Gain-adjustable millimeter wave low-noise amplification circuit and method

Abstract

The invention provides a gain-adjustable millimeter wave low-noise amplification circuit and method, and is characterized in that the gain-adjustable millimeter wave low-noise amplification circuit comprises a low-noise amplification stage, a low-gain amplification stage, a high-gain amplification stage, a first transistor switch control module and a second transistor switch control module, the output end of the low-noise amplifier stage is connected with the low-gain amplifier stage or the high-gain amplifier stage through the first transistor switch control module, and the low-gain amplifier stage or the high-gain amplifier stage outputs a radio frequency output signal through the second transistor switch control module. The gain-adjustable low-noise amplification circuit structure can be applied to a millimeter wave frequency band, and the noise does not change greatly.

Description

Technical Field

[0001] The present invention relates to the technical field of signal transmission equipment, and in particular to a gain-adjustable millimeter-wave low-noise amplifier circuit and method. Background Art

[0002] With the rapid development of modern communication systems, from 1G to 2G, 3G, 4G to 5G, the spectrum below 6GHz is widely used. The extremely wide bandwidth of millimeter waves is undoubtedly very attractive in today's tight frequency resources. As one of the most important components of the RF front-end system, the low noise amplifier (LNA) must fully consider its bandwidth, gain, noise figure, stability and other performance during the design process. With the rapid development of wireless communication technology, a wireless communication device often needs to face different communication standards. In some applications, the signal strength may vary greatly, so the gain needs to be adjusted to ensure that the system output remains in the optimal range. Figure 5 In the background art, a switch controls feedback and load to realize gain-adjustable low-noise amplifier, and the feedback circuit and load are selected and Input Matching1 and Input Matching2 are changed by the state of the switch, so as to realize gain-adjustable low-noise amplifier. However, this solution is difficult to apply to high frequency bands, and the noise is prone to large changes when the switch is switched. Summary of the invention

[0003] In view of the above problems, an embodiment of the present invention provides a gain-adjustable millimeter-wave low-noise amplifier circuit, comprising a low-noise amplifier stage, a low-gain amplifier stage, a high-gain amplifier stage, a first transistor switch control module and a second transistor switch control module, wherein the input end of the low-noise amplifier stage is used to receive a radio frequency input signal, the output end of the low-noise amplifier stage is connected to the low-gain amplifier stage or the high-gain amplifier stage through the first transistor switch control module, and the low-gain amplifier stage or the high-gain amplifier stage outputs a radio frequency output signal through the second transistor switch control module.

[0004] In one embodiment, the low-noise amplifier stage includes a GaN HEMT amplifier tube M1, a gate of the GaN HEMT amplifier tube M1 is connected to a gate bias voltage Vg1 through an inductor L2, a drain of the GaN HEMT amplifier tube M1 is connected to a drain bias voltage Vd1 through an inductor L3, a source of the GaN HEMT amplifier tube M1 is grounded through an inductor L4 and an inductor L5 connected in parallel, and a signal input end is connected to the gate of the GaN HEMT amplifier tube M1 through an input matching network.

[0005] In one embodiment, the input matching network includes a capacitor C1, a capacitor C2 and an inductor L1, wherein a first end of the capacitor C1 is connected to a signal input end, a second end of the capacitor C1 is connected to a first end of the capacitor C2 and a first end of the inductor L1, a second end of the capacitor C2 is grounded, and a second end of the inductor L1 is connected to a gate of the GaN HEMT amplifier tube M1;

[0006] The first end of the inductor L2 is connected to the first end of the resistor R1, the resistor R2 and the capacitor C3, the second end of the resistor R1 is grounded through the capacitor C4, the second end of the resistor R2 is connected to the gate bias voltage Vg1, and the second end of the capacitor C3 is grounded;

[0007] The first end of the inductor L3 is connected to the first end of the resistor R3 and the capacitor C6, the second end of the resistor R3 is grounded through the capacitor C5, and the second end of the capacitor C6 is grounded;

[0008] The drain of the GaN HEMT amplifier tube M1 is connected to the inductor L6 and the first end of the capacitor C8 via the capacitor C7, and the second end of the capacitor C8 is grounded.

[0009] In one embodiment, the low-gain amplifier stage includes a low-gain two-stage GaN HEMT amplifier tube M4, the gate of the low-gain two-stage GaN HEMT amplifier tube M4 is connected to the gate bias voltage Vg2 through the inductor L9, the drain of the low-gain two-stage GaN HEMT amplifier tube M4 is connected to the drain bias voltage Vd2 through the inductor L10, the source of the low-gain two-stage GaN HEMT amplifier tube M4 is grounded through the inductor L11 and the inductor L12 connected in parallel, and the low-noise amplifier stage is connected to the gate of the low-gain two-stage GaN HEMT amplifier tube M4 through the first inter-stage matching network.

[0010] In one embodiment, the first inter-stage matching network includes a capacitor C9, an inductor L7 and an inductor L8, wherein a first end of the capacitor C9 is connected to the low-noise amplifier stage through the inductor L7, a second end of the capacitor C9 is connected to a first end of the inductor L8, and a second end of the inductor L8 is connected to a gate of the low-gain second-stage GaN HEMT amplifier tube M4;

[0011] The first end of the inductor L9 is connected to the first end of the resistor R6, the resistor R7 and the capacitor C10, the second end of the resistor R6 is grounded through the capacitor C11, the second end of the resistor R7 is connected to the gate bias voltage Vg2, and the second end of the capacitor C10 is grounded;

[0012] A first end of the inductor L10 is connected to a first end of the resistor R8 and a first end of the capacitor C13 , a second end of the resistor R8 is grounded via the capacitor C12 , and a second end of the capacitor C13 is grounded.

[0013] In one embodiment, the low-gain amplifier stage includes a low-gain three-stage GaN HEMT amplifier tube M5, a gate of the low-gain three-stage GaN HEMT amplifier tube M5 is connected to a gate bias voltage Vg3 through an inductor L15, a drain of the low-gain three-stage GaN HEMT amplifier tube M5 is connected to a drain bias voltage Vd3 through an inductor L16, a source of the low-gain three-stage GaN HEMT amplifier tube M5 is grounded through an inductor L17 and an inductor L18 connected in parallel, and a drain of the low-gain two-stage GaN HEMT amplifier tube M4 is connected to the gate of the low-gain three-stage GaN HEMT amplifier tube M5 through a second inter-stage matching network.

[0014] In one embodiment, the second inter-stage matching network includes a capacitor C14, a capacitor C15 and an inductor L13, wherein a first end of the capacitor C14 is connected to the drain of the low-gain two-stage GaN HEMT amplifier tube M4, a second end of the capacitor C14 is connected to a first end of the inductor L13 and a first end of the capacitor C15, a second end of the capacitor C15 is grounded, and a second end of the inductor L13 is connected to a gate of the low-gain three-stage GaN HEMT amplifier tube M5;

[0015] The gate of the low-gain three-stage GaN HEMT amplifier tube M5 is connected to the drain of the low-gain three-stage GaN HEMT amplifier tube M5 through a resistor R9, a capacitor C16 and an inductor L14 connected in series in sequence, and the resistor R9, the capacitor C16 and the inductor L14 form an RLC feedback circuit of the low-gain three-stage GaN HEMT amplifier tube M5;

[0016] The first end of the inductor L15 is connected to the first end of the resistor R10, the resistor R11 and the capacitor C17, the second end of the resistor R10 is grounded through the capacitor C18, the second end of the resistor R11 is connected to the gate bias voltage Vg3, and the second end of the capacitor C17 is grounded;

[0017] The first end of the inductor L16 is connected to the first end of the resistor R12 and the capacitor C20, the second end of the resistor R12 is grounded through the capacitor C19, and the second end of the capacitor C20 is grounded;

[0018] The drain of the low-gain three-stage GaN HEMT amplifier tube M5 is sequentially connected in series with the capacitor C21 and the inductor L19, and the capacitor C21 and the inductor L19 constitute an output matching network of the low-gain amplifier stage.

[0019] In one embodiment, the high-gain amplifier stage includes a high-gain two-stage GaN HEMT amplifier tube M10, the gate of the high-gain two-stage GaN HEMT amplifier tube M10 is connected to the gate bias voltage Vg4 through the inductor L23, the drain of the high-gain two-stage GaN HEMT amplifier tube M10 is connected to the drain bias voltage Vd4 through the inductor L24, the source of the high-gain two-stage GaN HEMT amplifier tube M10 is grounded through the parallel inductor L25 and the inductor L26, and the low-noise amplifier stage is connected to the gate of the high-gain two-stage GaN HEMT amplifier tube M10 through the first inter-stage matching network.

[0020] In one embodiment, the first inter-stage matching network includes a capacitor C22, an inductor L21 and an inductor L22, wherein a first end of the capacitor C22 is connected to the low-noise amplifier stage through the inductor L21, a second end of the capacitor C22 is connected to a first end of the inductor L22, and a second end of the inductor L22 is connected to a gate of the high-gain second-stage GaN HEMT amplifier tube M10;

[0021] The first end of the inductor L23 is connected to the first end of the resistor R17, the resistor R18 and the capacitor C23, the second end of the resistor R17 is grounded through the capacitor C24, the second end of the resistor R18 is connected to the gate bias voltage Vg4, and the second end of the capacitor C23 is grounded;

[0022] A first end of the inductor L24 is connected to a first end of the resistor R19 and a first end of the capacitor C26 , a second end of the resistor R19 is grounded via the capacitor C25 , and a second end of the capacitor C26 is grounded.

[0023] In one embodiment, the high-gain amplifier stage includes a high-gain three-stage GaN HEMT amplifier tube M11, a gate of the high-gain three-stage GaN HEMT amplifier tube M11 is connected to a gate bias voltage Vg5 through an inductor L29, a drain of the high-gain three-stage GaN HEMT amplifier tube M11 is connected to a drain bias voltage Vd5 through an inductor L30, a source of the high-gain three-stage GaN HEMT amplifier tube M11 is grounded through an inductor L31 and an inductor L32 connected in parallel, and a drain of the high-gain two-stage GaN HEMT amplifier tube M10 is connected to the gate of the high-gain three-stage GaN HEMT amplifier tube M11 through a second inter-stage matching network.

[0024] In one embodiment, the second inter-stage matching network includes a capacitor C27, a capacitor C28 and an inductor L27, wherein a first end of the capacitor C27 is connected to the drain of the high-gain two-stage GaN HEMT amplifier tube M10, a second end of the capacitor C27 is connected to a first end of the inductor L27 and a first end of the capacitor C28, a second end of the capacitor C28 is grounded, and a second end of the inductor L27 is connected to a gate of the high-gain three-stage GaN HEMT amplifier tube M11;

[0025] The gate of the high-gain three-stage GaN HEMT amplifier tube M11 is connected to the drain of the high-gain three-stage GaN HEMT amplifier tube M11 through a resistor R20, a capacitor C29 and an inductor L28 connected in series in sequence, and the resistor R20, the capacitor C29 and the inductor L28 form an RLC feedback circuit of the high-gain three-stage GaN HEMT amplifier tube M11;

[0026] The first end of the inductor L29 is connected to the first end of the resistor R21, the resistor R22 and the capacitor C30, the second end of the resistor R21 is grounded through the capacitor C31, the second end of the resistor R22 is connected to the gate bias voltage Vg5, and the second end of the capacitor C30 is grounded;

[0027] The first end of the inductor L30 is connected to the first end of the resistor R23 and the capacitor C33, the second end of the resistor R23 is grounded through the capacitor C32, and the second end of the capacitor C33 is grounded;

[0028] The drain of the high-gain three-stage GaN HEMT amplifier tube M11 is sequentially connected in series with the capacitor C34 and the inductor L33, and the capacitor C34 and the inductor L33 constitute an output matching network of the low-gain amplifier stage.

[0029] In one embodiment, the first transistor switch control module includes:

[0030] GaN HEMT switch tube M2 and GaN HEMT switch tube M3, the gates of the GaN HEMT switch tube M2 and the GaN HEMT switch tube M3 are connected to the bias voltage Vsw1 through the resistor R4 and the resistor R5 respectively, the sources of the GaN HEMT switch tube M2 and the GaN HEMT switch tube M3 are grounded, and the drains of the GaN HEMT switch tube M2 and the GaN HEMT switch tube M3 are connected to the input end of the low gain amplifier stage;

[0031] GaN HEMT switch tube M8 and GaN HEMT switch tube M9, the gates of the GaN HEMT switch tube M8 and the GaN HEMT switch tube M9 are connected to the bias voltage Vsw3 through the resistor R15 and the resistor R16 respectively, the sources of the GaN HEMT switch tube M8 and the GaN HEMT switch tube M9 are grounded, and the drains of the GaN HEMT switch tube M8 and the GaN HEMT switch tube M9 are connected to the input end of the high gain amplifier stage.

[0032] In one embodiment, the second transistor switch control module includes:

[0033] GaN HEMT switch tube M6 and GaN HEMT switch tube M7, the gates of the GaN HEMT switch tube M6 and the GaN HEMT switch tube M7 are connected to the bias voltage Vsw2 through the resistor R13 and the resistor R14 respectively, the sources of the GaN HEMT switch tube M7 and the GaN HEMT switch tube M7 are grounded, and the drains of the GaN HEMT switch tube M6 and the GaN HEMT switch tube M7 are connected to the output end of the low gain amplifier stage;

[0034] GaN HEMT switch tube M12 and GaN HEMT switch tube M13, the gates of the GaN HEMT switch tube M12 and the GaN HEMT switch tube M13 are connected to the bias voltage Vsw4 through resistors R24 and R25 respectively, the sources of the GaN HEMT switch tube M12 and the GaN HEMT switch tube M13 are grounded, and the drains of the GaN HEMT switch tube M12 and the GaN HEMT switch tube M13 are connected to the output end of the high gain amplifier stage.

[0035] In one embodiment, the bias inductor, negative feedback inductor, and coupling inductor of the circuit are transmission lines.

[0036] In one of the embodiments, a third or multiple amplifier stages are also included.

[0037] In another aspect, the present invention provides a gain-adjustable millimeter-wave low-noise amplification method, which is applied to any of the above-mentioned gain-adjustable millimeter-wave low-noise amplification circuits, and the method comprises:

[0038] Setting a plurality of transistor switch-controlled amplifier stages, wherein the gains of the plurality of amplifier stages are different;

[0039] Receives RF input signal and processes it through a low noise amplifier stage with low noise figure;

[0040] The signal output by the low-noise amplifier stage is controlled by a SPDT switch controlled by a transistor switch to enter the amplifier stage of corresponding gain for processing;

[0041] Output RF output signal.

[0042] The above one or more technical solutions in the embodiments of the present application have at least one or more of the following technical effects:

[0043] The gain-adjustable millimeter-wave low-noise amplifier circuit provided in an embodiment of the present invention includes: a low-noise amplifier stage, a low-gain amplifier stage, a high-gain amplifier stage, a first transistor switch control module and a second transistor switch control module. Specifically, the low-noise amplifier stage is an amplifier stage with a low noise coefficient, and is also to ensure that the overall low-noise amplifier is in a noise-stable state. The low-gain amplifier stage and the high-gain amplifier stage are two amplifier stages with different gains. The low-gain amplifier stage and the high-gain amplifier stage are selected by an SPDT switch to achieve gain adjustment. Through the above design strategy, a gain-adjustable low-noise amplifier circuit structure that is applied to the millimeter-wave frequency band and does not significantly change the noise can be achieved.

[0044] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 is a schematic diagram of a circuit module in an embodiment of the present invention;

[0047] Figure 2 is an overall circuit schematic diagram in an embodiment of the present invention;

[0048] Figure 3 Schematic diagram of gain in two modes in an embodiment of the present invention;

[0049] Figure 4 Schematic diagram of gain in two modes in an embodiment of the present invention;

[0050] Figure 5 It is a schematic diagram of the prior art of the present invention;

[0051] Figure 6 A schematic diagram of a method flow in an embodiment of the present invention;

[0052] Explanation of reference numerals: 100, noise amplifier stage; 200, first transistor switch control module; 300, low gain amplifier stage; 400, high gain amplifier stage; 500, second transistor switch control module. DETAILED DESCRIPTION

[0053] The overall idea of ​​the technical solution provided by the present invention is as follows:

[0054] See also Figure 1 The gain-adjustable millimeter-wave low-noise amplifier circuit includes: a low-noise amplifier stage 100, a low-gain amplifier stage 300, a high-gain amplifier stage 400, a first transistor switch control module 200 and a second transistor switch control module 500. The input end of the low-noise amplifier stage 100 is used to receive a radio frequency input signal, and the output end of the low-noise amplifier stage 100 is connected to the low-gain amplifier stage 300 or the high-gain amplifier stage 400 through the first transistor switch control module 200. The low-gain amplifier stage 300 or the high-gain amplifier stage 400 outputs a radio frequency output signal through the second transistor switch control module 500.

[0055] GaN HEMT (gallium nitride high electron mobility transistor) amplifiers and switches are selected in the low-gain amplifier stage 300, the high-gain amplifier stage 400, and the transistor switch control module, providing extremely high electron mobility and a wide bandgap, which makes them have higher efficiency and lower noise figure under high-frequency operation, and are very suitable for RF amplification applications. GaN HEMT amplifiers can provide stable gain over a wide frequency range, which is critical for processing signals in the millimeter wave band. In addition, GaN HEMT amplifiers and switches can withstand higher voltages and power densities, which means they can provide greater output power without sacrificing performance. The high breakdown voltage characteristics of GaN HEMTs enable them to switch states quickly in switching applications, reduce switching losses, and improve the efficiency and reliability of the overall circuit. The use of GaN HEMTs can meet the strict performance requirements of RF amplifiers and ensure the stability and durability of the circuit under high-speed and high-power operations.

[0056] In summary, a hierarchical amplification structure is used to optimize the amplification process of the RF signal. The low-noise amplifier stage 100 receives the RF input signal and performs preliminary amplification without introducing too much noise. Subsequently, through the first transistor switch control module 200, the signal can be selectively distributed to the low-gain amplifier stage 300 or the high-gain amplifier stage 400, allowing the circuit to adjust the amplification level according to the signal strength or specific application requirements. The low-gain amplifier stage 300 and the high-gain amplifier stage 400 further amplify the signal to achieve the required output power. Finally, the second transistor switch control module 500 is responsible for outputting the amplified signal to ensure that the signal can be effectively transmitted to subsequent circuits or devices. Accurately controlling the flow direction and amplification level of the signal achieves efficient processing of the RF signal while maintaining good signal quality.

[0057] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] See also Figure 2 The low-noise amplifier stage 100 includes a GaN HEMT amplifier tube M1, a gate of the GaN HEMT amplifier tube M1 is connected to a gate bias voltage Vg1 through an inductor L2, a drain of the GaN HEMT amplifier tube M1 is connected to a drain bias voltage Vd1 through an inductor L3, a source of the GaN HEMT amplifier tube M1 is grounded through an inductor L4 and an inductor L5 connected in parallel, and a signal input end is connected to the gate of the GaN HEMT amplifier tube M1 through an input matching network.

[0059] See also Figure 2 , the input matching network includes a capacitor C1, a capacitor C2 and an inductor L1, wherein the first end of the capacitor C1 is connected to the signal input end, the second end of the capacitor C1 is connected to the first end of the capacitor C2 and the first end of the inductor L1, the second end of the capacitor C2 is grounded, and the second end of the inductor L1 is connected to the gate of the GaN HEMT amplifier tube M1;

[0060] The first end of the inductor L2 is connected to the first end of the resistor R1, the resistor R2 and the capacitor C3, the second end of the resistor R1 is grounded through the capacitor C4, the second end of the resistor R2 is connected to the gate bias voltage Vg1, and the second end of the capacitor C3 is grounded;

[0061] The first end of the inductor L3 is connected to the first end of the resistor R3 and the capacitor C6, the second end of the resistor R3 is grounded through the capacitor C5, and the second end of the capacitor C6 is grounded;

[0062] The drain of the GaN HEMT amplifier tube M1 is connected to the first end of the inductor L6 and the capacitor C8 through the capacitor C7, and the second end of the capacitor C8 is grounded. Vg1 and Vd1 provide the gate bias voltage and the drain bias voltage for the first-stage GaN HEMT amplifier tube M1 of LNA1 respectively; L2 and L3 constitute the gate bias inductor and the drain bias inductor of the first-stage GaN HEMT amplifier tube M1 of LNA1 respectively; L4 and L5 are both the source negative feedback inductors of the first-stage GaN HEMT amplifier tube M1; C1, C2, and L1 together constitute the input matching network (Input Matching Network, IMN) of the first-stage amplifier circuit of LNA1. The input matching network is an important component in the RF circuit. Its main function is to ensure that the signal transmitted from the signal source can be received by the input end of the amplifier with minimal loss and reflection. IMN optimizes the performance of the amplifier by adjusting the combination of inductance and capacitance to match a specific impedance value. .

[0063] See also Figure 2 The low-gain amplifier stage 300 includes a low-gain two-stage GaN HEMT amplifier tube M4, a gate of the low-gain two-stage GaN HEMT amplifier tube M4 is connected to a gate bias voltage Vg2 through an inductor L9, a drain of the low-gain two-stage GaN HEMT amplifier tube M4 is connected to a drain bias voltage Vd2 through an inductor L10, a source of the low-gain two-stage GaN HEMT amplifier tube M4 is grounded through an inductor L11 and an inductor L12 connected in parallel, and the low-noise amplifier stage 100 is connected to the gate of the low-gain two-stage GaN HEMT amplifier tube M4 through a first inter-stage matching network.

[0064] See also Figure 2 , the first inter-stage matching network includes a capacitor C9, an inductor L7 and an inductor L8, wherein the first end of the capacitor C9 is connected to the low-noise amplifier stage 100 through the inductor L7, the second end of the capacitor C9 is connected to the first end of the inductor L8, and the second end of the inductor L8 is connected to the gate of the low-gain second-stage GaN HEMT amplifier tube M4;

[0065] The first end of the inductor L9 is connected to the first end of the resistor R6, the resistor R7 and the capacitor C10, the second end of the resistor R6 is grounded through the capacitor C11, the second end of the resistor R7 is connected to the gate bias voltage Vg2, and the second end of the capacitor C10 is grounded;

[0066] The first end of the inductor L10 is connected to the first end of the resistor R8 and the capacitor C13, the second end of the resistor R8 is grounded through the capacitor C12, and the second end of the capacitor C13 is grounded. Vg2 and Vd2 provide gate bias voltage and drain bias voltage for the second-stage GaN HEMT amplifier M4 of LNA2 respectively; L9 and L10 constitute the gate bias inductor and drain bias inductor of the second-stage amplifier circuit of LNA2 respectively; L11 and L12 are both source negative feedback inductors of the second-stage GaN HEMT amplifier M2 of LNA2; C9, L7, and L8 together constitute the first inter-stage matching network (Inter Stage Matching Network) of LNA1 and LNA2. The inter-stage matching network is a key component in a multi-stage amplifier circuit. It is located between two amplifier stages and is used to ensure a smooth transition of the signal from one amplifier stage to the next. The main function of this network is to adjust and optimize the impedance matching between amplifiers at each stage to achieve the best signal transmission and amplification effect.

[0067] See also Figure 2 The low-gain amplifier stage 300 includes a low-gain three-stage GaN HEMT amplifier tube M5, a gate of the low-gain three-stage GaN HEMT amplifier tube M5 is connected to a gate bias voltage Vg3 through an inductor L15, a drain of the low-gain three-stage GaN HEMT amplifier tube M5 is connected to a drain bias voltage Vd3 through an inductor L16, a source of the low-gain three-stage GaN HEMT amplifier tube M5 is grounded through an inductor L17 and an inductor L18 connected in parallel, and a drain of the low-gain two-stage GaN HEMT amplifier tube M4 is connected to the gate of the low-gain three-stage GaN HEMT amplifier tube M5 through a second inter-stage matching network.

[0068] See also Figure 2 The second inter-stage matching network includes a capacitor C14, a capacitor C15 and an inductor L13, wherein the first end of the capacitor C14 is connected to the drain of the low-gain second-stage GaN HEMT amplifier tube M4, the second end of the capacitor C14 is connected to the first end of the inductor L13 and the first end of the capacitor C15, the second end of the capacitor C15 is grounded, and the second end of the inductor L13 is connected to the gate of the low-gain third-stage GaN HEMT amplifier tube M5;

[0069] The gate of the low-gain three-stage GaN HEMT amplifier tube M5 is connected to the drain of the low-gain three-stage GaN HEMT amplifier tube M5 through a resistor R9, a capacitor C16 and an inductor L14 connected in series in sequence, and the resistor R9, the capacitor C16 and the inductor L14 form an RLC feedback circuit of the low-gain three-stage GaN HEMT amplifier tube M5;

[0070] The first end of the inductor L15 is connected to the first end of the resistor R10, the resistor R11 and the capacitor C17, the second end of the resistor R10 is grounded through the capacitor C18, the second end of the resistor R11 is connected to the gate bias voltage Vg3, and the second end of the capacitor C17 is grounded;

[0071] The first end of the inductor L16 is connected to the first end of the resistor R12 and the capacitor C20, the second end of the resistor R12 is grounded through the capacitor C19, and the second end of the capacitor C20 is grounded;

[0072] The drain of the low-gain three-stage GaN HEMT amplifier tube M5 is connected in series with the capacitor C21 and the inductor L19 in sequence, and the capacitor C21 and the inductor L19 constitute the output matching network of the low-gain amplifier stage 300. Vg3 and Vd3 provide the gate bias voltage and the drain bias voltage for the third-stage GaN HEMT amplifier tube M3 of LNA2 respectively; L15 and L16 constitute the gate bias inductor and the drain bias inductor of the third-stage amplifier circuit of LNA2 respectively; L17 and L18 are both the source negative feedback inductors of the third-stage GaN HEMT amplifier tube M5 of LNA2; C14, C15, and L13 together constitute the second inter-stage matching network (Inter Stage Matching Network) of LNA1 and LNA2. R9, C16, and L14 are the RLC feedback circuit of the third-stage GaN HEMT amplifier tube M5 of LNA2. L19 and C21 together constitute the output matching network (Output Matching Network, OMN) of LNA2. The output matching network is a circuit component located at the output of an amplifier. Its main purpose is to ensure the best match between the output impedance of the amplifier and the load impedance. This match is critical to maximize power transfer, reduce signal reflections, and improve efficiency and stability, especially in RF amplifier design.

[0073] See also Figure 2 The high-gain amplifier stage 400 includes a high-gain two-stage GaN HEMT amplifier tube M10, the gate of the high-gain two-stage GaN HEMT amplifier tube M10 is connected to the gate bias voltage Vg4 through the inductor L23, the drain of the high-gain two-stage GaN HEMT amplifier tube M10 is connected to the drain bias voltage Vd4 through the inductor L24, the source of the high-gain two-stage GaN HEMT amplifier tube M10 is grounded through the inductor L25 and the inductor L26 connected in parallel, and the low-noise amplifier stage 100 is connected to the gate of the high-gain two-stage GaN HEMT amplifier tube M10 through the first inter-stage matching network.

[0074] See also Figure 2, the first inter-stage matching network includes a capacitor C22, an inductor L21 and an inductor L22, wherein the first end of the capacitor C22 is connected to the low-noise amplifier stage 100 through the inductor L21, the second end of the capacitor C22 is connected to the first end of the inductor L22, and the second end of the inductor L22 is connected to the gate of the high-gain second-stage GaN HEMT amplifier tube M10;

[0075] The first end of the inductor L23 is connected to the first end of the resistor R17, the resistor R18 and the capacitor C23, the second end of the resistor R17 is grounded through the capacitor C24, the second end of the resistor R18 is connected to the gate bias voltage Vg4, and the second end of the capacitor C23 is grounded;

[0076] The first end of the inductor L24 is connected to the first end of the resistor R19 and the capacitor C26, the second end of the resistor R19 is grounded through the capacitor C25, and the second end of the capacitor C26 is grounded. Vg4 and Vd4 provide gate bias voltage and drain bias voltage for the second-stage GaN HEMT amplifier M10 of LNA3 respectively; L23 and L24 constitute the gate bias inductor and drain bias inductor of the second-stage amplifier circuit of LNA2 respectively; L25 and L26 are both the source negative feedback inductors of the second-stage GaN HEMT amplifier M10 of LNA3; C22, L21, and L22 together constitute the first inter-stage matching network (Inter Stage Matching Network) of LNA1 and LNA3.

[0077] See also Figure 2The high-gain amplifier stage 400 includes a high-gain three-stage GaN HEMT amplifier tube M11, a gate of the high-gain three-stage GaN HEMT amplifier tube M11 is connected to a gate bias voltage Vg5 through an inductor L29, a drain of the high-gain three-stage GaN HEMT amplifier tube M11 is connected to a drain bias voltage Vd5 through an inductor L30, a source of the high-gain three-stage GaN HEMT amplifier tube M11 is grounded through an inductor L31 and an inductor L32 connected in parallel, and a drain of the high-gain two-stage GaN HEMT amplifier tube M10 is connected to the gate of the high-gain three-stage GaN HEMT amplifier tube M11 through a second inter-stage matching network. Vg5 and Vd5 provide gate bias voltage and drain bias voltage for the third-stage GaN HEMT amplifier M11 of LNA3 respectively; L29 and L30 constitute the gate bias inductor and drain bias inductor of the third-stage amplifier circuit of LNA3 respectively; L31 and L32 are both source negative feedback inductors of the third-stage GaN HEMT amplifier M11 of LNA3; C27, C28, and L27 together constitute the second inter-stage matching network (Inter Stage Matching Network) of LNA1 and LNA3. R20, C29, and L28 are the RLC feedback circuit of the third-stage GaN HEMT amplifier M11 of LNA3. The RLC feedback circuit is a feedback network containing resistors, inductors, and capacitors. It is used in electronic circuits to control the gain, bandwidth, stability, and frequency response of the circuit. This feedback circuit is realized by feeding back a part of the output signal to the input end, and the amount and phase of the feedback are determined by the combination of RLC elements.

[0078] See also Figure 2 The second inter-stage matching network includes a capacitor C27, a capacitor C28 and an inductor L27, wherein the first end of the capacitor C27 is connected to the drain of the high-gain two-stage GaN HEMT amplifier tube M10, the second end of the capacitor C27 is connected to the first end of the inductor L27 and the first end of the capacitor C28, the second end of the capacitor C28 is grounded, and the second end of the inductor L27 is connected to the gate of the high-gain three-stage GaN HEMT amplifier tube M11;

[0079] The gate of the high-gain three-stage GaN HEMT amplifier tube M11 is connected to the drain of the high-gain three-stage GaN HEMT amplifier tube M11 through a resistor R20, a capacitor C29 and an inductor L28 connected in series in sequence, and the resistor R20, the capacitor C29 and the inductor L28 form an RLC feedback circuit of the high-gain three-stage GaN HEMT amplifier tube M11;

[0080] The first end of the inductor L29 is connected to the first end of the resistor R21, the resistor R22 and the capacitor C30, the second end of the resistor R21 is grounded through the capacitor C31, the second end of the resistor R22 is connected to the gate bias voltage Vg5, and the second end of the capacitor C30 is grounded;

[0081] The first end of the inductor L30 is connected to the first end of the resistor R23 and the capacitor C33, the second end of the resistor R23 is grounded through the capacitor C32, and the second end of the capacitor C33 is grounded;

[0082] The drain of the high-gain three-stage GaN HEMT amplifier tube M11 is connected in series with the capacitor C34 and the inductor L33, and the capacitor C34 and the inductor L33 constitute the output matching network of the low-gain amplifier stage 300. The output matching network (OMN) is a key component in the electronic amplifier circuit and is located at the output end of the amplifier. Its main function is to ensure that the output impedance of the amplifier is optimally matched with the load impedance.

[0083] See also Figure 2 , the first transistor switch control module 200 includes:

[0084] GaN HEMT switch tube M2 and GaN HEMT switch tube M3, the gates of the GaN HEMT switch tube M2 and the GaN HEMT switch tube M3 are connected to the bias voltage Vsw1 through the resistor R4 and the resistor R5 respectively, the sources of the GaN HEMT switch tube M2 and the GaN HEMT switch tube M3 are grounded, and the drains of the GaN HEMT switch tube M2 and the GaN HEMT switch tube M3 are connected to the input end of the low-gain amplifier stage 300;

[0085] GaN HEMT switch tube M8 and GaN HEMT switch tube M9, the gates of the GaN HEMT switch tube M8 and the GaN HEMT switch tube M9 are connected to the bias voltage Vsw3 through the resistor R15 and the resistor R16 respectively, the sources of the GaN HEMT switch tube M8 and the GaN HEMT switch tube M9 are grounded, and the drains of the GaN HEMT switch tube M8 and the GaN HEMT switch tube M9 are connected to the input end of the high gain amplifier stage 400.

[0086] See also Figure 2 , the second transistor switch control module 500 includes:

[0087] GaN HEMT switch tube M6 and GaN HEMT switch tube M7, the gates of the GaN HEMT switch tube M6 and the GaN HEMT switch tube M7 are connected to the bias voltage Vsw2 through the resistor R13 and the resistor R14 respectively, the sources of the GaN HEMT switch tube M7 and the GaN HEMT switch tube M7 are grounded, and the drains of the GaN HEMT switch tube M6 and the GaN HEMT switch tube M7 are connected to the output end of the low-gain amplifier stage 300;

[0088] GaN HEMT switch tube M12 and GaN HEMT switch tube M13, the gates of the GaN HEMT switch tube M12 and the GaN HEMT switch tube M13 are connected to the bias voltage Vsw4 through the resistor R24 ​​and the resistor R25 respectively, the sources of the GaN HEMT switch tube M12 and the GaN HEMT switch tube M13 are grounded, and the drains of the GaN HEMT switch tube M12 and the GaN HEMT switch tube M13 are connected to the output end of the high gain amplifier stage 400.

[0089] SPDT uses a traditional traveling wave switch. Vsw1 provides a bias voltage for GaN HEMT switch tubes M2 and M3; Vsw2 provides a bias voltage for GaN HEMT switch tubes M6 and M7; Vsw3 provides a bias voltage for GaN HEMT switch tubes M8 and M9; Vsw2 provides a bias voltage for GaN HEMT switch tubes M12 and M13. R4, R5, R13, R14, R15, R16, R24, and R25 are large resistors of several thousand ohms. Vsw1, Vsw2, Vsw3, and Vsw4 are in the off state at -15V, and Vsw1, Vsw2, Vsw3, and Vsw4 are in the on state at 0V. When Vsw1 and Vsw2 are -15V, Vsw3, and Vsw4 are 0V, LNA1 and LNA2 are on, LNA3 is not on with LNA1, and the gain and noise factor are as follows. Figure 3 , Figure 4 The high gain shown; when Vsw1, Vsw2 are 0V, Vsw3, Vsw4 are -15V, LNA1 and LNA3 are turned on, LNA2 is not turned on with LNA1, the gain and noise coefficient are as follows Figure 3 , Figure 4 Low gain shown.

[0090] In both states, there is a significant change in gain within the frequency band of 24-30 GHz, but a small change in noise. This is only a rough result, indicating that the present application has the characteristic of adjustable gain.

[0091] See also Figure 2The bias inductor, negative feedback inductor and coupling inductor of the circuit are transmission lines. Since the above circuit works in the millimeter wave frequency band, the parasitic parameters of the inductor are much larger than those of the microstrip line. In order to improve various performances, especially the noise coefficient, the bias inductor, negative feedback inductor and coupling inductor are replaced by transmission lines.

[0092] See also Figure 2 , and also includes a third or multiple amplifier stages. When designing more gain-adjustable paths, only changing the number of the SPDT switch and the LNA should also fall within the protection scope of the present invention.

[0093] On the other hand, see Figure 6 , a gain-adjustable millimeter-wave low-noise amplification method, the method comprising the following steps:

[0094] S100 sets a plurality of transistor switch-controlled amplifier stages, wherein the gains of the plurality of amplifier stages are different;

[0095] The S200 receives the RF input signal and processes it through a low noise amplifier stage with a low noise figure;

[0096] S300 controls the signal output by the low-noise amplifier stage to enter the amplifier stage of corresponding gain for processing through the SPDT switch controlled by the transistor switch;

[0097] S400 outputs RF output signal.

[0098] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0099] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present invention without departing from the spirit and scope of the embodiments of the present invention. Thus, if these modifications and variations of the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A millimeter wave low noise amplifier circuit with adjustable gain, characterized in that: It includes a low-noise amplifier stage, a low-gain amplifier stage, a high-gain amplifier stage, a first transistor switch control module and a second transistor switch control module. The input end of the low-noise amplifier stage is used to receive a radio frequency input signal. The output end of the low-noise amplifier stage is connected to the low-gain amplifier stage or the high-gain amplifier stage through the first transistor switch control module. The low-gain amplifier stage or the high-gain amplifier stage outputs a radio frequency output signal through the second transistor switch control module.

2. The gain-adjustable millimeter-wave low-noise amplifier circuit according to claim 1, characterized in that: The low-noise amplifier stage includes a GaN HEMT amplifier tube M1, a gate of the GaN HEMT amplifier tube M1 is connected to a gate bias voltage Vg1 through an inductor L2, a drain of the GaN HEMT amplifier tube M1 is connected to a drain bias voltage Vd1 through an inductor L3, a source of the GaN HEMT amplifier tube M1 is grounded through an inductor L4 and an inductor L5 connected in parallel, and a signal input end is connected to the gate of the GaN HEMT amplifier tube M1 through an input matching network.

3. The gain-adjustable millimeter-wave low-noise amplifier circuit according to claim 2, characterized in that: The input matching network includes a capacitor C1, a capacitor C2 and an inductor L1, wherein a first end of the capacitor C1 is connected to a signal input end, a second end of the capacitor C1 is connected to a first end of the capacitor C2 and a first end of the inductor L1, a second end of the capacitor C2 is grounded, and a second end of the inductor L1 is connected to a gate of the GaN HEMT amplifier tube M1; The first end of the inductor L2 is connected to the first end of the resistor R1, the resistor R2 and the capacitor C3, the second end of the resistor R1 is grounded through the capacitor C4, the second end of the resistor R2 is connected to the gate bias voltage Vg1, and the second end of the capacitor C3 is grounded; The first end of the inductor L3 is connected to the first end of the resistor R3 and the capacitor C6, the second end of the resistor R3 is grounded through the capacitor C5, and the second end of the capacitor C6 is grounded; The drain of the GaN HEMT amplifier tube M1 is connected to the inductor L6 and the first end of the capacitor C8 via the capacitor C7, and the second end of the capacitor C8 is grounded.

4. The gain-adjustable millimeter-wave low-noise amplifier circuit according to claim 1, characterized in that: The low-gain amplifier stage includes a low-gain two-stage GaN HEMT amplifier tube M4, a gate of the low-gain two-stage GaN HEMT amplifier tube M4 is connected to a gate bias voltage Vg2 through an inductor L9, a drain of the low-gain two-stage GaN HEMT amplifier tube M4 is connected to a drain bias voltage Vd2 through an inductor L10, a source of the low-gain two-stage GaN HEMT amplifier tube M4 is grounded through an inductor L11 and an inductor L12 connected in parallel, and the low-noise amplifier stage is connected to the gate of the low-gain two-stage GaN HEMT amplifier tube M4 through a first inter-stage matching network.

5. The gain-adjustable millimeter-wave low-noise amplifier circuit according to claim 4, characterized in that: The first inter-stage matching network includes a capacitor C9, an inductor L7 and an inductor L8, wherein a first end of the capacitor C9 is connected to the low-noise amplifier stage through the inductor L7, a second end of the capacitor C9 is connected to a first end of the inductor L8, and a second end of the inductor L8 is connected to a gate of the low-gain second-stage GaN HEMT amplifier tube M4; The first end of the inductor L9 is connected to the first end of the resistor R6, the resistor R7 and the capacitor C10, the second end of the resistor R6 is grounded through the capacitor C11, the second end of the resistor R7 is connected to the gate bias voltage Vg2, and the second end of the capacitor C10 is grounded; A first end of the inductor L10 is connected to a first end of the resistor R8 and a first end of the capacitor C13 , a second end of the resistor R8 is grounded via the capacitor C12 , and a second end of the capacitor C13 is grounded.

6. The gain-adjustable millimeter-wave low-noise amplifier circuit according to claim 5, characterized in that: The low-gain amplifier stage includes a low-gain three-stage GaN HEMT amplifier tube M5, a gate of the low-gain three-stage GaN HEMT amplifier tube M5 is connected to a gate bias voltage Vg3 through an inductor L15, a drain of the low-gain three-stage GaN HEMT amplifier tube M5 is connected to a drain bias voltage Vd3 through an inductor L16, a source of the low-gain three-stage GaN HEMT amplifier tube M5 is grounded through an inductor L17 and an inductor L18 connected in parallel, and a drain of the low-gain two-stage GaN HEMT amplifier tube M4 is connected to the gate of the low-gain three-stage GaN HEMT amplifier tube M5 through a second inter-stage matching network.

7. The gain-adjustable millimeter-wave low-noise amplifier circuit according to claim 6, characterized in that: The second inter-stage matching network includes a capacitor C14, a capacitor C15 and an inductor L13, wherein a first end of the capacitor C14 is connected to the drain of the low-gain two-stage GaN HEMT amplifier tube M4, a second end of the capacitor C14 is connected to a first end of the inductor L13 and a first end of the capacitor C15, a second end of the capacitor C15 is grounded, and a second end of the inductor L13 is connected to a gate of the low-gain three-stage GaN HEMT amplifier tube M5; The gate of the low-gain three-stage GaN HEMT amplifier tube M5 is connected to the drain of the low-gain three-stage GaN HEMT amplifier tube M5 through a resistor R9, a capacitor C16 and an inductor L14 connected in series in sequence, and the resistor R9, the capacitor C16 and the inductor L14 form an RLC feedback circuit of the low-gain three-stage GaN HEMT amplifier tube M5; The first end of the inductor L15 is connected to the first end of the resistor R10, the resistor R11 and the capacitor C17, the second end of the resistor R10 is grounded through the capacitor C18, the second end of the resistor R11 is connected to the gate bias voltage Vg3, and the second end of the capacitor C17 is grounded; The first end of the inductor L16 is connected to the first end of the resistor R12 and the capacitor C20, the second end of the resistor R12 is grounded through the capacitor C19, and the second end of the capacitor C20 is grounded; The drain of the low-gain three-stage GaN HEMT amplifier tube M5 is sequentially connected in series with the capacitor C21 and the inductor L19, and the capacitor C21 and the inductor L19 constitute an output matching network of the low-gain amplifier stage.

8. The gain-adjustable millimeter-wave low-noise amplifier circuit according to claim 1, characterized in that: The high-gain amplifier stage includes a high-gain two-stage GaN HEMT amplifier tube M10, a gate of the high-gain two-stage GaN HEMT amplifier tube M10 is connected to a gate bias voltage Vg4 through an inductor L23, a drain of the high-gain two-stage GaN HEMT amplifier tube M10 is connected to a drain bias voltage Vd4 through an inductor L24, a source of the high-gain two-stage GaN HEMT amplifier tube M10 is grounded through an inductor L25 and an inductor L26 connected in parallel, and the low-noise amplifier stage is connected to the gate of the high-gain two-stage GaN HEMT amplifier tube M10 through a first inter-stage matching network.

9. The gain-adjustable millimeter-wave low-noise amplifier circuit according to claim 8, characterized in that: The first inter-stage matching network includes a capacitor C22, an inductor L21 and an inductor L22, wherein a first end of the capacitor C22 is connected to the low-noise amplifier stage through the inductor L21, a second end of the capacitor C22 is connected to a first end of the inductor L22, and a second end of the inductor L22 is connected to a gate of the high-gain second-stage GaN HEMT amplifier tube M10; The first end of the inductor L23 is connected to the first end of the resistor R17, the resistor R18 and the capacitor C23, the second end of the resistor R17 is grounded through the capacitor C24, the second end of the resistor R18 is connected to the gate bias voltage Vg4, and the second end of the capacitor C23 is grounded; A first end of the inductor L24 is connected to a first end of the resistor R19 and a first end of the capacitor C26 , a second end of the resistor R19 is grounded via the capacitor C25 , and a second end of the capacitor C26 is grounded.

10. The gain-adjustable millimeter-wave low-noise amplifier circuit according to claim 9, characterized in that: The high-gain amplifier stage includes a high-gain three-stage GaN HEMT amplifier tube M11, a gate of the high-gain three-stage GaN HEMT amplifier tube M11 is connected to a gate bias voltage Vg5 through an inductor L29, a drain of the high-gain three-stage GaN HEMT amplifier tube M11 is connected to a drain bias voltage Vd5 through an inductor L30, a source of the high-gain three-stage GaN HEMT amplifier tube M11 is grounded through an inductor L31 and an inductor L32 connected in parallel, and a drain of the high-gain two-stage GaN HEMT amplifier tube M10 is connected to the gate of the high-gain three-stage GaN HEMT amplifier tube M11 through a second inter-stage matching network.

11. The gain-adjustable millimeter-wave low-noise amplifier circuit according to claim 10, characterized in that: The second inter-stage matching network includes a capacitor C27, a capacitor C28 and an inductor L27, wherein a first end of the capacitor C27 is connected to the drain of the high-gain two-stage GaN HEMT amplifier tube M10, a second end of the capacitor C27 is connected to a first end of the inductor L27 and a first end of the capacitor C28, a second end of the capacitor C28 is grounded, and a second end of the inductor L27 is connected to a gate of the high-gain three-stage GaN HEMT amplifier tube M11; The gate of the high-gain three-stage GaN HEMT amplifier tube M11 is connected to the drain of the high-gain three-stage GaN HEMT amplifier tube M11 through a resistor R20, a capacitor C29 and an inductor L28 connected in series in sequence, and the resistor R20, the capacitor C29 and the inductor L28 form an RLC feedback circuit of the high-gain three-stage GaN HEMT amplifier tube M11; The first end of the inductor L29 is connected to the first end of the resistor R21, the resistor R22 and the capacitor C30, the second end of the resistor R21 is grounded through the capacitor C31, the second end of the resistor R22 is connected to the gate bias voltage Vg5, and the second end of the capacitor C30 is grounded; The first end of the inductor L30 is connected to the first end of the resistor R23 and the capacitor C33, the second end of the resistor R23 is grounded through the capacitor C32, and the second end of the capacitor C33 is grounded; The drain of the high-gain three-stage GaN HEMT amplifier tube M11 is sequentially connected in series with the capacitor C34 and the inductor L33, and the capacitor C34 and the inductor L33 constitute an output matching network of the low-gain amplifier stage.

12. The gain-adjustable millimeter-wave low-noise amplifier circuit according to claim 6, characterized in that: The first transistor switch control module comprises: GaN HEMT switch tube M2 and GaN HEMT switch tube M3, the gates of the GaN HEMT switch tube M2 and the GaN HEMT switch tube M3 are connected to the bias voltage Vsw1 through the resistor R4 and the resistor R5 respectively, the sources of the GaN HEMT switch tube M2 and the GaN HEMT switch tube M3 are grounded, and the drains of the GaN HEMT switch tube M2 and the GaN HEMT switch tube M3 are connected to the input end of the low gain amplifier stage; GaN HEMT switch tube M8 and GaN HEMT switch tube M9, the gates of the GaN HEMT switch tube M8 and the GaN HEMT switch tube M9 are connected to the bias voltage Vsw3 through the resistor R15 and the resistor R16 respectively, the sources of the GaN HEMT switch tube M8 and the GaN HEMT switch tube M9 are grounded, and the drains of the GaN HEMT switch tube M8 and the GaN HEMT switch tube M9 are connected to the input end of the high gain amplifier stage.

13. The gain-adjustable millimeter-wave low-noise amplifier circuit according to claim 11, characterized in that: The second transistor switch control module comprises: GaN HEMT switch tube M6 and GaN HEMT switch tube M7, the gates of the GaN HEMT switch tube M6 and the GaN HEMT switch tube M7 are connected to the bias voltage Vsw2 through the resistor R13 and the resistor R14 respectively, the sources of the GaN HEMT switch tube M7 and the GaN HEMT switch tube M7 are grounded, and the drains of the GaN HEMT switch tube M6 and the GaN HEMT switch tube M7 are connected to the output end of the low gain amplifier stage; GaN HEMT switch tube M12 and GaN HEMT switch tube M13, the gates of the GaN HEMT switch tube M12 and the GaN HEMT switch tube M13 are connected to the bias voltage Vsw4 through the resistor R24 ​​and the resistor R25 respectively, the sources of the GaN HEMT switch tube M12 and the GaN HEMT switch tube M13 are grounded, and the drains of the GaN HEMT switch tube M12 and the GaN HEMT switch tube M13 are connected to the output end of the high gain amplifier stage.

14. The gain-adjustable millimeter-wave low-noise amplifier circuit according to any one of claims 2 to 13, characterized in that: The bias inductor, negative feedback inductor and coupling inductor of the circuit are transmission lines.

15. The gain-adjustable millimeter-wave low-noise amplifier circuit according to any one of claims 1 to 13, characterized in that: A third or multiple amplifier stages are also included.

16. A gain-adjustable millimeter-wave low-noise amplification method, characterized in that: The method applied to the gain-adjustable millimeter-wave low-noise amplifier circuit according to any one of claims 1 to 15 comprises: Setting a plurality of transistor switch-controlled amplifier stages, wherein the gains of the plurality of amplifier stages are different; Receives RF input signal and processes it through a low noise amplifier stage with low noise figure; The signal output by the low-noise amplifier stage is controlled by a SPDT switch controlled by a transistor switch to enter the amplifier stage of corresponding gain for processing; Output RF output signal.

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