Low-noise amplifier and radio-frequency front-end module

Abstract

Disclosed in the present application are a low-noise amplifier and a radio-frequency front-end module. The low-noise amplifier comprises a signal input end, a signal output end, a plurality of amplification branches, at least one bypass branch and a reused switch, wherein first ends of the amplification branches are connected together to form a first common end which is connected to the signal input end, and second ends of the amplification branches are connected together to form a second common end which is connected to the signal output end; a first end of the bypass branch is connected to the first common end, and second ends of the bypass branch are connected together to form a third common end; and a first end of the reused switch is connected to the third common end, and a second end of the reused switch is connected to the second common end. The radio-frequency front-end module reuses one switch on the bypass branch as the reused switch, and by means of reducing parasitic capacitance in the bypass branch, the total parasitic capacitance at an output end of the low-noise amplifier is reduced, such that the gain of the low-noise amplifier can be effectively increased.

Description

Low noise amplifier and RF front-end module

[0001] This application is based on the Chinese application No. 202311834056.2 filed on December 27, 2023, entitled “Low Noise Amplifier and RF Front-End Module”, and claims priority. Technical Field

[0002] The present application relates to the field of radio frequency technology, and in particular to a low noise amplifier and a radio frequency front-end module. Background Art

[0003] In radio frequency (RF) technology, low-noise amplifiers (LNAs), key components in RF front-end modules, receive and amplify RF signals transmitted from the antenna. In related technologies, the bypass branch in the LNA generates significant parasitic capacitance when disconnected, which affects the amplifier's gain. Summary of the Invention

[0004] The present application provides a low-noise amplifier and a radio frequency front-end module, which solve the problem of low gain of the low-noise amplifier in the related art.

[0005] In a first aspect, the present application provides a low-noise amplifier, which includes: a signal input terminal and a signal output terminal; a plurality of amplifying branches, wherein the first end of each of the amplifying branches is connected together to form a first common terminal connected to the signal input terminal, and the second end of each of the amplifying branches is connected together to form a second common terminal connected to the signal output terminal; at least one bypass branch, wherein the first end of the bypass branch is connected to the first common terminal, and the second ends of the bypass branches are connected together to form a third common terminal; and a multiplexing switch, wherein the first end of the multiplexing switch is connected to the third common terminal, and the second end of the multiplexing switch is connected to the second common terminal.

[0006] The RF front-end module reuses one of the switches on the bypass branch as a multiplexing switch. This reduces the parasitic capacitance in the bypass branch, thereby reducing the total parasitic capacitance at the output of the low-noise amplifier, effectively improving the gain of the low-noise amplifier. This also reduces the number of switches connected in series on the bypass branch, improving bypass branch performance and reducing costs.

[0007] In the second aspect, the present application also provides a low-noise amplifier, which includes: multiple signal input terminals and a signal output terminal; multiple amplifying branches and multiple bypass branches, the first end of each amplifying branch is connected to a signal input terminal, the second end of each amplifying branch is connected together to form a fourth common terminal connected to the signal output terminal, the first end of each bypass branch is connected to the first end of the corresponding amplifying branch, and the second end of each bypass branch is connected together to form a fifth common terminal; a multiplexing switch, the first end of the multiplexing switch is connected to the fifth common terminal, and the second end of the multiplexing switch is connected to the fourth common terminal.

[0008] The aforementioned RF front-end module reuses one of the switches on the bypass branch as a multiplexing switch. This reduces the parasitic capacitance in the bypass branch, thereby reducing the total parasitic capacitance at the output of the low-noise amplifier, thereby effectively improving the gain of the low-noise amplifier. Furthermore, because the first end of the multiplexing switch is connected to a third common terminal formed by connecting the second ends of the bypass branches together, and the second end of the multiplexing switch is connected to a second common terminal formed by connecting the second ends of each of the amplification branches together, rather than to the signal output terminal, the subsequent circuitry between the second common terminal and the signal output terminal can be used to adjust the RF signal on the bypass branch, achieving a better echo effect.

[0009] In a third aspect, the present application also provides a radio frequency front-end module, which includes the above-mentioned low-noise amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0011] FIG1 is a schematic structural diagram of a radio frequency front-end module provided in an embodiment of the present application;

[0012] FIG2 is a schematic diagram of the circuit structure of a low noise amplifier provided in an embodiment of the present application;

[0013] FIG3 is a schematic diagram of the circuit structure of another low noise amplifier provided in an embodiment of the present application;

[0014] FIG4 is a schematic diagram of the circuit structure of another low noise amplifier provided in an embodiment of the present application;

[0015] FIG5 is a schematic diagram of the circuit structure of another low noise amplifier provided in an embodiment of the present application;

[0016] FIG6 is a schematic diagram of the circuit structure of another low noise amplifier provided in an embodiment of the present application;

[0017] FIG7 is a schematic diagram of the layout of a low noise amplifier on a substrate provided in an embodiment of the present application;

[0018] FIG8 is a schematic diagram of the circuit structure of another low noise amplifier provided in an embodiment of the present application;

[0019] FIG9 is a schematic diagram of the circuit structure of another low noise amplifier provided in an embodiment of the present application;

[0020] FIG10 is a schematic diagram of the circuit structure of another low noise amplifier provided in an embodiment of the present application;

[0021] FIG11 is a schematic diagram of the circuit structure of another low noise amplifier provided in an embodiment of the present application;

[0022] FIG12 is a schematic diagram of the circuit structure of another low noise amplifier provided in an embodiment of the present application;

[0023] FIG13 is a schematic diagram of the layout of another low noise amplifier on a substrate provided in an embodiment of the present application;

[0024] FIG14 is a schematic diagram of the circuit structure of another low noise amplifier provided in an embodiment of the present application;

[0025] FIG15 is a schematic diagram of the circuit structure of another low noise amplifier provided in an embodiment of the present application;

[0026] FIG16 is a schematic diagram of the circuit structure of another low noise amplifier provided in an embodiment of the present application;

[0027] FIG17 is a schematic diagram of the circuit structure of another low noise amplifier provided in an embodiment of the present application;

[0028] FIG18 is a schematic diagram of the circuit structure of another low noise amplifier provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0030] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, combined, or partially merged, so the actual execution order may vary depending on the actual situation.

[0031] It should be understood that the terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0032] It will also be understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0033] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0034] In related art, the bypass branch in a low-noise amplifier (LNA) typically includes multiple switches connected in series. Since the switches are equivalent to capacitors Coff when in the off state, when a LNA includes multiple bypass branches, or when the number of switches in the bypass branches is large, this is equivalent to connecting multiple parasitic capacitors in parallel at the output of the LNA. This results in a large parasitic capacitance at the output of the LNA, thereby reducing the gain of the LNA and, in turn, the output quality of the RF signal from the RF front-end module.

[0035] To this end, an embodiment of the present application provides a low-noise amplifier and a radio frequency front-end module, in which one of the switches on the bypass branch is multiplexed into a multiplexing switch, and the first end of the multiplexing switch is connected to the third common end formed by connecting the second end of the bypass branch, and the second end of the multiplexing switch is connected to the second common end formed by connecting the second end of each of the amplification branches. Therefore, not only can the parasitic capacitance in the bypass branch be reduced to reduce the total parasitic capacitance at the output end of the low-noise amplifier, thereby effectively improving the gain of the low-noise amplifier and thus improving the output quality of the radio frequency signal of the radio frequency front-end module, but the post-stage circuit between the second common end and the signal output end can also be used to adjust the radio frequency signal on the bypass branch to achieve a better echo effect. The following will explain in detail how to improve the gain of the low-noise amplifier.

[0036] Please refer to FIG. 1 , which is a schematic structural diagram of a radio frequency front-end module 10 provided in an embodiment of the present application. As shown in FIG. 1 , the radio frequency front-end module 10 may include a low noise amplifier 100 .

[0037] It should be noted that the RF front-end module 10 is a component that integrates one or more discrete components, such as an RF switch, a low-noise amplifier, a filter, a duplexer, and a power amplifier, into a single module, thereby improving integration and hardware performance while miniaturizing the module. The RF front-end module 10 in this embodiment can support carrier aggregation, dual connectivity, and multiple-input multiple-output (MIMO).

[0038] Specifically, the RF front-end module 10 can be applied to communication devices such as smartphones, tablets, smartwatches, and routers. These communication devices can include electronic devices such as smartphones, tablets, and smartwatches, as well as base stations and NFC (Near Field Communication) devices. The RF front-end module 10 can receive or transmit RF signals via an antenna in the communication device, and the low-noise amplifier 100 is used to amplify the received RF signals.

[0039] Please refer to Figure 2, which is a circuit structure diagram of a low-noise amplifier 100 provided in an embodiment of the present application. As shown in Figure 2, the low-noise amplifier 100 may include a signal input terminal 101, a signal output terminal 102, multiple amplification branches 103, at least one bypass branch 104 and a multiplexing switch 105.

[0040] The first end of each amplifying branch 103 is connected together to form a first common terminal 106 connected to the signal input terminal 101. The second end of each amplifying branch 103 is connected together to form a second common terminal 107 connected to the signal output terminal 102. The first end of the bypass branch 104 is connected to the first common terminal 106, and the second ends of the bypass branches 104 are connected together to form a third common terminal 108. The first end of the multiplexing switch 105 is connected to the third common terminal 108, and the second end of the multiplexing switch 105 is connected to the second common terminal 107.

[0041] It should be noted that the amplifying branch 103 is used to amplify the radio frequency signal, and the bypass branch 104 is used to transmit the radio frequency signal that does not need to be amplified or transmit the radio frequency signal that needs to be attenuated (for example, including the low gain gear of the low noise amplifier). For example, when the radio frequency signal is amplified by the amplifying branch 103, the bypass branch 104 can be turned off. For another example, when the radio frequency signal is transmitted through the bypass branch 104, the amplifying branch 103 can be turned off. Among them, the bypass branch 104 may include multiple switches. In an embodiment of the present application, one of the switches of each bypass branch 104 can be reused as a multiplexing switch 105, which can not only reduce the number of switches connected in series on the bypass branch, but also reduce the parasitic capacitance in the bypass branch 104, so as to reduce the total parasitic capacitance at the output end of the low noise amplifier 100.

[0042] For example, the multiplexing switch 105 may include, but is not limited to, a transistor, a metal-oxide-semiconductor field-effect transistor (MOS), an insulated gate bipolar transistor (IGBT), a relay, an optocoupler, and the like.

[0043] Exemplarily, as shown in FIG2 , the signal input terminal 101 in the low-noise amplifier 100 can be one, that is, the low-noise amplifier 100 is a single-input amplifier, and the low-noise amplifier 100 can be used to receive a radio frequency signal of a single frequency band. Multiple amplifying branches 103 can amplify the radio frequency signal of a single frequency band input to the low-noise amplifier 100 simultaneously or individually. The number of branches amplified by the amplifying branch 103 can be determined according to the gain required by the low-noise amplifier 100. For example, the greater the gain required by the low-noise amplifier 100, the more branches that need to be amplified by the amplifying branch 103. In this embodiment, the operating frequency band of the radio frequency signal input to the low-noise amplifier 100 is not specifically limited.

[0044] In the embodiment of the present application, one of the switches on the bypass branch 104 is reused as the multiplexing switch 105. By reducing the parasitic capacitance in the bypass branch 104, the total parasitic capacitance at the output of the low-noise amplifier 100 is reduced, thereby effectively improving the gain of the low-noise amplifier 100 and, in turn, improving the output quality of the RF signal of the RF front-end module 10. At the same time, the number of switches connected in series on the bypass branch 104 can also be reduced, thereby improving the performance of the bypass branch 104 and reducing costs.

[0045] Furthermore, as shown in FIG2 , the second end of the multiplexing switch 105 in this embodiment is directly connected to the second common terminal 107, and a subsequent circuit is not first provided at the second common terminal 107 before connecting to the multiplexing switch 105. The subsequent circuit may include an attenuator and / or a matching device and / or a switching switch, etc. In the related art, the second end of the multiplexing switch 105 is typically connected to the signal output terminal, that is, the second common terminals 107 corresponding to the multiple amplifying branches 103 are first connected to the subsequent circuit and then to the second end of the multiplexing switch 105. However, in this embodiment of the present application, to achieve a better echo effect for the RF signal, the second end of the multiplexing switch 105 is directly connected to the second common terminal 107, rather than to the signal output terminal. A subsequent circuit is provided between the second common terminal 107 and the signal output terminal. For example, the multiplexing switch 105 may be connected to the attenuator and / or matching device after being connected to the second common terminal 107. This allows the attenuation / matching of the subsequent circuit to adjust the RF signal on the bypass branch 104, achieving a better echo effect. In addition, by providing an attenuator at the connection point between the multiplexing switch 105 and the second common terminal 107 , the attenuator can also be used to attenuate the RF signal on the bypass branch 104 to varying degrees, thereby achieving more flexible signal gear adjustment.

[0046] Please refer to Figure 3, which is a schematic diagram of the circuit structure of another low-noise amplifier 100 provided in an embodiment of the present application. As shown in Figure 3, the number of amplifying branches 103 is the same as the number of bypass branches 104, each amplifying branch 103 is connected to a corresponding bypass branch 104, the first end of each bypass branch 104 is connected to the first end of the corresponding amplifying branch 103, and the second end of each bypass branch 104 is connected together to form a third common end 108.

[0047] Please refer to Figure 4, which is a circuit structure diagram of another low-noise amplifier 100 provided in an embodiment of the present application. As shown in Figure 4, the low-noise amplifier 100 may further include a plurality of matching inductors 109, wherein the first end of each matching inductor 109 is connected to the first end of the corresponding bypass branch 104, and the second end of the matching inductor 109 is connected to the first end of the corresponding amplification branch 103.

[0048] It should be noted that the matching inductor 109 is connected to the signal input path of the low noise amplifier 100 to achieve impedance matching at the input end of the low noise amplifier 100 .

[0049] In the embodiment of the present application, by arranging the matching inductor 109 between the input end of the amplifying branch 103 (such as the end A in FIG4 ) and the input end of the bypass branch 104 (such as the end B in FIG4 ), not only can the input end of the amplifying branch 103 and the input end of the bypass branch 104 be isolated, but the equivalent parasitic capacitance generated by the bypass branch 104 can also be offset, thereby weakening the feedback of the bypass branch 104 to the amplifying branch 103, reducing the parasitic capacitance and Miller effect of the amplifying branch 103, and thus improving the gain of the low-noise amplifier 100. At the same time, the impedance of the bypass branch 104 can also be increased, thereby improving the performance of the bypass branch 104.

[0050] It should be noted that the Miller effect refers to the distributed capacitance or parasitic capacitance between the input and output of an inverting amplifier circuit. Due to the amplifier's amplification, the capacitance equivalent to the input terminal is increased by 1+k times, where k is the voltage gain factor of the amplifier circuit. The equivalent parasitic capacitance refers to the capacitance Coff equivalent to the switch in bypass branch 104 when it is in the off state.

[0051] It can be understood that by connecting the input end of the bypass branch 104 to the first end of the matching inductor 109 in advance, when the RF signal is transmitted through the bypass branch 104, the RF signal can be directly input into the bypass branch 104 without passing through the matching inductor 109, which can reduce the imaginary part (inductive reactance) of the equivalent impedance of the bypass branch 104, thereby increasing the impedance of the bypass branch 104 and improving the performance of the bypass branch 104.

[0052] Please refer to Figure 5, which is a schematic diagram of the circuit structure of another low-noise amplifier 100 provided in an embodiment of the present application. As shown in Figure 5, in the low-noise amplifier 100, there is one bypass branch 104, the first end of the bypass branch 104 is connected to the first common end 106, and the second end of the bypass branch 104 is connected to the first end of the multiplexing switch 105.

[0053] It is understood that in a scenario where the low-noise amplifier 100 transmits a single-band RF signal, since the low-noise amplifier 100 only needs to transmit RF signals of one frequency band, when the bypass branch 104 is used for bypassing, all amplification branches 103 are turned off, and the RF signal can be transmitted through one bypass branch 104. Therefore, in a scenario where the low-noise amplifier 100 inputs a single-band RF signal, multiple amplification branches 103 can share one bypass branch 104.

[0054] In an embodiment of the present application, in the scenario of a single-band RF signal, by sharing a bypass branch 104, the number of bypass branches 104 can be reduced, which not only reduces the layout space occupied by the RF front-end module 10, making the overall structure of the RF front-end module 10 more compact and miniaturized, but also reduces costs.

[0055] Please refer to Figure 6, which is a circuit structure diagram of another low-noise amplifier 100 provided in an embodiment of the present application. As shown in Figure 6, the low-noise amplifier 100 may further include a matching inductor 109; the first end of the matching inductor 109 is connected to the first end of the bypass branch 104, and the second end of the matching inductor 109 is connected to the first common end 106.

[0056] It should be noted that in the embodiment of the present application, in a scenario where a bypass branch 104 is shared, multiple amplifying branches 103 can share a matching inductor 109. By connecting the first end of the matching inductor 109 to the first end of the bypass branch 104 and the second end of the matching inductor 109 to the first common terminal 106, it is possible to achieve that multiple amplifying branches 103 share a matching inductor 109. This not only allows the input ends of the bypass branch 104 and the input ends of each amplifying branch 103 to be isolated by the matching inductor 109, thereby improving the gain of the low-noise amplifier 100, but also reduces the number of matching inductors 109, thereby reducing costs.

[0057] Please refer to Figure 7, which is a schematic layout diagram of a low-noise amplifier 100 provided in an embodiment of the present application on a substrate. As shown in Figure 7, the low-noise amplifier 100 may further include a matching inductor 109 and a signal amplification chip 110. The signal amplification chip 110 is set on the substrate 20, the matching inductor 109 is configured in the substrate 109, and multiple amplification branches 103, at least one bypass branch 104 and the multiplexing switch 105 are all configured in the signal amplification chip 110.

[0058] The signal amplifying chip 110 may include a first pad 1100 and a second pad 1101 . The first pad 1100 is used to connect to the first common terminal 106 and the second end of the matching inductor 109 . The second pad 1101 is used to connect to the first end of the bypass branch 104 and the first end of the matching inductor 109 .

[0059] It should be noted that in the embodiment of the present application, in the scenario where the amplifying branch 103 and the bypass branch 104 are configured in the signal amplifying chip 110, by providing a first pad 1100 and a second pad 1101 on the signal amplifying chip 110, the first pad 1100 can be connected to the first common end 106 and to the second end of the matching inductor 109, and the second pad 1101 can be connected to the first end of the bypass branch 104 and to the second end of the matching inductor 109. This not only isolates the input end of the amplifying branch 103 and the input end of the bypass branch 104 through the matching inductor 109, but also offsets the equivalent parasitic capacitance generated by the bypass branch 104, thereby weakening the feedback of the bypass branch 104 to the amplifying branch 103, reducing the parasitic capacitance and Miller effect of the amplifying branch 103, and thus improving the gain of the low-noise amplifier 100.

[0060] Please refer to FIG8 , which is a schematic diagram of the circuit structure of another low noise amplifier 100 provided in an embodiment of the present application. As shown in FIG8 , the low noise amplifier 100 may further include a plurality of first switches 111 ; each first switch 111 is connected in series with a corresponding amplifying branch 103 .

[0061] Exemplarily, the first switch 111 may be connected to the first end of the corresponding amplifying branch 103 or to the second end of the corresponding amplifying branch 103. For example, as shown in FIG8 , the first switch 111 may be connected to the first end of the corresponding amplifying branch 103.

[0062] For example, the first switch 111 may include but is not limited to a transistor, a field effect transistor, an insulated gate bipolar transistor, a relay, an optical coupler, and the like.

[0063] It should be noted that when the first switch 111 is connected to the first end of the corresponding amplifying branch 103, the first switch 111 is used to control the opening and closing of the amplifying branch 103 to adjust the gain of the low-noise amplifier 100. For example, when the first switch 111 connected in series with each amplifying branch 103 is closed, the gain of the low-noise amplifier 100 is maximized. When the first switch 111 is connected to the second end of the corresponding amplifying branch 103, in addition to controlling the opening and closing of the amplifying branch 103 to adjust the gain of the low-noise amplifier 100, the first switch 111 can also be used to prevent the signal on the bypass branch 104 from leaking into the amplifying transistor of the amplifying branch 103. For example, when the bypass branch 104 is used for bypassing, the first switch 111 connected in series with the amplifying branch 103 can be controlled to be disconnected, thereby preventing the RF signal transmitted on the bypass branch 104 from leaking into the amplifying transistor of the amplifying branch 103.

[0064] Please refer to Figure 9, which is a circuit structure diagram of another low-noise amplifier 100 provided in an embodiment of the present application. As shown in Figure 9, the post-stage circuit may further include an attenuator 112, the first end of the attenuator 112 is connected to the second end of the multiplexing switch 105, and the second end of the attenuator 112 is connected to the signal output end 102.

[0065] In the embodiment of the present application, by connecting the second common terminal 107 formed by connecting the second ends of the multiplexer branches 103 to the connection point of the second end of the multiplexer switch 105, and then connecting to the attenuator 112, the attenuator 112 can attenuate the RF signal output by the bypass branch 104 to varying degrees, thereby achieving more flexible signal level adjustment. The specific structure of the attenuator 112 can be found in related art and is not limited here.

[0066] In the related art, the second end of the multiplexing switch 105 is typically directly connected to the signal output end. That is, the second common ends 107 corresponding to the multiple amplifying branches 103 are first connected to the subsequent circuit and then to the second end of the multiplexing switch 105. The second end of the multiplexing switch 105 is directly connected to the signal output end. However, in the embodiment of the present application, to achieve a better echo effect for the RF signal, the second end of the multiplexing switch 105 is directly connected to the second common end 107, rather than to the signal output end. A subsequent circuit is provided between the second common end 107 and the signal output end. For example, the attenuator 112 can be connected after the connection point between the multiplexing switch 105 and the second common end 107, so that the attenuation of the subsequent circuit can be used to adjust the RF signal on the bypass branch 104, achieving a better echo effect.

[0067] Please refer to Figure 10, which is a circuit structure diagram of another low-noise amplifier 100 provided in an embodiment of the present application. As shown in Figure 10, the low-noise amplifier 100 may further include a matcher 113, a first end of the matcher 113 is connected to the second end of the attenuator 112, and a second end of the matcher 113 is connected to the signal output end 102.

[0068] In the embodiment of the present application, by providing a matcher 113 at the output end of attenuator 112, matcher 113 can perform impedance matching on the attenuated RF signal output by attenuator 112, thereby reducing RF signal distortion and improving power transmission efficiency, thereby achieving a better echo effect. The specific structure of matcher 113 can be found in related art and is not limited here.

[0069] Please refer to Figure 11, which is a schematic diagram of the circuit structure of another low-noise amplifier 100 provided in an embodiment of the present application. As shown in Figure 11, the low-noise amplifier 100 may include multiple signal input terminals 101, a signal output terminal 102, multiple amplifying branches 103, multiple bypass branches 104, and a multiplexing switch 105. The first end of each amplifying branch 103 is connected to one of the signal input terminals 101, the second ends of each amplifying branch 103 are connected together to form a fourth common terminal 114 connected to the signal output terminal 102, the first end of each bypass branch 104 is connected to the first end of the corresponding amplifying branch 103, and the second ends of each bypass branch 104 are connected together to form a fifth common terminal 115. The first end of the multiplexing switch 105 is connected to the fifth common terminal 105, and the second end of the multiplexing switch 105 is connected to the fourth common terminal 114.

[0070] In the embodiment of the present application, one of the switches on each bypass branch 104 is reused as a multiplexing switch 105. By reducing the parasitic capacitance in the bypass branch 104, the total parasitic capacitance at the output of the low-noise amplifier 100 is reduced, thereby effectively improving the gain of the low-noise amplifier 100. At the same time, the number of switches connected in series on the bypass branch 104 can also be reduced, thereby improving the performance of the bypass branch 104 and reducing the cost.

[0071] It should be noted that in Figure 11, by setting multiple signal input terminals 101, the low-noise amplifier 100 can be suitable for application scenarios of multi-band RF signals. For example, RF signals of multiple different frequency bands are input into the corresponding amplification circuit through multiple signal input terminals 101, and multiple amplification branches selectively amplify the RF signals of the corresponding frequency bands.

[0072] As shown in Figure 11, the second end of the multiplexing switch 105 is directly connected to the second common terminal 107, rather than to the signal output terminal. That is, the second common terminal 107 is not first connected to the subsequent circuit and then to the multiplexing switch 105. The subsequent circuit may include an attenuator and / or a matcher. In the related art, the second end of the multiplexing switch 105 is usually connected to the signal output terminal. That is, the second common terminals 107 corresponding to the multiple amplifying branches 103 are first connected to the subsequent circuit and then to the second end of the multiplexing switch 105. However, in the embodiment of the present application, in order to achieve a better echo effect for the RF signal, the second end of the multiplexing switch 105 is connected to the second common terminal 107, rather than to the signal output terminal, and a subsequent circuit is provided between the second common terminal 107 and the signal output terminal. For example, the multiplexing switch 105 can be connected to the attenuator and / or matcher after being connected to the second common terminal 107, so that the attenuation / matching of the subsequent circuit can be used to adjust the RF signal on the bypass branch 104 to achieve a better echo effect. In addition, by providing an attenuator between the multiplexing switch 105 and the second common terminal 107 , the attenuator can be used to attenuate the radio frequency signal on the bypass branch 104 to varying degrees, thereby achieving more flexible signal gear adjustment.

[0073] Please refer to Figure 12, which is a circuit structure diagram of another low-noise amplifier 100 provided in an embodiment of the present application. As shown in Figure 12, the low-noise amplifier 100 may further include a plurality of matching inductors 109; the first end of each matching inductor 109 is connected to the first end of the corresponding bypass branch 104, and the second end of the matching inductor 109 is connected to the first end of the corresponding amplification branch 103.

[0074] It should be noted that in the embodiment of the present application, by providing a matching inductor 109 between the input end of the amplifying branch 103 and the input end of the bypass branch 104, not only can the input end of the amplifying branch 103 and the input end of the bypass branch 104 be isolated, but the equivalent parasitic capacitance generated by the bypass branch 104 can also be offset, thereby weakening the feedback of the bypass branch 104 to the amplifying branch 103, reducing the parasitic capacitance and Miller effect of the amplifying branch 103, and thus improving the gain of the low-noise amplifier 100. At the same time, the impedance of the bypass branch 104 can also be increased, thereby improving the performance of the bypass branch 104.

[0075] Please refer to Figure 13, which is a schematic layout diagram of another low-noise amplifier 100 provided in an embodiment of the present application on a substrate. As shown in Figure 13, the low-noise amplifier 100 may further include a signal amplification chip 110. The signal amplification chip 110 and a plurality of matching inductors 109 are arranged on the substrate 20, and the plurality of amplification branches 103, the plurality of bypass branches 104 and the multiplexing switch 105 are all configured in the signal amplification chip 110.

[0076] For example, as shown in FIG13 , by configuring multiple amplifying branches 103 and multiple bypass branches 104 in a signal amplifying chip 110 and disposing a matching inductor 109 on a substrate 20, not only can the input end of the corresponding amplifying branch 103 and the input end of the corresponding bypass branch 104 be isolated by the matching inductor 109, but the equivalent parasitic capacitance generated by the bypass branch 104 can also be offset, thereby weakening the feedback of the bypass branch 104 on the amplifying branch 103, reducing the parasitic capacitance and Miller effect of the amplifying branch 103, and thus improving the gain of the low-noise amplifier 100. As an example, the matching inductor 109 can be disposed on the substrate using surface mount technology (SMD) or wire winding.

[0077] Please refer to Figure 14, which is a circuit structure diagram of another low-noise amplifier 100 provided in an embodiment of the present application. As shown in Figure 14, the low-noise amplifier 100 may further include multiple signal amplification chips 110 and switch chips 116. The multiple signal amplification chips 110, the switch chips 116 and the multiple matching inductors 109 are arranged on the substrate 20, each amplification branch 103 and the corresponding connected bypass branch 104 are arranged in a corresponding signal amplification chip 110, and the multiplexing switch 105 is arranged in the switch chip 116.

[0078] It should be noted that by disposing multiple matching inductors 109 on the substrate 20 and disposing each amplifying branch 103 and the corresponding bypass branch 104 in a corresponding signal amplifying chip 110, it is possible to provide a matching inductor 109 between the input end of the amplifying branch 103 and the input end of the bypass branch 104. This not only isolates the input end of the amplifying branch 103 from the input end of the bypass branch 104, but also offsets the equivalent parasitic capacitance generated by the bypass branch 104, thereby weakening the feedback of the bypass branch 104 on the amplifying branch 103, reducing the parasitic capacitance and Miller effect of the amplifying branch 103, and thus improving the gain of the low-noise amplifier 100. By disposing the multiplexing switch 105 on the switch chip 116, it is possible to isolate the multiplexing switch 105 from the amplifying branch 103 and the bypass branch 104, thereby improving the isolation of the low-noise amplifier 100.

[0079] Please refer to Figure 15, which is a circuit structure diagram of another low-noise amplifier 100 provided in an embodiment of the present application. As shown in Figure 15, the low-noise amplifier 100 may further include a plurality of second switches 117, wherein the first end of each second switch 117 is connected to the second end of a corresponding amplification branch 103, and the second end of each second switch 117 is connected to the fourth common end 114.

[0080] In the embodiment of the present application, in the scenario of transmitting multi-band RF signals, the second switch 117 is used to prevent the signal on the bypass branch 104 from leaking into the amplifying transistor of the amplifying branch 103. For example, when the bypass branch 104 is used for bypassing, the second switch 117 connected in series with the amplifying branch 103 can be controlled to be disconnected, thereby preventing the RF signal transmitted on the bypass branch 104 from leaking into the amplifying transistor of the amplifying branch 103.

[0081] Please refer to Figure 16, which is a circuit structure diagram of another low-noise amplifier 100 provided in an embodiment of the present application. As shown in Figure 16, the low-noise amplifier 100 may further include an attenuator 112, the first end of the attenuator 112 is connected to the second end of the multiplexing switch 105, and the second end of the attenuator 112 is connected to the signal output end 102.

[0082] By connecting the second common terminal 107 formed by connecting the second ends of the multiple amplifying branches 103 to the second end of the multiplexing switch 105 and then to the attenuator 112, the attenuator 112 can attenuate the RF signal output by the bypass branch 104 to varying degrees, thereby achieving more flexible signal level adjustment. The specific structure of the attenuator 112 can be found in related art and is not limited here.

[0083] In related art, the second end of the multiplexing switch 105 is typically connected to the signal output end. Specifically, the second common terminals 107 corresponding to the multiple amplifying branches 103 are first connected to the subsequent circuitry and then to the second end of the multiplexing switch 105. However, in the embodiments of the present application, to achieve a better echo effect for the RF signal, the second end of the multiplexing switch 105 can be first connected to the second common terminal 107, and then the subsequent circuitry can be arranged after the connection point. For example, an attenuator 112 can be arranged after the connection point between the multiplexing switch 105 and the second common terminal 107, so that the attenuation of the subsequent circuitry can be used to adjust the RF signal on the bypass branch 104, achieving a better echo effect.

[0084] Please refer to Figure 17, which is a circuit structure diagram of another low-noise amplifier 100 provided in an embodiment of the present application. As shown in Figure 17, the low-noise amplifier 100 may further include a matcher 113, a first end of the matcher 113 is connected to the second end of the attenuator 112, and a second end of the matcher 113 is connected to the signal output end 102.

[0085] In the embodiment of the present application, by setting a matcher 113 at the output end of the attenuator 112, the matcher 113 can perform impedance matching on the attenuated RF signal output by the attenuator 112, so as to reduce the distortion of the RF signal and improve the power transmission efficiency, thereby achieving a better echo effect.

[0086] Please refer to Figure 18, which is a schematic diagram of the circuit structure of another low-noise amplifier 100 provided in an embodiment of the present application. As shown in Figure 18, the amplification branch 103 may include a first capacitor C1, a first amplification transistor T1, a first inductor L1, a second amplification transistor T2, a second inductor L2, and a second capacitor C2. The bypass branch 104 may include a third capacitor C3 and at least one switch K. In each bypass branch 104, at least one switch K is connected in series between the first end of the matching inductor 109 and the first end of the third capacitor C3, the second end of the third capacitor C3 is connected to the fifth common terminal 115, the fifth common terminal 115 is connected to the first end of the multiplexing switch 105, and the second end of the multiplexing switch 105 is connected to the fourth common terminal 114.

[0087] As an example, each of the bypass branches 104 includes a third capacitor C3 and a switch K. The switch K may include but is not limited to a triode, a metal-oxide-semiconductor field-effect transistor (MOS), an insulated gate bipolar transistor (IGBT), etc. In this embodiment, since the first end of the multiplexing switch is connected to the third common end formed by connecting the second end of each of the bypass branches together, and the second end of the multiplexing switch is connected to the second common end formed by connecting the second end of each of the amplifying branches together, the multiplexing switch 105 is a switch multiplexed by each bypass branch, which can not only reduce the parasitic capacitance in the bypass branch to reduce the total parasitic capacitance of the output end of the low-noise amplifier, thereby effectively improving the gain of the low-noise amplifier, but also use the post-stage circuit between the second common end and the signal output end to adjust the RF signal on the bypass branch to achieve a better echo effect.

[0088] One end of the first capacitor C1 is connected to the second end of the matching inductor 109, and the other end is connected to the first end of the first amplifier transistor T1. The second end of the first amplifier transistor T1 is grounded via the first inductor L1. The first end of the second amplifier transistor T2 is connected to the bias control terminal, the second end of the second amplifier transistor T2 is connected to the third end of the first amplifier transistor T1, the third end of the second amplifier transistor T2 is connected to the first end of the second capacitor C2, and the second end of the second capacitor C2 is connected to the fourth common terminal 114. The bias control terminal refers to the port connected to the bias circuit, which is not shown in the figure. The first end of the second inductor L2 is connected to the common terminal between the third end of the second amplifier transistor T2 and the second capacitor C2, and the second end of the second inductor L2 is connected to the power supply terminal Vdd. The second inductor L2 is used to block DC or provide output matching.

[0089] Exemplarily, the first terminal of the first amplifying transistor T1 is a gate, the second terminal of the first amplifying transistor T1 is a drain, and the third terminal of the first amplifying transistor T1 is a source; the first terminal of the second amplifying transistor T2 is a gate, the second terminal of the second amplifying transistor T2 is a source, and the third terminal of the second amplifying transistor T2 is a drain. Alternatively, the first terminal of the first amplifying transistor T1 is a gate, the second terminal of the first amplifying transistor T1 is a source, and the third terminal of the first amplifying transistor T1 is a drain; the first terminal of the second amplifying transistor T2 is a gate, the second terminal of the second amplifying transistor T2 is a drain, and the third terminal of the first amplifying transistor T2 is a source.

[0090] Exemplarily, the switch K may include but is not limited to a transistor, a field effect transistor, an insulated gate bipolar transistor, a relay, an optocoupler, and the like.

[0091] It should be noted that the switch K is used to control the on / off state of the bypass branch 104, thereby controlling whether to bypass the RF signal input to the low noise amplifier 100. The third capacitor C3 is used to block direct current.

[0092] It is understandable that Figure 18 only shows one of the multiple amplifying branches 103 and one of the multiple bypass branches 104 in Figures 2 to 17. The circuit structures of the amplifying branch 103 and the bypass branch 104 can be adaptively adjusted according to actual needs and are not limited here.

[0093] In an embodiment of the present application, by connecting at least one switch K in the bypass branch 104 in series to the first end of the matching inductor 109, and connecting the second end of the matching inductor 109 to the first end of the amplifying branch 103, not only can the input end of the amplifying branch 103 and the input end of the bypass branch 104 be isolated through the matching inductor 109, but the equivalent parasitic capacitance generated by the bypass branch 104 can also be offset, so as to weaken the feedback of the bypass branch 104 to the amplifying branch 103, reduce the parasitic capacitance and Miller effect of the amplifying branch 103, and thereby improve the gain of the low-noise amplifier 100.

[0094] The above are only specific embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and such modifications or substitutions should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A low-noise amplifier, wherein, Comprising: A signal input terminal and a signal output terminal; A plurality of amplification branches, a first end of each of the amplification branches being connected together to form a first common end connected to the signal input terminal, a second end of each of the amplification branches being connected together to form a second common end, and the second common end being connected to the signal output terminal through a subsequent stage circuit; At least one bypass branch, a first end of the bypass branch being connected to the first common end, and a second end of the bypass branch being connected together to form a third common end; A multiplexing switch, a first end of the multiplexing switch being connected to the third common end, and a second end of the multiplexing switch being connected to the second common end.

2. The low-noise amplifier according to claim 1, wherein, The number of the amplification branches is the same as the number of the bypass branches, each of the amplification branches correspondingly connects to a bypass branch, a first end of each of the bypass branches is connected to a first end of the corresponding amplification branch, and a second end of each of the bypass branches is connected together to form the third common end.

3. The low-noise amplifier according to claim 2, wherein, The low-noise amplifier further includes a plurality of matching inductors; a first end of each of the matching inductors is connected to a first end of the corresponding bypass branch, and a second end of the matching inductor is connected to a first end of the corresponding amplification branch.

4. The low-noise amplifier according to claim 1, wherein, There is one bypass branch, a first end of the bypass branch is connected to the first common end, and a second end of the bypass branch is connected to a first end of the multiplexing switch.

5. The low-noise amplifier according to claim 4, wherein The low-noise amplifier further includes a matching inductor; A first end of the matching inductor is connected to a first end of the bypass branch, and a second end of the matching inductor is connected to the first common end.

6. The low-noise amplifier according to claim 1, wherein, The low-noise amplifier further includes a matching inductor and a signal amplification chip, the signal amplification chip is disposed on a substrate, the matching inductor is configured in the substrate, and the plurality of amplification branches, the at least one bypass branch and the multiplexing switch are all configured in the signal amplification chip; wherein, the signal amplification chip includes a first pad and a second pad, the first pad is used for connecting to the first common end and a second end of the matching inductor, and the second pad is used for connecting to a first end of the bypass branch and a first end of the matching inductor.

7. The low-noise amplifier according to any one of claims 1-6, wherein, The low-noise amplifier further includes a plurality of first switches; each of the first switches is connected in series with a corresponding one of the amplification branches.

8. The low-noise amplifier according to claim 1, wherein, The subsequent stage circuit includes an attenuator, a first end of the attenuator is connected to a second end of the multiplexing switch, and a second end of the attenuator is connected to the signal output terminal.

9. The low-noise amplifier according to claim 8, wherein, The subsequent stage circuit further includes a matcher, a first end of the matcher is connected to a second end of the attenuator, and a second end of the matcher is connected to the signal output terminal.

10. A low-noise amplifier, wherein, Comprising: A plurality of signal input terminals and one signal output terminal; A plurality of amplification branches and a plurality of bypass branches, a first end of each of the amplification branches is connected to a signal input terminal, a second end of each of the amplification branches is connected together to form a fourth common end, the fourth common end is connected to the signal output terminal through a subsequent stage circuit, a first end of each of the bypass branches is connected to a first end of the corresponding amplification branch, and a second end of each of the bypass branches is connected together to form a fifth common end; A multiplexing switch, a first end of the multiplexing switch is connected to the fifth common end, and a second end of the multiplexing switch is connected to the fourth common end.

11. The low-noise amplifier according to claim 10, wherein, The low-noise amplifier further includes a plurality of matching inductors; a first end of each of the matching inductors is connected to a first end of a corresponding bypass branch, and a second end of the matching inductor is connected to a first end of a corresponding amplification branch.

12. The low-noise amplifier according to claim 11, wherein, The low-noise amplifier further includes a signal amplification chip, the signal amplification chip and the plurality of matching inductors are disposed on a substrate, and the plurality of amplification branches, the plurality of bypass branches, and the multiplexing switch are all configured in the signal amplification chip.

13. The low-noise amplifier according to claim 11, wherein, The low-noise amplifier further includes a plurality of signal amplification chips and a switch chip, the plurality of signal amplification chips, the switch chip, and the plurality of matching inductors are disposed on a substrate, each amplification branch and the corresponding connected bypass branch are disposed in a corresponding signal amplification chip, and the multiplexing switch is disposed in the switch chip.

14. The low-noise amplifier according to any one of claims 10-13, wherein, The low-noise amplifier further includes a plurality of second switches, a first end of each of the second switches is connected to a second end of a corresponding amplification branch, and a second end of each of the second switches is connected to the fourth common end.

15. The low-noise amplifier according to any one of claims 10-13, wherein, The post-stage circuit includes an attenuator, a first end of the attenuator is connected to a second end of the multiplexing switch, and a second end of the attenuator is connected to the signal output end.

16. The low-noise amplifier according to claim 15, wherein, The post-stage circuit further includes a matcher, a first end of the matcher is connected to a second end of the attenuator, and a second end of the matcher is connected to the signal output end.

17. A radio frequency front-end module, wherein, The RF front-end module includes the low-noise amplifier according to any one of claims 1 to 9, or the low-noise amplifier according to any one of claims 10 to 16.

Images