Broadband low-noise amplifier
Through the design of the cascade cascade structure and negative feedback loop, the problems of noise difference, high power consumption and large area of existing broadband amplifiers are solved, and a high gain, low noise and wide bandwidth amplifier design is realized.
Patent Information
- Application Number
- CN202421998346.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-16
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2034-08-16
AI Technical Summary
Existing broadband amplifiers have problems such as noise difference, high power consumption, large area, complex circuits and large size.
Using a cascaded structure of the co-gate and a negative feedback loop, the bandwidth is expanded and the gain is balanced by adjusting the gate grounding capacitance of the co-gate transistor and the RLC negative feedback loop of the common transistor.
Amplification effect of high gain, low noise, wide bandwidth and good isolation is achieved, reducing power consumption and optimizing circuit area.
Smart Images
Figure CN223141889U_ABST
Abstract
Description
Technical Field
[0001] The utility model patent relates to the field of monolithic microwave integrated circuits, and particularly relates to a broadband low-noise amplifier. Background Art
[0002] With the continuous development of radar systems, in order to adapt to application scenarios in different frequency bands, the radar receiver system has put forward higher requirements for bandwidth. The low-noise amplifier is located at the front end of the receiver system, responsible for amplifying the weak signals received by the antenna while maintaining good noise performance. The broadband low-noise amplifier can operate in a relatively wide frequency band, is convenient to apply, and has a wide range of usage scenarios. Its operating frequency band range and performance largely affect the performance of the entire receiver system.
[0003] At present, structures such as balanced and distributed amplifiers are often used for broadband amplifiers. Among them, the distributed amplifier can achieve a relatively wide bandwidth and has advantages such as flat gain and low standing wave, but has problems such as poor noise, high power consumption, and large area; the balanced type has better gain flatness and standing wave ratio, but the circuit is complex, the size is large, the bandwidth of the coupler is limited, and additional noise will be introduced. Summary of the Utility Model
[0004] In view of the above deficiencies in the prior art, a broadband low-noise amplifier provided by the utility model utilizes negative feedback to expand the bandwidth and balance the gain, and solves the problems of poor noise, high power consumption, large area, complex circuit, and large size existing in the existing broadband amplifier.
[0005] In order to achieve the above utility model purpose, the technical solution adopted by the utility model is: a broadband low-noise amplifier, including a common-source transistor M1 and a common-gate transistor M2. The source of the common-source transistor M1 is grounded. The drain of the common-source transistor M1 is connected to the source of the common-gate transistor M2. The gate of the common-source transistor M1 is connected to one end of an inductor L1. The other end of the inductor L1 is respectively connected to a grounding capacitor C1 and one end of an input DC bias circuit. The other end of the input DC bias circuit serves as the input end of the broadband low-noise amplifier;
[0006] The drain of the common-gate transistor M2 is connected to one end of an inductor L3. The other end of the inductor L3 is respectively connected to a grounding capacitor C4 and one end of an output DC bias circuit. The other end of the output DC bias circuit serves as the output end of the broadband low-noise amplifier;
[0007] The broadband low-noise amplifier further includes a negative feedback loop connected to both the gate and the drain of the common-gate transistor M2, and an RLC negative feedback loop connected to both the gate of the common-source transistor M1 and the drain of the common-gate transistor M2.
[0008] Further: The negative feedback loop includes a capacitor C3. One end of the capacitor C3 is respectively connected to the drain of the common-gate transistor M2 and one end of a resistor R4. The other end of the capacitor C3 is connected to a grounding resistor R2. The other end of the resistor R4 is respectively connected to one end of a resistor R3 and a grounding resistor R5. The other end of the resistor R3 is connected to the gate of the common-gate transistor M2.
[0009] Further: The RLC negative feedback loop includes a resistor R1, a capacitor C2, and an inductor L2 connected in sequence. The resistor R1 is connected to the gate of the common-source transistor M1. The inductor L2 is connected to the drain of the common-gate transistor M2.
[0010] Further: The size of the common-source transistor M1 is 4×60 μm.
[0011] Further: The size of the common-gate transistor M2 is 4×75 μm.
[0012] The beneficial effects of the present utility model are as follows:
[0013] 1. By adopting a first-stage common-source common-gate cascade structure and adjusting the gate grounding capacitance of the common-gate transistor, the high-frequency gain is improved.
[0014] 2. The common-source transistor M1 serves as the main amplifying transistor to provide the main gain. The common-gate transistor M2 serves as a current buffer, which can provide a large reverse isolation degree and suppress the Miller effect of the common-source transistor. Description of the Drawings
[0015] Figure 1 It is a topological structure diagram of a broadband low-noise amplifier.
[0016] Figure 2 It is a simulation result diagram of the amplifier gain.
[0017] Figure 3 It is a simulation result diagram of the input and output return loss of the amplifier.
[0018] Figure 4 It is a simulation result diagram of the noise figure of the amplifier.
[0019] Figure 5 It is a simulation result diagram of the stability of the amplifier.
[0020] Figure 6 It is a simulation result diagram of the P-1dB of the amplifier. Detailed Embodiment
[0021] The following describes the specific embodiments of the present utility model to facilitate those skilled in the art to understand the present utility model. However, it should be clear that the present utility model is not limited to the scope of the specific embodiments. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present utility model defined and determined by the appended claims, these changes are obvious, and all inventions and creations using the concept of the present utility model are within the scope of protection.
[0022] As Figure 1 shown, in an embodiment of the present utility model, a broadband low-noise amplifier is provided, which includes a common-source transistor M1 and a common-gate transistor M2. The source of the common-source transistor M1 is grounded. The drain of the common-source transistor M1 is connected to the source of the common-gate transistor M2. The gate of the common-source transistor M1 is connected to one end of an inductor L1. The other end of the inductor L1 is respectively connected to a grounding capacitor C1 and one end of an input DC biasing device. The other end of the input DC biasing device serves as the input end of the broadband low-noise amplifier.
[0023] The drain of the common-gate transistor M2 is connected to one end of an inductor L3. The other end of the inductor L3 is respectively connected to a grounding capacitor C4 and one end of an output DC biasing device. The other end of the output DC biasing device serves as the output end of the broadband low-noise amplifier.
[0024] The broadband low-noise amplifier further includes a negative feedback loop connected to both the gate and the drain of the common-gate transistor M2, and an RLC negative feedback loop connected to both the gate of the common-source transistor M1 and the drain of the common-gate transistor M2.
[0025] The negative feedback loop includes a capacitor C3. One end of the capacitor C3 is respectively connected to the drain of the common-gate transistor M2 and one end of a resistor R4. The other end of the capacitor C3 is connected to a grounding resistor R2. The other end of the resistor R4 is respectively connected to one end of a resistor R3 and a grounding resistor R5. The other end of the resistor R3 is connected to the gate of the common-gate transistor M2.
[0026] The RLC negative feedback loop includes a resistor R1, a capacitor C2, and an inductor L2 connected in sequence. The resistor R1 is connected to the gate of the common-source transistor M1. The inductor L2 is connected to the drain of the common-gate transistor M2.
[0027] Taking into comprehensive consideration factors such as noise, gain, and output power, the size of the common-source transistor M1 is 4×60μm, and the size of the common-gate transistor M2 is 4×75μm.
[0028] In this embodiment, the cascode structure composed of the common-source transistor M1 and the common-gate transistor M2 has advantages such as high gain, high output impedance, good input-output isolation, and wide bandwidth characteristics. Among them, the common-source transistor M1 is the main amplifying transistor and the main gain unit, and the noise figure and input matching of the circuit basically depend on this transistor. The common-gate transistor M2 acts as a current buffer, which can provide a large reverse isolation and suppress the Miller effect of the common-source transistor.
[0029] To achieve the gain design of ultra-wideband, a negative feedback composed of a capacitor C3 and a resistor R2 is added to the gate of the common-gate transistor M2, and a microstrip line is added to the drains of the common-source transistor M1 and the common-gate transistor M2 to improve the broadband gain characteristics, expand the bandwidth, and reduce the noise. An RLC negative feedback loop composed of a resistor R1, a capacitor C2, and an inductor L2 is formed between the gate of the common-source transistor M1 and the drain of the common-gate transistor M2, which increases the overall bandwidth and gain flatness of the chip and can improve the stability at the same time.
[0030] The drain of the common-gate transistor M2 is powered by a single 5V power supply, and the gate of the common-gate transistor M2 is powered by voltage division using resistors R3, R4, and R5. An inductor L3 and a parallel capacitor C4 are provided in the drain power supply branch.
[0031] The broadband low-noise amplifier chip is optimized using ADS software, and its simulation results are as shown in Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6 ;
[0032] According to Figures 2 - 6 it can be known that this low-noise amplifier has a wide bandwidth, good gain flatness, a small noise figure, and good return loss.
[0033] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "thickness", "upper", "lower", "horizontal", "top", "bottom", "inner", "outer", "radial", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of technical features. Therefore, the features defined by "first", "second", "third" may explicitly or implicitly include one or more of such features.
Claims
1. A broadband low-noise amplifier, characterized in that, It includes a common-source transistor M1 and a common-gate transistor M2. The source of the common-source transistor M1 is grounded. The drain of the common-source transistor M1 is connected to the source of the common-gate transistor M2. The gate of the common-source transistor M1 is connected to one end of an inductor L1. The other end of the inductor L1 is respectively connected to a grounded capacitor C1 and one end of an input DC bias circuit. The other end of the input DC bias circuit serves as the input terminal of the broadband low-noise amplifier. The drain of the common-gate transistor M2 is connected to one end of an inductor L3. The other end of the inductor L3 is respectively connected to a grounded capacitor C4 and one end of an output DC bias circuit. The other end of the output DC bias circuit serves as the output terminal of the broadband low-noise amplifier. The broadband low-noise amplifier further includes a negative feedback loop connected to both the gate and the drain of the common-gate transistor M2, and an RLC negative feedback loop connected to both the gate of the common-source transistor M1 and the drain of the common-gate transistor M2.
2. The broadband low-noise amplifier according to claim 1, wherein The negative feedback loop includes a capacitor C3. One end of the capacitor C3 is respectively connected to the drain of the common-gate transistor M2 and one end of a resistor R4. The other end of the capacitor C3 is connected to a grounded resistor R2. The other end of the resistor R4 is respectively connected to one end of a resistor R3 and a grounded resistor R5. The other end of the resistor R3 is connected to the gate of the common-gate transistor M2.
3. The broadband low-noise amplifier according to claim 1, characterized in that, The RLC negative feedback loop includes a resistor R1, a capacitor C2, and an inductor L2 connected in sequence. The resistor R1 is connected to the gate of the common-source transistor M1. The inductor L2 is connected to the drain of the common-gate transistor M2.
4. The broadband low-noise amplifier according to claim 1, characterized in that, The size of the common-source transistor M1 is 4×60μm.
5. The broadband low-noise amplifier according to claim 1, characterized in that The size of the common-gate transistor M2 is 4×75μm.