Feature extraction device and use method thereof

Abstract

The invention provides a feature extraction device and a use method thereof. The device comprises a spin torque ferromagnetic resonance device, the spin torque ferromagnetic resonance device comprises a ferromagnetic material layer, a heavy metal material layer and an electrode structure, spin torque ferromagnetic resonance is formed between the ferromagnetic material layer and the heavy metal material layer, and the electrode structure is connected with the ferromagnetic material layer and the heavy metal material layer; the signal input unit is used for inputting a signal to be processed to the spin torque ferromagnetic resonance device; the signal acquisition unit is used for acquiring a signal processed by the spin torque ferromagnetic resonance device; and the current generation unit is used for transmitting direct current to the spin torque ferromagnetic resonance device and enhancing or weakening magnetic relaxation of the spin torque ferromagnetic resonance device so as to regulate and control a signal output by the spin torque ferromagnetic resonance device.

Description

Technical Field

[0001] The present invention belongs to the technical field of signal processing, and in particular relates to a feature extraction device and a use method thereof. Background Art

[0002] In the era of big data, feature extraction is a key step in data processing and analysis. Its core is to extract meaningful features from raw data to improve the efficiency and accuracy of machine learning and data analysis. First, feature extraction simplifies high-dimensional data by reducing the dimension of the data, which not only reduces the computational complexity but also improves the running speed and performance of the model. Second, feature extraction helps filter noise, remove redundant information, and extract the most relevant and valuable features, thereby enhancing the robustness and accuracy of the model.

[0003] Effective feature extraction is crucial to improving model performance. High-quality features enable the model to more accurately capture the laws and patterns of the data and improve the accuracy of prediction and classification. In addition, feature extraction can transform complex high-dimensional data into low-dimensional data that is easy to understand and interpret, which helps data visualization, enabling data scientists and business analysts to better understand the data and discover hidden patterns and trends. At the same time, reducing the dimension of data through feature extraction can significantly reduce data storage costs. In practical applications, feature extraction plays an important role. For example, in the field of image processing, feature extraction is used to extract information such as edges, textures, and colors from images for image classification and object detection. In the field of natural language processing, feature extraction is used to extract keywords and topics from text for text classification and sentiment analysis. In financial data analysis, feature extraction helps extract useful information from data such as stock prices and trading volumes for market forecasting and risk management.

[0004] However, traditional feature extraction methods mainly rely on spectrum analyzers and filter groups. These devices are not only bulky and slow in response, but more importantly, the feature accuracy is difficult to adjust because the filter bandwidth is not adjustable. Summary of the invention

[0005] The present invention provides a feature extraction device and a method for using the same. The feature extraction device has an adjustable filtering bandwidth, so that the accuracy of the feature can be selectively adjusted.

[0006] In one aspect, a feature extraction device is provided, comprising: A spin torque ferromagnetic resonance device comprises a ferromagnetic material layer, a heavy metal material layer and an electrode structure, wherein a spin torque ferromagnetic resonance is formed between the ferromagnetic material layer and the heavy metal material layer, and the electrode structure is connected to the ferromagnetic material layer and the heavy metal material layer; A signal input unit, used for inputting a signal to be processed into the spin torque ferromagnetic resonance device; A signal acquisition unit, used for acquiring a signal processed by a spin torque ferromagnetic resonance device; The current generating unit is used to transmit direct current to the spin torque ferromagnetic resonance device to enhance or weaken the magnetic relaxation of the spin torque ferromagnetic resonance device so as to regulate the signal output by the spin torque ferromagnetic resonance device.

[0007] Optionally, when the current generating unit transmits a forward direct current to the spin torque ferromagnetic resonance device, the filtering bandwidth of the spin torque ferromagnetic resonance device increases; when the current generating unit transmits a reverse direct current to the spin torque ferromagnetic resonance device, the filtering bandwidth of the spin torque ferromagnetic resonance device decreases.

[0008] Optionally, the ferromagnetic material layer is formed of yttrium iron garnet or permalloy.

[0009] Optionally, the heavy metal material layer is formed of Pt.

[0010] Optionally, the thickness of the heavy metal material layer is 5-10 nm.

[0011] Optionally, the thickness of the ferromagnetic material layer is 10-100 nm.

[0012] Optionally, the electrode structure is arranged on the side of the ferromagnetic material layer and the heavy metal material layer, and the electrode structure and the stacked ferromagnetic material layer and the heavy metal material layer form an E-shaped structure or a Hall stripe structure.

[0013] Optionally, the signal acquisition unit is a voltmeter or a phase lock.

[0014] On the other hand, a method for using a feature extraction device is provided, the method being applied to the feature extraction device as described in any one of the above items, comprising: Inputting a signal to be processed into the spin torque ferromagnetic resonance device; Acquiring a signal output by a spin torque ferromagnetic resonance device; When the signal output by the spin torque ferromagnetic resonance device does not meet the requirement, a direct current is transmitted to the spin torque ferromagnetic resonance device to regulate the signal output by the spin torque ferromagnetic resonance device.

[0015] Optionally, delivering a direct current to the spin torque ferromagnetic resonance device to regulate a signal output by the spin torque ferromagnetic resonance device includes: When the accuracy of the signal output by the spin torque ferromagnetic resonance device does not meet the requirements, a reverse direct current is supplied to the spin torque ferromagnetic resonance device; or when the noise of the signal output by the spin torque ferromagnetic resonance device does not meet the requirements, a forward direct current is supplied to the spin torque ferromagnetic resonance device.

[0016] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects: In an embodiment of the present disclosure, a feature extraction device is provided, which includes a spin torque ferromagnetic resonance (ST-FMR) device, which drives ferromagnetic resonance through a spin torque induced by an alternating current. When the signal to be processed is transmitted to the spin torque ferromagnetic resonance device in the form of an alternating current, due to the strong spin-orbit coupling of the heavy metal material layer, non-uniform spins will be generated and accumulated at the interface between the ferromagnetic material layer and the heavy metal material layer. These spins will diffuse to the ferromagnetic material layer, thereby exerting a torque on the magnetic moment of the ferromagnetic material layer. Since the injected charge flow is oscillating, the torque induced by the alternating current is also oscillating, so that the magnetic moment of the ferromagnetic material layer undergoes Larmor precession near the effective magnetic field of the ferromagnetic material layer, and the Larmor precession will eventually generate a DC voltage in the device, which can be detected by a voltmeter or a phase-locked device. More specifically, in a spin-torque ferromagnetic resonance device, the coupling of the oscillating magnetoresistance and the microwave current (that is, the signal to be processed that we input) generates a DC voltage that can be measured by a DC voltmeter or a phase-locked device. The device also includes a current generating unit. When the signal needs to be processed, an additional DC current is applied to the spin-torque ferromagnetic resonance device through the current generating unit. When the direction of the input DC current is positive, for example, when the angle between the direction of the DC current and the direction of the magnetic field of the ferromagnetic material layer is an acute angle (such as 45°), a DC current with a polarization direction parallel to the magnetization direction is injected into the ferromagnetic material layer, and the generated spin magnetic moment enhances magnetic relaxation. The enhanced magnetic relaxation will increase the line width of ST-FMR. On the contrary, when the direction of the injected DC current is negative, for example, the angle between the direction of the DC current and the direction of the magnetic field of the ferromagnetic material layer is an obtuse angle (such as 225°), according to the symmetry of the spin Hall angle effect, the polarization direction of the injected spin current is parallel to the magnetization direction but opposite in direction, which will weaken the magnetic relaxation of the spin torque ferromagnetic resonance device, thereby reducing the line width of the spin torque ferromagnetic resonance device. By injecting an additional DC current into the spin torque ferromagnetic resonance device, the signal to be processed input to the spin torque ferromagnetic resonance device is processed, and the size or direction of the injected DC current is adjusted to extract features of the signal to be processed and obtain a signal that meets the requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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.

[0018] Figure 1 A structural schematic diagram of a feature extraction device provided in an embodiment of the present disclosure; Figure 2 A schematic diagram of the structure of another feature extraction device provided in an embodiment of the present disclosure; Figure 3 A method flow chart of a method for using a feature extraction device provided in an embodiment of the present disclosure; Figure 4 A performance diagram of a ST-FMR device provided by an embodiment of the present disclosure; Figure 5 A waveform diagram of an input signal of a ST-FMR device provided in an embodiment of the present disclosure; Figure 6 A performance diagram of another ST-FMR device provided by an embodiment of the present disclosure; Figure 7 A waveform diagram of an output signal of a ST-FMR device provided in an embodiment of the present disclosure; Figure 8 A performance diagram of another ST-FMR device provided by an embodiment of the present disclosure; Fig. 9 A waveform diagram of an input signal of another ST-FMR device provided in an embodiment of the present disclosure; Fig.10 A waveform diagram of an output signal of another ST-FMR device provided in an embodiment of the present disclosure; Fig.11 A performance diagram of another ST-FMR device provided by an embodiment of the present disclosure; Fig.12 A waveform diagram of an output signal of another ST-FMR device provided in an embodiment of the present disclosure; Fig.13 A performance diagram of another ST-FMR device provided by an embodiment of the present disclosure; Fig.14 A performance diagram of another ST-FMR device provided by an embodiment of the present disclosure; Fig.15 A performance diagram of another ST-FMR device provided by an embodiment of the present disclosure; Fig.16 A graph of an output signal of another ST-FMR device provided in an embodiment of the present disclosure.

[0019] The accompanying drawings are numbered as follows: 1: ST-FMR device; 11: ferromagnetic material layer; 12: heavy metal material layer; 13: electrode structure; 2: Signal input unit; 3: Signal acquisition unit; 4: Current generating unit. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings 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.

[0021] This paper proposes a new feature extraction device based on spin electronics. This device not only significantly reduces the area occupied, but its inherent fast Fourier transform (FFT) function greatly speeds up the response time. In addition, the filter bandwidth of the device is adjustable, so that the feature extraction accuracy can be freely adjusted according to needs. This innovation is of great significance in the field of feature extraction and provides a more efficient and flexible solution for big data analysis and intelligent applications. Through the application of this new spin electronics device, feature extraction technology will usher in new development opportunities and provide more solid technical support for the intelligent and data-driven decision-making of various industries.

[0022] Figure 1 A structural diagram of a feature extraction device provided in an embodiment of the present disclosure. Figure 1 A top view of the feature extraction device.

[0023] Figure 2 A schematic diagram of another feature extraction device provided in an embodiment of the present disclosure. Figure 2 For feature extraction device Figure 1 Cross-sectional view along the dashed line AA`.

[0024] See also Figure 1 and Figure 2 , the device comprises: The spin torque ferromagnetic resonance device 1 comprises a ferromagnetic material layer 11, a heavy metal material layer 12 and an electrode structure 13, wherein a spin torque ferromagnetic resonance is formed between the ferromagnetic material layer 11 and the heavy metal material layer 12, and the electrode structure 13 is connected to the ferromagnetic material layer 11 and the heavy metal material layer 12; A signal input unit 2, used for inputting a signal to be processed into the spin torque ferromagnetic resonance device 1; A signal acquisition unit 3, used for acquiring a signal processed by the spin torque ferromagnetic resonance device 1; The current generating unit 4 is used to transmit direct current to the spin torque ferromagnetic resonance device 1 to enhance or weaken the magnetic relaxation of the spin torque ferromagnetic resonance device 1 to control the filtering bandwidth of the spin torque ferromagnetic resonance device 1, thereby adjusting the signal output by the spin torque ferromagnetic resonance device 1.

[0025] In an embodiment of the present disclosure, a feature extraction device is provided, which includes a spin torque ferromagnetic resonance (ST-FMR) device, which drives ferromagnetic resonance through a spin torque induced by an alternating current. When the signal to be processed is transmitted to the spin torque ferromagnetic resonance device in the form of an alternating current, due to the strong spin-orbit coupling of the heavy metal material layer, non-uniform spins will be generated and accumulated at the interface between the ferromagnetic material layer and the heavy metal material layer. These spins will diffuse to the ferromagnetic material layer, thereby exerting a torque on the magnetic moment of the ferromagnetic material layer. Since the injected charge flow is oscillating, the torque induced by the alternating current is also oscillating, so that the magnetic moment of the ferromagnetic material layer undergoes Larmor precession near the effective magnetic field of the ferromagnetic material layer, and the Larmor precession will eventually generate a DC voltage in the device, which can be detected by a voltmeter or a phase-locked amplifier. More specifically, in the spin torque ferromagnetic resonance device, the oscillating magnetoresistance and microwave current coupling will generate a DC voltage that can be measured by a DC voltmeter or a phase-locked amplifier. The device also includes a current generating unit. When the signal needs to be processed, an additional current is applied to the spin torque ferromagnetic resonance device through the current generating unit. When the direction of the input DC current is positive, for example, the angle between the direction of the DC current and the direction of the magnetic field of the ferromagnetic material layer is an acute angle (such as 45°), the DC current with a polarization direction parallel to the magnetization direction is injected into the ferromagnetic material layer, and the generated spin magnetic moment enhances the magnetic relaxation. The enhanced magnetic relaxation will increase the line width of the ST-FMR. Conversely, when the direction of the injected DC current is negative, for example, the angle between the direction of the DC current and the direction of the magnetic field of the ferromagnetic material layer is an obtuse angle (such as 225°), according to the symmetry of the spin Hall angle effect, the polarization direction of the injected spin current is parallel to the magnetization direction but in the opposite direction, which will weaken the magnetic relaxation of the spin torque ferromagnetic resonance device, thereby reducing the line width of the spin torque ferromagnetic resonance device. By additionally injecting a direct current into the spin torque ferromagnetic resonance device, the signal to be processed input to the spin torque ferromagnetic resonance device is processed, and the size or direction of the injected direct current is adjusted to extract features of the signal to be processed and obtain a signal that meets the requirements.

[0026] In an example provided in the present disclosure, the signal to be processed may be an audio signal. Of course, the above single processing signal is only an example, and the signal to be processed may also be other signals.

[0027] In the embodiment of the present disclosure, when the current generating unit transmits a positive direct current to the spin-torque ferromagnetic resonance device, the filtering bandwidth of the spin-torque ferromagnetic resonance device increases; when the current generating unit transmits a reverse direct current to the spin-torque ferromagnetic resonance device, the filtering bandwidth of the spin-torque ferromagnetic resonance device decreases.

[0028] In the embodiments disclosed herein, by transmitting direct currents in different directions to the spin torque ferromagnetic resonance device, the filtering bandwidth of the spin torque ferromagnetic resonance device can be increased or decreased, and the magnitude of the direct current can affect the degree of increase or decrease in the filtering bandwidth, thereby forming a feature extraction device with adjustable filtering bandwidth.

[0029] The direction of the positive DC current means that the angle between the direction of the DC current and the magnetic field direction of the ferromagnetic material layer in the spin torque ferromagnetic resonance device is an acute angle. The direction of the reverse DC current means that the angle between the direction of the DC current and the magnetic field direction of the ferromagnetic material layer in the spin torque ferromagnetic resonance device is an obtuse angle.

[0030] In the disclosed embodiment, the ferromagnetic material layer 11 is formed of yttrium iron garnet or permalloy. When yttrium iron garnet is used as the ferromagnetic material layer, since the resistance coefficient of yttrium iron garnet is small, it is beneficial to the signal control effect of the subsequent input direct current, making the control effect of the direct current on the spin torque ferromagnetic resonance device more obvious. When permalloy is used, the signal intensity output by the spin torque ferromagnetic resonance device will be higher.

[0031] In the disclosed embodiment, the heavy metal material layer is formed of Pt. Pt has a relatively large spin Hall angle, and using Pt as the heavy metal material layer is more conducive to forming a strong spin-orbit coupling effect, and the performance of the formed spin-torque ferromagnetic resonance device is better.

[0032] In the disclosed embodiment, the thickness of the heavy metal material layer is 5-10 nm.

[0033] Exemplarily, the thickness of the heavy metal material layer is 8 nm.

[0034] In the disclosed embodiment, the thickness of the heavy metal material layer should not be too thick or too thin. When the signal (DC voltage) output by the spin torque ferromagnetic resonance device is subsequently obtained, the signal will be measured on the surface of the heavy metal material layer. If the thickness of the heavy metal material layer is thick, it is not conducive to the signal passing through the heavy metal material layer. If the thickness of the heavy metal material layer is too thin, the spin-orbit coupling effect of the heavy metal material layer is poor, which is not conducive to the performance of the spin torque ferromagnetic resonance device.

[0035] In the disclosed embodiment, the thickness of the ferromagnetic material layer is 10-100 nm.

[0036] Exemplarily, the thickness of the ferromagnetic material layer is 18 nm.

[0037] In the disclosed embodiment, the thickness of the ferromagnetic material layer should not be too thick, as too thick a thickness is not conducive to the size of the device and the manufacturing cost, while too thin a thickness will result in a weak signal generated by the ST-FMR device.

[0038] In the disclosed embodiment, the electrode structure 13 is disposed on the side of the ferromagnetic material layer 11 and the heavy metal material layer 12 , and the electrode structure 13 and the stacked ferromagnetic material layer 11 and the heavy metal material layer 12 form an E-shaped structure or a Hall stripe structure.

[0039] In the embodiments of the present disclosure, an E-shaped structure or a Hall stripe structure is used to obtain a larger spin-orbit torque and a larger current density, thereby enhancing the signal of the ST-FMR device.

[0040] In the embodiment of the present disclosure, the signal acquisition unit 2 is a voltmeter or a phase lock.

[0041] In the disclosed embodiment, the signal output by the ST-FMR device can be accurately acquired through a voltmeter or a phase lock.

[0042] In the disclosed embodiment, Figure 1 The size parameters of the middle electrode are as follows: Width part: D1 is 29.71nm, D2 is 217nm, D3 is 150nm, D4 is 524nm, D5 is 100nm, and D6 is 50nm.

[0043] Length and spacing part: L1 is 296nm, L2 is 40.8nm, L3 is 481nm, and L4 is 400.7nm.

[0044] Angle part: α is 135°, β is 145.6°.

[0045] By adjusting the size parameters of the electrodes, the frequency range of the microwave current allowed to pass through the ST-FMR device can be adjusted. At the same time, the impedance matching of the ST-FMR can be ensured, thereby ensuring good performance of the ST-FMR device. The above parameters are an example provided in the embodiment of the present disclosure, and the actual size of the ST-FMR device can be set as needed.

[0046] In an example provided by an embodiment of the present disclosure, the signal input unit 2 may be a waveguide, the signal acquisition unit 3 may be a voltmeter, and the current generation unit 4 may be a direct current source.

[0047] Figure 3 A method flow chart of a method for using a feature extraction device provided in an embodiment of the present disclosure. Figure 3 The method steps include: S101 . Input a signal to be processed into a spin torque ferromagnetic resonance device.

[0048] The signal to be processed is input into the ST-FMR device in the form of a radio frequency signal.

[0049] S102, obtaining a signal output by a spin torque ferromagnetic resonance device.

[0050] The voltage signal output by the ST-FMR device is obtained through a voltmeter or a phase-locked device, thereby generating an ST-FMR curve.

[0051] The test formula of ST-FMR curve is as follows:

[0052] Among them, V A and V S are the strengths of the antisymmetric and symmetric line shapes, respectively. H and H 0 are the filter line width and resonance peak position of the ST-FMR signal. The resonance peak position and line width corresponding to the test frequency can be obtained. Combining these parameters, the ST-FMR curve shape corresponding to the RF signal of any frequency can be obtained.

[0053] S103, when the signal output by the spin torque ferromagnetic resonance device does not meet the requirement, transmitting a direct current to the spin torque ferromagnetic resonance device to enhance or weaken the magnetic relaxation of the spin torque ferromagnetic resonance device to regulate the signal output by the spin torque ferromagnetic resonance device.

[0054] In step S103, when the accuracy of the signal output by the spin torque ferromagnetic resonance device does not meet the requirements, a reverse direct current is supplied to the spin torque ferromagnetic resonance device; or when the noise of the signal output by the spin torque ferromagnetic resonance device does not meet the requirements, a forward direct current is supplied to the spin torque ferromagnetic resonance device.

[0055] By determining the performance of a certain part of the signal that is important in feature extraction, determining the direction of the input DC current, and regulating the magnitude of the DC current, a signal that meets the requirements can be obtained.

[0056] In the embodiment of the present disclosure, a feature extraction method is also provided, by inputting a direct current into the ST-FMR device, regulating the magnetic relaxation of the ST-FMR device to regulate the signal output by the ST-FMR device, thereby obtaining a signal that meets the requirements. At the same time, by inputting direct currents of different directions and magnitudes, a feature extraction device with adjustable filter bandwidth can be obtained, and by regulating the filter bandwidth of the ST-FMR device, the waveform of the signal output by the ST-FMR device can be regulated.

[0057] Figure 4 This is a performance diagram of a ST-FMR device provided by an embodiment of the present disclosure. Figure 4 , Figure 4 The horizontal axis represents the magnetic field size of the ST-FMR device, and the vertical axis represents the measured signal output by the ST-FMR.

[0058] Among them, a single frequency radio frequency signal is used to measure the performance of the ST-FMR device, such as Figure 4 The performance of the ST-FMR device was measured using signals at 8 GHz, 8.5 GHz, 9 GHz, 9.5 GHz and 10 GHz, and five performance curves were obtained.

[0059] Figure 5 The waveform diagram of the input signal of a ST-FMR device provided by the embodiment of the present disclosure. Figure 5 , the input signal is a 5.0GHz RF signal.

[0060] Figure 6 A performance diagram of another ST-FMR device provided in an embodiment of the present disclosure. Figure 6 is based on Figure 4 The performance parameters of the ST-FMR device actually measured in the figure and the filtering performance diagram of the ST-FMR device simulated in the simulation software.

[0061] Figure 7 This is a waveform diagram of an output signal of a ST-FMR device provided by an embodiment of the present disclosure. Figure 5 , Figure 6 and Figure 7 ,when Figure 5 The input signal in Figure 6 After processing the ST-FMR device in Figure 7 The waveform of the output signal in .

[0062] exist Figure 7 In the example, the waveform of the output signal is a point value. By performing a dot product operation on the point values, multiple points are fitted into an output curve.

[0063] Figure 8Another performance diagram of ST-FMR device provided by the embodiment of the present disclosure. Figure 8 ,exist Figure 8 The relationship between the filter line width of the ST-FMR device and the direction of the input DC current is shown in Figure 2. When the angle φ between the direction of the DC current input to the ST-FMR device and the direction of the magnetic field inside the ST-FMR device is H =45°, the filter line width of the ST-FMR device ( H W ) and the input DC current (I dc ) is negatively correlated. When the angle φ between the direction of the DC current input to the ST-FMR device and the direction of the magnetic field inside the ST-FMR device H =225°, the filter line width of the ST-FMR device is related to the input DC current (I dc ) is positively correlated with its size.

[0064] Figure 8 The YIG in the ST-FMR device indicates that the ferromagnetic material layer is made of yttrium iron garnet, and the Pt indicates that the heavy metal material layer is made of Pt.

[0065] Fig. 9 This is a waveform diagram of an input signal of another ST-FMR device provided by an embodiment of the present disclosure. Fig. 9 ,exist Fig. 9 A complex input signal waveform is provided in .

[0066] Fig.10 This is a waveform diagram of an output signal of another ST-FMR device provided by an embodiment of the present disclosure. Fig.10 , Fig. 9 The input signal in Figure 6 After processing the ST-FMR device in Fig.10 The output signal in .

[0067] Fig.11 Another performance diagram of ST-FMR device provided by the embodiment of the present disclosure. Fig.11 , Figure 1 for Figure 6 A partial enlarged view of the ST-FMR device performance curve in FIG. Among them, the DC current I dc The size is 0mA.

[0068] Fig.12 This is a waveform diagram of an output signal of another ST-FMR device provided by an embodiment of the present disclosure. Fig.12 ,right Fig.10 After performing dot product on the output signal in, the fitted curve is Fig.12 The curve in .

[0069] Fig.13 This is a performance diagram of another ST-FMR device provided by an embodiment of the present disclosure. Fig.13 ,exist Fig.11 On this basis, a forward DC current of 3mA is input into the ST-FMR device, and the filtering bandwidth of the ST-FMR device increases.

[0070] Fig.14 This is a performance diagram of another ST-FMR device provided by an embodiment of the present disclosure. Fig.14 , Fig. 9 The input signal in Fig.13 After processing the ST-FMR device in Fig.14 The output signal.

[0071] Fig.14 and Fig.12 The waveform of the input signal is different. The difference is Fig.14 A 3mA DC current was input into the ST-FMR device, which changed the filter bandwidth of the ST-FMR device, so that the waveform of the signal output by the ST-FMR device was different.

[0072] Fig.15 This is a performance diagram of another ST-FMR device provided by an embodiment of the present disclosure. Fig.15 , a reverse DC current of 3mA is input into the ST-FMR device, and the filter line width of the ST-FMR device is reduced.

[0073] Fig.16 A graph of the output signal of another ST-FMR device provided in an embodiment of the present disclosure. Fig.16 , Fig.16 and Fig.12 , Fig.14 The waveforms of the output curves in are all different. The difference is that: Fig.16 A reverse DC current of 3 mA was input into the ST-FMR device, reducing the filter line width of the ST-FMR device.

[0074] It is worth mentioning that Fig.12 , Fig.14 and Fig.16 The input signals are Fig. 9 The signal in .

[0075] It is worth mentioning that Figures 10 to 16 The attached figure is obtained by simulation.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A feature extraction device, characterized in that: include: A spin torque ferromagnetic resonance device comprises a ferromagnetic material layer, a heavy metal material layer and an electrode structure, wherein a spin torque ferromagnetic resonance is formed between the ferromagnetic material layer and the heavy metal material layer, and the electrode structure is connected to the ferromagnetic material layer and the heavy metal material layer; A signal input unit, used for inputting a signal to be processed into the spin torque ferromagnetic resonance device; A signal acquisition unit, used for acquiring a signal processed by a spin torque ferromagnetic resonance device; The current generating unit is used to transmit direct current to the spin torque ferromagnetic resonance device to enhance or weaken the magnetic relaxation of the spin torque ferromagnetic resonance device so as to regulate the signal output by the spin torque ferromagnetic resonance device.

2. The feature extraction device according to claim 1, characterized in that: When the current generating unit transmits a positive direct current to the spin torque ferromagnetic resonance device, the filtering bandwidth of the spin torque ferromagnetic resonance device increases; when the current generating unit transmits a reverse direct current to the spin torque ferromagnetic resonance device, the filtering bandwidth of the spin torque ferromagnetic resonance device decreases.

3. The feature extraction device according to claim 1, characterized in that: The ferromagnetic material layer is formed of yttrium iron garnet or permalloy.

4. The feature extraction device according to claim 1, characterized in that: The heavy metal material layer is formed of Pt.

5. The feature extraction device according to claim 1, characterized in that: The thickness of the heavy metal material layer is 5-10 nm.

6. The feature extraction device according to claim 1, characterized in that: The thickness of the ferromagnetic material layer is 10-100 nm.

7. The feature extraction device according to claim 1, characterized in that: The electrode structure is arranged on the side of the ferromagnetic material layer and the heavy metal material layer, and the electrode structure and the stacked ferromagnetic material layer and the heavy metal material layer form an E-shaped structure or a Hall stripe structure.

8. The feature extraction device according to claim 1, characterized in that: The signal acquisition unit is a voltmeter or a phase lock.

9. A method for using a feature extraction device, characterized in that: The method is applied to the feature extraction device according to any one of claims 1 to 8, comprising: Inputting a signal to be processed into the spin torque ferromagnetic resonance device; Acquiring a signal output by a spin torque ferromagnetic resonance device; When the signal output by the spin torque ferromagnetic resonance device does not meet the requirement, a direct current is transmitted to the spin torque ferromagnetic resonance device to regulate the signal output by the spin torque ferromagnetic resonance device.

10. The method for using the feature extraction device according to claim 9, characterized in that: Transmitting a direct current to the spin torque ferromagnetic resonance device to regulate a signal output by the spin torque ferromagnetic resonance device includes: When the accuracy of the signal output by the spin torque ferromagnetic resonance device does not meet the requirements, a reverse direct current is supplied to the spin torque ferromagnetic resonance device; or when the noise of the signal output by the spin torque ferromagnetic resonance device does not meet the requirements, a forward direct current is supplied to the spin torque ferromagnetic resonance device.

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