A high gain low noise amplifier

Abstract

The application discloses a high-gain low-noise amplifier, comprising an input matching circuit, a main amplification circuit, an auxiliary amplification circuit and an output matching circuit; the input matching circuit is used for realizing input end impedance matching and receiving a radio frequency signal; the main amplification circuit is connected with the input matching circuit and is used for amplifying the radio frequency signal; the main amplification circuit is a common-source and common-gate structure amplification circuit; the auxiliary amplification circuit is connected with the input matching circuit and the main amplification circuit and is used for assisting the main amplification circuit to amplify the radio frequency signal and simultaneously improving the equivalent transconductance of the common-source tube and the common-gate tube in the main amplification circuit; and the output matching circuit is connected with the main amplification circuit and is used for realizing output end impedance matching and outputting the amplified radio frequency signal.

Description

Technical Field

[0001] This invention belongs to the field of microelectronics technology, specifically relating to a high-gain, low-noise amplifier. Background Technology

[0002] As the first stage of active amplifier circuit in the front end of an RF receiver, the higher the amplification gain of the low-noise amplifier (LNOA), the larger the amplitude of the output RF signal, and the stronger its ability to suppress noise in subsequent circuits. Simultaneously, to improve the overall receiver sensitivity, the LNOA should also have a high signal-to-noise ratio (SNR), meaning its inherent noise should be as low as possible. Therefore, when designing an LNOA, it is necessary to balance its various performance aspects, minimizing its noise while meeting gain and input matching requirements.

[0003] Currently, the cascode (cas-source, cas-gate) architecture has become one of the most commonly used architectures in low-noise amplifiers due to its high gain and high output power characteristics. The structure of a cascode low-noise amplifier is as follows: Figure 1 As shown, it outputs the amplified signal through a passive network composed of resistors, inductors, and capacitors.

[0004] See Figure 1 As shown, the cascode circuit can improve the efficiency of transistor M. a and M b The current in the branch or the load resistance R should be increased. L The resistance value can be adjusted to increase circuit gain while reducing noise. However, increasing circuit gain through these two methods will increase the load resistance R. L The voltage divider increases, transistor M b The drain voltage of transistor M decreases. b A decrease in the drain voltage leads to a decrease in the circuit voltage margin. When the voltage margin is too low or insufficient, the transistors in the cascode structure will operate in the linear region instead of the saturation region, at which point the circuit cannot function properly. The voltage margin refers to the maximum voltage range within which both the cascode and common-source transistors operate simultaneously in the saturation region; this voltage is... Figure 1 Middle transistor M b The drain voltage. Therefore, under the premise of ensuring the normal operation of the cascode circuit, the gain of the low-noise amplifier can only be increased to a limited extent through the above two methods. Therefore, how to increase the gain of the low-noise amplifier while ensuring its normal operation and without degrading the circuit performance is a technical challenge. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, the present invention provides a high-gain, low-noise amplifier.

[0006] The technical problem to be solved by this invention is achieved through the following technical solution:

[0007] In a first aspect, the present invention provides a high-gain low-noise amplifier, comprising: an input matching circuit, a main amplification circuit, an auxiliary amplification circuit, and an output matching circuit;

[0008] The input matching circuit is used to achieve impedance matching at the input terminal and to receive radio frequency signals.

[0009] The main amplifier circuit is connected to the input matching circuit and is used to amplify the radio frequency signal; the main amplifier circuit is a common-source common-gate amplifier circuit.

[0010] The auxiliary amplifier circuit is connected to the input matching circuit and the main amplifier circuit, and is used to assist the main amplifier circuit in amplifying the radio frequency signal, while improving the equivalent transconductance of the common source transistor and common gate transistor in the main amplifier circuit.

[0011] The output matching circuit is connected to the main amplifier circuit and is used to achieve impedance matching at the output end and output the amplified radio frequency signal.

[0012] In one embodiment, the main amplifier circuit of the present invention includes: a DC bias resistor R1, a transistor M1, a transistor M2, and a load resistor R3;

[0013] Wherein, both transistor M1 and transistor M2 are N-channel transistors;

[0014] One end of the DC bias resistor R1 is connected to the first DC bias voltage, and the other end is connected to the gate of the transistor M1.

[0015] The gate of transistor M1 is connected to the output terminal of the input matching circuit, and the drain is connected to the source of transistor M2, with the source grounded.

[0016] The gate of transistor M2 is connected to the RF output terminal of the auxiliary amplifier circuit, the drain is connected to the input terminal of the output matching circuit and connected to the power supply voltage through the load resistor R3, and the source is connected to the drain of transistor M1.

[0017] The node N2, where the drain of transistor M1 and the source of transistor M2 are interconnected, is connected to the second DC bias voltage of the auxiliary amplifier circuit via a coupling capacitor.

[0018] In one embodiment, the auxiliary amplifier circuit of the present invention includes: a DC bias resistor R2, a transistor M3, and a transistor M4;

[0019] Wherein, both transistor M3 and transistor M4 are P-channel transistors;

[0020] The gate of transistor M3 is connected to the output terminal of the input matching circuit, the drain is connected to node N2, and the source is connected to the drain of transistor M4.

[0021] The gate of transistor M4 is connected to the second DC bias voltage through the DC bias resistor R2, and the drain is connected to the source of transistor M3, which is connected to the power supply voltage.

[0022] The node N3, where the source of transistor M3 and the drain of transistor M4 are interconnected, constitutes the radio frequency output terminal of the auxiliary amplifier circuit.

[0023] In one embodiment, the main amplifier circuit of the present invention includes: a DC bias resistor R1, a transistor M1, a transistor M2, and a load resistor R3;

[0024] Wherein, both transistor M1 and transistor M2 are P-channel transistors;

[0025] One end of the DC bias resistor R1 is connected to the first DC bias voltage, and the other end is connected to the gate of the transistor M1.

[0026] The gate of transistor M1 is connected to the output terminal of the input matching circuit, and the drain is connected to the source of transistor M2, with the source connected to the power supply voltage.

[0027] The gate of transistor M2 is connected to the RF output terminal of the auxiliary amplifier circuit, the drain is connected to the input terminal of the output matching circuit and grounded through the load resistor R3, and the source is connected to the drain of transistor M1.

[0028] The node N2, where the drain of transistor M1 and the source of transistor M2 are interconnected, is connected to the second DC bias voltage of the auxiliary amplifier circuit via a coupling capacitor.

[0029] In one embodiment, the auxiliary amplifier circuit of the present invention includes: a DC bias resistor R2, a transistor M3, and a transistor M4;

[0030] Wherein, both transistor M3 and transistor M4 are N-channel transistors;

[0031] The gate of transistor M3 is connected to the output terminal of the input matching circuit, the drain is connected to node N2, and the source is connected to the drain of transistor M4.

[0032] The gate of transistor M4 is connected to the second DC bias voltage through the DC bias resistor R2, and the drain is connected to the source of transistor M3, with the source connected to ground.

[0033] The node N3, where the source of transistor M3 and the drain of transistor M4 are interconnected, constitutes the radio frequency output terminal of the auxiliary amplifier circuit.

[0034] In one embodiment, transistors M1, M2, M3, and M4 of the present invention all operate in the saturation region.

[0035] In one embodiment, the high-gain, low-noise amplifier of the present invention is applied to a communication receiver.

[0036] The high-gain, low-noise amplifier provided by this invention has the following advantages:

[0037] 1. Effectively improves the gain of low-noise amplifiers with cascode and common-source architecture:

[0038] In this invention, the introduction of an auxiliary amplifier circuit increases the equivalent transconductance of the common-source and common-gate transistors in the main amplifier circuit. This increased equivalent transconductance ensures increased gain in the amplifier circuit. Simultaneously, the shunting effect of the auxiliary amplifier circuit on the main amplifier circuit expands its voltage margin, thus guaranteeing its performance.

[0039] 2. Effectively reduces the noise of low-noise amplifiers with cascode and common-source architecture:

[0040] In this invention, the introduction of an auxiliary amplifier circuit increases the equivalent transconductance of the common-source transistor and the common-gate transistor, while the common-source transistor and the load resistor R in the amplifier circuit... L The noise factor is inversely proportional to the equivalent transconductance of the common source transistor, thus reducing the noise factor of each component in the circuit. In other words, the low-noise amplifier with auxiliary amplification circuit provided by this invention can achieve lower noise while increasing gain.

[0041] In summary, by introducing an auxiliary amplifier circuit, the low-noise amplifier can achieve higher gain and lower noise, while ensuring sufficient voltage margin. This achieves the goal of increasing the gain of the low-noise amplifier while ensuring its normal operation and maintaining circuit performance.

[0042] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the structure of an existing low-noise amplifier with a common source and common gate architecture;

[0044] Figure 2 This is a schematic diagram of the structure of a high-gain, low-noise amplifier provided in an embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram of another high-gain low-noise amplifier provided in an embodiment of the present invention;

[0046] Figure 4 This is a simulation diagram comparing the gains of a high-gain low-noise amplifier and a traditional common-source cascode amplifier provided in an embodiment of the present invention.

[0047] Figure 5 This is a simulation diagram of the noise figure of the high-gain, low-noise amplifier provided in an embodiment of the present invention. Detailed Implementation

[0048] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0049] Low-noise amplifiers are used to amplify small received signals to supply subsequent circuits. They should ensure that the gain is increased while keeping the noise figure as low as possible. In order to obtain both a low noise figure and a high gain, amplifier circuits often use a common source and common gate structure. Figure 1 This is a common-source, common-gate structure commonly used in low-noise amplifier circuits in related technologies. This circuit structure includes an input matching circuit, a DC bias resistor R, and a transistor M. a Transistor M b Load resistance R L And the output matching circuit, in which the radio frequency signal enters transistor M a The gate of the transistor M is also connected to the DC bias resistor R. a The gate of the transistor M a The source is grounded, transistor M a Drain-connected transistor M b The source of the transistor M b The gate of transistor M is grounded. b The drain is connected to the output matching circuit and connected to the load resistor R. L Connect the power supply voltage.

[0050] Figure 1 The gain expression for the traditional common-source cascode amplifier circuit shown is:

[0051] A v =g ma ·[(g mb r oa r ob +r oa +r ob ) / / R L ]≈g ma ·R L ;

[0052] Among them, g ma g mb Transistor M a and transistor Mb transconductance, r oa and r ob Transistor M a and transistor M b The output resistance, here we assume r oa and r ob R is infinite. L The load resistance of the cascode circuit is given by the above formula; the gain A of the traditional cascode structure can be obtained from the formula. v and transistor M a transconductance g ma and load R L Proportional.

[0053] For the traditional common-source cascode structure, its transistor M a Transistor M b and load resistance R L The noise factors are as follows:

[0054]

[0055]

[0056]

[0057]

[0058] Where γ is a process-related parameter, R s The internal resistance of the signal source, Indicates transistor M a noise factor Indicates transistor M b noise factor Represents the load resistance R L noise factor, I D V represents the branch current of the main amplifier circuit. gs1 Indicates transistor M a Small-signal gate-source voltage, V TH1 Indicates transistor M a The threshold voltage. From the above formula, we can obtain the transistor M. a transconductance g ma With the branch current I of the amplifier circuit D Proportional, transistor M a The noise and its transconductance g ma Inversely proportional, transistor M b The noise is 0, and the load resistance R L Noise and transistor M a transconductance g ma The square of and R LResistance is inversely proportional to resistance. Therefore, to reduce the noise figure of the circuit, it is necessary to increase the transistor M. a transconductance g ma Or load R L The resistance value of transistor M is increased. a transconductance g ma This will cause the branch current I D This will increase the load resistance R L The voltage drop increases; similarly, increasing the load resistance R... L The resistance value will also affect the load resistance R. L The voltage drop across the load increases. The load resistance R... L An increase in the voltage divider will reduce the voltage margin of the circuit. If the voltage margin is too low, transistor M... a and transistor M b There is a possibility that the transistor may operate in the linear region, which could cause the circuit to malfunction. Therefore, the circuit needs to have sufficient voltage margin to ensure the normal operation of the transistor.

[0059] To improve the gain of a low-noise amplifier while ensuring its proper operation and maintaining circuit performance, this invention provides a high-gain low-noise amplifier. The amplifier may include an input matching circuit, a main amplification circuit, an auxiliary amplification circuit, and an output matching circuit.

[0060] The circuit includes an input matching circuit for impedance matching at the input and for receiving radio frequency (RF) signals; a main amplifier circuit connected to the input matching circuit for amplifying the RF signals; the main amplifier circuit is a common-source, common-gate amplifier circuit; an auxiliary amplifier circuit connected to the input matching circuit and the main amplifier circuit for assisting the main amplifier circuit in amplifying the RF signals and improving the equivalent transconductance of the common-gate transistor in the main amplifier circuit; and an output matching circuit connected to the main amplifier circuit for impedance matching at the output and for outputting the amplified RF signals.

[0061] The input matching circuit and the output matching circuit can be implemented using any of the following methods, but not limited to gold wire inductors, on-chip active or passive devices, or off-chip discrete devices. This embodiment of the invention does not limit the specific implementation of these methods.

[0062] The main amplifier circuit employs a common-source, common-gate structure. For example, in one implementation, such as... Figure 2 As shown, the main amplifier circuit may include: a DC bias resistor R1, a transistor M1, a transistor M2, and a load resistor R3; both transistor M1 and transistor M2 are N-channel transistors.

[0063] One end of the DC bias resistor R1 is connected to the first DC bias voltage, and the other end is connected to the gate of the transistor M1.

[0064] The gate of transistor M1 is connected to the output of the input matching circuit, and its drain is connected to the source of transistor M2, with the source grounded.

[0065] The gate of transistor M2 is connected to the RF output terminal of the auxiliary amplifier circuit, the drain is connected to the input terminal of the output matching circuit and connected to the power supply voltage through the load resistor R3, and the source is connected to the drain of transistor M1.

[0066] The node N2, where the drain of transistor M1 and the source of transistor M2 are interconnected, is connected to the second DC bias voltage of the auxiliary amplifier circuit through a coupling capacitor.

[0067] Correspondingly, such as Figure 2 As shown, the auxiliary amplifier circuit may include: a DC bias resistor R2, a transistor M3, and a transistor M4; both transistor M3 and transistor M4 are P-channel transistors.

[0068] In this circuit, the gate of transistor M3 is connected to the output of the input matching circuit, the drain is connected to node N2, and the source is connected to the drain of transistor M4.

[0069] The gate of transistor M4 is connected to the second DC bias voltage through DC bias resistor R2, and the drain is connected to the source of transistor M3, which is connected to the power supply voltage.

[0070] The node N3, where the source of transistor M3 and the drain of transistor M4 are interconnected, constitutes the radio frequency output terminal of the auxiliary amplifier circuit.

[0071] In another implementation, such as Figure 3 As shown, the main amplifier circuit may include: a DC bias resistor R1, a transistor M1, a transistor M2, and a load resistor R3; both transistor M1 and transistor M2 are P-channel transistors.

[0072] One end of the DC bias resistor R1 is connected to the first DC bias voltage, and the other end is connected to the gate of the transistor M1.

[0073] The gate of transistor M1 is connected to the output of the input matching circuit, and its drain is connected to the source of transistor M2, with the source connected to the power supply voltage.

[0074] The gate of transistor M2 is connected to the RF output terminal of the auxiliary amplifier circuit, the drain is connected to the input terminal of the output matching circuit and grounded through the load resistor R3, and the source is connected to the drain of transistor M1.

[0075] The node N2, where the drain of transistor M1 and the source of transistor M2 are interconnected, is connected to the second DC bias voltage of the auxiliary amplifier circuit through a coupling capacitor.

[0076] Correspondingly, such as Figure 3The auxiliary amplifier circuit shown includes: a DC bias resistor R2, a transistor M3, and a transistor M4; both transistor M3 and transistor M4 are N-channel transistors.

[0077] In this circuit, the gate of transistor M3 is connected to the output of the input matching circuit, the drain is connected to node N2, and the source is connected to the drain of transistor M4.

[0078] The gate of transistor M4 is connected to the second DC bias voltage through DC bias resistor R2, and the drain is connected to the source of transistor M3, and the source is connected to ground.

[0079] The node N3, where the source of transistor M3 and the drain of transistor M4 are interconnected, constitutes the radio frequency output terminal of the auxiliary amplifier circuit.

[0080] Furthermore, the specific circuits and connections of the main amplifier circuit and auxiliary amplifier circuit are not limited to... Figure 2 and Figure 3 The two types shown can be any combination of transistors M1, M2, M3 and M4, except for all being N-channel transistors or all being P-channel transistors. They will not be listed one by one in the embodiments of the present invention.

[0081] Furthermore, transistors M1, M2, M3, and M4 are not limited to field-effect transistors (FETs) and can also be bipolar junction transistors (BJTs).

[0082] In this embodiment of the invention, transistors M1, M2, M3, and M4 all operate in the saturation region.

[0083] The low-noise amplifier provided in this invention effectively improves the gain of a low-noise amplifier with a common-source, common-gate structure. Specifically, by introducing an auxiliary amplifier circuit, this invention increases the equivalent transconductance of the common-gate transistor in the main amplifier circuit. This increased equivalent transconductance ensures both increased gain and a sufficiently large voltage margin for the amplifier circuit. Therefore, by introducing the auxiliary amplifier circuit, the low-noise amplifier can achieve greater gain while maintaining the performance of the amplifier circuit.

[0084] Meanwhile, the embodiments of the present invention effectively reduce the noise of the low-noise amplifier with a common-source, common-gate structure. Specifically, after introducing an auxiliary amplification circuit in the embodiments of the present invention, the transistors in the auxiliary amplification circuit and the transistors in the main amplification circuit enhance each other through transconductance, thereby increasing the equivalent transconductance of the common-gate transistor. Since the noise factor in the amplification circuit is inversely proportional to the equivalent transconductance, it can also reduce the noise factor of each component in the circuit. That is, the low-noise amplifier with an auxiliary amplification circuit provided by the present invention can achieve lower noise while increasing gain.

[0085] In summary, by introducing an auxiliary amplification circuit, the embodiments of the present invention enable the low-noise amplifier to achieve higher gain and lower noise, while ensuring sufficient voltage margin. This achieves the goal of improving the gain of the low-noise amplifier while ensuring its normal operation and without degrading its circuit performance.

[0086] The following is based on Figure 2 Taking the high-gain low-noise amplifier shown as an example, the beneficial effect of the high-gain low-noise amplifier provided in the embodiments of the present invention, which can effectively improve the gain of the traditional cascode amplifier circuit and suppress the noise of the cascode amplifier circuit, will be further illustrated by example.

[0087] See Figure 2 As shown, after adding an auxiliary amplifier, the circuit gain becomes:

[0088] A v =(g m1 +g append )·[(g' m2 r o1 r o2 +r o1 +r o2 ) / / R3]≈(g m1 +g append )·R3

[0089]

[0090]

[0091] Where g append g' represents the transconductance of the auxiliary amplifier circuit. m2 This represents the effective transconductance of transistor M2 after the addition of the auxiliary amplifier circuit, g. m3 and g m4 These represent the transconductances of transistors M3 and M4, respectively. From the above equation, it can be seen from a principle analysis perspective that the gain of the circuit is improved by adding an auxiliary amplifier circuit in this embodiment of the invention.

[0092] The following simulation data will be used to prove the conclusion about increasing the gain:

[0093] Within the 2-18 GHz frequency band, the gains of related technologies and this invention were simulated and compared using Cadence simulation tools. The simulation employed an SMIC 40nm CMOS process model to model each transistor, with the power supply voltage VDD set to 1.8V and the overall circuit current at 7mA. Simulation results are available in [link to simulation results]. Figure 4 The horizontal axis represents frequency, and the vertical axis Gmax represents the gain when both input and output are perfectly matched.

[0094] Figure 4In the diagram, the solid line represents the gain of the related technology as a function of operating frequency, while the dashed line represents the gain of the present invention as a function of operating frequency. From... Figure 4 As can be seen from the data, the gain of the embodiments of the present invention is higher than that of related technologies across the entire frequency band, and Gmax > 20dB.

[0095] See also Figure 2 As shown, after adding the auxiliary amplifier, the noise factors of each component of the circuit are:

[0096]

[0097]

[0098]

[0099]

[0100]

[0101] in, and These represent the noise factors of transistors M3 and M4, respectively. From the above formulas, it can be seen from a principle analysis perspective that the noise of load R3 is greatly suppressed after adding the auxiliary amplifier circuit.

[0102] Meanwhile, due to the presence of the auxiliary amplifier circuit, the overall circuit current follows the formula:

[0103]

[0104] in The current flowing through transistor M1, The current flowing through transistor M2, This is the current flowing through transistor M3. Therefore, without changing the overall current... Under these conditions, the current flowing through transistor M2 Therefore, from the perspective of principle analysis, it can be seen that, under the premise of ensuring voltage margin, the introduction of the auxiliary amplifier circuit can increase the resistance of load R3, thereby further reducing the noise of load R3.

[0105] The following simulation data will be used to prove the above conclusion on noise reduction:

[0106] Within the frequency band of 2-18 GHz, the noise figure of this invention was simulated using Cadence simulation tools. The simulation employed an SMIC 40nm CMOS process model to model each transistor, with a power supply voltage VDD of 1.8V and an overall circuit current of 7mA. The simulation results are shown below. Figure 5 .Depend on Figure 5As can be seen, the noise figure is 2.66dB to 3.23dB in the simulation frequency band, which achieves good noise performance over a wide bandwidth. Through comparative simulation, it can be concluded that the noise performance of the present invention has been greatly improved.

[0107] In summary, the high-gain low-noise amplifier provided by the embodiments of the present invention can achieve higher gain and lower noise, and can ensure sufficient voltage margin, thus ensuring normal operation and no reduction in circuit performance while increasing the gain of the low-noise amplifier; its operating frequency range can be adjusted to any frequency band in 2-18GHz, so it can be applied to communication receivers under various communication standards.

[0108] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0109] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings and the disclosure, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the description of this invention, the word "comprising" does not exclude other components or steps, "a" or "an" does not exclude a plurality, and "a plurality" means two or more, unless otherwise explicitly specified. Furthermore, while different embodiments may describe certain measures, this does not mean that these measures cannot be combined to produce good results.

[0110] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A high-gain, low-noise amplifier, characterized in that, include: Input matching circuit, main amplifier circuit, auxiliary amplifier circuit, and output matching circuit; The input matching circuit is used to achieve impedance matching at the input terminal and to receive radio frequency signals. The main amplifier circuit is connected to the input matching circuit and is used to amplify the radio frequency signal; the main amplifier circuit is a common-source common-gate amplifier circuit. The auxiliary amplifier circuit is connected to the input matching circuit and the main amplifier circuit. This is used to assist the main amplifier circuit in amplifying the radio frequency signal, and at the same time improve the equivalent transconductance of the common source transistor and common gate transistor in the main amplifier circuit; The output matching circuit is connected to the main amplifier circuit and is used to achieve impedance matching at the output terminal and output the amplified radio frequency signal. The main amplifier circuit includes: a DC bias resistor R1, a transistor M1, a transistor M2, and a load resistor R3; Wherein, both transistor M1 and transistor M2 are N-channel transistors; One end of the DC bias resistor R1 is connected to the first DC bias voltage, and the other end is connected to the gate of the transistor M1. The gate of transistor M1 is connected to the output terminal of the input matching circuit, and the drain is connected to the source of transistor M2, with the source grounded. The gate of transistor M2 is connected to the RF output terminal of the auxiliary amplifier circuit, the drain is connected to the input terminal of the output matching circuit and connected to the power supply voltage through the load resistor R3, and the source is connected to the drain of transistor M1. The node N2, where the drain of transistor M1 and the source of transistor M2 are interconnected, is connected to the second DC bias voltage of the auxiliary amplifier circuit through a coupling capacitor. The auxiliary amplifier circuit includes: a DC bias resistor R2, a transistor M3, and a transistor M4; Wherein, both transistor M3 and transistor M4 are P-channel transistors; The gate of transistor M3 is connected to the output terminal of the input matching circuit, the drain is connected to node N2, and the source is connected to the drain of transistor M4. The gate of transistor M4 is connected to the second DC bias voltage through the DC bias resistor R2, and the drain is connected to the source of transistor M3, which is connected to the power supply voltage. The node N3, where the source of transistor M3 and the drain of transistor M4 are interconnected, constitutes the radio frequency output terminal of the auxiliary amplifier circuit.

2. A high-gain, low-noise amplifier, characterized in that, include: Input matching circuit, main amplifier circuit, auxiliary amplifier circuit, and output matching circuit; The input matching circuit is used to achieve impedance matching at the input terminal and to receive radio frequency signals. The main amplifier circuit is connected to the input matching circuit and is used to amplify the radio frequency signal; the main amplifier circuit is a common-source common-gate amplifier circuit. The auxiliary amplifier circuit is connected to the input matching circuit and the main amplifier circuit. This is used to assist the main amplifier circuit in amplifying the radio frequency signal, and at the same time improve the equivalent transconductance of the common source transistor and common gate transistor in the main amplifier circuit; The output matching circuit is connected to the main amplifier circuit and is used to achieve impedance matching at the output terminal and output the amplified radio frequency signal. The main amplifier circuit includes: a DC bias resistor R1, a transistor M1, a transistor M2, and a load resistor R3; Wherein, both transistor M1 and transistor M2 are P-channel transistors; One end of the DC bias resistor R1 is connected to the first DC bias voltage, and the other end is connected to the gate of the transistor M1. The gate of transistor M1 is connected to the output terminal of the input matching circuit, and the drain is connected to the source of transistor M2, with the source connected to the power supply voltage. The gate of transistor M2 is connected to the RF output terminal of the auxiliary amplifier circuit, the drain is connected to the input terminal of the output matching circuit and grounded through the load resistor R3, and the source is connected to the drain of transistor M1. The node N2, where the drain of transistor M1 and the source of transistor M2 are interconnected, is connected to the second DC bias voltage of the auxiliary amplifier circuit through a coupling capacitor. The auxiliary amplifier circuit includes: a DC bias resistor R2, a transistor M3, and a transistor M4; Wherein, both transistor M3 and transistor M4 are N-channel transistors; The gate of transistor M3 is connected to the output terminal of the input matching circuit, the drain is connected to node N2, and the source is connected to the drain of transistor M4. The gate of transistor M4 is connected to the second DC bias voltage through the DC bias resistor R2, and the drain is connected to the source of transistor M3, with the source connected to ground. The node N3, where the source of transistor M3 and the drain of transistor M4 are interconnected, constitutes the radio frequency output terminal of the auxiliary amplifier circuit.

3. The high-gain, low-noise amplifier according to claim 1 or 2, characterized in that, Transistors M1, M2, M3, and M4 all operate in the saturation region.

4. The high-gain, low-noise amplifier according to claim 1 or 2, characterized in that, It is used in communication receivers.

Images