Defect coupling low-noise amplifier

Abstract

The invention discloses a defect coupling low-noise amplifier. The low-noise amplifier solves the problem that the performance of a low-noise amplifier in the prior art is influenced by a grid source inductance coupling coefficient. Forward coupling of an input inductor and a grid inductor and reverse coupling of the input inductor and a source inductor are achieved through a unique defect coupling transformer matching network, meanwhile, reverse coupling of a grid inductor and the source inductor is achieved, and the coupling coefficient of the grid-source inductor is reduced through coupling counteracting inductance; by combining a differential common-source transconductance amplification stage, a four-order magnetic coupling resonance unit, a differential transconductance amplification stage with a neutralizing capacitor and an output transformer matching network, the characteristics of high gain bandwidth and low noise are realized; simulation and actual tests verify that the low-noise amplifier can effectively reduce the noise coefficient and broaden the input matching range, has good compatibility and wide application prospects based on a conventional integrated circuit production process, can be applied to a phased array system, and can also form a receiver system with other circuits.

Description

Technical Field

[0001] This invention belongs to the technical field of wireless communication and relates to a defect-coupled low-noise amplifier, which is particularly suitable for communication application scenarios in millimeter-wave bands such as V-band and E-band. Background Technology

[0002] In modern multi-standard wireless systems, such as 5G NR, radar systems, and high-capacity backhaul communications, the demand for extremely high data rate links is increasing. To meet the ever-increasing channel bandwidth requirements, broadband wireless communication systems in millimeter-wave bands such as V-band and E-band have developed rapidly in recent years. As key sub-modules in broadband wireless systems, low-noise amplifiers and receivers need to have lower noise figures, higher linearity, higher gain-bandwidth products, and smaller sizes at high frequencies.

[0003] In existing technology, one approach uses a three-phase coupling transformer connected to a differential amplifier circuit. The radio frequency (RF) signal is transmitted to the differential amplifier circuit via the three-phase coupling transformer. The three-phase coupling transformer aims to eliminate the thermal noise of the MOSFETs in the differential amplifier circuit and increase the transconductance of the MOSFETs. The differential amplifier circuit amplifies the RF signal, and finally, the amplified RF signal is output after impedance matching by an impedance matching circuit. However, this technology has significant drawbacks. In the three-phase coupling transformer used in this approach, when there are strong coupling coefficients between the front-stage inductor and the gate inductor, and between the front-stage inductor and the source inductor, the coupling coefficient between the gate inductor and the source inductor will naturally be very high due to physical spatial relationships. A high gate-source inductance coupling coefficient will disrupt the noise self-cancellation, gain enhancement, and input impedance matching conditions originally provided by the three-phase coupling transformer, ultimately leading to a decrease in the overall performance of the low-noise amplifier.

[0004] Therefore, how to design a low-noise amplifier with high gain, bandwidth, and low noise under conventional integrated circuit manufacturing processes, and how to simultaneously reduce the noise figure and widen the input matching range through effective technical means under the condition of low gain of millimeter-wave single-stage amplifiers, have become urgent technical problems to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a defect-coupled low-noise amplifier that solves the aforementioned technical problems.

[0006] The technical solution adopted in this invention is as follows: A defect-coupled low-noise amplifier includes a defect-coupled transformer matching network, a differential common-source transconductance amplifier stage, a fourth-order magnetically coupled resonant unit, a differential transconductance amplifier stage with a neutralization capacitor, and an output transformer matching network. Input inductance L in defect-coupled transformer matching network IN With gate inductor L GForward coupling, with a coupling coefficient of k GIN Input inductance L IN Source-level inductor L S Reverse coupling, with a coupling coefficient of k SIN Gate inductance L G Source-level inductor L S Reverse coupling, with a coupling coefficient of k GS Furthermore, a coupling cancellation inductor L is provided at the tail of the source inductor. S 'Used to offset gate inductance L G Source-level inductor L S Coupling coefficient k GS ; The differential common-source transconductance amplifier stage is connected to the defect-coupled transformer matching network and is used to amplify the radio frequency signal processed by the defect-coupled transformer matching network. A fourth-order magnetically coupled resonant unit is used as an interstage matching unit to improve the overall gain-bandwidth product. A differential transconductance amplifier stage with a neutralization capacitor is used to further improve gain and enhance reverse isolation; The output transformer matching network is used to match the amplified signal at the output.

[0007] The working principle of this invention is as follows: the radio frequency signal is input to the input inductor L. IN Then, using the input inductance L IN With gate inductor L G Forward coupling coefficient k GIN and source-level inductor L S The reverse coupling coefficient k SIN The signal is transmitted to the gate and source of the first-stage amplifier circuit respectively, thereby increasing the signal gain. Simultaneously, the noise generated by the MOSFET in the first-stage amplifier circuit is absorbed through the source inductor L. S and gate inductor L G The reverse coupling coefficient k GS Returning to the MOSFET gate, noise self-cancellation is achieved. A coupling cancellation inductor L is added at the tail of the source inductor. S The reverse induced current generated by it cancels out the gate inductance L. G Source-level inductor L S The coupling current between them reduces the actual k GS This optimizes noise matching and input matching conditions.

[0008] In the subsequent circuit, the fourth-order magnetically coupled resonant unit performs inter-stage matching of the signal through the principle of magnetic coupling resonance, thereby improving the gain-bandwidth product. The differential gain stage with a neutralizing capacitor utilizes the characteristics of the neutralizing capacitor to compensate for parasitic capacitance in the circuit, improve the gain and enhance the reverse isolation, ultimately achieving high-performance operation of the low-noise amplifier in the millimeter-wave band.

[0009] Furthermore: the input inductor L IN The gate inductor L is placed in the middle layer. G Source-level inductor L S These are placed on its upper and lower sides respectively, and implemented using metal layers of different thicknesses. This design ensures k GIN and k SIN Strong coupling is a crucial physical foundation. Through a rational spatial layout, physical principles are utilized to enhance the coupling effect between the input inductor and the gate and source inductors, while reducing the coupling between the gate inductor and the source inductor, thus providing a structural guarantee for achieving the optimal coupling coefficient relationship.

[0010] Furthermore: Clarify the coupling cancellation inductance L S 'Using through-holes to connect to the top layer. This connection method can achieve optimal coupling cancellation while minimizing its impact on k.' GIN and k SIN The influence of other coupling coefficients is also considered. By placing the coupling cancellation inductor at the top layer, its spatial position and electromagnetic coupling with other inductors can be precisely controlled, ensuring that its primary function is to cancel out k-coupling. GS This ensures the stability and reliability of the defect-coupled transformer matching network without interfering with beneficial coupling relationships.

[0011] Furthermore: MOSFET noise is transmitted through the source inductor L S and gate inductor L G Reverse coupling to the MOS transistor gate enables noise self-cancellation. This characteristic is an important supplement to the noise figure reduction of this invention, and together with the reduction in coupling cancellation inductance, it lowers the noise level by k. GS By combining these technical means, the amplifier's noise suppression capability has been further enhanced, ensuring the achievement of low-noise performance.

[0012] Furthermore, it is explained that the fourth-order magnetically coupled resonant unit achieves inter-stage matching through the principle of magnetic coupling resonance. This principle can effectively broaden the matching bandwidth, improve the inter-stage signal transmission efficiency, thereby enhancing the overall gain-bandwidth product of the low-noise amplifier and enabling the amplifier to maintain good performance over a wider frequency range.

[0013] Furthermore, it is pointed out that the differential transconductance amplifier stage with a neutralizing capacitor compensates for parasitic capacitance in the circuit. In high-frequency circuits, parasitic capacitance can adversely affect signal gain and reverse isolation. The introduction of a neutralizing capacitor can counteract the effect of parasitic capacitance, thereby further improving the amplifier gain, enhancing reverse isolation, reducing signal feedback and interference, and improving the amplifier's stability and performance.

[0014] Furthermore, the low-noise amplifier is specified to be manufactured using conventional integrated circuit production processes. This requirement emphasizes the process feasibility and economy of the invention, indicating that it does not rely on special or expensive process technologies, is easy to implement in existing mature integrated circuit manufacturing processes, and is conducive to the promotion and industrial application of the technology.

[0015] Furthermore, it specifies that the conventional integrated circuit manufacturing process is SMIC's 40nm conventional CMOS process. A practical and feasible example of process selection is provided, offering a clear process reference for the specific manufacturing of this low-noise amplifier, thus enhancing the practicality and operability of the patent.

[0016] Furthermore, this demonstrates that the low-noise amplifier can be integrated with mixers, intermediate frequency amplifiers, and other circuits to form a receiver system. This indicates that the low-noise amplifier does not exist in isolation but can be integrated with other related circuit modules to form a fully functional receiver system, further expanding its application scope and practical value.

[0017] Furthermore, it is clarified that the low-noise amplifier can be applied to phased array systems. Phased array systems have an urgent need for amplifiers with low noise and high gain bandwidth. The low-noise amplifier of this invention can meet this need and helps to reduce the chip overhead of phased array systems and improve the overall system performance. This application direction reflects the practical value of this invention in a specific high-end field.

[0018] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. A defect-coupled low-noise amplifier, the core of which lies in canceling out inductance L through coupling. S 'Effectively reduce gate inductance L G Source-level inductor L S The coupling coefficient k between GS Simulation results clearly show that when the input inductance L... IN With gate inductor L G Coupling coefficient k GIN and input inductance L IN Source-level inductor L S Coupling coefficient k SIN Both are strongly coupled, and k GSWith weak coupling, a 2dB noise figure reduction can be achieved; this improvement enables the low-noise amplifier to more effectively suppress noise interference and improve signal quality when operating at high frequencies, providing a cleaner input signal for subsequent signal processing.

[0019] 2. In this invention, in k GIN and k SIN Strong coupling, k GS Under weak coupling conditions, the area of ​​the noise figure circle reaches its maximum. This means that on the Smith chart, more matching points can achieve a noise figure of 4dB, greatly expanding the range of input matching options. At the same time, the center of the noise figure circle is closer to the center of the non-reflection matching circle, indicating that better input matching can be achieved under this condition, reducing signal reflection loss, improving signal transmission efficiency, and enhancing the amplifier's adaptability to different operating environments and signal conditions.

[0020] 3. In this invention, the coupling cancellation technique of this invention can ensure k GIN and k SIN While maintaining strong coupling and ensuring that the coupling coefficient is almost unaffected, make k GS Further reduction of 46.5%. A defect-coupled transformer matching network with strong input-gate coupling, extremely strong input-source coupling, and extremely weak / zero gate-source coupling was successfully constructed; this specific coupling relationship is the key to achieving low noise and high gain bandwidth performance, laying a solid foundation for the high-performance operation of low-noise amplifiers.

[0021] 4. In this invention, the invention is designed and implemented based on conventional integrated circuit manufacturing processes such as SMIC's 40nm conventional CMOS process, without the need for special process steps or expensive manufacturing equipment; this feature reduces production difficulty and cost, facilitates large-scale mass production, and improves the scalability and practical application value of the technology.

[0022] 5. In this invention, the low-noise amplifier has a wide range of applications due to its excellent characteristics such as low noise and high gain bandwidth; it can be applied to phased array systems, effectively reducing chip overhead and improving the overall performance of the phased array system; at the same time, it can be flexibly combined with mixers, intermediate frequency amplifiers and other circuits to form a receiver system, meeting the needs of different wireless communication scenarios, such as 5G NR, radar systems and high-capacity backhaul communication, providing strong support for the development of modern broadband wireless systems. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 Circuit diagram of a defect-coupled low-noise amplifier; Figure 2 Schematic diagram and three-dimensional structure diagram of induced current cancellation in defect-coupled transformer matching network; Figure 3 Simulation results of noise figure under different coupling coefficients; Figure 4 Simulation graphs of noise figure circles under different combinations of coupling coefficients; Figure 5 Simulation diagrams of different coupling coefficients in a matching network for a coupled transformer based on coupling cancellation defects; Figure 6 This is a schematic diagram of one of the existing technologies.

[0024] Detailed explanation of each figure: Figure 1 The overall circuit structure of the defect-coupled low-noise amplifier of the present invention is shown, clearly demonstrating the connection relationship between the defect-coupled transformer matching network, the differential common-source transconductance amplifier stage, the fourth-order magnetically coupled resonant unit, the differential transconductance amplifier stage with neutralization capacitor, and the output transformer matching network.

[0025] Figure 2 The left figure is a schematic diagram of induced current cancellation in a defect-coupled transformer matching network, which intuitively explains how inductance L is canceled through coupling. S 'Reduce the gate-source inductive coupling coefficient k GS The principle; the right figure is a three-dimensional structural diagram, which shows in detail the layout of the three-turn inductor using metal layers of different thicknesses and the coupling cancellation inductor L. S The connection position of '.

[0026] Figure 3 The simulation results of the noise figure of a defect-coupled low-noise amplifier designed using SMIC's 40nm conventional CMOS process under different combinations of coupling coefficients are presented, clearly showing k GIN k SIN and k GS The effect of changes in coupling coefficient on noise figure.

[0027] Figure 4The simulation diagram of the noise figure circle under different combinations of coupling coefficients clearly shows the changes in the input matching range and matching conditions under different coupling coefficients by changing the area and center position of the noise figure circle.

[0028] Figure 5 Simulation results of different coupling coefficients for a coupled transformer matching network based on coupling cancellation defects are presented, highlighting the effectiveness of the coupling cancellation technique of this invention for k... GS The effect of reducing the coupling coefficient and on k GIN and k SIN The preservation of coupling coefficients. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0031] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0032] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0033] Example 1

[0034] This invention discloses a defect-coupled low-noise amplifier, and the specific implementation of this embodiment is as follows: Design Scheme: Using SMIC's conventional 40nm CMOS process, a structure such as... Figure 1 The defect-coupled low-noise amplifier shown includes a defect-coupled transformer matching network and a differential common-source transconductance amplifier stage, two fourth-order magnetically coupled resonant units, two differential transconductance amplifier stages with neutralization capacitors, and an output transformer matching network.

[0035] In a defect-coupled transformer network, the input inductance L IN With gate inductor L G Forward coupling, with a coupling coefficient of k GIN Input inductance L IN Source-level inductor L S Reverse coupling, with a coupling coefficient of k SIN Gate inductance L G Source-level inductor L S Reverse coupling, with a coupling coefficient of k GS The signal is applied from the RF input terminal to the input inductor L. IN Above, through the gate inductor L G Forwardly coupled to the gate of the first-stage amplifier circuit, through the source inductor L S It is reverse-coupled to the source of the first-stage amplifier circuit to achieve a gain boost for the radio frequency signal.

[0036] The noise from the MOSFET in the first-stage amplifier circuit passes through the source inductor L. S and gate inductor L G It is reverse-coupled to the gate of the MOSFET to achieve noise self-cancellation; in particular, a coupling cancellation inductor L is added to the tail of the source inductor. S ', used to offset gate inductance L G Source-level inductor L S Coupling coefficient k GS Make the gate inductance L G Source-level inductor L S The actual coupling coefficient is reduced, thereby achieving optimal simultaneous noise matching and input matching.

[0037] In the subsequent circuit, a fourth-order magnetically coupled resonant unit is used as an interstage matching unit to improve the overall gain-bandwidth product. The gain is further improved and the reverse isolation is enhanced through a differential gain stage with a neutralizing capacitor.

[0038] From a three-dimensional structural design perspective, the three coils of inductor are implemented using metal layers of different thicknesses, with L... IN Placed in the middle layer, L G and L S Placed in L respectively IN Top and bottom sides, to ensure k GIN k SINStrong coupling, and reducing k through physical principles GS Coupling cancellation inductance L S By using through-holes to connect to the top layer, the optimal coupling cancellation effect can be achieved while reducing its impact on the remaining coupling coefficients.

[0039] Simulation verification: Noise figure simulation was performed on the design scheme. The results show that when k GIN For strong coupling, k SIN When it is weakly coupled, regardless of k GS Neither strong nor weak noise can achieve the optimal noise figure; while when k GIN and k SIN When both are strongly coupled, decrease k GS It helps reduce the noise figure across the entire frequency band, as shown in simulation results. Figure 3 As shown, k GIN k SIN Strong coupling, k GS Weak coupling can reduce the noise figure by 2dB.

[0040] Simultaneously, simulations were performed on the noise figure circles under different combinations of coupling coefficients to obtain... Figure 4 When k GIN and k SIN Strong coupling, k GS When the coupling is weak, the area of ​​the noise figure circle is the largest, which means that there are more matching points on the Smith original that can achieve a noise figure of 4dB. Furthermore, the center of the noise figure circle is closer to the center of the non-reflection matching circle, indicating that a larger input matching range and better input matching conditions can be achieved at this time.

[0041] Furthermore, simulations were performed on different coupling coefficients of the coupling-compensation defect-coupled transformer matching network to obtain... Figure 5 By utilizing the coupling cancellation technology of this patent, it is possible to achieve k GIN and k SIN To maintain strong coupling, k GS It decreased further by 46.5%.

[0042] Example 2

[0043] This invention discloses a defect-coupled low-noise amplifier, and the specific implementation of this embodiment is as follows: Process adjustments: While using the same 40nm conventional CMOS process from SMIC, the selection and thickness of the metal layer were fine-tuned during the inductor fabrication process.

[0044] While ensuring that the three-turn inductor is implemented using metal layers of different thicknesses, optimize L IN L G and L S The metal layer thickness distribution further improves kGIN and k SIN To minimize the strong coupling effect, while minimizing k GS The overall structure of the defect-coupled low-noise amplifier is the same as that in Embodiment 1, including a defect-coupled transformer matching network and a differential common-source transconductance amplifier stage, two fourth-order magnetically coupled resonant units, two differential transconductance amplifier stages with neutralizing capacitors, and an output transformer matching network; wherein the coupling relationship of each inductor in the defect-coupled transformer network and the setting of the coupling cancellation inductor are the same as in Embodiment 1.

[0045] Performance Testing: After circuit fabrication, actual performance testing was conducted. In the millimeter-wave band, the noise figure, gain, and input-output matching of the low-noise amplifier were measured. Test results show that, compared to Example 1, under the same coupling coefficient conditions, the noise figure is further reduced, the input matching range is wider, and the overall performance of the amplifier is significantly improved. Specifically, the noise figure in the k... GIN and k SIN Strong coupling, k GS The loss was reduced to 1.8 dB with weak coupling, and the number of available matching points on the Smith original map increased by 15%.

[0046] Example 3

[0047] This invention discloses a defect-coupled low-noise amplifier, and the specific implementation of this embodiment is as follows: Circuit integration: The defect-coupled low-noise amplifier of the present invention is integrated with the mixer, intermediate frequency amplifier and other circuits to construct a complete receiver system; wherein the structure of the defect-coupled low-noise amplifier is the same as that of Embodiment 1, including a defect-coupled transformer matching network and a differential common-source transconductance amplifier stage, two fourth-order magnetically coupled resonant units, two differential transconductance amplifier stages with neutralization capacitors and an output transformer matching network; during the integration process, the signal transmission and interference problems between the circuits are fully considered and the circuit structure is reasonably laid out.

[0048] System testing: A comprehensive test was conducted on the integrated receiver system, including reception performance tests under different signal strengths and frequencies. The test results showed that, due to the advantages of the low-noise amplifier, which has low noise, high gain, and bandwidth, the signal reception capability of the entire receiver system in complex electromagnetic environments was significantly enhanced, and the bit error rate was significantly reduced.

[0049] At a signal strength of -80dBm and a frequency of 24GHz, the bit error rate was reduced by 30% compared to receiver systems using traditional low-noise amplifiers, effectively improving the reliability and stability of the communication system.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A defect-coupled low-noise amplifier, characterized in that: It includes a defect-coupled transformer matching network, a differential common-source transconductance amplifier stage, a fourth-order magnetically coupled resonant unit, a differential transconductance amplifier stage with a neutralizing capacitor, and an output transformer matching network; The input inductance L in the defect-coupled transformer matching network IN With gate inductor L G Forward coupling, with a coupling coefficient of k GIN Input inductance L IN Source-level inductor L S Reverse coupling, with a coupling coefficient of k SIN Gate inductance L G Source-level inductor L S Reverse coupling, with a coupling coefficient of k GS Furthermore, a coupling cancellation inductor L is provided at the tail of the source inductor. S 'Used to offset gate inductance L G Source-level inductor L S Coupling coefficient k GS ; The differential common-source transconductance amplifier stage is connected to the defect-coupled transformer matching network and is used to amplify the radio frequency signal processed by the defect-coupled transformer matching network. The fourth-order magnetically coupled resonant unit is used as an interstage matching unit to improve the overall gain-bandwidth product. The differential transconductance amplifier stage with a neutralizing capacitor is used to further improve the gain and enhance the reverse isolation. The output transformer matching network is used to perform output matching on the amplified signal.

2. The defect-coupled low-noise amplifier according to claim 1, characterized in that: The input inductance L IN Gate inductor L G Source-level inductor L S These are achieved using metal layers of different thicknesses, with the input inductance L... IN The gate inductor L is placed in the middle layer. G Source-level inductor L S Placed respectively on the input inductor L IN The top and bottom sides.

3. The defect-coupled low-noise amplifier according to claim 1, characterized in that: The coupling cancellation inductor L S Connect to the top layer using through holes.

4. A defect-coupled low-noise amplifier according to claim 1, characterized in that: The MOSFET noise in the differential common-source transconductance amplifier stage is transmitted through the source inductor L. S and gate inductor L G It is reverse-coupled to the gate of the MOS transistor to achieve noise self-cancellation.

5. A defect-coupled low-noise amplifier according to claim 1, characterized in that: The fourth-order magnetically coupled resonant unit achieves inter-stage matching through the principle of magnetic coupling resonance.

6. A defect-coupled low-noise amplifier according to claim 1, characterized in that: The differential transconductance amplifier stage with a neutralizing capacitor compensates for parasitic capacitance in the circuit to improve gain and enhance reverse isolation.

7. A defect-coupled low-noise amplifier according to claim 1, characterized in that: The low-noise amplifier is manufactured using conventional integrated circuit production processes.

8. A defect-coupled low-noise amplifier according to claim 7, characterized in that: The conventional integrated circuit manufacturing process is SMIC's 40nm conventional CMOS process.

9. A defect-coupled low-noise amplifier according to claim 1, characterized in that: The low-noise amplifier can be combined with the circuitry of the mixer and intermediate frequency amplifier to form a receiver system.

10. A defect-coupled low-noise amplifier according to claim 1, characterized in that: The low-noise amplifier can be applied to phased array systems.

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