Low-noise amplifier, radio frequency front-end module and electronic equipment

Abstract

The invention relates to the technical field of radio frequency devices, and discloses a low-noise amplifier, a radio frequency front-end module and electronic equipment. A radio frequency output terminal; the power end is used for providing a power supply signal; the input end of the amplifying circuit is connected with the radio frequency input end; the first end of the protection circuit is connected with the output end of the amplification circuit, and the second end is connected with the radio frequency output end and the power supply end; the input end of the bypass circuit is connected with the radio frequency input end, and the output end of the bypass circuit is connected with the radio frequency output end; the protection circuit is configured to enable the direct-current voltage value of the output end of the amplifying circuit to be smaller than the direct-current voltage value of the second end of the protection circuit when the bypass circuit is in the on state. The protection circuit is arranged between the output end and the power supply end of the amplifying circuit, so that when the bypass circuit is in a conducting state, direct current voltage generated by superposition of a signal flowing in from the bypass circuit and a power supply signal is blocked, and a transistor of the amplifying circuit is prevented from being broken down by overlarge voltage.

Description

Technical Field

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

[0002] Low-noise amplifiers are an important component of wireless transceiver systems. They are mainly used to amplify received radio frequency signals. The performance indicators of low-noise amplifiers include gain, noise, and linearity.

[0003] In related technologies, low-noise amplifiers include amplification circuits and bypass circuits, and have switchable amplification and bypass modes. Specifically, in amplification mode, the low-noise amplifier amplifies radio frequency (RF) signals, while in bypass mode, the input RF signal can be directly transmitted to the signal output. However, in bypass mode, when the input signal swing of the low-noise amplifier is large, the transistors in the low-noise amplifier are at risk of breakdown.

[0004] Therefore, improving the tolerance and safety of low-noise amplifiers is an urgent problem to be solved. Summary of the Invention

[0005] This application provides a low-noise amplifier, a radio frequency front-end module, and an electronic device, which aim to protect the amplification circuit in the low-noise amplifier, especially the transistors that perform amplification, and prevent the transistors from being damaged.

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

[0007] RF input terminal;

[0008] RF output terminal;

[0009] The power supply side is configured to provide a power supply signal;

[0010] An amplifier circuit, the input terminal of which is connected to the radio frequency input terminal;

[0011] The protection circuit has its first terminal connected to the output terminal of the amplifier circuit, and its second terminal connected to both the RF output terminal and the power supply terminal; and...

[0012] The bypass circuit has a switchable on and off state, and the input terminal of the bypass circuit is connected to the RF input terminal, and the output terminal of the bypass circuit is connected to the RF output terminal.

[0013] The protection circuit is configured to make the DC voltage at the output of the amplifier circuit less than the DC voltage at the second terminal of the protection circuit when the bypass circuit is in the on state.

[0014] In some implementations, the protection circuit includes a first switching transistor and a protection capacitor, and the first switching transistor and the protection capacitor are connected in parallel between the output terminal and the power supply terminal of the amplifier circuit.

[0015] The first switching transistor is configured to disconnect when the bypass switch is in the ON state and to turn on when the bypass switch is in the OFF state.

[0016] In some implementations, the first switching transistor is a field-effect transistor or a bipolar transistor.

[0017] In some implementations, the protection circuit further includes a first inductor connected in series with the protection capacitor between the output terminal and the power supply terminal of the amplifier circuit.

[0018] In some implementations, when the low-noise amplifier operates at a frequency greater than or equal to 3 GHz, the capacitance of the protection capacitor is greater than or equal to 5 pF.

[0019] When the operating frequency of the low-noise amplifier is less than 3GHz, the capacitance of the protection capacitor should be greater than or equal to 8pF.

[0020] In some embodiments, the low-noise amplifier further includes a control unit configured to control the first switch to turn off when the bypass circuit is on and to control the first switch to turn on when the bypass circuit is off.

[0021] In some implementations, the amplifier circuit includes at least one amplifying transistor;

[0022] The low-noise amplifier also includes a first chip, a first switching transistor and a protection capacitor integrated with the amplifying transistor on the first chip;

[0023] Alternatively, the low-noise amplifier may also include different first and second chips, with the first switching transistor and protection capacitor disposed on the first chip, and the amplifying transistor disposed on the second chip.

[0024] In some implementations, the bypass circuit includes at least one bypass switch connected between the RF input and the RF output.

[0025] In some implementations, the amplifier circuit includes a first amplifying transistor and a second amplifying transistor;

[0026] In this circuit, the first terminal of the first amplifying transistor is grounded, the second terminal of the first amplifying transistor is connected to the first terminal of the second amplifying transistor, the third terminal of the first amplifying transistor is connected to the RF input terminal as the input terminal of the amplifying circuit, the second terminal of the second amplifying transistor is connected to the first terminal of the protection circuit as the output terminal of the amplifying circuit, and the third terminal of the second amplifying transistor is connected to the bias control terminal.

[0027] In some implementations, the low-noise amplifier further includes a second inductor connected between a first terminal of the first amplifying transistor and ground.

[0028] In some implementations, the amplifier circuit includes a third amplifying transistor;

[0029] The first terminal of the third amplifying transistor is grounded, the second terminal of the third amplifying transistor is connected to the RF input terminal as the input terminal of the amplifying circuit, and the third terminal of the third amplifying transistor is connected to the first terminal of the protection circuit as the output terminal of the amplifying circuit.

[0030] In some implementations, the amplifying transistor in the amplifier circuit is a field-effect transistor, with its first terminal being the source, its second terminal the drain, and its third terminal the gate; or,

[0031] The amplifying transistor in the amplifier circuit is a triode. The first terminal of the amplifying transistor is the emitter, the second terminal is the collector, and the third terminal is the base.

[0032] In some implementations, the voltage rating of the first switching transistor is greater than that of the second amplifying transistor.

[0033] In some implementations, the first switching transistor has a withstand voltage greater than or equal to 2.5V, and the second amplifying transistor has a withstand voltage less than 2.5V.

[0034] In some implementations, the withstand voltage of the first switching transistor is greater than or equal to the withstand voltage of the bypass switch.

[0035] In some implementations, the voltage of the power supply signal is at least 0.6V higher than the withstand voltage of the second amplifying transistor.

[0036] In some implementations, the low-noise amplifier further includes an output matching circuit connected between the output of the amplifier circuit and the RF output, and configured to match the output impedance of the low-noise amplifier.

[0037] In some implementations, the low-noise amplifier further includes a third inductor connected between the power supply terminal and the output terminal of the protection circuit.

[0038] In some implementations, the DC voltage of the power supply signal is greater than or equal to 1.8V.

[0039] Secondly, embodiments of this application also provide another low-noise amplifier, including:

[0040] RF input terminal;

[0041] RF output terminal;

[0042] The power supply side is configured to provide a power supply signal;

[0043] An amplifier circuit, the input terminal of which is connected to the radio frequency input terminal, includes a second amplifying transistor;

[0044] The protection circuit has its first terminal connected to the output terminal of the second amplifying transistor, and its second terminal connected to the RF output terminal and the power supply terminal.

[0045] The voltage of the power supply signal output from the power supply terminal is at least 0.6V higher than the withstand voltage of the second amplifying transistor; and,

[0046] The bypass circuit has a switchable on and off state, and the input terminal of the bypass circuit is connected to the RF input terminal, and the output terminal of the bypass circuit is connected to the RF output terminal.

[0047] The protection circuit is configured to make the DC voltage at the output of the amplifier circuit less than the DC voltage at the second terminal of the protection circuit when the bypass circuit is in the on state.

[0048] In some implementations, the amplifier circuit further includes a first amplifying transistor;

[0049] In this circuit, the first terminal of the first amplifying transistor is grounded, the second terminal of the first amplifying transistor is connected to the first terminal of the second amplifying transistor, the third terminal of the first amplifying transistor is connected to the RF input terminal as the input terminal of the amplification circuit, the second terminal of the second amplifying transistor is the output terminal of the second amplifying transistor, and the third terminal of the second amplifying transistor is connected to the bias control terminal.

[0050] In some implementations, the amplifying transistor in the amplifier circuit is a field-effect transistor, with its first terminal being the source, its second terminal the drain, and its third terminal the gate; or,

[0051] The amplifying transistor in the amplifier circuit is a triode. The first terminal of the amplifying transistor is the emitter, the second terminal is the collector, and the third terminal is the base.

[0052] In some implementations, the protection circuit includes a first switching transistor and a protection capacitor, and the first switching transistor and the protection capacitor are connected in parallel between the output terminal and the power supply terminal of the amplifier circuit.

[0053] The first switching transistor is configured to disconnect when the bypass switch is in the ON state and to turn on when the bypass switch is in the OFF state.

[0054] In some implementations, the protection circuit further includes a first inductor connected in series with the protection capacitor between the output terminal and the power supply terminal of the amplifier circuit.

[0055] In some implementations, the voltage rating of the first switching transistor is greater than that of the second amplifying transistor.

[0056] Thirdly, embodiments of this application also provide another type of low-noise amplifier, which includes:

[0057] RF input terminal;

[0058] RF output terminal;

[0059] The power supply side is configured to provide a power supply signal;

[0060] An amplifier circuit, the input terminal of which is connected to the radio frequency input terminal;

[0061] A protection circuit includes a first switching transistor and a protection capacitor, wherein the first switching transistor and the protection capacitor are connected in parallel between the output terminal and the power supply terminal of the amplifier circuit, wherein the first switching transistor is configured to be turned off when the bypass switch is in the on state and turned on when the bypass switch is in the off state; and,

[0062] The bypass circuit has a switchable on and off state, and the input terminal of the bypass circuit is connected to the RF input terminal, and the output terminal of the bypass circuit is connected to the RF output terminal.

[0063] Fourthly, embodiments of this application also provide a radio frequency front-end module, including a low-noise amplifier as provided in any embodiment of this application.

[0064] Fifthly, embodiments of this application also provide an electronic device, including a low-noise amplifier as provided in any embodiment of this application or a radio frequency front-end module as provided in any embodiment of this application.

[0065] In summary, embodiments of this application provide a low-noise amplifier, an RF front-end module, and an electronic device. One of the low-noise amplifiers includes: an RF input terminal; an RF output terminal; a power supply terminal configured to provide a power supply signal; an amplifier circuit whose input terminal is connected to the RF input terminal; a protection circuit whose first terminal is connected to the output terminal of the amplifier circuit, and whose second terminal is connected to both the RF output terminal and the power supply terminal; and a bypass circuit having a switchable on / off state, with its input terminal connected to the RF input terminal and its output terminal connected to the RF output terminal. The protection circuit is configured to, when the bypass circuit is in the on state, ensure that the DC voltage at the output terminal of the amplifier circuit is less than the DC voltage at the second terminal of the protection circuit. It should be understood that by setting a protection circuit between the output terminal and the power supply terminal of the amplifier circuit, the protection circuit can block the DC voltage generated by the superposition of the signal flowing from the bypass circuit and the power supply signal when the bypass circuit is in the conducting state, without affecting the normal operation of the amplifier circuit. This prevents the excessive voltage from breaking down the transistors in the amplifier circuit, thereby protecting the amplifier circuit and improving the tolerance, safety and reliability of the amplifier circuit and even the entire low-noise amplifier. Attached Figure Description

[0066] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0067] Figure 1 This is a schematic diagram of a module structure of a low-noise amplifier provided in an embodiment of this application;

[0068] Figure 2 A schematic diagram of a circuit structure for a low-noise amplifier provided in an embodiment of this application;

[0069] Figure 3 A schematic diagram of another circuit structure of a low-noise amplifier provided in an embodiment of this application;

[0070] Figure 4 A schematic diagram of another circuit structure of a low-noise amplifier provided in an embodiment of this application;

[0071] Figure 5 A schematic diagram of another circuit structure of a low-noise amplifier provided in an embodiment of this application;

[0072] Figure 6 A schematic diagram of another circuit structure of a low-noise amplifier provided in an embodiment of this application;

[0073] Figure 7 A schematic diagram of another circuit structure of a low-noise amplifier provided in an embodiment of this application;

[0074] Figure 8 A schematic diagram of another circuit structure of a low-noise amplifier provided in an embodiment of this application;

[0075] Figure 9 Another circuit structure for a low-noise amplifier provided in one embodiment of this application;

[0076] Figure 10 Another circuit structure for a low-noise amplifier provided in one embodiment of this application;

[0077] Figure 11 A schematic block diagram of a radio frequency front-end module provided in an embodiment of this application;

[0078] Figure 12 A schematic block diagram of an electronic device provided in an embodiment of this application;

[0079] Figure label:

[0080] 1. Low-noise amplifier; 10. RF input terminal; 20. RF output terminal; 30. Power supply terminal; 40. Amplification circuit; 50. Protection circuit; 60. Bypass circuit; 71. Control unit; 72. Bias control terminal; 81. First chip; 82. Second chip; 90. Output matching circuit;

[0081] S1, First switching transistor; S2, Bypass switch; C1, Protection capacitor; L1, First inductor; L2, Second inductor; L3, Third inductor; M1, First amplifying transistor; M2, Second amplifying transistor; M3, Third amplifying transistor;

[0082] 2. Radio frequency front-end module; 3. Electronic equipment. Detailed Implementation

[0083] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be decomposed, combined, or partially merged; therefore, the actual execution order may change according to the actual situation.

[0084] Low-noise amplifiers are an important component of wireless transceiver systems. They are mainly composed of transistors and their main function is to amplify the input radio frequency signal, featuring high gain and low noise.

[0085] In related technologies, low-noise amplifiers (LNO) include amplification circuits and bypass circuits, and have switchable amplification and bypass modes. Specifically, in amplification mode, LNO achieves lower noise and ensures better sensitivity, while in bypass mode, large input signals can be directly transmitted, achieving better linearity. However, in bypass mode, when the signal swing transmitted by the LNO is large, the transistors in the LNO are at risk of breakdown. Therefore, improving the robustness and safety of LNO amplifiers is a problem that urgently needs to be solved.

[0086] To address the aforementioned issues, embodiments of this application provide a low-noise amplifier, a radio frequency front-end module, and an electronic device. The technical solution of this application will be described below with reference to the accompanying drawings.

[0087] Please see Figures 1 to 2 , Figure 1 This is a schematic diagram of a module structure of a low-noise amplifier 1 provided in an embodiment of this application. Figure 2 This is a schematic diagram of a circuit structure of a low-noise amplifier 1 provided in an embodiment of this application.

[0088] like Figures 1 to 2 As shown, this application embodiment provides a low-noise amplifier 1, which includes at least an RF input terminal 10, an RF output terminal 20, a power supply terminal 30, an amplification circuit 40, a protection circuit 50, and a bypass circuit 60.

[0089] It should be noted that the RF input terminal 10 is configured to receive RF signals, the RF output terminal is configured to output the RF signal processed by the low-noise amplifier 1 to the subsequent circuit, and the power supply terminal 30 is configured to provide a power supply signal (e.g., power supply voltage). Specifically, the RF signal input from the outside enters the internal circuit of the low-noise amplifier 1 through the RF input terminal 10, such as the amplification circuit 40, bypass circuit 60, etc., and the internal circuit of the low-noise amplifier 1 processes the RF signal accordingly before outputting it to the subsequent circuit through the RF output terminal. For example, the low-noise amplifier 1 amplifies the RF signal, or it may not amplify the RF signal, allowing the input RF signal to be directly transmitted to the RF output terminal 20. Specifically, the power supply signal provided by the power supply terminal 30 is used to power the transistors that perform amplification in the amplification circuit 40 to ensure the normal operation of the transistors, thereby enabling the amplification circuit 40 to amplify the RF signal.

[0090] The structure and function of amplifier circuit 40, protection circuit 50 and bypass circuit 60 are explained in detail below.

[0091] Specifically, the input terminal of the amplifier circuit 40 is connected to the RF input terminal 10, and the amplifier circuit 40 is configured to amplify the RF signal input from its input terminal and output the amplified RF signal from its output terminal; the protection circuit 50 has a first terminal and a second terminal, and the first terminal of the protection circuit 50 is connected to the output terminal of the amplifier circuit 40, and the second terminal of the protection circuit 50 is connected to the RF output terminal 20 and the power supply terminal 30; the bypass circuit 60 has a switchable on state and off state, and the input terminal of the bypass circuit 60 is connected to the RF input terminal 10, and the output terminal of the bypass circuit 60 is connected to the RF output terminal 20.

[0092] That is, the low-noise amplifier 1 internally forms an amplification path consisting of an RF input terminal 10, an amplification circuit 40, a protection circuit 50, and an RF output terminal 20, as well as a bypass path consisting of an RF input terminal 10, a bypass circuit 60, and an RF output terminal 20. The low-noise amplifier 1 can choose to amplify and output the input RF signal through the amplification path, or it can choose not to amplify the input RF signal and directly transmit the RF signal to the RF output terminal 20 through the bypass path.

[0093] As one embodiment, the low-noise amplifier 1 has an active mode and a bypass mode, and can switch between the two. Specifically, in active mode, the bypass circuit 60 is off, the radio frequency (RF) signal enters the amplifier circuit 40, and the amplifier circuit 40 amplifies the RF signal. The amplified RF signal then flows out through the protection circuit 50. In bypass mode, the bypass circuit 60 is on, the RF signal is input to the bypass circuit 60, and flows out from the bypass circuit 60.

[0094] For example, when the power of the radio frequency signal input from the radio frequency input terminal 10 is low, the low noise amplifier 1 can operate in amplification mode, amplifying the received weak radio frequency signal before outputting it. When the power of the radio frequency signal input from the radio frequency input terminal 10 is high, the low noise amplifier 1 can operate in bypass mode, thereby directly outputting the received radio frequency signal or outputting it after attenuation.

[0095] Specifically, the protection circuit 50 is configured to make the DC voltage value at the output terminal of the amplifier circuit 40 less than the DC voltage value at the second terminal of the protection circuit 50 when the bypass circuit 60 is in the on state.

[0096] It should be noted that when the low-noise amplifier 1 is in amplification mode, the bypass circuit 60 is in the off state. The power supply signal provided by the power supply terminal 30 flows through the protection circuit 50 and is transmitted to the amplifier circuit 40 to supply power to the transistors that play an amplification role in the amplifier circuit 40, so as to ensure that the amplifier circuit 40 amplifies the radio frequency signal.

[0097] In at least one embodiment, when the low-noise amplifier 1 is in bypass mode, the bypass circuit 60 is in the conducting state. The radio frequency signal input from the radio frequency input terminal 10 flows through the bypass circuit 60 to the output terminal of the bypass circuit 60. Since the second terminal of the protection circuit 50 is connected to the radio frequency output terminal 20 and the power supply terminal 30, the radio frequency signal and the power supply signal provided by the power supply terminal 30 will be superimposed on the second terminal of the protection circuit 50, that is, the connection point between the amplification path and the bypass path, so that the DC voltage value of the second terminal of the protection circuit 50 is pulled up.

[0098] It should also be noted that, as an embodiment, the amplifier circuit 40 includes transistors for amplification. These transistors each have a maximum withstand voltage threshold. When the voltage applied to the transistor exceeds this maximum withstand voltage threshold, the transistor will break down. Furthermore, since the transistor needs to amplify the radio frequency (RF) signal, to ensure the gain and linearity of the transistor in the amplifier circuit 40 during amplification, the transistor's withstand voltage (maximum voltage threshold) cannot be too high. An excessively high withstand voltage (maximum voltage threshold) would sacrifice its gain and linearity. Therefore, as mentioned earlier, when the low-noise amplifier 1 is in bypass mode, the DC voltage generated by the superposition of the RF signal and the power supply signal directly acts on the transistor in the amplifier circuit 40, which will break down the transistor, especially when the RF signal swing is large and / or under conditions of large amplitude.

[0099] Based on this, the low-noise amplifier 1 provided in this application embodiment provides a protection circuit 50 between the output terminal of the amplifier circuit 40 and the power supply terminal 30. Without affecting the normal operation of the amplifier circuit, the protection circuit 50 also blocks the DC voltage generated by the superposition of the radio frequency signal and the power supply signal when the bypass circuit 60 is in the conducting state. This reduces the DC voltage input to the output terminal of the amplifier circuit 40, making the DC voltage value at the output terminal of the amplifier circuit 40 less than the DC voltage value at the second terminal of the protection circuit 50. This effectively prevents the transistors in the amplifier circuit 40 from being damaged due to excessively high voltage values ​​at the output terminal of the amplifier circuit 40, thereby protecting the amplifier circuit 40 and improving the tolerance, safety, and reliability of the amplifier circuit 40 and even the entire low-noise amplifier 1.

[0100] like Figure 2As shown, in some embodiments, the protection circuit 50 includes a first switching transistor S1 and a protection capacitor C1, and the first switching transistor S1 and the protection capacitor C1 are connected in parallel between the output terminal of the amplifier circuit 40 and the power supply terminal 30.

[0101] The first switch S1 is configured to be disconnected when the bypass switch S2 is in the on state and to be turned on when the bypass switch S2 is in the off state.

[0102] Specifically, when the low-noise amplifier 1 is in amplification mode, the bypass circuit 60 is off, and the first switch S1 is on. The radio frequency signal input from the radio frequency input terminal 10 enters the amplifier circuit 40, which amplifies the radio frequency signal and outputs it. After amplification, the radio frequency signal flows through the on-state first switch S1 and the protection capacitor C1 through the protection circuit 50, allowing the amplified radio frequency signal to flow unimpeded through the protection circuit 50 to the radio frequency output terminal 20 without affecting the normal amplification operation of the low-noise amplifier 1 in amplification mode, thus improving the signal quality of the output of the low-noise amplifier 1.

[0103] In at least one embodiment, when the low-noise amplifier 1 is in bypass mode, the bypass circuit 60 is in the on state, and the first switch S1 is off. The radio frequency signal input from the radio frequency input terminal 10 flows through the on-state bypass circuit 60 to the output terminal of the bypass circuit 60. Since the second terminal of the protection circuit 50 is connected to the radio frequency output terminal 20 and the power supply terminal 30, the radio frequency signal and the power supply signal provided by the power supply terminal 30 will be superimposed on the second terminal of the protection circuit 50, causing the DC voltage value of the second terminal of the protection circuit 50 to be pulled high.

[0104] At this time, the first switch S1, which is turned off, can block or reduce the DC voltage at the second terminal of the protection circuit 50. At the same time, since the protection capacitor C1 has the characteristic of blocking DC signals, the protection capacitor C1 can also block the DC voltage at the second terminal of the protection circuit 50, so that the DC voltage value at the output terminal of the amplifier circuit 40 is less than the DC voltage value at the second terminal of the protection circuit 50, thereby reducing the possibility of the amplifier circuit 40 being broken down, especially the transistors that play an amplification role in the amplifier circuit 40, thereby improving the tolerance and safety of the amplifier circuit 40 and even the entire low-noise amplifier 1.

[0105] In some implementations, the first switch S1 is a field-effect transistor (MOS) or a bipolar junction transistor (BJT). Specifically, the first switch S1 can be switched on and off under the action of an external control signal.

[0106] For example, the first switch S1 can be one of an N-channel MOSFET, a P-channel MOSFET, a PNP transistor, and an NPN transistor. Taking an N-channel MOSFET as an example, the source of the first switch S1 is electrically connected to the output terminal of the amplifier circuit 40, the drain of the first switch S1 is connected to the RF output terminal 20 and the power supply terminal 30, and the first switch S1 is configured to receive a control signal through its gate to turn the first switch S1 on or off based on the control signal.

[0107] like Figure 3 As shown, in some embodiments, the protection circuit 50 further includes a first inductor L1, which is connected in series with the protection capacitor C1 between the output terminal of the amplifier circuit 40 and the power supply terminal 30.

[0108] In some implementations, when the low-noise amplifier 1 operates at a frequency greater than or equal to 3 GHz, the capacitance of the protection capacitor C1 is greater than or equal to 5 pF.

[0109] When the operating frequency band of low-noise amplifier 1 is less than 3GHz, the capacitance of the protection capacitor C1 is greater than or equal to 8pF.

[0110] It should be understood that the above-mentioned capacitance design of the protection capacitor C1 enables the protection capacitor C1 to produce a better blocking effect on the DC voltage at the second terminal of the protection circuit 50 when the bypass circuit 60 is in the conducting state. Furthermore, the capacitance design of the protection capacitor C1 needs to be matched with the operating frequency of the low noise amplifier 1 so that when the bypass circuit 60 is in the off state, the AC signal component in the radio frequency signal can flow through the protection circuit 50 through the protection capacitor C1.

[0111] As one embodiment, the capacitance of the protection capacitor C1 is less than 10pF to reduce the difficulty of circuit implementation and avoid making the protection capacitor C1 too large.

[0112] like Figure 4 As shown, in some embodiments, the low-noise amplifier 1 further includes a control unit 70, which is configured to control the first switch S1 to turn off when the bypass circuit 60 is in the on state, and to control the first switch S1 to turn on when the bypass circuit 60 is in the off state.

[0113] Specifically, the control unit 70 is used to control the conduction and cutoff of the first switching transistor S1 according to the on / off state of the bypass circuit 60, to ensure the coordination between the bypass circuit 60 and the first switching transistor S1, so that the protection circuit 50 can effectively protect the amplifier circuit 40 when the bypass circuit 60 is in the conducting state, and that the radio frequency signal amplified by the amplifier circuit 40 can stably pass through the protection circuit 50 when the bypass circuit 60 is in the cutoff state.

[0114] As one embodiment, the first switch S1 has an input terminal, an output terminal, and a controlled terminal. Taking an N-channel MOSFET as an example, the drain of the first switch S1 is the input terminal, the source of the first switch S1 is the output terminal, and the first switch S1 is configured to receive a control signal through its gate. The control unit 70 is connected to the controlled terminal of the first switch S1 and is used to output a control signal to the controlled terminal to control the switching on and off between the input and output terminals of the first switch S1.

[0115] like Figure 3 and Figure 5 As shown, in some embodiments, the bypass circuit 60 includes at least one bypass switch S2 connected between the RF input terminal 10 and the RF output terminal 20.

[0116] Specifically, the bypass switch S2 has a switchable on or off state to adjust the state of the bypass circuit 60. When the bypass switch S2 is in the on state, the bypass circuit 60 is on; when the bypass switch S2 is in the off state, the bypass circuit 60 is off. The bypass switch S2 can switch the on or off state of the bypass circuit 60.

[0117] It should also be noted that the number of bypass switches S2 can be one or at least two.

[0118] When the bypass switch S2 includes only one bypass switch S2, such as Figure 3 As shown, one end of the bypass switch S2 is connected to the RF input terminal 10, and the other end is connected to the RF output terminal 20.

[0119] When the bypass circuit 60 includes at least two bypass switches S2, the at least two bypass switches S2 can be as follows: Figure 5 As shown, it is connected in series between the RF input terminal 10 and the RF output terminal 20.

[0120] In at least one embodiment, the bypass circuit 60 further includes a parallel switch connected to ground. When the bypass circuit is on, that is, when the bypass switch is on, the parallel switch connected to ground is off; when the bypass circuit is off, that is, when the bypass switch is off, the parallel switch connected to ground is on, thereby preventing radio frequency signals on other paths from leaking to the signal output terminal through the bypass switch.

[0121] Taking at least two bypass switches S2 connected in series between the RF input terminal 10 and the RF output terminal 20 as an example, when all at least two bypass switches S2 are turned off, the bypass circuit 60 switches to the off state. When all at least two bypass switches S2 are turned on, the bypass circuit 60 switches to the on state.

[0122] The circuit structure of amplifier circuit 40 is described in detail. As an implementation and not a limitation, amplifier circuit 40 can be connected between RF input terminal 10 and the first terminal of protection circuit 50 in a common source and common gate manner, or it can be connected between RF input terminal 10 and the first terminal of protection circuit 50 in a common source manner.

[0123] like Figure 3 As shown, the following provides a detailed explanation of the common source, common gate connection method:

[0124] In some embodiments, the amplifier circuit 40 includes a first amplifying transistor M1 and a second amplifying transistor M2.

[0125] Specifically, when the first amplifying transistor M1 and the second amplifying transistor M2 are connected in a common-source, common-gate configuration between the RF input terminal 10 and the first terminal of the protection circuit 50, the first terminal of the first amplifying transistor M1 is grounded, the second terminal of the first amplifying transistor M1 is connected to the first terminal of the second amplifying transistor M2, and the third terminal of the first amplifying transistor M1 is the input terminal of the amplifying circuit 40, which can be connected to the RF input terminal 10 to receive the input RF signal; the second terminal of the second amplifying transistor M2 is the output terminal of the amplifying circuit 40 and is connected to the first terminal of the protection circuit 50, which can be connected to the RF output terminal 20 through the protection circuit 50 to output the amplified RF signal, and connected to the power supply terminal 30 through the protection circuit 50 to receive the power supply signal; the third terminal of the second amplifying transistor M2 is connected to the bias control terminal, which can be used to receive the bias signal output by the bias control terminal.

[0126] It should be noted that, unless otherwise specified, the term "connection" in this application can refer to a direct connection or an indirect connection. For example, the third terminal of the first amplifying transistor M1 can be directly connected to the RF input terminal 10, or it can be connected to the RF input terminal 10 through a capacitor. Similarly, the first terminal of the first amplifying transistor M1 can be directly grounded, or it can be indirectly grounded through at least one component such as an inductor, capacitor, or resistor. Furthermore, the second terminal of the second amplifying transistor M2 can be directly connected to the first terminal of the protection circuit 50, or it can be indirectly connected to the first terminal of the protection circuit 50 through at least one component such as an inductor, capacitor, resistor, switch, or choke.

[0127] In some embodiments, the low-noise amplifier 1 further includes a second inductor L2 connected between a first terminal of the first amplifying transistor M1 and ground.

[0128] Specifically, a second inductor L2 is provided between the first terminal of the first amplifying transistor M1 and ground, which can be used to increase the real part of the input impedance and improve the stability of the low-noise amplifier 1.

[0129] like Figure 6As shown below, the connection method of common source is explained in detail:

[0130] In some other embodiments, the amplifier circuit 40 includes a third amplifying transistor M3.

[0131] Specifically, the first terminal of the third amplifying transistor M3 is grounded, the second terminal of the third amplifying transistor M3 serves as the input terminal of the amplifying circuit 40, and can be connected to the RF input terminal 10 to receive the input RF signal. The third terminal of the third amplifying transistor M3 serves as the output terminal of the amplifying circuit 40, and can be connected to the RF output terminal 20 through the protection circuit 50 to output the amplified RF signal, and can also be connected to the power supply terminal 30 through the protection circuit 50 to receive the power supply signal.

[0132] In some embodiments, the amplifying transistor in the amplifying circuit 40 is a field-effect transistor, with its first terminal being the source, its second terminal the drain, and its third terminal the gate; or,

[0133] The amplifying transistor in amplifier circuit 40 is a triode, with the first terminal being the emitter, the second terminal being the collector, and the third terminal being the base.

[0134] Specifically, the amplifier circuit 40 includes one or at least two amplifying transistors, which are used to amplify radio frequency signals individually or in combination. For example, the amplifying transistors may include the first amplifying transistor M1 and the second amplifying transistor M2 described above, or they may include the third amplifying transistor M3 described above.

[0135] The amplifying transistor can be one of the following: an N-channel field-effect transistor, a P-channel field-effect transistor, a PNP transistor, or an NPN transistor.

[0136] Taking the common-source common-gate architecture of amplifier circuit 40 as an example, when both the first amplifier transistor M1 and the second amplifier transistor M2 are N-channel field-effect transistors, the source of the first amplifier transistor M1 is grounded, the drain of the first amplifier transistor M1 is connected to the source of the second amplifier transistor M2, the gate of the first amplifier transistor M1 is the input terminal of amplifier circuit 40, and can be connected to the RF input terminal 10 to receive the input RF signal; the drain of the second amplifier transistor M2 is the output terminal of amplifier circuit 40 and is connected to the source of protection circuit 50, and can be connected to the RF output terminal 20 through protection circuit 50 to output the amplified RF signal, and connected to the power supply terminal 30 through protection circuit 50 to receive the power supply signal, and the gate of the second amplifier transistor M2 is connected to the bias control terminal, which can be used to receive the bias signal output by the bias control terminal.

[0137] like Figure 7 As shown, in some embodiments, the amplifier circuit 40 includes at least one amplifying transistor;

[0138] The low-noise amplifier 1 also includes a first chip 81, a first switching transistor S1 and a protection capacitor C2 integrated with the amplifying transistor in the first chip 81.

[0139] The amplifying transistors in the amplifying circuit 40 are used to amplify the radio frequency signal individually or in combination. For example, the amplifying transistors may include the first amplifying transistor M1 and the second amplifying transistor M2 described above, or the third amplifying transistor M3 described above.

[0140] Specifically, by placing the first switching transistor S1, the protection capacitor C2, and the amplification transistor in the amplifier circuit 40 on the same chip, the area occupied by the amplifier circuit 40 and the protection circuit 50 can be effectively reduced, the integration of the low-noise amplifier 1 can be improved, and the size of the low-noise amplifier 1 can be reduced.

[0141] It should be noted that, in the embodiments of this application, the first switching transistor S1, the protection capacitor C2, and any one of the amplifying transistors in the amplifying circuit 40 can be disposed on the chip using at least one of the following processes: CMOS (Complementary Metal Oxide Semiconductor), SOI (Silicon-On-Insulator), PHEMT (Pseudomorphic High Electron Mobility Transistor), and GaAs.

[0142] It should also be noted that in the embodiment where the first switching transistor S1, the protection capacitor C2, and the amplifying transistor in the amplifier circuit 40 are integrated into the first chip 81, the same process must be used to place the first switching transistor S1, the protection capacitor C2, and the amplifying transistor in the amplifier circuit 40 onto the first chip 81.

[0143] In other embodiments, the low-noise amplifier 1 further includes different first chips 81 and second chips 82, with a first switching transistor S1 and a protection capacitor C1 disposed on the first chip 81, and an amplifying transistor disposed on the second chip 82.

[0144] It should be noted that placing the first switching transistor S1 and the protection capacitor C1 on the first chip 81, and placing the amplifying transistor on the second chip 82, can be done using the same process, or different processes can be used respectively. Optional processes include, but are not limited to, the aforementioned CMOS, SOI, PHEMT, and GaAs. This application does not impose specific limitations on the embodiments herein.

[0145] like Figure 3As shown, in some embodiments, the low-noise amplifier 1 further includes a third inductor L3, which is connected between the power supply terminal 30 and the output terminal of the protection circuit 50.

[0146] Specifically, the third inductor L3 can act as a choke to isolate signal interference between the power supply signal and the radio frequency signal, thereby improving the stability and reliability of the low-noise amplifier 1.

[0147] It should also be noted that, based on the setting of the third inductor L3, the setting position of the first switch S1 ensures that the third inductor L3 can participate in impedance matching in the low-noise amplifier 1 in bypass mode (i.e., when the bypass circuit 60 is on and the first switch S1 is off), so as to optimize the input echo and output echo of the low-noise amplifier 1.

[0148] In some implementations, the withstand voltage of the first switching transistor S1 is greater than that of the second amplifying transistor M2. Specifically, the aforementioned withstand voltage design aims to improve the withstand capability of the first switching transistor S1 against the voltage generated by the superposition of the radio frequency signal and the power supply signal, reduce the possibility of the first switching transistor S1 being damaged, and improve the protection safety of the protection circuit 50 for the second amplifying transistor M2.

[0149] As one embodiment, the first switching transistor S1 has a withstand voltage greater than or equal to 2.5V, and the second amplifying transistor M2 has a withstand voltage less than 2.5V.

[0150] As one embodiment, in the low-noise amplifier 1, both the first switching transistor S1 and the second amplifying transistor M2 can be implemented using field-effect transistors. However, it should be noted that the main function of the second amplifying transistor M2 is to amplify the signal. In order to ensure the gain and linearity performance of the second amplifying transistor M2 when amplifying the signal, the voltage rating of the second amplifying transistor M2 cannot be made too large. On the other hand, the main function of the first switching transistor S1 is to switch, so the voltage rating of the first switching transistor S1 can be made very large.

[0151] In some implementations, the withstand voltage of the first switching transistor S1 is greater than or equal to the withstand voltage of the bypass switch S2. Specifically, when the bypass circuit 60 is in the on state, the voltage at the connection point between the first switching transistor S1 and the output terminal of the bypass circuit 60 is formed by the superposition of the radio frequency signal flowing in from the bypass circuit 60 and the power supply signal. Therefore, the DC voltage that this connection point needs to withstand is greater than the DC voltage that the bypass switch S2 needs to withstand. Thus, the aforementioned withstand voltage design can effectively improve the first switching transistor S1's tolerance to the voltage generated by the superposition of the radio frequency signal and the power supply signal, reduce the possibility of the first switching transistor S1 being broken down, and improve the protection safety of the protection circuit 50 for the second amplifying transistor M2.

[0152] For example, the low-noise amplifier 1 provided in this application embodiment can be applied to industrial scenarios or Internet of Things application scenarios, which have high requirements for the response speed and input power of the low-noise amplifier 1.

[0153] It should be noted that the low-noise amplifier 1 provided in this application can be mainly applied to scenarios with high input power, where the input power specifically refers to the input power of the radio frequency signal.

[0154] As one example, the input power of the radio frequency signal is greater than or equal to 30 dBm.

[0155] It should be understood that because the input power of the radio frequency signal is high, the superposition of the high-power radio frequency signal and the power supply signal will generate a large DC voltage value, which will cause the amplification transistor in the low noise amplifier 1 to break down. Therefore, in this embodiment, a protection circuit 50 is provided between the output terminal of the amplifier circuit 40 and the power supply terminal 30 to ensure the application of the low noise amplifier 1 under high input power.

[0156] In some implementations, the voltage of the power supply signal is at least 0.6V higher than the withstand voltage of the second amplifying transistor M2.

[0157] It should be noted that in actual scenarios where the low-noise amplifier 1 is used to process radio frequency signals, the voltage value of the power supply signal provided by the power supply terminal 30 to the amplifier circuit 40 is relatively high to ensure the normal operation of the amplifying transistor, thereby enabling the amplifier circuit 40 to amplify the radio frequency signal. Therefore, in this scenario, a protection circuit 50 is set between the output terminal of the amplifier circuit 40 and the power supply terminal 30. Without affecting the normal operation of the amplifier circuit, the protection circuit 50 also blocks the voltage generated by the superposition of the radio frequency signal and the power supply signal when the bypass circuit 60 is in the conducting state, thereby reducing the DC voltage value input to the output terminal of the amplifier circuit 40. This makes the DC voltage value at the output terminal of the amplifier circuit 40 less than the DC voltage value at the second terminal of the protection circuit 50, effectively preventing the amplifying transistor in the amplifier circuit 40 from being damaged due to excessive DC voltage at the output terminal of the amplifier circuit 40, thus protecting the amplifier circuit 40 and improving the tolerance, safety and reliability of the amplifier circuit 40 and even the entire low-noise amplifier 1.

[0158] As one embodiment, the DC voltage value of the power supply signal is greater than or equal to 1.8V to meet the voltage requirements of the amplifier circuit 40 for amplifying the radio frequency signal using the power supply signal.

[0159] like Figure 3 As shown, in some embodiments, the low-noise amplifier 1 further includes an output matching circuit 90, which is connected between the output terminal of the amplifier circuit 40 and the radio frequency output terminal 20, and is configured to match the output impedance of the low-noise amplifier 1.

[0160] It should be noted that in practical applications of the low-noise amplifier 1, the RF output terminal 20 of the low-noise amplifier 1 is also connected to the subsequent stage circuit. The output matching circuit 90 can be used to match the output impedance of the amplifier circuit 40 with the input impedance of the subsequent stage circuit to reduce the loss of the amplified RF signal during transmission from the RF output terminal 20 to the subsequent stage circuit. Optionally, the output matching circuit 90 may include at least one capacitor and / or inductor, and this application does not limit its specific circuit structure.

[0161] like Figure 9 As shown in the embodiments of this application, another low-noise amplifier 1 is also provided, including:

[0162] RF input terminal 10;

[0163] RF output terminal 20;

[0164] Power supply terminal 30 is configured to provide a power supply signal;

[0165] Amplifier circuit 40, the input terminal of amplifier circuit 40 is connected to RF input terminal 10, and amplifier circuit 40 includes a second amplifying transistor M2;

[0166] The first terminal of the protection circuit 50 is connected to the output terminal of the second amplifying transistor M2, and the second terminal of the protection circuit 50 is connected to the RF output terminal 20 and the power supply terminal 30.

[0167] The voltage of the power supply signal output from power supply terminal 30 is at least 0.6V higher than the withstand voltage of the second amplifying transistor M2; and,

[0168] The bypass circuit 60 has a switchable on state and off state, and the input terminal of the bypass circuit 60 is connected to the RF input terminal 10, and the output terminal of the bypass circuit 60 is connected to the RF output terminal 20.

[0169] The protection circuit 50 is configured to make the DC voltage value at the output terminal of the amplifier circuit 40 less than the DC voltage value at the second terminal of the protection circuit 50 when the bypass circuit 60 is in the conducting state.

[0170] Specifically, the input terminal of the amplifier circuit 40 is connected to the RF input terminal 10, and the amplifier circuit 40 is configured to amplify the RF signal input from its input terminal and output the amplified RF signal from its output terminal. The amplifier circuit 40 includes a transistor for amplification, at least a second amplifying transistor M2, the output terminal of which is connected to the first terminal of the protection circuit 50 as the output terminal of the amplifier circuit 40.

[0171] It should be noted that in actual scenarios where the low-noise amplifier 1 is used to process radio frequency signals, the voltage value of the power supply signal provided by the power supply terminal 30 to the amplifier circuit 40 is relatively high to ensure the normal operation of the amplifying transistors (including at least the second amplifying transistor M2), thereby enabling the amplifier circuit 40 to amplify the radio frequency signal. Therefore, in this scenario, a protection circuit 50 is set between the output terminal of the amplifier circuit 40 and the power supply terminal 30. Without affecting the normal operation of the amplifier circuit, the protection circuit 50 also blocks the voltage generated by the superposition of the radio frequency signal and the power supply signal when the bypass circuit 60 is in the conducting state, thereby reducing the DC voltage value input to the output terminal of the amplifier circuit 40. This makes the DC voltage value at the output terminal of the amplifier circuit 40 less than the DC voltage value at the second terminal of the protection circuit 50, effectively preventing the amplifying transistors in the amplifier circuit 40 from being damaged due to excessive DC voltage at the output terminal of the amplifier circuit 40. This protects the amplifier circuit 40 and improves the tolerance, safety, and reliability of the amplifier circuit 40 and even the entire low-noise amplifier 1.

[0172] As one embodiment, the DC voltage value of the power supply signal is greater than or equal to 1.8V to meet the voltage requirements of the amplifier circuit 40 for amplifying the radio frequency signal using the power supply signal.

[0173] It should also be noted that, in the embodiments of this application, the specific descriptions of the RF input terminal 10, RF output terminal 20, power supply terminal 30, amplifier circuit 40, protection circuit 50, bypass circuit 60 and other circuit structures of low noise amplifier 1 can be referred to the corresponding descriptions and specific implementation methods in the foregoing embodiments, and will not be repeated here.

[0174] like Figure 2 As shown, in some embodiments, the amplifier circuit 40 further includes a first amplifying transistor M1;

[0175] In this circuit, the first terminal of the first amplifying transistor M1 is grounded, the second terminal of the first amplifying transistor M1 is connected to the first terminal of the second amplifying transistor M2, the third terminal of the first amplifying transistor M1 is connected to the RF input terminal 10 as the input terminal of the amplifying circuit 40, the second terminal of the second amplifying transistor M2 is the output terminal of the second amplifying transistor M2, and the third terminal of the second amplifying transistor M2 is connected to the bias control terminal.

[0176] Specifically, when the first amplifying transistor M1 and the second amplifying transistor M2 are connected in a common-source, common-gate configuration between the RF input terminal 10 and the first terminal of the protection circuit 50, the first terminal of the first amplifying transistor M1 is grounded, the second terminal of the first amplifying transistor M1 is connected to the first terminal of the second amplifying transistor M2, and the third terminal of the first amplifying transistor M1 is the input terminal of the amplifying circuit 40, which can be connected to the RF input terminal 10 to receive the input RF signal; the second terminal of the second amplifying transistor M2 is the output terminal of the amplifying circuit 40 and is connected to the first terminal of the protection circuit 50, which can be connected to the RF output terminal 20 through the protection circuit 50 to output the amplified RF signal, and connected to the power supply terminal 30 through the protection circuit 50 to receive the power supply signal; the third terminal of the second amplifying transistor M2 is connected to the bias control terminal, which can be used to receive the bias signal output by the bias control terminal.

[0177] In some embodiments, the amplifying transistor in the amplifying circuit 40 is a field-effect transistor, with its first terminal being the source, its second terminal the drain, and its third terminal the gate; or,

[0178] The amplifying transistor in amplifier circuit 40 is a triode, with the first terminal being the emitter, the second terminal being the collector, and the third terminal being the base.

[0179] Specifically, the amplifier circuit 40 includes one or at least two amplifying transistors, which are used to amplify radio frequency signals individually or in combination. For example, the amplifying transistors may include the first amplifying transistor M1 and the second amplifying transistor M2 described above.

[0180] The amplifying transistor can be one of the following: an N-channel field-effect transistor, a P-channel field-effect transistor, a PNP transistor, or an NPN transistor.

[0181] Taking the common-source common-gate architecture of amplifier circuit 40 as an example, when both the first amplifier transistor M1 and the second amplifier transistor M2 are N-channel field-effect transistors, the source of the first amplifier transistor M1 is grounded, the drain of the first amplifier transistor M1 is connected to the source of the second amplifier transistor M2, the gate of the first amplifier transistor M1 is the input terminal of amplifier circuit 40, and can be connected to the RF input terminal 10 to receive the input RF signal; the drain of the second amplifier transistor M2 is the output terminal of amplifier circuit 40 and is connected to the source of protection circuit 50, and can be connected to the RF output terminal 20 through protection circuit 50 to output the amplified RF signal, and connected to the power supply terminal 30 through protection circuit 50 to receive the power supply signal, and the gate of the second amplifier transistor M2 is connected to the bias control terminal, which can be used to receive the bias signal output by the bias control terminal.

[0182] like Figure 2As shown, in some embodiments, the protection circuit 50 includes a first switching transistor S1 and a protection capacitor C1, and the first switching transistor S1 and the protection capacitor C1 are connected in parallel between the output terminal of the amplifier circuit 40 and the power supply terminal 30.

[0183] The first switch S1 is configured to be disconnected when the bypass switch S2 is in the on state and to be turned on when the bypass switch S2 is in the off state.

[0184] Specifically, when the low-noise amplifier 1 is in amplification mode, the bypass circuit 60 is off, and the first switch S1 is on. The radio frequency signal input from the radio frequency input terminal 10 enters the amplifier circuit 40, which amplifies the radio frequency signal and outputs it. After amplification, the radio frequency signal flows through the on-state first switch S1 and the protection capacitor C1 through the protection circuit 50, allowing the amplified radio frequency signal to flow unimpeded through the protection circuit 50 to the radio frequency output terminal 20 without affecting the normal amplification operation of the low-noise amplifier 1 in amplification mode, thus improving the signal quality of the output of the low-noise amplifier 1.

[0185] In at least one embodiment, when the low-noise amplifier 1 is in bypass mode, the bypass circuit 60 is in the on state, and the first switch S1 is off. The radio frequency signal input from the radio frequency input terminal 10 flows through the on-state bypass circuit 60 to the output terminal of the bypass circuit 60. Since the second terminal of the protection circuit 50 is connected to the radio frequency output terminal 20 and the power supply terminal 30, the radio frequency signal and the power supply signal provided by the power supply terminal 30 will be superimposed on the second terminal of the protection circuit 50, causing the DC voltage value of the second terminal of the protection circuit 50 to be pulled high.

[0186] At this time, the first switch S1, which is turned off, can block or reduce the voltage at the second terminal of the protection circuit 50. At the same time, since the protection capacitor C1 has the characteristic of blocking DC signals, the protection capacitor C1 can also block the DC voltage at the second terminal of the protection circuit 50, so that the DC voltage value at the output terminal of the amplifier circuit 40 is less than the DC voltage value at the second terminal of the protection circuit 50, thereby reducing the possibility of the amplifier circuit 40 being broken down, especially the transistors that play an amplification role in the amplifier circuit 40, thereby improving the tolerance and safety of the amplifier circuit 40 and even the entire low-noise amplifier 1.

[0187] In some implementations, the first switch S1 is a field-effect transistor (MOS) or a bipolar junction transistor (BJT). Specifically, the first switch S1 can be switched on and off under the action of an external control signal.

[0188] For example, the first switch S1 can be one of an N-channel MOSFET, a P-channel MOSFET, a PNP transistor, and an NPN transistor. Taking an N-channel MOSFET as an example, the source of the first switch S1 is electrically connected to the output terminal of the amplifier circuit 40, the drain of the first switch S1 is connected to the RF output terminal 20 and the power supply terminal 30, and the first switch S1 is configured to receive a control signal through its gate to turn the first switch S1 on or off based on the control signal.

[0189] In some embodiments, the protection circuit 50 further includes a first inductor L1, which is connected in series with the protection capacitor C1 between the output terminal of the amplifier circuit 40 and the power supply terminal 30.

[0190] In some implementations, the withstand voltage of the first switching transistor S1 is greater than the withstand voltage of the second amplifying transistor M2.

[0191] Specifically, the aforementioned withstand voltage design aims to improve the withstand voltage of the first switching transistor S1 generated by the superposition of radio frequency signals and power supply signals, reduce the possibility of the first switching transistor S1 being broken down, and improve the protection safety of the protection circuit 50 for the second amplifying transistor M2.

[0192] like Figure 10 As shown, this application embodiment also provides another low-noise amplifier 1, characterized in that the low-noise amplifier 1 includes:

[0193] RF input terminal 10;

[0194] RF output terminal 20;

[0195] Power supply terminal 30 is configured to provide a power supply signal;

[0196] Amplifier circuit 40, the input terminal of amplifier circuit 40 is connected to RF input terminal 10;

[0197] Protection circuit 50 includes a first switching transistor S1 and a protection capacitor C1, wherein the first switching transistor S1 and the protection capacitor C1 are connected in parallel between the output terminal of amplifier circuit 40 and power supply terminal 30. The first switching transistor S1 is configured to be turned off when bypass switch S2 is in the on state and turned on when bypass switch S2 is in the off state; and...

[0198] The bypass circuit 60 has a switchable on state and off state, and the input terminal of the bypass circuit 60 is connected to the RF input terminal 10, and the output terminal of the bypass circuit 60 is connected to the RF output terminal 20.

[0199] Specifically, when the low-noise amplifier 1 is in amplification mode, the bypass circuit 60 is off, and the first switch S1 is on. The radio frequency signal input from the radio frequency input terminal 10 enters the amplifier circuit 40, which amplifies the radio frequency signal and outputs it. After amplification, the radio frequency signal flows through the on-state first switch S1 and the protection capacitor C1 through the protection circuit 50, allowing the amplified radio frequency signal to flow unimpeded through the protection circuit 50 to the radio frequency output terminal 20 without affecting the normal amplification operation of the low-noise amplifier 1 in amplification mode, thus improving the signal quality of the output of the low-noise amplifier 1.

[0200] In at least one embodiment, when the low-noise amplifier 1 is in bypass mode, the bypass circuit 60 is in the on state, and the first switch S1 is off. The radio frequency signal input from the radio frequency input terminal 10 flows through the on-state bypass circuit 60 to the output terminal of the bypass circuit 60. Since the second terminal of the protection circuit 50 is connected to the radio frequency output terminal 20 and the power supply terminal 30, the radio frequency signal and the power supply signal provided by the power supply terminal 30 will be superimposed on the second terminal of the protection circuit 50, causing the DC voltage value of the second terminal of the protection circuit 50 to be pulled high.

[0201] At this time, the first switch S1, which is turned off, can block or reduce the voltage at the second terminal of the protection circuit 50. At the same time, since the protection capacitor C1 has the characteristic of blocking DC signals, the protection capacitor C1 can also block the DC voltage at the second terminal of the protection circuit 50, so that the DC voltage value at the output terminal of the amplifier circuit 40 is less than the DC voltage value at the second terminal of the protection circuit 50, thereby reducing the possibility of the amplifier circuit 40 being broken down, especially the transistors that play an amplification role in the amplifier circuit 40, thereby improving the tolerance and safety of the amplifier circuit 40 and even the entire low-noise amplifier 1.

[0202] In some implementations, the first switch S1 is a field-effect transistor (MOS) or a bipolar junction transistor (BJT). Specifically, the first switch S1 can be switched on and off under the action of an external control signal.

[0203] For example, the first switch S1 can be one of an N-channel MOSFET, a P-channel MOSFET, a PNP transistor, and an NPN transistor. Taking an N-channel MOSFET as an example, the source of the first switch S1 is electrically connected to the output terminal of the amplifier circuit 40, the drain of the first switch S1 is connected to the RF output terminal 20 and the power supply terminal 30, and the first switch S1 is configured to receive a control signal through its gate to turn the first switch S1 on or off based on the control signal.

[0204] It should also be noted that, in the embodiments of this application, the specific descriptions of the RF input terminal 10, RF output terminal 20, power supply terminal 30, amplifier circuit 40, protection circuit 50, bypass circuit 60 and other circuit structures of low noise amplifier 1 can be referred to the corresponding descriptions and specific implementation methods in the foregoing embodiments, and will not be repeated here.

[0205] like Figure 11 As shown, this application embodiment also provides a radio frequency front-end module 2, including a low-noise amplifier 1 as provided in any embodiment of this application.

[0206] As one embodiment, the RF front-end module 21 is a component that integrates one or more discrete devices such as RF switches, low-noise amplifiers 1, filters, duplexers, and power amplifiers into a single module, thereby improving integration and hardware performance, and miniaturizing the size. Specifically, the RF front-end module 2 can be applied to communication devices, which may include electronic devices 3 such as smartphones, tablets, and smartwatches, as well as communication devices such as base stations and NFC (Near Field Communication) devices. The RF front-end module 2 can receive or transmit RF signals through the antenna in the communication device, and the low-noise amplifier 1 is used to amplify the received RF signals. In some embodiments, the RF front-end module 2 can support carrier aggregation, dual connectivity, and multiple-input multiple-output (MIMO).

[0207] Furthermore, the RF front-end module 2 may also include at least one other device such as a control chip, a switching chip, a filter, a duplexer, a surface mount inductor, and a surface mount capacitor. Of course, it may also exclude other discrete devices other than the low-noise amplifier 1, and this application does not limit this.

[0208] like Figure 12 As shown, this application embodiment also provides an electronic device 3, including a low-noise amplifier 1 as provided in any embodiment of this application or a radio frequency front-end module 2 as provided in any embodiment of this application.

[0209] Among them, electronic device 3 can be a mobile phone, tablet computer, vehicle terminal or other communication device. Of course, it can also be other communication devices with communication functions. The embodiments of this application do not limit the specific type of electronic device 3.

[0210] 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 scope of the technology disclosed in this application. These modifications or substitutions should all be covered within the scope of protection of this application, and the scope of protection of this application should be determined by the scope of the claims.

[0211] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection via an intermediate medium; or a connection within two elements. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances. As used in this specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a," "an," and "the" are intended to include the plural forms. It should also be understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. In this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system.

Claims

1. A low-noise amplifier, characterized in that, The low-noise amplifier includes: RF input terminal; RF output terminal; The power supply side is configured to provide a power supply signal; An amplifier circuit, wherein the input terminal of the amplifier circuit is connected to the radio frequency input terminal; A protection circuit, wherein the first terminal of the protection circuit is connected to the output terminal of the amplifier circuit, and the second terminal of the protection circuit is connected to the radio frequency output terminal and the power supply terminal; A bypass circuit has switchable on and off states, and the input terminal of the bypass circuit is connected to the RF input terminal, and the output terminal of the bypass circuit is connected to the RF output terminal; and, The protection circuit is configured such that, when the bypass circuit is in the conducting state, the DC voltage value at the output terminal of the amplifier circuit is less than the DC voltage value at the second terminal of the protection circuit.

2. The low-noise amplifier as described in claim 1, characterized in that, The protection circuit includes a first switching transistor and a protection capacitor, and the first switching transistor and the protection capacitor are connected in parallel between the output terminal of the amplifier circuit and the power supply terminal. The first switch is configured to be disconnected when the bypass switch is in the ON state and to be turned on when the bypass switch is in the OFF state.

3. The low-noise amplifier as described in claim 2, characterized in that, The first switching transistor is a field-effect transistor or a bipolar transistor.

4. The low-noise amplifier as described in claim 2, characterized in that, The protection circuit also includes a first inductor, which is connected in series with the protection capacitor between the output terminal of the amplifier circuit and the power supply terminal.

5. The low-noise amplifier as described in claim 2, characterized in that, When the low-noise amplifier operates at a frequency greater than or equal to 3GHz, the capacitance of the protection capacitor is greater than or equal to 5pF. When the operating frequency band of the low-noise amplifier is less than 3GHz, the capacitance of the protection capacitor is greater than or equal to 8pF.

6. The low-noise amplifier as described in claim 2, characterized in that, The low-noise amplifier further includes a control unit configured to control the first switch to turn off when the bypass circuit is in the on state, and to control the first switch to turn on when the bypass circuit is in the off state.

7. The low-noise amplifier as described in claim 2, characterized in that, The amplifier circuit includes at least one amplifying transistor; The low-noise amplifier further includes a first chip, in which the first switching transistor and the protection capacitor are integrated with the amplifying transistor. Alternatively, the low-noise amplifier may further include different first and second chips, with the first switching transistor and the protection capacitor disposed on the first chip, and the amplifying transistor disposed on the second chip.

8. The low-noise amplifier as described in claim 1, characterized in that, The bypass circuit includes at least one bypass switch, which is connected between the RF input terminal and the RF output terminal.

9. The low-noise amplifier as described in claim 2, characterized in that, The amplifier circuit includes a first amplifying transistor and a second amplifying transistor; Wherein, the first terminal of the first amplifying transistor is grounded, the second terminal of the first amplifying transistor is connected to the first terminal of the second amplifying transistor, the third terminal of the first amplifying transistor is connected to the radio frequency input terminal as the input terminal of the amplifying circuit, the second terminal of the second amplifying transistor is connected to the first terminal of the protection circuit as the output terminal of the amplifying circuit, and the third terminal of the second amplifying transistor is connected to the bias control terminal.

10. The low-noise amplifier as claimed in claim 9, characterized in that, The low-noise amplifier further includes a second inductor connected between the first terminal of the first amplifying transistor and ground.

11. The low-noise amplifier as claimed in claim 1, characterized in that, The amplifier circuit includes a third amplifying transistor; The first terminal of the third amplifying transistor is grounded, the second terminal of the third amplifying transistor is connected to the radio frequency input terminal as the input terminal of the amplifying circuit, and the third terminal of the third amplifying transistor is connected to the first terminal of the protection circuit as the output terminal of the amplifying circuit.

12. The low-noise amplifier as described in claim 9 or 11, characterized in that, The amplifying transistor in the amplifier circuit is a field-effect transistor, with its first terminal being the source, its second terminal the drain, and its third terminal the gate; or... The amplifying transistor in the amplifying circuit is a triode, with its first terminal being the emitter, its second terminal being the collector, and its third terminal being the base.

13. The low-noise amplifier as claimed in claim 9, characterized in that, The voltage rating of the first switching transistor is greater than that of the second amplifying transistor.

14. The low-noise amplifier as claimed in claim 13, characterized in that, The first switching transistor has a withstand voltage greater than or equal to 2.5V, and the second amplifying transistor has a withstand voltage less than 2.5V.

15. The low-noise amplifier as claimed in claim 6, characterized in that, The withstand voltage of the first switching transistor is greater than or equal to the withstand voltage of the bypass switch.

16. The low-noise amplifier as claimed in claim 9, characterized in that, The voltage value of the power supply signal is at least 0.6V higher than the withstand voltage value of the second amplifying transistor.

17. The low-noise amplifier as claimed in claim 1, characterized in that, The low-noise amplifier further includes an output matching circuit connected between the output terminal of the amplifier circuit and the radio frequency output terminal, and configured to match the output impedance of the low-noise amplifier.

18. The low-noise amplifier as claimed in claim 1, characterized in that, The low-noise amplifier also includes a third inductor connected between the power supply terminal and the output terminal of the protection circuit.

19. The low-noise amplifier as claimed in claim 1, characterized in that, The DC voltage value of the power supply signal is greater than or equal to 1.8V.

20. A low-noise amplifier, characterized in that, The low-noise amplifier includes: RF input terminal; RF output terminal; The power supply side is configured to provide a power supply signal; An amplifier circuit, wherein the input terminal of the amplifier circuit is connected to the radio frequency input terminal, and the amplifier circuit includes a second amplifying transistor; A protection circuit, wherein the first terminal of the protection circuit is connected to the output terminal of the second amplifying transistor, and the second terminal of the protection circuit is connected to the radio frequency output terminal and the power supply terminal; The voltage value of the power supply signal output from the power supply terminal is at least 0.6V higher than the withstand voltage value of the second amplifying transistor; and, A bypass circuit has a switchable on state and off state, and the input terminal of the bypass circuit is connected to the radio frequency input terminal, and the output terminal of the bypass circuit is connected to the radio frequency output terminal. The protection circuit is configured such that, when the bypass circuit is in the conducting state, the DC voltage value at the output terminal of the amplifier circuit is less than the DC voltage value at the second terminal of the protection circuit.

21. The low-noise amplifier as claimed in claim 20, characterized in that, The amplifier circuit also includes a first amplifying transistor; Wherein, the first terminal of the first amplifying transistor is grounded, the second terminal of the first amplifying transistor is connected to the first terminal of the second amplifying transistor, the third terminal of the first amplifying transistor is connected to the RF input terminal as the input terminal of the amplification circuit, the second terminal of the second amplifying transistor is the output terminal of the second amplifying transistor, and the third terminal of the second amplifying transistor is connected to the bias control terminal.

22. The low-noise amplifier as claimed in claim 21, characterized in that, The amplifying transistor in the amplifier circuit is a field-effect transistor, with its first terminal being the source, its second terminal the drain, and its third terminal the gate; or... The amplifying transistor in the amplifying circuit is a triode, with its first terminal being the emitter, its second terminal being the collector, and its third terminal being the base.

23. The low-noise amplifier as claimed in claim 20, characterized in that, The protection circuit includes a first switching transistor and a protection capacitor, and the first switching transistor and the protection capacitor are connected in parallel between the output terminal of the amplifier circuit and the power supply terminal. The first switch is configured to be disconnected when the bypass switch is in the ON state and to be turned on when the bypass switch is in the OFF state.

24. The low-noise amplifier as claimed in claim 23, characterized in that, The protection circuit also includes a first inductor, which is connected in series with the protection capacitor between the output terminal of the amplifier circuit and the power supply terminal.

25. The low-noise amplifier as claimed in claim 23, characterized in that, The voltage rating of the first switching transistor is greater than that of the second amplifying transistor.

26. A low-noise amplifier, characterized in that, The low-noise amplifier includes: RF input terminal; RF output terminal; The power supply side is configured to provide a power supply signal; An amplifier circuit, wherein the input terminal of the amplifier circuit is connected to the radio frequency input terminal; A protection circuit includes a first switching transistor and a protection capacitor, wherein the first switching transistor and the protection capacitor are connected in parallel between the output terminal of the amplifier circuit and the power supply terminal, wherein the first switching transistor is configured to be turned off when the bypass switch is in the on state and turned on when the bypass switch is in the off state; and, The bypass circuit has a switchable on and off state, and the input terminal of the bypass circuit is connected to the radio frequency input terminal, and the output terminal of the bypass circuit is connected to the radio frequency output terminal.

27. A radio frequency front-end module, characterized in that, Including the low-noise amplifier as described in any one of claims 1-26.

28. An electronic device, characterized in that, Includes the low-noise amplifier as described in any one of claims 1-27 or the radio frequency front-end module as described in claim 28.

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