conduct when receiving a fourth control voltage; among them, the fourth control voltage is greater than the first control voltage. Optionally, the fourth control voltage and the second control voltage may be the same or different. Exemplarily, the fourth control voltage is the same as the second control voltage, for example, both are 5V. In this way, the sixth switch S6 and the third switch S3 can both have good switching performance, and the number of control voltages required for the low-noise amplifier can be reduced, simplifying the design of the control circuit of the low-noise amplifier.

[0078] Among them, the sixth switch S6 and the third switch S3 can be of the same type of switching tube. For specific reference, please refer to the description of the third switch S3 above, and details will not be repeated here.

[0079] As an implementation, when the low-noise amplifier operates in the bypass mode, the sixth switch S6 is turned off to increase the impedance of the amplifying circuit 141 to the first radio frequency signal RF_1, so that the first radio frequency signal RF_1 is transmitted from the bypass circuit 142.

[0080] As an implementation, when the low-noise amplifier is not working, the sixth switch S6 is turned off to further improve the isolation between the radio frequency input end 11 and the radio frequency output end 12.

[0081] In some embodiments, as Figure 7 shown, the bias circuit 131 includes a first output end and a second output end. The first output end is used to output a first bias signal Vb1, and the second output end is used to output a second bias signal Vb2. The amplifying circuit 14 includes a first transistor M1 and a second transistor M2. The third end of the first transistor M1 is used to receive the first bias signal Vb1, and the third end of the second transistor is used to receive the first radio frequency signal RF_1 and the second bias signal Vb2. The second end of the first transistor M1 is connected to the first end of the second transistor M2, and the second end of the second transistor M2 is used to be grounded. Among them, at least one pull-down switch includes a first switch S11. One end of the first switch S11 is connected to the first output end or the second output end of the bias circuit 131, and the other end is grounded.

[0082] Similar to the switching transistor, the first transistor M1 and the second transistor M2 can be unipolar transistors (such as field effect transistors) or bipolar transistors. The specific types can be MOS transistors, SOI transistors, PHEMTs, homojunction triodes or HBT transistors. The application does not limit the types of the first transistor M1 and the second transistor M2.

[0083] Taking the field effect transistor as an example, the first end and the second end of the first transistor M1 and the second transistor M2 are the drain and the source respectively, and the third end is the gate. Taking the bipolar transistor as an example, the first end and the second end of the first transistor M1 and the second transistor M2 are the collector and the emitter respectively, and the third end is the base.

[0084] In the embodiment of the application, the first transistor M1 and the second transistor M2 are connected to form a cascode amplifying circuit. Among them, the third end of the second transistor M2 serves as the input end of the cascode amplifying circuit and is used to receive the first radio frequency signal RF_1 to be amplified. Specifically, the third end of the second transistor M2 is connected to the radio frequency input end 11 to receive the first radio frequency signal RF_1 input from the radio frequency input end 11. The first end of the first transistor M1 serves as the output end of the cascode amplifying circuit and is used to output the second radio frequency signal RF_2 amplified based on the first radio frequency signal RF_1.

[0085] The bias circuit 131 can generate a first bias signal Vb1 and a second bias signal Vb2. When the low-noise amplifier operates in the amplification mode, the first output terminal of the bias circuit 131 outputs the first bias signal Vb1 to the third terminal of the first transistor M1, thereby providing a bias for the first transistor M1; the second output terminal of the bias circuit 131 outputs the second bias signal Vb2 to the third terminal of the second transistor M2, thereby providing a bias for the second transistor M2, so that the cascode amplifier circuit formed by the first transistor M1 and the second transistor M2 can operate normally.

[0086] In the embodiment of the present application, the bias module has at least one pull-down switch, and at least one output terminal of the bias circuit 131 is grounded through the pull-down switch. When the pull-down switch is turned on, the voltage of the output terminal of the bias circuit 131 connected to the pull-down switch is pulled down to the reference potential (such as zero potential), and the bias for the transistor connected to the output terminal is stopped, so that the cascode amplifier circuit formed by the first transistor M1 and the second transistor M2 stops operating. Optionally, the pull-down switch can be turned on when the low-noise amplifier operates in the bypass mode or when the low-noise amplifier stops operating.

[0087] As an implementation manner, the number of pull-down switches can be one, such as the first switch S11. One end of the first switch S11 is connected to the first output terminal or the second output terminal of the bias circuit 131, and the other end of the first switch S11 is grounded. When the first switch S11 is turned on, the output voltage of the first output terminal or the second output terminal of the bias circuit 131 is pulled down to the reference potential (such as zero potential), and the bias signal for the first transistor M1 or the second transistor M2 is stopped, so that the cascode amplifier circuit formed by the first transistor M1 and the second transistor M2 stops operating.

[0088] As an implementation manner, as Figure 4 shown, the number of pull-down switches can be at least two. For example, the pull-down switches include a first switch S11 and a second switch S12. One end of the first switch S11 is connected to the first output terminal of the bias circuit, and the other end of the first switch is grounded; one end of the second switch S12 is connected to the second output terminal of the bias circuit, and the other end of the second switch is grounded. Among them, when the low-noise amplifier is in the bypass mode or not working, both the first switch S11 and the second switch S12 are turned on, pulling down the output voltages of the first output terminal and the second output terminal of the bias circuit 131, thereby further reducing the power consumption of the low-noise amplifier.

[0089] As an implementation, since the third terminal of the second transistor M2 needs to receive the first radio frequency signal RF_1 and the second bias signal Vb2 simultaneously, in order to prevent the second bias signal Vb2 from leaking to the radio frequency input terminal 11, a capacitor can be connected in series between the third terminal of the second transistor M2 and the radio frequency input terminal 11. This capacitor blocks the DC signal (such as the second bias signal Vb2) and can prevent the second bias signal Vb2 from leaking to the radio frequency input terminal 11.

[0090] In some possible embodiments, such as Figure 4 shown, the amplifying circuit 14 further includes a first capacitor C1 and a first inductor L1. Among them, one end of the first capacitor C1 is connected to the third terminal of the first transistor, and the other end is grounded; one end of the first inductor L1 is connected to the second terminal of the second transistor, and the other end is grounded. The first capacitor C1 and the first inductor L1 can be used to match the impedance of the input signal.

[0091] Optionally, the other ends of the first capacitor C1 and the first inductor L1 can be grounded through the same ground terminal. For example, when the low-noise amplifier is integrated on a chip, the other ends of the first capacitor C1 and the first inductor L1 can be first connected through the internal wiring of the chip and then grounded through the ground terminal connected to this wiring. Among them, this ground terminal can be a conductive via connected to the chip surface or the internal ground metal layer of the chip. By setting the first capacitor C1 and the first inductor L1 to share a ground terminal, the number of ground terminals can be reduced, and the area occupied by the ground terminals can be saved.

[0092] Optionally, one end of the first capacitor C1 and one end of the first inductor L1 can be grounded through different ground terminals respectively. Exemplarily, when the low-noise amplifier is integrated on a chip, a ground metal layer is provided on the outer surface or inside of the chip. The other end of the first capacitor C1 is connected to the ground metal layer through a first conductive via, and the other end of the first inductor L1 is connected to the ground metal layer through a second conductive via. By setting the first capacitor C1 and the first inductor L1 to be grounded respectively, the mutual influence between the other end of the first capacitor C1 and the other end of the first inductor L1 can be avoided, making their grounding more ideal, and thus improving the performance of the low-noise amplifier.

[0093] In some possible implementation manners, the bias circuit 131 can generate the required first bias signal Vb1 and second bias voltage Vb2 based on a reference current and some voltage dividing elements, where the voltage dividing elements include but are not limited to resistors, transistors, or a combination of the two.

[0094] As an implementation, such as Figure 9As shown, the input terminal of the bias circuit is used to receive a reference current Iref. The bias circuit includes at least two series-connected third transistors M3. The first end and the third end of each third transistor M3 are short-circuited. The second end of each third transistor M3 is connected to the first end of another adjacent third transistor M3 or grounded, and the first end of at least one third transistor is connected to the first output terminal and / or the second output terminal of the bias circuit.

[0095] Optionally, the third transistor M3 can be a unipolar transistor (such as a field effect transistor) or a bipolar transistor. The specific type can be a MOS transistor, a SOI transistor, a PHEMT, a homojunction triode, or an HBT transistor. The present application does not limit the type of the third transistor M3. Taking the field effect transistor as an example, the first end and the second end of the third transistor M3 are the drain and the source respectively, and the third end is the gate. Taking the bipolar transistor as an example, the first end and the second end of the third transistor M3 are the collector and the emitter respectively, and the third end is the base.

[0096] When the bias circuit works, the third transistor M3 is turned on, and there is a specific voltage difference between the third end and the second end of each third transistor M3. If there are N series-connected transistors in the bias circuit, and the voltage difference between the third end and the second end of each third transistor M3 is denoted as V1, then in the order from the input terminal of the bias circuit to the ground terminal, the gate voltages of the second to the Nth third transistors M3 are (N - 1)V1, (N - 2)V1... V1 respectively. Therefore, connecting the first output terminal or the second output terminal of the bias circuit 131 to the gate of one of the third transistors M3 can use the gate voltage of one of the third transistors M3 as the first bias signal Vb1 or the second bias signal Vb2. Optionally, the first output terminal and the second output terminal of the bias circuit 131 can also be connected to the gates of two different third transistors M3 to obtain two different voltages as the first bias signal Vb1 and the second bias signal Vb2.

[0097] As an alternative embodiment, as Figure 10 shown, the bias circuit further includes a first resistor R1. The first resistor R1 is connected in series with each third transistor M3 to increase the voltage that the bias circuit can generate. Optionally, the first resistor R1 can be connected in series between any two third transistors M3, or between the input terminal of the bias circuit and the first third transistor M3, or between the last third transistor M3 and the ground terminal. Herein, the first third transistor M3 and the last third transistor M3 refer to the first and the last third transistors M3 connected in series in sequence in the order from the input terminal of the bias circuit to the ground terminal.

[0098] Optionally, for the required voltage magnitudes of the specific first bias signal Vb1 and second bias signal Vb2, it is possible to connect the first output terminal and the second output terminal of the bias circuit to the gates of two different third transistors M3 respectively, or it is also possible to connect one of the first output terminal and the second output terminal to the gate of one of the third transistors M3, and the other to one end of the first resistor R1.

[0099] Exemplarily, one end of the first resistor R1 is connected to the first output terminal of the bias circuit to output the first bias signal Vb2, and the other end of the first resistor is grounded through at least two third transistors connected in series. The first end of one of the third transistors M3 is connected to the second output terminal of the bias circuit to output the second bias signal Vb2.

[0100] Take Figure 10 as an example. When the number of the third transistors M3 is 3, the first resistor R1 is connected in series between the first third transistor M3 and the second third transistor M3, and the common connection end of the first resistor R1 and the first third transistor M3 is connected to the first output terminal of the bias circuit, the voltage magnitude of the first bias signal is Vb1 = 2V1 + Iref * R1. When the third end of the last third transistor M3 is connected to the second output terminal of the bias circuit, the voltage magnitude of the second bias signal is Vb2 = V1.

[0101] In the embodiments of the present application, by setting a plurality of third transistors, or setting a plurality of third transistors and at least one resistor, the first bias signal and the second bias signal can be generated with fewer devices and a smaller circuit area, thereby reducing the overall area of the low-noise amplifier.

[0102] In the embodiments of the present application, different control voltages are provided for the switches in the bias module 13 and the switches in the amplification module 14, so that the conduction control voltage (i.e., the second control voltage) of at least one switch in the amplification module 14 is greater than the conduction control voltage (i.e., the first control voltage) of at least one switch in the bias module 13, thereby enabling the switches in the amplification module 14 to have a faster response speed and more excellent switching performance. In addition, making the first control voltage less than the second control voltage can reduce the leakage of the switches in the bias module 13 on the premise of meeting the performance requirements of the switches in the bias module 13. Therefore, the embodiments of the present application can improve the overall performance of the low-noise amplifier.

[0103] Please refer to Figure 11, The embodiment of the present application further provides a radio frequency front-end module 20 including the above low-noise amplifier. The radio frequency front-end module 20 is a component that integrates two or more discrete devices such as radio frequency switches, low-noise amplifiers, filters, duplexers, and power amplifiers (PAs) into an independent module, thereby improving the integration and hardware performance and miniaturizing the volume.

[0104] The radio frequency front-end module 20 of the embodiment of the present application can be applied to wireless communication terminals, including but not limited to devices with wireless communication functions such as mobile phones, tablet computers, smart watches, smart bracelets, and vehicle-mounted terminals.

[0105] There is also a radio frequency transceiver module and an antenna in the wireless communication terminal. The radio frequency front-end module 20 of the present application can be connected between the radio frequency transceiver module and the antenna, and is at least used to perform low-noise amplification or bypass output on the radio frequency signal received by the antenna through the low-noise amplifier 10 and transmit it to the radio frequency transceiver module.

[0106] The radio frequency front-end module 20 in the embodiment of the present application may include a substrate 21 and a first chip 22 disposed on the substrate, wherein the above low-noise amplifier is integrated in the first chip 22.

[0107] As an implementation manner, the radio frequency front-end module 20 may further include a second chip 23. The second chip 23 is also disposed on the substrate 21 and is electrically connected to the first chip 22. The second chip 23 is used to provide a control voltage for the low-noise amplifier in the first chip 22. For example, it can provide a first control voltage, a second control voltage, a third control voltage, a fourth control voltage, etc. for controlling the switch.

[0108] Optionally, the first chip 22 and the second chip 23 can be generated based on the same process or different processes, and the present application does not make a limitation. Exemplarily, both the first chip 22 and the second chip 23 are chips generated based on the SOI process; or, both the first chip 22 and the second chip 23 are chips generated based on the PHEMT process; or, the first chip 22 is a chip generated based on the PHEMT process, and the second chip 23 is a chip generated based on the SOI process or the CMOS process.

[0109] In a low-noise amplifier, by providing different control voltages for the switches in the bias module 13 and the switches in the amplification module 14, the turn-on control voltage (i.e., the second control voltage) of at least one switch in the amplification module 14 is made greater than the turn-on control voltage (i.e., the first control voltage) of at least one switch in the bias module 13, so that the switches in the amplification module 14 have a faster response speed and superior switching performance, thereby improving the overall performance of the low-noise amplifier. In addition, making the first control voltage less than the second control voltage can reduce the leakage of the switches in the bias module 13 on the premise of meeting the performance requirements of the switches in the bias module 13. Furthermore, the overall performance of the radio frequency front-end module 20 is improved.

[0110] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A low noise amplifier, comprising a radio frequency input terminal and a radio frequency output terminal, characterized in that: The low noise amplifier further comprises a bias module and an amplification module, wherein the amplification module comprises an amplification circuit and a bypass circuit; The bias module includes a bias circuit and at least one pull-down switch, wherein the output end of the bias circuit is connected to the amplifier circuit; one end of the pull-down switch is connected to the output end of the bias circuit, and the other end is grounded, and the pull-down switch is used to be turned on when receiving a first control voltage; The amplifying circuit is connected between the RF input terminal and the RF output terminal, and is used to amplify the first RF signal input from the RF input terminal to obtain a second RF signal; The bypass circuit is connected between the RF input terminal and the RF output terminal, and includes at least one bypass switch, wherein the bypass switch is configured to be turned on when receiving a second control voltage; The value of the second control voltage is greater than the value of the first control voltage.

2. The low noise amplifier according to claim 1, characterized in that: The bias circuit comprises a first output terminal and a second output terminal, the first output terminal is used to output a first bias signal, and the second output terminal is used to output a second bias signal; The amplifier circuit includes a first transistor and a second transistor, the third end of the first transistor is used to receive the first bias signal, the third end of the second transistor is used to receive the first radio frequency signal and the second bias signal, the second end of the first transistor is connected to the first end of the second transistor, and the second end of the second transistor is used to be grounded; Wherein, at least one of the pull-down switches includes a first switch, one end of the first switch is connected to the first output end or the second output end of the bias circuit, and the other end is grounded.

3. The low noise amplifier according to claim 2, characterized in that: At least one of the pull-down switches further comprises a second switch, wherein: One end of the first switch is connected to the first output end of the bias circuit, and the other end of the first switch is grounded; One end of the second switch is connected to the second output end of the bias circuit, and the other end of the second switch is grounded.

4. The low noise amplifier according to claim 2, characterized in that: The amplifying circuit further comprises: A first capacitor, wherein one end of the first capacitor is connected to the third end of the first transistor, and the other end of the first capacitor is grounded; A first inductor, wherein one end of the first inductor is connected to the second end of the second transistor, and the other end of the first inductor is grounded.

5. The low noise amplifier according to claim 4, characterized in that: The low noise amplifier is integrated in the chip, a grounding metal layer is provided on the outer surface of the chip or inside the chip, the other end of the first capacitor is connected to the grounding metal layer through a first conductive via, and the other end of the first inductor is connected to the grounding metal layer through a second conductive via.

6. The low noise amplifier according to claim 2, characterized in that: The input end of the bias circuit is used to receive a reference current. The bias circuit includes at least two third transistors connected in series. The first end of each of the third transistors is short-circuited with the third end. The second end of each of the third transistors is connected to the first end of another adjacent third transistor or is grounded. The first end of at least one of the third transistors is connected to the first output end and / or the second output end of the bias circuit.

7. The low noise amplifier according to claim 6, characterized in that: The bias circuit also includes a first resistor, one end of which is connected to the first output end of the bias circuit, and the other end of which is grounded through at least two third transistors connected in series, wherein a first end of one of the third transistors is connected to the second output end of the bias circuit.

8. The low noise amplifier according to claim 1, characterized in that: At least one of the bypass switches includes a third switch, a first end of the third switch is connected to the RF input end, a second end of the third switch is used to connect to the RF output end, and the third switch is turned on when the third end receives the second control voltage.

9. The low noise amplifier according to claim 8, characterized in that: The bypass circuit further includes a second resistor and a fourth switch, wherein the second resistor and the fourth switch are connected in series between the second end of the third switch and the RF output end.

10. The low noise amplifier according to claim 9, characterized in that: The bypass circuit also includes a fifth switch, a first end of the fifth switch is connected to a connection node between the second resistor and the fourth switch, a second end of the fifth switch is grounded, and the fifth switch is configured to be turned on when a third end receives a third control voltage, wherein the third control voltage is greater than or equal to the first control voltage.

11. The low noise amplifier according to claim 1, characterized in that: The amplifying circuit comprises an amplifying unit and a sixth switch, wherein the sixth switch is connected in series between the output end of the amplifying unit and the RF output end, and the sixth switch is configured to be turned on when receiving a fourth control voltage; The fourth control voltage is greater than the first control voltage.

12. The low noise amplifier according to any one of claims 1 to 11, characterized in that: The pull-down switch and the bypass switch are both turned on when the low-noise amplifier circuit is in a bypass mode.

13. The low noise amplifier according to any one of claims 1 to 11, characterized in that: The low noise amplifier is integrated in a chip, and the chip is produced based on a pseudo-matched high electron mobility transistor process.

14. The low noise amplifier according to any one of claims 1 to 11, characterized in that: The low noise amplifier further includes a voltage source circuit for generating the first control voltage and the second control voltage.

15. A low noise amplifier, characterized in that: It includes a bias module and an amplification module, wherein the bias module and the amplification module respectively include at least one switch, wherein at least one switch in the bias module is turned on when receiving a first control voltage, and at least one switch in the amplification module is turned on when receiving a second control voltage, and the value of the second control voltage is greater than the value of the first control voltage.

16. A radio frequency front-end module, characterized in that: It comprises a substrate and a first chip arranged on the substrate, wherein the first chip is provided with a low-noise amplifier as described in any one of claims 1 to 15.

17. The RF front-end module according to claim 16, characterized in that: It also includes a second chip, which is disposed on the substrate and electrically connected to the first chip, and is used to output the second control voltage and the first control voltage.

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