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

Abstract

The embodiment of the utility model provides a low-noise amplifier, a radio frequency front-end module and electronic equipment. The low-noise amplifier comprises a signal input end, a signal output end, an amplifying circuit, a first switching circuit and a first adjusting circuit, the first end of the amplifying circuit is connected with the signal input end, and the second end is connected with the signal output end; the first switching circuit and the first adjusting circuit are connected in series and connected with the first end of the amplifying circuit. When the first switching circuit is switched to the connected state, part of power of a radio frequency signal input by the signal input end is discharged through the first adjusting circuit, and the low-noise amplifier can be prevented from generating gain compression; when the first switching circuit is switched to the off state, noise introduced by the first adjusting circuit can be prevented from entering the amplifying circuit to be amplified, and it is guaranteed that the output signal has the high signal-to-noise ratio.

Description

TECHNICAL FIELD

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

[0002] A low noise amplifier (LNA) is an important component in a radio frequency chip such as a radio frequency front-end module, which can be used to receive a radio frequency signal transmitted from an antenna and amplify the received radio frequency signal. Ideally, the gain of the low noise amplifier should be fixed at the same gain level, but in reality, when the input signal power is too large, the gain of the low noise amplifier will decrease, and the output and input are no longer in a linear relationship, resulting in distortion of the output signal. SUMMARY

[0003] The present application provides a low noise amplifier, a radio frequency front-end module and an electronic device, which can prevent the output signal of the low noise amplifier from being distorted, and the signal output by the noise amplifier has a high signal-to-noise ratio.

[0004] In a first aspect, the embodiments of the present application provide a low noise amplifier, which comprises a signal input end, a signal output end and:

[0005] an amplification circuit, a first end of the amplification circuit being connected to the signal input end, and a second end of the amplification circuit being connected to the signal output end;

[0006] a first switch circuit and a first adjustment circuit, which are connected to the first end of the amplification circuit, and the first switch circuit and the first adjustment circuit are connected in series;

[0007] When the first switch circuit is switched to a connected state, part of the power of the radio frequency signal input by the signal input end is discharged through the first adjustment circuit; when the first switch circuit is switched to a disconnected state, the power of the radio frequency signal input by the signal input end is input to the first end of the amplification circuit.

[0008] In a second aspect, the embodiments of the present application provide a low noise amplifier, which comprises a signal input end, a signal output end and:

[0009] an amplification circuit, a first end of the amplification circuit being connected to the signal input end, and a second end of the amplification circuit being connected to the signal output end;

[0010] a second adjustment circuit, a first end of the second adjustment circuit being connected to a third end of the amplification circuit, and a second end of the second adjustment circuit being grounded;

[0011] The second switch circuit and the third adjusting circuit are connected with the second end of the second adjusting circuit, and the second switch circuit and the third adjusting circuit are connected in series.

[0012] In a third aspect, the embodiments of the present application provide a radio frequency front-end module, which comprises the low noise amplifier.

[0013] In a fourth aspect, the embodiments of the present application provide an electronic device, which comprises the low noise amplifier or the radio frequency front-end module.

[0014] The low noise amplifier, the radio frequency front-end module and the electronic device provided by the embodiments of the present application, the low noise amplifier comprises a signal input end, a signal output end, an amplifying circuit, a first switch circuit and a first adjusting circuit; the first end of the amplifying circuit is connected with the signal input end, and the second end of the amplifying circuit is connected with the signal output end; the first switch circuit and the first adjusting circuit are connected with the first end of the amplifying circuit, and the first switch circuit and the first adjusting circuit are connected in series; when the first switch circuit is switched to a connected state, part of the power of the radio frequency signal input from the signal input end is discharged through the first adjusting circuit; when the first switch circuit is switched to a disconnected state, the power of the radio frequency signal input from the signal input end is input to the first end of the amplifying circuit. In the case that the first switch circuit is switched to the connected state, the input power of the radio frequency input signal input to the first end of the amplifying circuit is less than the power of the radio frequency signal input from the signal input end, so that the output power of the amplifying circuit is not easy to be saturated, and the output power and the input power of the low noise amplifier can be kept linear, and the gain compression of the low noise amplifier is prevented; when the first switch circuit is switched to the disconnected state, the noise introduced by the first adjusting circuit can be prevented from entering the amplifying circuit to be amplified, so as to ensure that the output signal has a high signal-to-noise ratio.

[0015] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the disclosure of the embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0017] Figure 1 is a schematic block diagram of a low noise amplifier provided by the embodiments of the present application;

[0018] Figure 2 and Figure 3 is a schematic diagram of a low noise amplifier in some embodiments of the present application;

[0019] Figure 4a and Figure 4b is a schematic diagram of a first regulating circuit in some embodiments of the present application;

[0020] Figure 5 is a schematic diagram of a low noise amplifier in some embodiments of the present application;

[0021] Figure 6a and Figure 6b is a schematic diagram of a second regulating circuit in some embodiments of the present application;

[0022] Figures 7 to 10 is a schematic diagram of a low noise amplifier in some embodiments of the present application;

[0023] Figure 11 is a schematic diagram of a low noise amplifier in some embodiments of the present application;

[0024] Figure 12 is a schematic diagram of a radio frequency front-end module in some embodiments of the present application;

[0025] Figure 13 is a schematic diagram of a radio frequency front-end module in some embodiments of the present application;

[0026] Figure 14 is a schematic diagram of an electronic device in some embodiments of the present application.

[0027] Legend of reference signs:

[0028] 101, signal input terminal; 101a, first signal input terminal; 101b, second signal input terminal; 102, signal output terminal; 103, amplification circuit; C1, first capacitor; T1, first transistor; T2, second transistor; 104, first switch circuit; K1, first switch; 105, first regulating circuit; R1, first resistor; K2, second switch;

[0029] 106, second regulating circuit; K3, third switch; L1, first inductor; 107, second switch circuit; K4, fourth switch;

[0030] 108, third regulating circuit; R2, second resistor;

[0031] 10, substrate; 11, external signal input port; 12, antenna port; 13, filter. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely in the description below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative effort belong to the scope of the present application.

[0033] It should be understood that the present application can be implemented in different forms and should not be interpreted as being limited to the embodiments set forth herein. On the contrary, the embodiments are provided so that the disclosure will be thorough and complete and will fully convey the scope of the present application to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions can be exaggerated for clarity, and the same reference numerals are used throughout the drawings to represent the same elements.

[0034] In order to fully understand the present application, detailed structures and steps will be described in the following description to explain the technical solutions provided by the present application. The preferred embodiments of the present application are described in detail as follows, however, the present application can have other implementation manners in addition to the detailed description.

[0035] Some embodiments of the present application will be described in detail below with reference to the drawings. The embodiments described below and the features in the embodiments can be combined with each other without conflict.

[0036] Please refer to Figure 1 , Figure 1 is a schematic block diagram of a low noise amplifier provided by an embodiment of the present application. In some embodiments, the low noise amplifier can be applied to a radio frequency front-end module.

[0037] The radio frequency front-end module is an element that integrates one or more than one discrete device such as a radio frequency switch, a low noise amplifier, a filter 13, a duplexer, a power amplifier, etc. into an independent module, thereby improving the integration and hardware performance and miniaturizing the volume. Specifically, the radio frequency front-end module can be applied to a communication device, wherein the communication device can include an electronic device such as a smart phone, a tablet computer, a smart watch, etc., and can also include a communication device such as a base station, an NFC (Near Field Communication) device, etc. The radio frequency front-end module can receive or transmit a radio frequency signal through an antenna in the communication device, and the low noise amplifier is used for signal amplification of the received radio frequency signal. In some embodiments, the radio frequency front-end module can support carrier aggregation, dual connectivity and MIMO (Multiple Input Multiple Output).

[0038] As Figure 1As shown, the low noise amplifier comprises a signal input end 101, a signal output end 102, an amplification circuit 103, a first switch circuit 104 and a first adjustment circuit 105.

[0039] The first end of the amplification circuit 103 is connected to the signal input end 101, and the second end of the amplification circuit 103 is connected to the signal output end 102. The signal input end 101 is used for inputting a radio frequency signal, the amplification circuit 103 is used for amplifying the radio frequency signal input by the signal input end 101, and the amplified radio frequency signal is output through the signal output end 102. As an implementation manner, the amplification circuit 103 further comprises a third end, and the third end of the amplification circuit 103 is used for grounding. Optionally, the third end of the amplification circuit 103 can be directly grounded without passing through other components, or can be indirectly grounded through inductors, resistors and the like, or impedance matching networks, gain adjustment networks and the like.

[0040] In some embodiments, the amplification circuit 103 can adopt a common-source common-gate architecture. For example, the amplification circuit 103 comprises a first transistor T1 and a second transistor T2. Figure 2 The first end of the first transistor T1 is connected to the first end of the amplification circuit 103, the second end of the first transistor T1 is connected to the third end of the second transistor T2, the second end of the second transistor T2 is connected to the second end of the amplification circuit 103, and the third end of the first transistor T1 is connected to the third end of the amplification circuit 103. The first end of the first transistor T1 and the first end of the second transistor T2 are also used for receiving a bias signal. In an embodiment, the second end of the second transistor T2 is also connected to a power supply end Vdd, and the power supply end Vdd is used for supplying power to the amplification circuit 103.

[0041] Optionally, the amplification circuit 103 can further comprise a first capacitor C1. For example, the first end of the first capacitor C1 is connected to the first end of the amplification circuit 103, and the second end of the first capacitor C1 is connected to the first end of the first transistor T1, i.e. the first end of the first transistor T1 is connected to the first end of the amplification circuit 103 through the first capacitor C1.

[0042] For example, the first transistor T1 and the second transistor T2 can be Metal Oxide Semiconductor Field Effect Transistors (MOSFETs). The first end of the first transistor T1 and the second transistor T2 is a gate, the second end is a drain, and the third end is a source. Specifically, the gate of the first transistor T1 is connected to the first end of the amplification circuit 103 through the first capacitor C1, the drain of the first transistor T1 is connected to the source of the second transistor T2, the source of the first transistor T1 is connected to the third end of the amplification circuit 103, and the drain of the second transistor T2 is connected to the second end of the amplification circuit 103. Of course, the first transistor T1 and the second transistor T2 can also be other types of transistors, for example, the first transistor T1 and the second transistor T2 can be Bipolar Junction Transistors (BJTs), Complementary Metal-Oxide-Semiconductors (CMOSs), Silicon-on-insulator (SOI) substrate based field effect transistors, or High Electron Mobility Transistors (HEMTs), etc. The embodiments of the present application do not limit the type of transistors in the amplification circuit 103.

[0043] Optionally, the source and the drain of the first transistor T1 and the second transistor T2 can be interchanged. For example, the gate of the first transistor T1 is connected to the first end of the amplification circuit 103 through the first capacitor C1, the source of the first transistor T1 is connected to the drain of the second transistor T2, and the drain of the first transistor T1 is connected to the third end of the amplification circuit 103. The source of the second transistor T2 is connected to the second end of the amplification circuit 103.

[0044] In some embodiments, the amplification circuit 103 can adopt a common gate architecture. For example, please refer to Figure 3 , Figure 3 is another circuit structure schematic diagram of a low-noise amplifier provided by the embodiments of the present application. Please refer to Figure 2 , Figure 3 , Figure 3 The difference between the amplification circuit 103 in Figure 2 and the amplification circuit 103 in Figure 3As shown, the amplifier circuit 103 includes a first transistor T1 and may also include a first capacitor C1; wherein, the first terminal of the first capacitor C1 is connected to the first terminal of the amplifier circuit 103, the second terminal of the first capacitor C1 is connected to the first terminal of the first transistor T1, the second terminal of the first transistor T1 is connected to the second terminal of the amplifier circuit 103, and the third terminal of the first transistor T1 is connected to the third terminal of the amplifier circuit 103, wherein the first terminal of the first transistor T1 is also used to receive a bias signal.

[0045] It should be noted that, based on the above architecture, the amplifier circuit 103 may also include other circuit elements. For example, at least one feedback element may be provided between any two ends of the first transistor T1; and / or, one or more bypass elements, feedback elements, etc. may be provided between the second end of the second transistor T2 and the first end of the first transistor T1; and / or, a source degradation inductor / source degradation resistor may be connected in series at the third end of the first transistor T1.

[0046] In addition, the amplifier circuit 103 in this application embodiment may not be limited to a common source architecture or a common source cascode architecture. In some other embodiments, the amplifier circuit 103 may also adopt a common code architecture or a distributed amplifier architecture.

[0047] Please combine Figure 1 See Figure 2 or Figure 3 The first switching circuit 104 and the first adjustment circuit 105 are connected to the first end of the amplifier circuit 103.

[0048] In some implementations, such as Figure 2 As shown, the first terminal of the amplifier circuit 103 is also connected to the first terminal of the first transistor T1 through the first capacitor C1. The first terminal of the first transistor T1 is also used to receive the bias signal. By setting the first capacitor C1 between the first terminal of the first transistor T1 and the first switching circuit 104 and the first adjustment circuit 105, the influence on the bias signal of the first transistor T1 can be prevented.

[0049] Please combine Figure 1 See Figure 2 or Figure 3 The first switching circuit 104 is connected in series with the first regulating circuit 105. For example, as... Figure 1 The first terminal of the first switching circuit 104 is connected to the first terminal of the amplifier circuit 103, and the second terminal of the first switching circuit 104 is connected to the first terminal of the first adjustment circuit 105, and the second terminal of the first adjustment circuit 105 is grounded; or the first terminal of the first adjustment circuit 105 is connected to the first terminal of the amplifier circuit 103, and the second terminal of the first adjustment circuit 105 is connected to the first terminal of the first switching circuit 104, and the second terminal of the first switching circuit 104 is grounded.

[0050] In some implementations, such as Figure 2 or Figure 3 As shown, the first adjustment circuit 105 includes a first resistor R1, and the first switch circuit 104 includes a first switch K1, which is connected in series with the first resistor R1.

[0051] Specifically, when the first switching circuit 104 switches to the connected state, the signal input terminal 101 is grounded through the first adjustment circuit 105, and part of the power of the radio frequency signal input to the signal input terminal 101 is discharged through the first adjustment circuit 105.

[0052] In some embodiments, the first adjustment circuit 105 is configured to adjust the gain level of the low-noise amplifier and adjust the input power of the low-noise amplifier to the first terminal of the amplifier circuit 103 at different gain levels. It should be noted that the input power of the first terminal of the amplifier circuit 103 refers to the power input to the amplifier circuit 103. Specifically, the input power of the first terminal of the amplifier circuit 103 is equal to the power difference between the power of the radio frequency signal input from the signal input terminal 101 and the power discharged by the first adjustment circuit 105. Therefore, when the first switching circuit 104 switches to the connected state, the input power of the first terminal of the amplifier circuit 103 is less than the power of the radio frequency signal input from the signal input terminal 101.

[0053] When the first switching circuit 104 switches to the connected state, the first adjustment circuit 105 can guide a portion of the input power of the radio frequency signal input from the signal input terminal 101 to ground, thereby reducing the input power input to the first terminal of the amplifier circuit 103. Understandably, the input power of the radio frequency input signal to the first terminal of the amplifier circuit 103 is less than the power of the radio frequency signal input from the signal input terminal 101.

[0054] In some embodiments, the power of the radio frequency signal input from the signal input terminal 101 is a first power, the power of the radio frequency signal input from the first terminal of the amplifier circuit 103 is a second power, and the first adjustment circuit 105 is configured to make the second power less than the first power. For example, since the second terminal of the first adjustment circuit 105 is grounded, a portion of the power of the radio frequency input signal can be directed to ground; therefore, the first adjustment circuit 105 can make the second power less than the first power.

[0055] In some implementations, the resistance value of the first adjustment circuit 105 is adjustable.

[0056] For example, the first adjustment circuit 105 may include an adjustable resistor. When the first switching circuit 104 is switched to the on state, the resistance value of the adjustable resistor can be adjusted to change the resistance value connected to the low-noise amplifier by the first adjustment circuit 105, thereby adjusting the input power input to the first terminal of the amplifier circuit 103. The first adjustment circuit 105 is configured to adjust the input power input to the first terminal of the amplifier circuit 103 by changing the resistance value connected to the low-noise amplifier.

[0057] Optional, such as Figure 4a As shown, the first adjustment circuit 105 includes multiple parallel resistor branches, at least one of which includes a second switch K2 and a first resistor R1 connected in series. By controlling the on / off state of the second switch K2 in at least one resistor branch, the resistance value connected to the low-noise amplifier from the first adjustment circuit 105 can be changed, thereby adjusting the input power to the first terminal of the amplifier circuit 103. For example, the first adjustment circuit 105 includes multiple resistor branches, each including a second switch K2 and a first resistor R1 connected in series, and the multiple resistor branches are connected in parallel; the resistance values ​​of the first resistor R1 in different resistor branches can be the same or different. It should be noted that since multiple resistor branches are connected in parallel, and each resistor branch includes a second switch K2 and a first resistor R1 connected in series, when it is necessary to increase the resistance value connected to the first adjustment circuit 105, the number of times the second switch K2 is turned on can be reduced; when it is necessary to decrease the resistance value connected to the first adjustment circuit 105, the number of times the second switch K2 is turned on can be increased. By configuring the first adjustment circuit 105 to include multiple parallel resistor branches, and each resistor branch including a second switch K2 and a first resistor R1 connected in series, the resistance value connected to the low noise amplifier can be reduced by increasing the number of second switches K2 that are turned on, thereby increasing the power discharged by the first adjustment circuit 105 and reducing the input power from the first adjustment circuit 105 to the first terminal of the amplifier circuit 103.

[0058] Optional, such as Figure 4bAs shown, the first adjusting circuit 105 includes a plurality of first resistors R1 connected in series and at least one second switch K2 connected in parallel with the first resistors R1. By controlling the on and off of the second switches K2 connected in parallel with the first resistors R1 in the first adjusting circuit 105, the resistance value of the first adjusting circuit 105 connected to the low noise amplifier can be changed, thereby adjusting the input power input to the first end of the amplifying circuit 103. For example, the first adjusting circuit 105 includes a plurality of first resistors R1 connected in series and a plurality of second switches K2 connected in parallel with the corresponding first resistors R1, respectively. It should be noted that since the plurality of first resistors R1 are connected in series, each first resistor R1 is connected in parallel with the corresponding second switch K2. Therefore, when it is needed to increase the resistance value of the first adjusting circuit 105, the number of the on second switches K2 can be reduced, and when it is needed to decrease the resistance value of the first adjusting circuit 105, the number of the on second switches K2 can be increased. By increasing the number of the on second switches K2, the resistance value connected to the low noise amplifier can be decreased, the power dissipated by the first adjusting circuit 105 can be increased, and thus the input power input to the first end of the amplifying circuit 103 by the first adjusting circuit 105 can be decreased.

[0059] For example, the first switch K1 can include, but is not limited to, a triode, a metal-oxide semiconductor field effect transistor, a field effect transistor based on an SOI substrate, a high electron mobility transistor, an insulated gate bipolar transistor (IGBT), etc. In this case, the type of the first switch K1 can be the same as or different from the type of the transistor in the amplifying circuit 103. Compared with the case where the type of the first switch K1 is different from the type of the transistor in the amplifying circuit 103, the case where the type of the first switch K1 is the same as the type of the transistor in the amplifying circuit 103 can simplify the processing technology of the low noise amplifier.

[0060] In some embodiments, the resistance value of the first adjusting circuit 105 connected to the low noise amplifier is negatively correlated with the power dissipated by the first adjusting circuit 105, and the power dissipated by the first adjusting circuit 105 is negatively correlated with the input power input to the first end of the amplifying circuit 103. That is, when the power of the radio frequency signal input from the signal input end 101 is unchanged, the smaller the resistance value of the first adjusting circuit 105 connected to the low noise amplifier, the greater the power dissipated by the first adjusting circuit 105, and the smaller the input power input to the first end of the amplifying circuit 103.

[0061] When the first switch circuit 104 is switched to the on state, the power dissipated by the first regulating circuit 105 increases when the resistance value of the first regulating circuit 105 decreases, and the power dissipated by the first regulating circuit 105 decreases when the resistance value of the first regulating circuit 105 increases. The resistance value of the first regulating circuit 105 connected to the low noise amplifier is negatively correlated with the power dissipated by the first regulating circuit 105. When the power of the radio frequency signal input at the signal input end 101 remains unchanged or is a fixed value, since the power dissipated by the first regulating circuit 105 and the input power input at the first end of the amplifying circuit 103 are the power of the radio frequency input signal, when the power dissipated by the first regulating circuit 105 increases, the input power input at the first end of the amplifying circuit 103 decreases, and when the power dissipated by the first regulating circuit 105 decreases, the input power input at the first end of the amplifying circuit 103 increases. Therefore, the power dissipated by the first regulating circuit 105 is negatively correlated with the input power input at the first end of the amplifying circuit 103. In addition, it can also be understood that when the power of the radio frequency signal input at the signal input end 101 remains unchanged, the resistance value of the first regulating circuit 105 connected to the low noise amplifier is positively correlated with the input power input at the first end of the amplifying circuit 103 when the first switch circuit 104 is switched to the on state.

[0062] By configuring the first regulating circuit 105 to change the resistance value connected to the low noise amplifier to regulate the input power at the first end of the amplifying circuit 103, and the resistance value connected to the low noise amplifier is negatively correlated with the power dissipated by the first regulating circuit 105, and the power dissipated by the first regulating circuit 105 is negatively correlated with the input power input at the first end of the amplifying circuit 103, the power dissipated by the first regulating circuit 105 can be increased by reducing the resistance value of the first regulating circuit 105 when the input power at the first end of the amplifying circuit 103 is too large, thereby reducing the input power at the first end of the amplifying circuit 103. Therefore, the output power of the amplifying circuit 103 is not easy to saturate, the output power of the low noise amplifier can be kept linear, and gain compression of the low noise amplifier can be prevented. Therefore, the third order intermodulation distortion (IIP3) of the low noise amplifier can be optimized, and the 1 decibel compression output power (P1dB) of the low noise amplifier can be improved, thereby improving the linearity of the low noise amplifier at different gain levels when gain switching is performed.

[0063] In some embodiments, the resistance value of the first regulating circuit 105 connected to the amplifying circuit 103 is greater than or equal to 200 ohms when the first switch circuit 104 is switched to the on state.

[0064] It should be noted that when the resistance value of the first adjusting circuit 105 is too small, the radio frequency signal input from the signal input end 101 is easily released to the ground too much, and then the input power input to the first end of the amplifying circuit 103 is too small. Therefore, by setting a lower limit value, for example, greater than or equal to 200 ohms, for the resistance value of the first adjusting circuit 105, it can effectively prevent the radio frequency signal input from the signal input end 101 from being released to the ground, resulting in too small input power input to the first end of the amplifying circuit 103.

[0065] In some embodiments, the first adjusting circuit 105 is configured to adjust the input power input to the first end of the amplifying circuit 103 based on the current gain step of the low noise amplifier.

[0066] For example, the gain steps of the low noise amplifier can include a gain step G0 (for example: the gain is 20 dB), a gain step G1 (for example: the gain is 17 dB), a gain step G2 (for example: the gain is 14 dB),..., a gain step G6 (for example: the gain is 2 dB), and the like. Optionally, the gain corresponding to each gain step can be a gain range, for example, the gain range corresponding to the gain step G0 is 21.5 dB-18.5 dB; the gain range corresponding to the gain step G1 is 18.4 dB-15.5 dB.

[0067] It should be noted that when the first switch circuit 104 is turned on, the resistance in the first adjusting circuit 105 is connected to the low noise amplifier, which will increase the noise figure (NF) of the low noise amplifier to some extent. Specifically, the smaller the resistance value of the first adjusting circuit 105, the greater the power discharged, and the greater the noise figure (NF) of the low noise amplifier. In some application scenarios, different gain steps have different requirements for the noise figure, and therefore, by configuring the first adjusting circuit 105 to adjust the input power input to the first end of the amplifying circuit 103 based on the current gain step of the low noise amplifier, the different requirements of different gain steps for linearity and noise figure can be considered, so that the output power of the amplifying circuit 103 under a certain gain step can be kept linear, and under some other gain steps, the noise figure can be smaller.

[0068] For example, the first adjusting circuit 105 is configured such that the resistance value of the first adjusting circuit is positively correlated with the gain step, that is, for a higher gain step, the resistance value of the first adjusting circuit is greater, so that the influence on the noise figure is smaller.

[0069] For example, the low noise amplifier can be an amplifier supporting multiple gain stages, and the resistance value of the first adjusting circuit 105 is configured to be positively correlated with the gain stage of the amplifying circuit 103. For example, since the low noise amplifier has a higher tolerance to noise figure at a low gain stage, by reducing the resistance value of the first adjusting circuit 105 at the low gain stage, the input power input to the first end of the amplifying circuit 103 can be reduced to prevent the input power from being too large, thereby preventing the low noise amplifier from generating gain compression at the low gain stage and optimizing the third-order intermodulation distortion of the low noise amplifier at the low gain stage. Since the low noise amplifier has a lower tolerance to noise figure at a high gain, the resistance value of the first adjusting circuit 105 can be increased at a higher gain, or the first switching circuit 104 can be disconnected to reduce or even avoid the deterioration of the noise figure caused by the connection of the first adjusting circuit 105.

[0070] For example, when the first switching circuit 104 is switched to the connected state, the upper limit of the resistance value of the first adjusting circuit 105 can be greater than or equal to 1 kilo-ohm, for example, the maximum value of the resistance in the first adjusting circuit 105 is greater than or equal to 1 kilo-ohm, so that at the gain stage where the linearity needs to be improved but the tolerance to noise figure is low, the resistance value of the first adjusting circuit 105 can be adjusted to a level greater than or equal to 1 kilo-ohm, thereby improving the linearity of the low noise amplifier while maintaining a small noise figure of the low noise amplifier.

[0071] In some embodiments, the power of the radio frequency signal input from the signal input end 101 is -30dBm; when the resistance value of the first adjusting circuit 105 connected to the low noise amplifier is greater than 1000 ohms, the input power input to the first end of the amplifying circuit 103 ranges from -30dBm to -31dBm; when the resistance value of the first adjusting circuit 105 connected to the low noise amplifier ranges from greater than 500 ohms to less than or equal to 1000 ohms, the input power input to the first end of the amplifying circuit 103 ranges from -31dBm to -32dBm; when the resistance value of the first adjusting circuit 105 is greater than 300 ohms and less than or equal to 500 ohms, the input power input to the first end of the amplifying circuit 103 ranges from -31.5dBm to -32.5dBm.

[0072] It should be noted that when the power of the radio frequency signal input from the signal input end 101 remains unchanged or is a fixed value, the resistance value of the first adjusting circuit 105 is positively correlated with the input power input to the first end of the amplifying circuit 103, so that the resistance value of the first adjusting circuit 105 can be reduced when the input power input to the first end of the amplifying circuit 103 is too large, thereby reducing the input power input to the first end of the amplifying circuit 103.

[0073] In some embodiments, when the resistance value of the first adjusting circuit 105 is greater than 1000 ohms at the same gain level, the third-order intermodulation distortion of the low noise amplifier is -7dBm; when the resistance value of the first adjusting circuit 105 is greater than 500 ohms and less than or equal to 1000 ohms, the third-order intermodulation distortion is -4dBm; and when the resistance value of the first adjusting circuit 105 is greater than 300 ohms and less than or equal to 500 ohms, the third-order intermodulation distortion is -2.5dBm. It can be understood that when the power of the radio frequency signal input at the signal input end 101 remains unchanged or is a fixed value, the third-order intermodulation distortion of the low noise amplifier can be reduced by reducing the resistance value of the first adjusting circuit 105 at the same gain level.

[0074] It should be noted that, since the index requires the gain of the low gain level and the optimization of the third-order intermodulation distortion of the low noise amplifier, when the input power at the first end of the amplifying circuit 103 is too large, the first adjusting circuit 105 connected to the ground on the path between the signal input end 101 and the first end of the amplifying circuit 103 is adjusted by adjusting the resistance value of the first adjusting circuit 105, so that the input power input to the first end of the amplifying circuit 103 can be flexibly adjusted to reduce the input power input to the first end of the amplifying circuit 103, and then the low noise amplifier works at the low gain level and the third-order intermodulation distortion of the low noise amplifier at the low gain level is improved.

[0075] In some embodiments, the first adjusting circuit 105 is configured to reduce the input power input to the first end of the amplifying circuit 103 when the gain of the low noise amplifier is reduced, i.e., when the gain compression occurs.

[0076] When the input power of the low noise amplifier increases to a certain extent, the output power of the low noise amplifier no longer increases linearly with the input power, i.e., the gain compression occurs. It should be noted that when the low noise amplifier occurs gain compression, if the input power of the first end of the amplifying circuit 103 is not reduced, the output power of the amplifying circuit 103 is easy to saturate due to the excessive input power. When the gain compression occurs, the amplification factor of the third-order intermodulation signal of the low noise amplifier is greater than that of the fundamental wave, thereby causing the third-order intermodulation distortion of the low noise amplifier to deteriorate, and then the linearity of the low noise amplifier cannot meet the requirements.

[0077] The embodiments of the present application reduce the input power input to the first end of the amplifying circuit 103 by the first adjusting circuit 105 when the low noise amplifier occurs gain compression, so that the output power is not easy to saturate, thereby optimizing the third-order intermodulation distortion (IIP3) of the low noise amplifier at the low gain level and improving the 1 decibel compression output power (P1dB) of the low noise amplifier.

[0078] In the embodiment of the present application, when the first switch circuit 104 is switched to the off state, the power of the radio frequency signal input from the signal input end 101 is input to the first end of the amplification circuit 103, and in the case of not considering the signal transmission loss, the input power of the radio frequency input signal input to the first end of the amplification circuit 103 is equal to the power of the radio frequency signal input from the signal input end 101. Of course, if the signal transmission loss is considered, the actual input power of the radio frequency input signal input to the first end of the amplification circuit 103 will be slightly less than the power of the radio frequency signal input from the signal input end 101.

[0079] By switching the first switch circuit 104 to the off state, the noise introduced by the first adjusting circuit 105 can be prevented from entering the amplification circuit 103 for amplification and then being output together with the amplified radio frequency signal; therefore, the signal output by the low noise amplifier of the embodiment of the present application has a high signal-to-noise ratio.

[0080] In some embodiments, the first switch circuit 104 is switched to the on state in the case that the gain of the amplification circuit 103 is less than or equal to the gain threshold value; and is switched to the off state in the case that the gain of the amplification circuit 103 is greater than the gain threshold value.

[0081] The greater the gain of the amplification circuit 103, the higher the requirement of the low noise amplifier on the noise figure and the lower the acceptable noise level, i.e., the low noise amplifier is more sensitive to noise when working in the high gain position. By switching the first switch circuit 104 to the off state in the case that the gain of the amplification circuit 103 is greater than the gain threshold value, the noise introduced by the first adjusting circuit 105 can be prevented from entering the amplification circuit 103 together with the radio frequency signal of small power (the radio frequency signal input in the high gain position is usually of small power) to interfere with the radio frequency signal, and therefore, the signal output by the low noise amplifier of the embodiment of the present application has a high signal-to-noise ratio.

[0082] For example, when the first switch circuit 104 is switched to the off state, the resistance value of the resistance accessed to the low noise amplifier by the first adjusting circuit 105 is equal to infinity, and the power of the radio frequency signal input from the signal input end 101 will not be dissipated by the first adjusting circuit 105 and can be completely transmitted to the first end of the amplification circuit 103; in the case that the power of the radio frequency signal input from the signal input end 101 is small, the power input to the first end of the amplification circuit 103 can be prevented from being too small.

[0083] It should be noted that in the case that the power of the radio frequency signal input at the signal input end 101 is small, the gain of the amplification circuit 103 is usually high to meet the power requirement of the output radio frequency signal; and the small power radio frequency signal is more susceptible to noise interference, and therefore by setting the first switch circuit 104 to be switched to the open state in the case that the gain of the amplification circuit 103 is greater than the gain threshold, the signal output by the low noise amplifier can be ensured to have a high signal-to-noise ratio.

[0084] For example, the gain threshold corresponds to a noise figure (NF) of 2 decibels to 6 decibels. Generally, the lower the noise figure, the better the performance of the low noise amplifier. In the case that the gain of the amplification circuit 103 is greater than the gain threshold, the noise figure corresponding to the gain of the amplification circuit 103 is greater than the noise figure corresponding to the gain threshold, the first switch circuit 104 is switched to the open state, which can prevent the noise figure of the low noise amplifier from being greater than the noise figure corresponding to the gain threshold.

[0085] In some embodiments, the first switch circuit 104 is switched to the connected state in the case that the gain of the amplification circuit 103 is less than or equal to the gain threshold. Since the low noise amplifier is more sensitive to noise when working in the high gain gear, by increasing the resistance value of the first adjustment circuit 105, the noise is less likely to be introduced into the amplification circuit 103 through the first adjustment circuit 105. The embodiments of the present application can configure the resistance value of the first adjustment circuit 105 to be positively correlated with the gain of the amplification circuit 103, which can reduce the level of noise introduced by the first adjustment circuit 105 to the amplification circuit 103.

[0086] In some embodiments, as shown in Figure 5 The low noise amplifier also includes a second adjustment circuit 106, the third end of the amplification circuit 103 is connected to the first end of the second adjustment circuit 106, and the second end of the second adjustment circuit 106 is grounded. The second adjustment circuit 106 can also adjust the gain gear of the low noise amplifier and adjust the input power of the low noise amplifier input to the first end of the amplification circuit 103 at different gain gears, prevent the low noise amplifier from generating gain compression, and make the output power less likely to be saturated, so as to optimize the third order intermodulation distortion (IIP3) of the low noise amplifier and improve the 1 decibel compression output power (P1dB) of the low noise amplifier, and thus the linearity of the low noise amplifier at multiple different gain gears when performing gain switching can be improved.

[0087] By connecting the second adjusting circuit 106 to the third end of the amplifying circuit 103 and connecting the first adjusting circuit 105 to the first end of the amplifying circuit 103, the second adjusting circuit 106 and the first adjusting circuit 105 can cooperate to adjust the gain level of the low noise amplifier and adjust the input power of the low noise amplifier input to the first end of the amplifying circuit 103 at different gain levels, prevent the low noise amplifier from generating gain compression, and make the output power not easy to saturate, so as to optimize the third-order intermodulation distortion (IIP3) of the low noise amplifier and improve the 1 decibel compression output power (P1dB) of the low noise amplifier, and further improve the linearity of the low noise amplifier at multiple different gain levels when gain switching is performed.

[0088] In other embodiments, when the first adjusting circuit 105 is not connected to the first end of the amplifying circuit 103, for example, when the first switch circuit 104 is switched to the off state, the second adjusting circuit 106 can also adjust the gain level of the low noise amplifier and adjust the input power of the low noise amplifier input to the first end of the amplifying circuit 103 at different gain levels, prevent the low noise amplifier from generating gain compression, and make the output power not easy to saturate, so as to optimize the third-order intermodulation distortion (IIP3) of the low noise amplifier and improve the 1 decibel compression output power (P1dB) of the low noise amplifier, and further improve the linearity of the low noise amplifier at multiple different gain levels when gain switching is performed.

[0089] In some embodiments, the second adjusting circuit 106 is configured to adjust the gain level of the low noise amplifier, and the first adjusting circuit 105 is configured to adjust the input power of the low noise amplifier input to the first end of the amplifying circuit 103 at different gain levels, so that the second adjusting circuit 106 and the first adjusting circuit 105 can cooperate to improve the third-order intermodulation distortion and the 1 decibel compression output power of the low noise amplifier at different gain levels, and further improve the linearity of the low noise amplifier at multiple different gain levels.

[0090] For example, the impedance of the second adjusting circuit 106 is adjustable. By adjusting the impedance of the second adjusting circuit 106, the gain of the low noise amplifier can be adjusted.

[0091] Optionally, as shown in FIG. 1, the second adjusting circuit 106 includes a plurality of parallel switch branches, and at least one of the switch branches includes a third switch K3 and a first inductor L1 connected in series. Figure 6a Optionally, as shown in FIG. 1, the second adjusting circuit 106 includes a plurality of parallel switch branches, and at least one of the switch branches includes a third switch K3 and a first inductor L1 connected in series.

[0092] Optionally, as shown in FIG. 1, the second adjusting circuit 106 includes a plurality of parallel switch branches, and at least one of the switch branches includes a third switch K3 and a first inductor L1 connected in series. Figure 6bAs shown, the second adjusting circuit 106 includes a plurality of first inductors L1 connected in series and at least one third switch K3 connected in parallel with the first inductor L1. By controlling the on and off of the third switch K3 connected in parallel with the first inductor L1 in the second adjusting circuit 106, the impedance value accessed to the low noise amplifier by the second adjusting circuit 106 can be changed, thereby adjusting the gain level of the low noise amplifier. It should be noted that, Figure 6b The second adjusting circuit 106 shown is smaller in size than Figure 6a The second adjusting circuit 106 shown is smaller in size than

[0093] In some embodiments, as shown, Figure 7 The low noise amplifier further includes a second switch circuit 107 and a third adjusting circuit 108.

[0094] The second switch circuit 107 and the third adjusting circuit 108 are connected in series and connected to the third end of the amplifying circuit 103; for example, the second switch circuit 107 and the third adjusting circuit 108 are connected in series and connected to the third end of the amplifying circuit 103 through the second adjusting circuit 106. Please refer to Figure 7 Referring to Figure 8 The first end of the second switch circuit 107 is connected to the third end of the amplifying circuit 103 through the second adjusting circuit 106, the second end of the second switch circuit 107 is connected to the first end of the third adjusting circuit 108, and the second end of the third adjusting circuit 108 is grounded. In other embodiments, the first end of the third adjusting circuit 108 is connected to the third end of the amplifying circuit 103 through the second adjusting circuit 106, the second end of the third adjusting circuit 108 is connected to the first end of the second switch circuit 107, and the second end of the second switch circuit 107 is grounded, which can also achieve the series connection of the second switch circuit 107 and the third adjusting circuit 108.

[0095] For example, as shown, Figure 8 The second switch circuit 107 includes a fourth switch K4, and the third adjusting circuit 108 includes a second resistor R2, and the fourth switch K4 and the second resistor R2 are connected in series.

[0096] When the second switch circuit 107 is switched to the connected state, the power at the third end of the amplifying circuit 103 can be discharged through the third adjusting circuit 108, so that the power output through the second end of the amplifying circuit 103 is lower than the power output when the power is discharged through the third adjusting circuit 108, thereby preventing the low noise amplifier from generating gain compression, so that the output power and the input power of the low noise amplifier can remain linear; thereby the third order intermodulation distortion (IIP3) of the low noise amplifier can be optimized and the 1 decibel compression output power (P1dB) of the low noise amplifier can be improved, thereby the linearity of the low noise amplifier at different gain levels when gain switching is performed can be improved.

[0097] In some embodiments, the third adjusting circuit 108 has an adjustable resistance. For example, the second adjusting circuit 106 can include an adjustable resistor, or the third adjusting circuit 108 can have an adjustable resistance according to the circuit structure of the first adjusting circuit 105.

[0098] When the second switch circuit 107 is switched to the connected state, the power dissipated by the third adjusting circuit 108 can be adjusted by adjusting the resistance of the third adjusting circuit 108, so as to adjust the power outputted by the second terminal of the amplifying circuit 103. For example, when the gain of the amplifying circuit 103 is high, the power dissipated by the third adjusting circuit 108 can be increased by reducing the resistance of the third adjusting circuit 108, so as to reduce the power outputted by the second terminal of the amplifying circuit 103, and prevent the output power of the amplifying circuit 103 from being saturated.

[0099] When the second switch circuit 107 is switched to the disconnected state, the amplifying circuit 103 does not dissipate power through the third adjusting circuit 108, and the power outputted by the amplifying circuit 103 can be completely outputted through the second terminal of the amplifying circuit 103. When the power of the radio frequency signal inputted by the signal input terminal 101 is small, the power inputted to the first terminal of the amplifying circuit 103 can be prevented from being too small.

[0100] For example, the second switch circuit 107 is switched to the connected state when the gain of the amplifying circuit 103 is less than or equal to a gain threshold, and is switched to the disconnected state when the gain of the amplifying circuit 103 is greater than the gain threshold.

[0101] It should be noted that when the power of the radio frequency signal inputted by the signal input terminal 101 is small, the gain of the amplifying circuit 103 is usually high to meet the power requirement of the outputted radio frequency signal. However, the small power radio frequency signal is more easily interfered by noise, and thus the second switch circuit 107 is switched to the disconnected state when the gain of the amplifying circuit 103 is greater than the gain threshold, so as to ensure that the signal outputted by the low noise amplifier has a high signal-to-noise ratio.

[0102] In some embodiments, as shown in Figure 9a or Figure 9b The low noise amplifier includes a plurality of signal input terminals 101.

[0103] For example, as shown in Figure 9aAs shown, the amplification circuit 103 comprises a plurality of amplification branches, and the input end of each amplification branch is connected to the corresponding signal input end 101. For example, the plurality of amplification branches are connected to the plurality of signal input ends 101 one by one. Optionally, each amplification branch comprises one or more transistors. In the case where each amplification branch comprises a plurality of transistors, a plurality of amplification branches can share some transistors. As shown in FIG. 9, the plurality of amplification branches share the second transistor T2, so as to reduce the number of transistors required by the amplification circuit 103, and facilitate the miniaturization design of the low-noise amplifier. Optionally, the input end of at least one amplification branch is connected to the corresponding signal input end 101 through a switch circuit. When the switch circuit corresponding to any signal input end 101 is connected, the radio frequency signal input by the signal input end 101 is transmitted to the corresponding amplification branch for amplification processing, and the radio frequency signal after the amplification processing is output through the second end of the amplification circuit 103.

[0104] For example, as shown in FIG. 8, Figure 9b As shown, the amplification circuit 103 comprises at least one amplification branch, and the amplification circuit 103 comprises, for example, the first transistor T1 and the second transistor T2. At least two signal input ends 101 are connected to the input end of the same amplification branch through the corresponding input switch circuit. For example, the amplification circuit 103 comprises a plurality of amplification branches, and the input end of some of the amplification branches can be connected to a plurality of signal input ends 101 at the same time. As shown in FIG. 8, when the switch circuit corresponding to any signal input end 101 is connected, the radio frequency signal input by the signal input end 101 is transmitted to the corresponding amplification branch for amplification processing. The radio frequency signals input by a plurality of signal input ends 101 can be amplified by the same amplification branch, so as to reduce the number of amplification tubes required by the amplification circuit 103, and facilitate the miniaturization design of the low-noise amplifier.

[0105] For example, as shown in FIG. 8, Figure 9a or Figure 9b As shown in FIG. 8, the low-noise amplifier comprises a plurality of signal input ends 101, at least one first switch circuit 104, and at least one first adjustment circuit 105. At least some of the plurality of signal input ends 101 are connected to the corresponding first switch circuit 104 and first adjustment circuit 105.

[0106] For convenience of description, in some embodiments, the signal input end 101 connected to the corresponding first switch circuit 104 and first adjustment circuit 105 can be referred to as the first signal input end 101a, and the signal input end 101 not connected to the first switch circuit 104 and first adjustment circuit 105 can be referred to as the second signal input end 101b.

[0107] In some embodiments, the plurality of signal input terminals 101 include at least a first signal input terminal 101a and a second signal input terminal 101b; the first signal input terminal 101a is used to input a radio frequency signal of a first frequency, and the second signal input terminal 101b is used to input a radio frequency signal of a second frequency, wherein the first frequency is less than the second frequency. The first signal input terminal 101a is connected to the corresponding first switching circuit 104 and first adjustment circuit 105, while the second signal input terminal 101b is not connected to the first switching circuit 104 and the first adjustment circuit 105.

[0108] The second signal input terminal 101b is used to input higher frequency radio frequency (RF) signals. The higher the frequency of the RF signal, the lower its tolerance for noise; that is, lower levels of noise can have a more severe adverse effect on higher frequency RF signals. Instead of connecting the first switching circuit 104 and the first adjustment circuit 105 to each signal input terminal 101, by not connecting the first switching circuit 104 and the first adjustment circuit 105 to the second signal input terminal 101b corresponding to the higher frequency RF signal, it is possible to prevent noise introduced by the first adjustment circuit 105 from entering the amplifier circuit 103 for amplification when amplifying higher frequency RF signals, thus ensuring a higher signal-to-noise ratio. Furthermore, it reduces the number of components in the low-noise amplifier, which is beneficial for the miniaturization design of the low-noise amplifier.

[0109] In some implementations, such as Figure 10 As shown, the plurality of signal input terminals 101 include at least a first signal input terminal 101a and a second signal input terminal 101b; a low noise amplifier is disposed on a substrate 10, and the substrate 10 is also provided with an external signal input port 11, an antenna port 12 and a filter 13. The first signal input terminal 101a is used to connect to the antenna port 12 through the filter 13, and the second signal input terminal 101b is used to connect to the external signal input port 11.

[0110] For example, at least one first signal input terminal 101a is connected to a corresponding first switching circuit 104 and a first adjustment circuit 105.

[0111] Since the quality of the radio frequency signal corresponding to the antenna port 12 is usually required to be high, the first switching circuit 104 and the first adjustment circuit 105 can be connected to the first signal input terminal 101a corresponding to the antenna port 12. This makes it less likely for the output power of the amplifier circuit 103 to saturate when processing the radio frequency signal corresponding to the antenna port 12, and allows the output power of the low noise amplifier to remain linear with the input power. Alternatively, the first switching circuit 104 can be switched to the off state to ensure that the output signal has a high signal-to-noise ratio.

[0112] The at least one second signal input terminal 101b can not be connected to the first switch circuit 104 and the first adjusting circuit 105. By not connecting the first switch circuit 104 and the first adjusting circuit 105 to the second signal input terminal 101b corresponding to the external signal input port 11, the number of devices of the low noise amplifier can be reduced, and the low noise amplifier can be designed to be smaller.

[0113] In some embodiments, the resistance value of the first adjusting circuit 105 connected to the first signal input terminal 101a corresponding to the antenna port 12 is greater than or equal to the resistance value of the first adjusting circuit 105 connected to the second signal input terminal 101b corresponding to the external signal input port 11. The at least one second signal input terminal 101b can also be connected to the first switch circuit 104 and the first adjusting circuit 105.

[0114] Optionally, the resistance value of the first adjusting circuit 105 connected to the first signal input terminal 101a is greater than the resistance value of the first adjusting circuit 105 connected to the second signal input terminal 101b at the same gain level. Since the quality of the radio frequency signal corresponding to the antenna port 12 is usually required to be higher, for example, the radio frequency signal corresponding to the antenna port 12 has a more stringent requirement on the noise figure than the radio frequency signal corresponding to the external signal input port 11, by connecting a first adjusting circuit 105 with a larger resistance value to the first signal input terminal 101a corresponding to the antenna port 12, the noise is not easily introduced into the amplification circuit 103 through the first adjusting circuit 105 corresponding to the antenna port 12, and the adverse effects of the noise introduced into the amplification circuit 103 by the first adjusting circuit 105 on the radio frequency signal corresponding to the antenna port 12 are reduced, for example, the noise figure of the radio frequency signal corresponding to the antenna port 12 is reduced.

[0115] The low noise amplifier provided by the embodiment of the application comprises a signal input end 101, a signal output end 102, an amplification circuit 103, a first switch circuit 104 and a first regulating circuit 105; the first end of the amplification circuit 103 is connected with the signal input end 101, and the second end of the amplification circuit 103 is connected with the signal output end 102; the first switch circuit 104 and the first regulating circuit 105 are connected with the first end of the amplification circuit 103, and the first switch circuit 104 and the first regulating circuit 105 are connected in series; wherein when the first switch circuit 104 is switched to a connected state, part of the power of the radio frequency signal input from the signal input end 101 is discharged through the first regulating circuit 105; when the first switch circuit 104 is switched to a disconnected state, the power of the radio frequency signal input from the signal input end 101 is input to the first end of the amplification circuit 103. In the case that the first switch circuit 104 is switched to the connected state, the input power of the radio frequency input signal input to the first end of the amplification circuit 103 is less than the power of the radio frequency signal input from the signal input end 101, so that the output power of the amplification circuit 103 is not easy to be saturated, and the output power and the input power of the low noise amplifier can be kept linear, so as to prevent the low noise amplifier from generating gain compression; switching the first switch circuit 104 to the disconnected state can prevent the noise introduced by the first regulating circuit 105 from entering the amplification circuit 103 for amplification, so as to ensure that the output signal has a high signal-to-noise ratio.

[0116] Please refer to the low noise amplifier provided by another embodiment of the application shown in the schematic block diagram of Figure 11 , Figure 11 .

[0117] The low noise amplifier comprises a signal input end 101, a signal output end 102, an amplification circuit 103, a second regulating circuit 106, a second switch circuit 107 and a third regulating circuit 108.

[0118] The first end of the amplification circuit 103 is connected with the signal input end 101, and the second end of the amplification circuit 103 is connected with the signal output end 102; the third end of the amplification circuit 103 is connected with the first end of the second regulating circuit 106, and the second end of the second regulating circuit 106 is grounded; the second switch circuit 107 and the third regulating circuit 108 are connected with the second end of the second regulating circuit 106, and the second switch circuit 107 and the third regulating circuit 108 are connected in series.

[0119] The low noise amplifier of the embodiment of the present application is different from the low noise amplifier described in the previous embodiment in that the low noise amplifier of the embodiment of the present application can not be provided with the first adjusting circuit 105; or can be provided with the first adjusting circuit 105 but not provided with the first switch circuit 104, or can be provided with both the first adjusting circuit 105 and the first switch circuit 104 but the first switch circuit 104 is always in the connected state, that is, the first adjusting circuit 105 is always connected with the first end of the amplifying circuit 103.

[0120] The embodiment of the present application can adjust the gain position of the low noise amplifier and adjust the input power of the low noise amplifier input to the first end of the amplifying circuit 103 at different gain positions by connecting the second adjusting circuit 106 at the third end of the amplifying circuit 103, so as to prevent the low noise amplifier from generating gain compression, so that the output power is not easy to saturate, thereby optimizing the third-order intermodulation distortion (IIP3) of the low noise amplifier and improving the 1 decibel compression output power (P1dB) of the low noise amplifier, and further improving the linearity of the low noise amplifier at multiple different gain positions when gain switching is performed.

[0121] When the second switch circuit 107 is switched to the connected state, the power at the third end of the amplifying circuit 103 can be discharged through the third adjusting circuit 108, so that the power output through the second end of the amplifying circuit 103 is lower than the power output when the power is discharged through the third adjusting circuit 108, thereby preventing the output power of the amplifying circuit 103 from being easy to saturate, and preventing the low noise amplifier from generating gain compression.

[0122] When the second switch circuit 107 is switched to the disconnected state, the amplifying circuit 103 does not discharge power through the third adjusting circuit 108, and the power output by the amplifying circuit 103 can be completely output through the second end of the amplifying circuit 103; in the case that the power of the radio frequency signal input at the signal input end 101 is small, the power input to the first end of the amplifying circuit 103 can be prevented from being too small.

[0123] In some embodiments, the first end of the second switch circuit 107 is connected with the second end of the second adjusting circuit 106, the second end of the second switch circuit 107 is connected with the first end of the third adjusting circuit 108, and the second end of the third adjusting circuit 108 is grounded; or

[0124] The first end of the third adjusting circuit 108 is connected with the second end of the second adjusting circuit 106, the second end of the third adjusting circuit 108 is connected with the first end of the second switch circuit 107, and the second end of the second switch circuit 107 is grounded.

[0125] In some embodiments, the second switch circuit 107 switches to the connected state when the gain of the amplification circuit 103 is less than or equal to the gain threshold value, and switches to the disconnected state when the gain of the amplification circuit 103 is greater than the gain threshold value.

[0126] In some embodiments, the second switch circuit 107 includes a third switch K3, and the third adjustment circuit 108 includes a second resistor R2, and the third switch K3 is connected in series with the second resistor R2.

[0127] The specific principle and implementation of the low noise amplifier provided by the embodiments of the present application are the same as or similar to those of the low noise amplifier of the foregoing embodiments, and will not be described here again.

[0128] Please refer to Figure 12 As shown in Figure 12 is a schematic block diagram of a radio frequency front-end module provided by the embodiments of the present application; the radio frequency front-end module includes the foregoing low noise amplifier.

[0129] In some embodiments, the radio frequency front-end module can further include at least one of a radio frequency switch, a radio frequency power amplifier, a filter, a duplexer, etc., which can be integrated into one module, thereby improving the integration and performance, and miniaturizing the volume.

[0130] In some embodiments, as shown in Figure 13 The radio frequency front-end module includes a substrate and a radio frequency front-end circuit arranged on the substrate, and the radio frequency front-end circuit can include a switch circuit, a filter, a radio frequency power amplifier chip and a low noise amplifier between a radio frequency receiving port RX, a radio frequency transmitting port TX and an antenna port, and a radio frequency signal transmission path is formed through the above radio frequency devices.

[0131] The radio frequency front-end circuit can select to send a radio frequency signal to the antenna port or receive a radio frequency signal from the antenna port, to realize amplification, filtering and other processing of the radio frequency analog signal.

[0132] As an embodiment, the radio frequency front-end module can include a plurality of chips, and the plurality of chips at least include a low noise amplifier chip integrated with the foregoing low noise amplifier 100. Further, the radio frequency front-end module can further include at least one other chip such as a power amplifier chip, a control chip, a switch chip, a filter chip, etc.

[0133] Exemplarily, different chips can adopt different processes, for example, the low-noise amplifier chip and the control chip can adopt at least one of a Silicon On Insulator (SOI) process, a High electron mobility transistor (HEMT) process, and a Pseudomorphic HEMT (PHEMT) process; the power amplifier chip can adopt a HBT (Heterojunction bipolar transistor) process, also referred to as a HBT chip, and the control chip can adopt a CMOS process, also referred to as a CMOS chip.

[0134] Exemplarily, the radio frequency front-end module can further include a filter chip, and one or more filters 230 can be integrated in the filter chip, which can constitute a single filter, a duplexer, or a multiplexer, and be configured to perform filtering processing on the radio frequency signal.

[0135] The specific principle and implementation manner of the radio frequency front-end module provided by the embodiments of the present application are similar to those of the low-noise amplifier of the foregoing embodiments, and will not be described herein again.

[0136] Please refer to Figure 14 As Figure 14 shown is a schematic block diagram of an electronic device provided by another embodiment of the present application. The electronic device includes the foregoing low-noise amplifier; or includes the foregoing radio frequency front-end module.

[0137] The electronic device can be a mobile phone, a tablet computer, a vehicle-mounted terminal, or other communication devices having a communication function, and the embodiments of the present application do not limit the specific types of the electronic device.

[0138] The specific principle and implementation manner of the electronic device provided by the embodiments of the present application are similar to those of the low-noise amplifier or the radio frequency front-end module of the foregoing embodiments, and will not be described herein again.

[0139] It should be understood that the terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0140] It will be understood that when an element or layer is referred to as being "on", "adjacent", "connected to" or "coupled to" another element or layer, it can be directly on, adjacent, connected or coupled to the other element or layer or intervening elements or layers can be present. In contrast, when an element is referred to as being "directly on", "directly adjacent", "directly connected to", or "directly coupled to" another element or layer, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application.

[0141] Spatially relative terms, such as "beneath", "below", "lower", "under", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0142] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0143] The specific embodiments described hereinabove are illustrative examples of the present application and, as such, numerous other modifications and / or improvements made to the application as described hereinabove can be made by those skilled in the art without departing from the scope of the application. The scope of the application is not to be limited by the specific illustrative embodiments described hereinabove. Rather, the scope of the application is to be defined solely by the claims that follow.

Claims

1. A low noise amplifier, characterized by, The low-noise amplifier comprises a signal input end, a signal output end, and an amplification circuit, a first end of the amplification circuit being connected to the signal input end, a second end of the amplification circuit being connected to the signal output end; a first switch circuit and a first regulating circuit, the first end of the amplification circuit being connected to the first switch circuit and the first regulating circuit, the first switch circuit being connected in series to the first regulating circuit; wherein, when the first switch circuit is switched to a connected state, part of the power of the radio frequency signal input by the signal input end is discharged through the first regulating circuit; and when the first switch circuit is switched to a disconnected state, the power of the radio frequency signal input by the signal input end is input to the first end of the amplification circuit.

2. The low noise amplifier of claim 1, wherein, The first end of the first switch circuit is connected to the first end of the amplification circuit, the second end of the first switch circuit is connected to the first end of the first regulating circuit, and the second end of the first regulating circuit is grounded; or the first end of the first regulating circuit is connected to the first end of the amplification circuit, the second end of the first regulating circuit is connected to the first end of the first switch circuit, and the second end of the first switch circuit is grounded.

3. The low noise amplifier of claim 1, wherein, The first regulating circuit comprises a first resistor, and the first switch circuit comprises a first switch, the first switch being connected in series to the first resistor.

4. The low noise amplifier of claim 1, wherein, The first switch circuit is switched to the connected state when the gain of the amplification circuit is less than or equal to a gain threshold value, and is switched to the disconnected state when the gain of the amplification circuit is greater than the gain threshold value.

5. The low noise amplifier of claim 4, wherein, The resistance value of the first regulating circuit is adjustable.

6. The low noise amplifier of claim 5, wherein, The resistance value of the first regulating circuit is configured to be positively correlated with the gain of the amplification circuit.

7. The low noise amplifier of claim 5, wherein, The first regulating circuit comprises a plurality of parallel resistance branches, at least one of the resistance branches comprising a second switch and a first resistor connected in series; alternatively, the first regulating circuit comprises a plurality of first resistors connected in series and at least one second switch connected in parallel to the first resistors.

8. The low noise amplifier of claim 1, wherein, The low-noise amplifier further comprises a second regulating circuit, a third end of the amplification circuit being connected to a first end of the second regulating circuit, and a second end of the second regulating circuit being grounded.

9. The low noise amplifier of claim 8, wherein, The impedance of the second regulating circuit is adjustable.

10. The low noise amplifier of claim 9, wherein, The second regulating circuit comprises a plurality of parallel switching branches, at least one of the switching branches comprising a third switch and a first inductor connected in series; alternatively, the second regulating circuit comprises a plurality of first inductors connected in series and at least one third switch connected in parallel to the first inductors.

11. The low noise amplifier of claim 1, wherein, The low-noise amplifier further comprises a second switch circuit and a third regulating circuit. The first end of the second switch circuit is connected to the third end of the amplification circuit, the second end of the second switch circuit is connected to the first end of the third regulating circuit, and the second end of the third regulating circuit is grounded; or The first end of the third regulating circuit is connected to the third end of the amplification circuit, the second end of the third regulating circuit is connected to the first end of the second switch circuit, and the second end of the second switch circuit is grounded.

12. The low noise amplifier of claim 11, wherein, The second switch circuit comprises a fourth switch, and the third regulating circuit comprises a second resistor, the fourth switch being connected in series to the second resistor.

13. The low noise amplifier of claim 11, wherein, The resistance of the third adjusting circuit is adjustable.

14. The low noise amplifier of claim 11, wherein, The second switch circuit is switched to the connected state when the gain of the amplifying circuit is less than or equal to the gain threshold, and is switched to the disconnected state when the gain of the amplifying circuit is greater than the gain threshold.

15. The low noise amplifier of any one of claims 1-7, wherein, The low-noise amplifier comprises a plurality of signal input terminals, at least one first switch circuit and at least one first adjusting circuit, at least part of the plurality of signal input terminals are connected to the corresponding first switch circuit and first adjusting circuit respectively; wherein, The amplifying circuit comprises a plurality of amplifying branches, the input terminal of the amplifying branch is connected to the corresponding signal input terminal of the amplifying branch; and / or The amplifying circuit comprises at least one amplifying branch, and at least two signal input terminals are connected to the input terminal of the same amplifying branch through the corresponding input switch circuit.

16. The low noise amplifier of claim 15, wherein, The plurality of signal input terminals at least comprises a first signal input terminal and a second signal input terminal, the first signal input terminal is used for inputting radio frequency signals of a first frequency, the second signal input terminal is used for inputting radio frequency signals of a second frequency, and the first frequency is less than the second frequency. The first signal input terminal is connected to the corresponding first switch circuit and first adjusting circuit, and the second signal input terminal is not connected to the first switch circuit and first adjusting circuit.

17. The low noise amplifier of claim 15, wherein, The plurality of signal input terminals at least comprises a first signal input terminal and a second signal input terminal. The low-noise amplifier is arranged on a substrate, and the substrate is further provided with an external signal input port, an antenna port and a filter, the first signal input terminal is used for being connected to the antenna port through the filter, and the second signal input terminal is used for being connected to the external signal input port.

18. The low noise amplifier of claim 17, wherein, At least one first signal input terminal is connected to the corresponding first switch circuit and first adjusting circuit.

19. The low noise amplifier of any of claims 17-18, wherein, The resistance value of the first adjusting circuit connected to the first signal input terminal is greater than or equal to the resistance value of the first adjusting circuit connected to the second signal input terminal.

20. The low noise amplifier of any one of claims 1-14, wherein, The amplifying circuit comprises a first capacitor, a first transistor and a second transistor, the first end of the first capacitor is connected to the first end of the amplifying circuit, the second end of the first capacitor is connected to the first end of the first transistor, the second end of the first transistor is connected to the third end of the second transistor, the second end of the second transistor is connected to the second end of the amplifying circuit, and the third end of the first transistor is connected to the third end of the amplifying circuit. The first end of the first transistor and the first end of the second transistor are also used for receiving a bias signal.

21. A low noise amplifier, characterized by The low-noise amplifier comprises a signal input terminal, a signal output terminal and: An amplifying circuit, the first end of the amplifying circuit is connected to the signal input terminal, and the second end of the amplifying circuit is connected to the signal output terminal; A second adjusting circuit, the third end of the amplifying circuit is connected to the first end of the second adjusting circuit, and the second end of the second adjusting circuit is grounded; A second switch circuit and a third adjusting circuit, which are connected to the second end of the second adjusting circuit, and the second switch circuit and the third adjusting circuit are connected in series.

22. The low noise amplifier of claim 21, wherein, The first end of the second switch circuit is connected to the second end of the second adjusting circuit, the second end of the second switch circuit is connected to the first end of the third adjusting circuit, and the second end of the third adjusting circuit is grounded. The first end of the third adjusting circuit is connected to the second end of the second adjusting circuit, the second end of the third adjusting circuit is connected to the first end of the second switch circuit, and the second end of the second switch circuit is grounded.

23. The low noise amplifier of claim 21, wherein, The second switch circuit switches to the connected state when the gain of the amplification circuit is less than or equal to a gain threshold, and switches to the disconnected state when the gain of the amplification circuit is greater than the gain threshold.

24. The low noise amplifier of claim 21, wherein, The second switch circuit comprises a third switch, and the third adjusting circuit comprises a second resistor, the third switch being connected in series with the second resistor.

25. A radio frequency front end module, comprising: The radio frequency front end module comprises the low noise amplifier according to any one of claims 1 to 24.

26. An electronic device, comprising: The electronic device comprises the low noise amplifier according to any one of claims 1 to 24, or comprises the radio frequency front end module according to claim 25.

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