Low noise amplifier and radio frequency terminal

Abstract

A low noise amplifier and a radio frequency terminal. The low noise amplifier comprises: an input matching network connected to a signal input end, and used for impedance matching between the signal input end and an input end of an amplifier circuit; the amplifier circuit connected to the input matching network, and used for amplifying an input signal at the signal input end; an output matching network connected to the amplifier circuit, and used for impedance matching between an output end of the amplifier circuit and a signal output end, and outputting an amplified signal by means of the signal output end; and a bandwidth adjustment circuit connected to the output matching network, and used for adjusting the operating bandwidth of the low noise amplifier. By means of the described solution, the operating bandwidth of the low noise amplifier can be increased.

Description

Low noise amplifier and radio frequency terminal

[0001] The present application claims priority to the Chinese patent application No. 202410855757.2, filed on June 27, 2024, and entitled "Low noise amplifier and radio frequency terminal", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of electronic circuit, in particular to a low noise amplifier and a radio frequency terminal. BACKGROUND

[0003] With the development and application of 5G communication technology, the radio frequency front end needs to support more and wider frequency bands, and the front-end radio frequency structure is becoming more and more complex, requiring the radio frequency device design to support multi-mode and multi-frequency integration and digital reconfigurable application to reduce the cost of radio frequency devices and save printed circuit board (PCB) space.

[0004] The new 5G technology needs to support n77 (3.3-4.2GHz) and n79 (4.4-5GHz) frequency bands in the sub-8GHz frequency band, and the bandwidth is as high as 900MHz and 600MHz respectively. However, the traditional common-source common-gate low noise amplifier has narrow-band matching for input and output, which cannot meet the bandwidth requirement.

[0005] SUMMARY

[0006] The problem to be solved by the present application is how to improve the working bandwidth of the low noise amplifier.

[0007] To solve the above problems, an embodiment of the present application provides a low noise amplifier, which comprises:

[0008] An input matching network connected with a signal input end, used for matching the impedance between the signal input end and the input end of an amplification circuit;

[0009] The amplification circuit is connected with the input matching network, and is used for amplifying the input signal of the signal input end;

[0010] An output matching network connected with the amplification circuit, used for matching the impedance between the output end of the amplification circuit and the signal output end, and outputting the amplified signal through the signal output end;

[0011] And a bandwidth adjustment circuit connected with the output matching network, used for adjusting the working bandwidth of the low noise amplifier.

[0012] In a possible embodiment, the bandwidth adjustment circuit comprises at least one of:

[0013] a series resonant sub-circuit between the output matching network and the amplification circuit, for adjusting the working bandwidth of the low-noise amplifier by compensating and neutralizing the parasitic capacitance of the output end of the amplification circuit to ground;

[0014] a feedback sub-circuit between the output matching network and the input end of the amplification circuit, for adjusting the working bandwidth of the low-noise amplifier by changing the feedback depth between the signal output end and the input end of the amplification circuit.

[0015] In a possible embodiment, the series resonant sub-circuit comprises:

[0016] a series inductor connected in series between the input end of the output matching network and the output end of the amplification circuit; the inductance value of the series inductor is adjustable.

[0017] In a possible embodiment, the series resonant sub-circuit further comprises:

[0018] a series inductor switch connected in parallel with the series inductor, for controlling the access of the series inductor based on the current working frequency band.

[0019] In a possible embodiment, the feedback sub-circuit comprises:

[0020] a feedback capacitor connected with the output matching network;

[0021] a feedback resistance unit having one end connected with the feedback capacitor and the other end connected with the input end of the amplification circuit;

[0022] wherein the resistance value of the feedback resistance unit is adjustable.

[0023] In a possible embodiment, the feedback resistance unit comprises:

[0024] a first feedback resistor connected in series with the feedback capacitor;

[0025] a second feedback resistor connected in series with the first feedback resistor.

[0026] In a possible embodiment, the feedback resistance unit further comprises:

[0027] a feedback resistance switch connected in parallel with the second feedback resistor, for controlling the access of the second feedback resistor based on the current working frequency band.

[0028] In a possible embodiment, the input matching network is a dual-frequency input matching network.

[0029] In a possible embodiment, the input matching network comprises:

[0030] a first capacitor;

[0031] a first inductor connected in series with the first capacitor;

[0032] a first resistor having one end connected to the first inductor and the other end connected to a bias voltage output terminal;

[0033] a first LC frequency band adjustment unit located between the first inductor and an input terminal of the amplification circuit, and configured to adjust a matching capacitance or a matching inductance of the input matching network based on a current operating frequency band.

[0034] In a possible embodiment, the first LC frequency band adjustment unit comprises a second inductor, a first switch, a second capacitor and a second switch, wherein the second inductor is connected in series with the first switch, the other end of the second inductor is connected to the first inductor and the second capacitor, and the other end of the first switch is grounded; and the second capacitor is connected in parallel with the second switch.

[0035] In a possible embodiment, the first switch is configured to be turned on when the low-noise amplifier operates in a low frequency band, and turned off when the low-noise amplifier operates in a high frequency band; and the second switch is configured to be turned off when the low-noise amplifier operates in the low frequency band, and turned on when the low-noise amplifier operates in the high frequency band.

[0036] In a possible embodiment, the output matching network is a dual-frequency matching network.

[0037] In a possible embodiment, the output matching network comprises:

[0038] a third inductor located between an output terminal of the amplification circuit and a power voltage output terminal;

[0039] a third capacitor located between the output terminal of the amplification circuit and a signal output terminal;

[0040] a second LC frequency band adjustment unit connected in parallel with the third capacitor, and configured to adjust a matching capacitance of the output matching network based on a current operating frequency band.

[0041] In a possible embodiment, the second LC frequency band adjustment unit comprises:

[0042] a fourth capacitor;

[0043] a third switch connected in series with the fourth capacitor.

[0044] In a possible embodiment, the third switch is configured to be turned on when the low-noise amplifier operates in a low frequency band.

[0045] In a possible embodiment, the low noise amplifier further comprises:

[0046] a frequency band control unit, configured to receive a frequency band indication signal and generate a low frequency control signal and a high frequency control signal.

[0047] The embodiment of the present application further provides a radio frequency terminal, which comprises any of the low noise amplifiers.

[0048] Compared with the prior art, the technical scheme of the embodiment of the present application has the following advantages:

[0049] By using the scheme of the present application, the working bandwidth of the low noise amplifier can meet the bandwidth requirement by setting the bandwidth adjustment circuit and adjusting the working bandwidth of the low noise amplifier through the bandwidth adjustment circuit. BRIEF DESCRIPTION OF DRAWINGS

[0050] Fig. 1 is a circuit structure schematic diagram of a low noise amplifier;

[0051] Fig. 2 is a curve diagram of performance parameters of the low noise amplifier in Fig. 1 varying with frequency;

[0052] Fig. 3 is a structure schematic diagram of a low noise amplifier in an embodiment of the present application;

[0053] Fig. 4 is a circuit structure schematic diagram of a low noise amplifier in an embodiment of the present application;

[0054] Fig. 5 is a circuit structure schematic diagram of another low noise amplifier in an embodiment of the present application;

[0055] Fig. 6 is a curve diagram of performance parameters of a low noise amplifier in an embodiment of the present application varying with working frequency. DETAILED DESCRIPTION

[0056] Fig. 1 is a circuit structure schematic diagram of a low noise amplifier in an embodiment of the present application; in Fig. 1 is a circuit structure schematic diagram of a low noise amplifier in an embodiment of the present application; o and peripheral devices. The peripheral devices can include a first AC coupling capacitor C g , a second AC coupling capacitor C d , a first inductor L g , a second inductor L d , a third inductor L s and a resistor Rb. Wherein, one end of the first AC coupling capacitor C g serves as an input end for receiving an input signal RF in , the second NMOS transistor M oThe drain is used as the output terminal to output the low-noise amplifier's output signal RF. out .

[0057] Figure 2 is a schematic diagram showing the performance parameters of the low-noise amplifier in Figure 1 as a function of frequency. Specifically, referring to Figure 2, the forward gain S21 curve, input reflection parameter S11 curve, and output parameter S22 of the low-noise amplifier in Figure 1 are shown in Figure 2. As can be seen from Figure 2, the low-noise amplifier in Figure 1 operates in a single frequency band, with an operating frequency range of 2.3GHz to 2.6GHz and an operating bandwidth of less than 400MHz. This clearly cannot meet the bandwidth requirements of the new 5G technology.

[0058] To address this problem, the present invention provides a low-noise amplifier, which incorporates a bandwidth adjustment circuit, thereby enabling the low-noise amplifier to operate at bandwidth requirements.

[0059] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0060] Referring to Figure 3, an embodiment of the present invention provides a low-noise amplifier 30, which may include: an input matching network 31, an amplification circuit 32, an output matching network 33, and a bandwidth adjustment circuit 34. Wherein:

[0061] The input matching network 31 is connected to the signal input terminal and is used to match the impedance between the signal input terminal and the input terminal of the amplifier circuit 32.

[0062] The amplifier circuit 32 is connected to the input matching network 31 and is used to amplify the input signal RF at the signal input terminal. in Magnification processing is performed;

[0063] The output matching network 33 is connected to the amplifier circuit 32 and is used to match the impedance between the output terminal of the amplifier circuit 32 and the signal output terminal, and output the amplified signal RFout through the signal output terminal.

[0064] The bandwidth adjustment circuit 34 is connected to the output matching network 33 and is used to adjust the operating bandwidth of the low noise amplifier 30.

[0065] By setting up the bandwidth adjustment circuit 34, the operating bandwidth of the low-noise amplifier can be adjusted so that the operating bandwidth of the low-noise amplifier 30 can meet the bandwidth requirements.

[0066] Figure 4 is a schematic diagram of a low noise amplifier according to an embodiment of the present application. Referring to Figure 4, the input matching network 31 can be a single frequency input matching network, i.e. it can only receive input signals within a single frequency band and perform impedance matching. The output matching network 33 can be a single frequency output matching network, i.e. it can only output signals within a single frequency band and perform impedance matching. The amplification circuit 32 can be an amplification circuit formed by a common source and common gate MOS transistor.

[0067] In particular, referring to Figure 4, the input matching network 31 can include a first capacitor C g , a first inductor L g and a first resistor Rb. The first capacitor C g is connected in series with the first inductor L g . One end of the first resistor Rb is connected to the other end of the first inductor L g and the input of the amplification circuit 32, and the other end is connected to the bias voltage output Vb.

[0068] The output matching network 33 can include a third inductor L d and a third capacitor C d . The third inductor L d is located between the output of the amplification circuit 32 and the power supply voltage output Vdd. The third capacitor C d is located between the output of the amplification circuit 32 and the signal output.

[0069] The amplification circuit 32 can include a first NMOS transistor M in and a second NMOS transistor M o . The gate of the first NMOS transistor M in is connected to the first inductor L g and the first resistor Rb, the source is connected to ground via a fourth inductor L s , and the drain is connected to the source of the second NMOS transistor M o . The gate of the second NMOS transistor M o is connected to the power supply voltage output Vdd, and the drain is connected to the output matching network 33.

[0070] The input signal RF in is input to the amplification circuit 32 via the input matching network 31. The input matching network 31 can match the impedance of the signal input to the gate impedance of the first NMOS transistor M in , thereby reducing signal reflection. The amplification circuit 32 amplifies the input signal RF in , thereby increasing the power of the input signal RF in . The output matching network 33 can match the drain impedance of the second NMOS transistor M oThe drain impedance is matched with the signal output impedance, so that the reflection of the amplified signal can be reduced.

[0071] In an embodiment of the present application, the bandwidth adjustment circuit 34 can include at least one of:

[0072] a series resonance sub-circuit between the output matching network and the amplification circuit, for adjusting the working bandwidth of the low-noise amplifier by compensating and neutralizing the parasitic capacitance of the output end of the amplification circuit;

[0073] a feedback sub-circuit between the output matching network and the input end of the amplification circuit, for adjusting the working bandwidth of the low-noise amplifier by changing the feedback depth between the signal output end and the input end of the amplification circuit.

[0074] In a specific implementation, either of the series resonance sub-circuit and the feedback sub-circuit can improve the working bandwidth of the low-noise amplifier, and the series resonance sub-circuit or the feedback sub-circuit can be selected according to the actual bandwidth requirement. It can be understood that when the actual bandwidth requirement is narrow, either of the series resonance sub-circuit and the feedback sub-circuit can be selected as the bandwidth adjustment circuit 34. When the actual bandwidth requirement is wide, the series resonance sub-circuit and the feedback sub-circuit can be selected as the bandwidth adjustment circuit 34.

[0075] For example, when the actual bandwidth requirement is 500MHZ-600MHZ, the bandwidth adjustment circuit 34 can be implemented by only using the series resonance sub-circuit or only using the feedback sub-circuit. When the actual bandwidth requirement is more than 600MHZ, the bandwidth adjustment circuit 34 can include both the series resonance sub-circuit and the feedback sub-circuit, so that the working bandwidth of the low-noise amplifier is wider.

[0076] In a specific implementation, by setting the series resonance sub-circuit, the voltage and current in the circuit can resonate under certain conditions. In the resonance state, the energy in the circuit reaches the maximum value, and the circuit is in the resonance state. The series resonance sub-circuit can be implemented by using various circuit structures.

[0077] In an embodiment, referring to FIG. 4, the series resonance sub-circuit can include a series inductor L peak . The series inductor L peak is connected in series between the output matching network 33 and the output end of the amplification circuit 32. The inductance value of the series inductor L peak is adjustable.

[0078] Specifically, the series inductor L peak has the function of storing electromagnetic energy, and the second NMOS tube M oThe parasitic capacitance of the second NMOS transistor M peak The inductance value of the series inductor L peak The parasitic capacitance of the second NMOS transistor M o The parasitic capacitance of the second NMOS transistor M peak The parasitic capacitance of the second NMOS transistor M o The parasitic capacitance of the second NMOS transistor M o The parasitic capacitance of the second NMOS transistor M o The parasitic capacitance of the second NMOS transistor M

[0079] In an embodiment, referring to FIG. 4, the feedback sub-circuit 342 can include a feedback capacitor Cf and a feedback resistance unit. One end of the feedback capacitor Cf is connected to the output matching network 33, and the other end is connected to the feedback resistance unit. The feedback resistance unit is connected in series with the feedback capacitor Cf. The resistance value of the feedback resistance unit is adjustable

[0080] Specifically, one end of the feedback capacitor Cf is connected to the third inductor L d and the third capacitor C d The other end of the feedback capacitor Cf is connected to the feedback resistance unit. The other end of the feedback resistance unit is connected to the gate of the first NMOS transistor M in Thus, a feedback loop is formed between the output end and the input end of the amplification circuit 32. By changing the resistance value of the feedback resistance unit, the feedback depth between the output end and the input end of the amplification circuit 32 can be changed, and thus the gain of the low-noise amplifier can be changed, so as to control the working bandwidth of the low-noise amplifier.

[0081] In a specific implementation, the feedback resistance unit can be implemented by an adjustable resistance.

[0082] In an embodiment, referring to FIG. 4, the feedback resistance unit can include a first feedback resistance Rf and a second feedback resistance Rfb. The second feedback resistance Rfb is connected in series with the first feedback resistance Rf, and the resistance value of the second feedback resistance Rfb is adjustable.

[0083] In other embodiments, the feedback resistance unit can also be composed of more than three resistances, and the connection mode between the resistances is not limited to series connection, but can also be parallel connection, or a combination of series connection and parallel connection. As long as the resistance value of the feedback resistance unit can be changed.

[0084] Figure 5 is a schematic diagram of a circuit structure of a low noise amplifier according to another embodiment of the present application. Referring to Figure 5, the input matching network 31 is a dual-band matching network, i.e., it can receive input signals in two different frequency bands and perform impedance matching. The output matching network 33 can also be a dual-band output matching network, i.e., it can output signals in two frequency bands and perform impedance matching.

[0085] Specifically, with reference to Figure 4, in addition to the first capacitor C g , the first inductor L g , and the first resistor Rb, the input matching network 31 can further include a first LC frequency band adjustment unit. The first LC frequency band adjustment unit is located between the first inductor L g and the input end of the amplification circuit (i.e., the gate of the first NMOS transistor M in ), and is configured to adjust the matching capacitance or the matching inductance of the input matching network 31 based on the current operating frequency band.

[0086] In an embodiment, with reference to Figure 5, the first LC frequency band adjustment unit can include a second inductor L Mi , a first switch SW1, a second capacitor C Mi , and a second switch SW2. The second inductor L Mi is connected in series with the first switch SW1, one end of the second inductor L Mi is connected to the first inductor L g and the second capacitor C Mi , and the other end of the first switch SW1 is grounded. The second capacitor C Mi is connected in parallel with the second switch SW2.

[0087] In a specific implementation, the first switch SW1 is configured to be turned on when the low noise amplifier operates in a low frequency band and turned off when the low noise amplifier operates in a high frequency band, and the second switch SW2 is configured to be turned off when the low noise amplifier operates in a low frequency band and turned on when the low noise amplifier operates in a high frequency band.

[0088] Specifically, when a low frequency band (e.g., the n77 frequency band) is set, the low frequency control signal LEN is set to logic “1” and the high frequency control signal HEN is set to logic “0”. Correspondingly, when a high frequency band is set, the low frequency control signal LEN is set to logic “0” and the high frequency control signal HEN is set to logic “1”. The control end of the first switch SW1 is connected to the low frequency control signal LEN, and the control end of the second switch SW2 is connected to the high frequency control signal HEN.

[0089] When the low noise amplifier operates in a low frequency band, the first switch SW1 is turned on and the second switch SW2 is turned off, so that the second inductor L Mi and the second capacitor C MiBoth access the low noise amplifier, at this time, the input matching network is T-shaped, which can be called T-shaped matching network.

[0090] When the low noise amplifier works in a high frequency band (for example, the n79 frequency band), the first switch SW1 is turned off, and the second switch SW2 is turned on, so that the second inductor L Mi floats, the second capacitor C Mi is short-circuited, and the second inductor L Mi and the second capacitor C Mi are not accessed to the low noise amplifier. At this time, the input matching network is L-shaped, which can be called L-shaped matching network.

[0091] It should be noted that the specific input frequency band range corresponding to the low noise amplifier can be adjusted according to the inductance value and the capacitance value in the input matching network 31. By setting the first LC frequency band adjustment unit, the input frequency band of the low noise amplifier can be changed, so that the low noise amplifier can work in a dual frequency band, which is more suitable for multi-frequency applications. Moreover, the dual-frequency matching network structure in the embodiment of the application is simple, which can save space and cost.

[0092] Referring to FIG. 5, in addition to the third inductor L d and the third capacitor C d , the output matching network 33 can further include a second LC frequency band adjustment unit. The second LC frequency band adjustment unit is connected in parallel with the third capacitor C d , and is used to adjust the matching capacitance of the output matching network 33 based on the current working frequency band.

[0093] Specifically, the second LC frequency band adjustment unit can include a fourth capacitor C Mo and a third switch SW3. The third switch SW3 is connected in series with the fourth capacitor C Mo . When the third switch SW3 is turned on, the matching capacitance of the output matching network 33 is C Mo +C d , and when the third switch SW3 is turned off, the matching capacitance of the output matching network 33 is only C d .

[0094] In an embodiment, the control end of the third switch SW3 can access a low-frequency control signal. Through the low-frequency control signal, the third switch SW3 can be controlled to be turned on when the low noise amplifier works in a low frequency band, thereby increasing the matching capacitance of the output matching network 33, so as to change the output frequency band of the low noise amplifier.

[0095] By setting the second LC frequency band adjustment unit, the matching capacitance of the output LC matching of the output matching network 33 under different frequency bands can be controlled, so as to realize the output under different frequency bands.

[0096] In a specific implementation, when the input matching network 31 and the output matching network 33 are both dual-band matching networks, if the matching capacitance and the matching inductance in the input matching network 31 are increased, the output matching network 33 is increased in matching capacitance, and vice versa, if the matching capacitance and the matching inductance in the input matching network 31 are not increased, the output matching network 33 is not increased in matching capacitance, so that the frequency bands of the input matching network 31 and the output matching network 33 are the same.

[0097] In other embodiments, the input matching network 31 is a dual-band matching network, and the output matching network 33 is a single-band matching network. Alternatively, the input matching network 31 is a single-band matching network, and the output matching network 33 is a dual-band matching network. At this time, specific implementation can be implemented with reference to the above description of the input matching network 31 and the output matching network 33 in FIG. 4 and FIG. 5, which will not be repeated here.

[0098] In a specific implementation, for the application scenario that any one of the input matching network 31 and the output matching network 33 is a dual-band matching network, there is often a problem that different frequency band bandwidth requirements are inconsistent, that is, the working bandwidth requirement in the low frequency band may be different from that in the high frequency band.

[0099] In order to realize different bandwidths in different frequency bands, in an embodiment of the present application, a bandwidth adjustment circuit can be provided to adjust the working bandwidth for different operations. Specifically, at least one of the series resonant sub-circuit and the feedback sub-circuit can be controlled to adjust the working bandwidth for different operations.

[0100] Specifically, in an embodiment, referring to FIG. 5, in addition to the series inductance L peak , the series resonant sub-circuit 341 can further include a series inductance switch SW4. The series inductance switch SW4 is connected in parallel with the series inductance L peak , and is used to control the access of the series inductance L peak based on the current working frequency band.

[0101] By setting the series inductance switch SW4, the series inductance L peak can be controlled to be accessed when the low noise amplifier works in the low frequency band, and the series inductance L peak is accessed through the series peak inductance resonance technology, thereby assisting to improve the bandwidth. When the low noise amplifier works in the high frequency band, the series inductance switch SW4 conductor can be controlled to close the series inductance L peak , thereby optimizing the high frequency band noise and gain.

[0102] Specifically, a control terminal of the series inductor switch SW4 can be connected to a high frequency control signal HEN, and the series inductor switch SW4 is controlled to be turned off in a low frequency band and turned on in a high frequency band by the high frequency control signal HEN, so as to control the series inductor L peak whether to be connected.

[0103] In another embodiment, referring to FIG. 5, the feedback resistance unit can further include a feedback resistance switch SW5. The feedback resistance switch SW5 can be connected in parallel with the second feedback resistance Rfd, and used to control the connection of the second feedback resistance Rfd based on a current working frequency band.

[0104] By setting the feedback resistance switch SW5, when the feedback resistance switch SW5 is turned on, the second feedback resistance Rfd is short-circuited, and a lower feedback resistance is achieved, so that the feedback depth and bandwidth can be improved. When the feedback resistance switch SW5 is turned off, the second feedback resistance Rfd is connected, so that a larger feedback resistance, i.e., a lower feedback depth and bandwidth, can be achieved. In this way, by setting the feedback resistance switch SW5, the adjustable resistance feedback depth control in dual frequency bands can be comprehensively achieved.

[0105] Specifically, a control terminal of the feedback resistance switch SW5 can be connected to a low frequency control signal LEN, and the feedback resistance switch SW5 is controlled to be turned off in a low frequency band and turned on in a high frequency band by the low frequency control signal LEN, so as to control whether the second feedback resistance Rfd is connected.

[0106] It should be noted that, in specific implementation, the first switch SW1, the second switch SW2, the third switch SW3, the series inductor switch SW4 and the feedback resistance switch SW5 can be implemented by any switch device, which is not limited herein, for example, can be implemented by a Metal Oxide Semiconductor Field Effect Transistor (MOSFET), or can be implemented by an Insulated Gate Bipolar Transistor (IGBT) or other semiconductor device.

[0107] In an embodiment of the present application, referring to FIG. 5, the low noise amplifier can further include a frequency band control unit 35. The frequency band control unit 35 can receive a frequency band indication signal, and generate a low frequency control signal LEN and a high frequency control signal HEN.

[0108] Specifically, the frequency band control unit 35 has a frequency band indication end through which a frequency band indication signal can be input. The frequency band indication signal is used to indicate the current working frequency band of the low noise amplifier. The frequency band control unit 35 can be composed of a first inverter and a second inverter in series. The first inverter outputs a low frequency control signal LEN, and the second inverter outputs a high frequency control signal HEN. The low frequency control signal LEN and the high frequency control signal HEN generated by the frequency band control unit 35 are input to other functional modules of the low noise amplifier, so as to control the low noise amplifier to be able to work at dual frequencies, and the working bandwidth is adjustable.

[0109] Figure 6 is a schematic diagram of the performance parameters of the low noise amplifier in the embodiment of the application varying with the working frequency. Referring to Figure 6, the low noise amplifier in the embodiment of the application can support n77 (3.3-4.2GHz) and n79 (4.4-5GHz) frequency bands. Under the n77 frequency band, the gain and matching bandwidth of the low noise amplifier are greater than 900MHz. Under the n79 frequency band, the gain and matching bandwidth of the low noise amplifier are 600MHz.

[0110] From the above, it can be seen that the low noise amplifier in the embodiment of the application adopts a digitally controlled dual-frequency matching network, and expands the bandwidth through a dual-frequency adjustable resistance feedback depth control and series inductance peak resonance compensation technology, so as to realize high working bandwidth under dual-frequency matching, efficiently optimize the frequency band width, and help save space and cost for multi-frequency application.

[0111] The embodiment of the application also provides a radio frequency terminal, which can include the low noise amplifier of any one of the above embodiments.

[0112] The low noise amplifier in the embodiment of the application can support multi-mode multi-frequency integrated integration and digital reconfigurable application, so as to reduce the cost of radio frequency devices and save PCB space.

[0113] Although the application is disclosed as above, the application is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the application, and the protection scope of the application should be subject to the scope defined by the claims.

Claims

1. A low-noise amplifier, characterized in that, include: An input matching network, connected to the signal input terminal, is used to match the impedance between the signal input terminal and the input terminal of the amplifier circuit. The amplifier circuit is connected to the input matching network and is used to amplify the input signal at the signal input terminal. An output matching network, connected to the amplifier circuit, is used to match the impedance between the output terminal of the amplifier circuit and the signal output terminal, and outputs the amplified signal through the signal output terminal. And a bandwidth adjustment circuit, connected to the output matching network, for adjusting the operating bandwidth of the low-noise amplifier.

2. The low-noise amplifier as described in claim 1, characterized in that, The bandwidth adjustment circuit includes at least one of the following: A series resonant circuit, located between the output matching network and the amplifier circuit, is used to adjust the operating bandwidth of the low-noise amplifier by compensating for and neutralizing the parasitic capacitance of the amplifier circuit output terminal to ground. A feedback sub-circuit, located between the output matching network and the input terminal of the amplifier circuit, is used to adjust the operating bandwidth of the low-noise amplifier by changing the feedback depth between the signal output terminal and the input terminal of the amplifier circuit.

3. The low-noise amplifier as described in claim 2, characterized in that, The series resonator circuit includes: A series inductor is connected in series between the input terminal of the output matching network and the output terminal of the amplifier circuit; the inductance value of the series inductor is adjustable.

4. The low-noise amplifier as described in claim 3, characterized in that, The series resonator circuit further includes: A series inductor switch, connected in parallel with the series inductor, is used to control the connection of the series inductor based on the current operating frequency band.

5. The low-noise amplifier as described in claim 2, characterized in that, The feedback sub-circuit includes: A feedback capacitor is connected to the output matching network; The feedback resistor unit has one end connected to the feedback capacitor and the other end connected to the input terminal of the amplifier circuit; The resistance value of the feedback resistor unit is adjustable.

6. The low-noise amplifier as described in claim 5, characterized in that, The feedback resistor unit includes: The first feedback resistor is connected in series with the feedback capacitor; The second feedback resistor is connected in series with the first feedback resistor.

7. The low-noise amplifier as described in claim 6, characterized in that, The feedback resistor unit further includes: A feedback resistor switch, connected in parallel with the second feedback resistor, is used to control the connection of the second feedback resistor based on the current operating frequency band.

8. The low-noise amplifier according to any one of claims 1 to 7, characterized in that, The input matching network is a dual-frequency input matching network.

9. The low-noise amplifier as described in claim 8, characterized in that, The input matching network includes: First capacitor; The first inductor is connected in series with the first capacitor; The first resistor has one end connected to the first inductor and the other end connected to the bias voltage output terminal. The first LC frequency band adjustment unit is located between the first inductor and the input terminal of the amplifier circuit, and is used to adjust the matching capacitor or matching inductor of the input matching network based on the current operating frequency band.

10. The low-noise amplifier as claimed in claim 9, characterized in that, The first LC frequency band adjustment unit includes: a second inductor, a first switch, a second capacitor, and a second switch; wherein, the second inductor is connected in series with the first switch, the other end of the second inductor is connected to the first inductor and the second capacitor, and the other end of the first switch is grounded; the second capacitor is connected in parallel with the second switch.

11. The low-noise amplifier as claimed in claim 10, characterized in that, The first switch is configured to be turned on when the low-noise amplifier is operating in the low-frequency band and turned off when the low-noise amplifier is operating in the high-frequency band; the second switch is configured to be turned off when the low-noise amplifier is operating in the low-frequency band and turned on when the low-noise amplifier is operating in the high-frequency band.

12. The low-noise amplifier according to any one of claims 1 to 7, characterized in that, The output matching network is a dual-frequency matching network.

13. The low-noise amplifier as claimed in claim 12, characterized in that, The output matching network includes: The third inductor is located between the output terminal of the amplifier circuit and the power supply voltage output terminal. The third capacitor is located between the output terminal and the signal output terminal of the amplifier circuit. The second LC band adjustment unit is connected in parallel with the third capacitor and is used to adjust the matching capacitor of the output matching network based on the current operating frequency band.

14. The low-noise amplifier as claimed in claim 13, characterized in that, The second LC band adjustment unit includes: Fourth capacitor; The third switch is connected in series with the fourth capacitor.

15. The low-noise amplifier as claimed in claim 14, characterized in that, The third switch is used to turn on when the low-noise amplifier is operating in the low-frequency band.

16. The low-noise amplifier as claimed in claim 1, characterized in that, Also includes: The frequency band control unit is used to receive frequency band indication signals and generate low-frequency control signals and high-frequency control signals.

17. A radio frequency terminal, characterized in that, Includes the low-noise amplifier as described in any one of claims 1 to 16.

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