Method and system for representing high-frequency characteristic of magnetic passive device

Abstract

The invention discloses a magnetic passive device high-frequency characteristic characterization method and system, and the method comprises the steps: carrying out the denoising, blocking and Fourier transformation of collected voltage and current signals, and obtaining the frequency spectrum information of the signals; obtaining impedance data of the inductor at different frequencies by calculating the ratio of the voltage spectrum to the current spectrum; synchronously calibrating and compensating parasitic parameters in the test system and time delay of the test system; and performing fitting calculation and analysis on the obtained impedance data to obtain an impedance characteristic curve of the inductor under high frequency and large signals. The system comprises a built test system, the test system comprises a signal generation module, a data acquisition module and a data processing module, the problems that delay caused by a probe and an experimental device and generation of system parasitic parameters must be considered are solved, the impedance characteristic of the inductor can be accurately measured under the conditions of high frequency and large signals, and the measurement accuracy is improved. And analysis and compensation of delay and parasitic parameters are also realized.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic material characterization, and in particular to a method and system for characterizing high-frequency characteristics of a magnetic passive device. Background Art

[0002] Power on chip (PwrSoC) is one of the most promising technologies that can achieve higher integration, smaller size and more reliable voltage regulation in low-power electronic devices. Due to the quality and integration of magnetic materials in the device structure, silicon integrated magnetic components are the key bottleneck to achieve PwrSoC; air-core inductors built on silicon substrates are the simplest solution, but require a large surface area to meet the inductance requirements of the converter and EMI issues. Thin-film core inductors are considered to be a promising technology that can achieve high efficiency and high area utilization.

[0003] Compared with traditional core ferrites, most soft magnetic films have higher losses, especially in terms of eddy current losses, because of their higher conductivity. The low volume of magnetic materials in these devices means that there is a strong dependence of device behavior on the level of the excitation signal. The optimal design of dc-dc converters requires accurate electrical parameters of magnetic devices, but existing commercial measurement instruments usually provide current excitation measurements of up to tens of milliamperes at the frequencies involved in integrated silicon converters. Currently, small signal impedance analyzers are widely used to characterize high-frequency power devices. However, they can only provide information on certain loss factors that affect device performance, namely copper loss and eddy current loss. In order to accurately measure device performance under "real circuit" conditions, larger voltage signals need to be applied. With these larger signals, iron losses including eddy current losses, hysteresis losses and abnormal losses can be fully measured. For some magnetic materials, hysteresis losses may be more dominant than eddy currents. Large signal measurement systems must be based on generating sufficient excitation signals and measuring equivalent impedance with high precision. Impedance measurements are performed by extracting the ratio between the voltage and current waveforms in the device. Voltage and current measurements can be easily performed using a wide-band oscilloscope. However, due to limited bandwidth and probe mismatch, accurate extraction of voltage and current waveforms and elimination of time delays become important challenges. Summary of the invention

[0004] The purpose of the present invention is to provide a method and system for characterizing the high-frequency characteristics of a magnetic passive device. By generating high-frequency large-signal excitation, accurately collecting voltage and current signals, extracting fundamental and harmonic components, and combining digital signal processing technology, the present invention can achieve accurate measurement of the inductor impedance at a maximum frequency of 70Mhz and a maximum excitation current of 200mA, so as to solve the problem that the prior art cannot accurately measure the inductor impedance under large-signal conditions.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a high-frequency characteristic characterization system of a magnetic passive device, including a constructed test system, the test system including the following functional modules: a signal generating module, a data acquisition module, and a data processing module, the signal generating module is used to generate a large signal at a high frequency, the data acquisition module is used to collect the voltage signal at both ends of the inductor and the current signal flowing through the inductor, and the data processing module is used to denoise, isolate DC and Fourier transform the collected voltage and current signals to obtain the frequency spectrum information of the signal.

[0006] Preferably, the signal generating module comprises a signal generator and a power amplifier, the signal generator is used to generate a large signal at a high frequency, and the power amplifier is used to amplify the signal to meet the test requirements and apply it to the inductor to be tested; the data acquisition module comprises a voltage probe, a current probe, a coaxial cable, and an oscilloscope, the voltage probe and the current probe are used to collect the voltage signal at both ends of the inductor and the current signal flowing through the inductor, the coaxial cable is used to transmit the signal to the oscilloscope, and the oscilloscope is used to capture the details of the high-frequency signal through a high-precision ADC chip.

[0007] Preferably, the signal generator adopts direct digital frequency synthesis technology to generate high-frequency signals with a frequency range from 1μHz to 150MHz and an amplitude from 1mVPP to 20VPP; the power amplifier adopts a broadband linear amplifier to provide power output in the entire frequency range, with a maximum output power of 100W; the current probe is a non-contact current probe based on a Hall effect sensor, with a bandwidth of up to 100MHz, a sensitivity of up to 10mA / div, and an AC accuracy of ±3%; the voltage probe has a bandwidth of up to 200MHz, a high input impedance of 10MΩ and a low parasitic capacitance of 15pF.

[0008] According to the above technical solution, the high-frequency characteristic characterization system of a magnetic passive device uses a high-frequency characteristic characterization method of a magnetic passive device, and the method includes the following steps:

[0009] Step S1: performing denoising, filtering and baseline correction preprocessing on the collected voltage and current signals, and performing Fourier transform on the preprocessed signals to obtain the spectrum information of the signals;

[0010] Preferably, the denoising specifically includes:

[0011] S101: Select Daubechies wavelet basis as the wavelet basis for high frequency signal denoising;

[0012] S102: Determine the number of wavelet decomposition layers according to the signal frequency range;

[0013] S103: using a soft threshold method to perform threshold processing on the wavelet coefficients to remove high-frequency noise components;

[0014] S104: Perform wavelet reconstruction on the processed wavelet coefficients to obtain a denoised signal.

[0015] Preferably, the filtering specifically includes: using a digital filter for filtering: that is, selecting a bandpass filter with a passband range of 10MHz to 70MHz and a stopband attenuation greater than 60dB, and filtering the denoised signal by using an FIR filter and a window function method to remove out-of-band noise;

[0016] Preferably, the baseline correction specifically includes: calculating the mean value of the signal as a baseline estimation value, subtracting the baseline estimation value from the original signal to obtain a corrected signal, and the baseline correction is used to eliminate the DC bias in the signal;

[0017] Preferably, the Fourier transform comprises: performing windowing processing using a Blackman-Harris window, performing a fast Fourier transform (FFT) on the windowed signal to obtain a spectrum of the signal, and finally improving the spectrum resolution by an interpolation FFT algorithm.

[0018] Step S2: Obtaining impedance data of the inductor at different frequencies by calculating the ratio of the voltage spectrum to the current spectrum;

[0019] Step S3: synchronously calibrating and compensating for parasitic parameters and test system delay in the test system;

[0020] Preferably, the calibration comprises: performing system calibration by adopting three standard states of open circuit, short circuit and load, and the compensation comprises: compensating the measured impedance data according to the system calibration result to eliminate the influence of system delay and parasitic parameters.

[0021] Step S4: fitting calculation and analysis are performed on the obtained impedance data to obtain an impedance characteristic curve of the inductor under high frequency and large signal.

[0022] Preferably, the fitting, calculation and analysis of the impedance data includes: using the least squares method to perform curve fitting and calculation on the impedance data to obtain the impedance characteristic curve of the inductor with a large signal at a high frequency, and by analyzing the shape and characteristic points of the curve, evaluating the key parameters of the inductor's inductance, quality factor, and loss density, and by comparing the impedance characteristics under different signal strengths, the nonlinear characteristics of the output inductor under large signal conditions, that is, the impedance characteristic curve of the output inductor with a large signal at a high frequency.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) Through a specially designed test system and signal processing technology, the impedance characteristics of inductors can be accurately measured under high frequency (up to 70MHz) and large signal (maximum 200mA excitation current) conditions, covering most of the operating frequencies of inductors in practical applications;

[0025] (2) Through wavelet transform, Fourier transform, least squares fitting and other methods, the influence of external interference on measurement accuracy is greatly reduced;

[0026] (3) Through system calibration and compensation, the influence of time delay and parasitic parameters in the test system is effectively eliminated, the sensitivity of loss to high frequency is reduced, and the measurement accuracy is further improved;

[0027] (4) The test frequency range is from 10MHz to 70MHz, which can cover most of the operating frequencies of inductors in practical applications. By analyzing the impedance characteristics at different frequencies, we can fully understand the frequency response characteristics of the inductor, providing an important reference for circuit and inductor design;

[0028] (5) By comparing the impedance characteristics under different signal strengths, the nonlinear characteristics of the inductor under large signal conditions are studied, providing an important basis for the design and optimization of the inductor;

[0029] (6) The inductor adopts a PCB hole design, which can realize the replacement test of different core materials and facilitate the performance evaluation of inductors with different cores under high frequency and large signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0031] Figure 1 It is a schematic diagram of the system module composition provided by an embodiment of the present invention;

[0032] Figure 2 is a flowchart of the method steps provided by an embodiment of the present invention;

[0033] Figure 3 is a schematic diagram of a test system provided by an embodiment of the present invention;

[0034] Figure 4 It is a circuit schematic diagram of a test PCB board provided by an embodiment of the present invention;

[0035] Figure 5 is a physical diagram of a test system provided by an embodiment of the present invention;

[0036] Figure 6 It is a finite element simulation model diagram of the inductor to be tested provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0038] The present invention is combined in this embodiment Figure 1 , providing the following technical solutions: a high-frequency characteristic characterization system for a magnetic passive device, including a constructed test system, the test system including the following functional modules: a signal generation module, a data acquisition module, and a data processing module, the signal generation module is used to generate a large signal at a high frequency, the data acquisition module is used to collect the voltage signal at both ends of the inductor and the current signal flowing through the inductor, and the data processing module is used to perform denoising, DC isolation, and Fourier transformation on the collected voltage and current signals to obtain the spectrum information of the signal;

[0039] In this embodiment, the hardware design of the test system is the key to realizing the large signal impedance test of the inductor at high frequency. The signal generation module includes a signal generator and a power amplifier. The signal generator is used to generate a large signal at high frequency. The power amplifier is used to amplify the signal to meet the test requirements and apply it to the inductor to be tested. The data acquisition module includes a voltage probe, a current probe, a coaxial cable, and an oscilloscope. Among them, the voltage probe and the current probe are used to collect the voltage signal at both ends of the inductor and the current signal flowing through the inductor. The coaxial cable is used to transmit the signal to the oscilloscope. The oscilloscope is used to capture the details of the high-frequency signal through a high-precision ADC chip.

[0040] For example, Figure 1 In the schematic diagram of the test system shown, C1 is a DC blocking capacitor, R1 is an equivalent resistance of the test inductor loss, L1 is the inductance of the test inductor, R2 is the winding resistance, L2 is the winding inductance, and C2 includes the parasitic capacitance of the voltage probe and the parasitic capacitance of the test inductor winding;

[0041] Specifically, the signal generator uses direct digital frequency synthesis (DDS) technology, which can generate high-frequency signals with a frequency range from 1μHz to 150MHz and an amplitude from 1mVPP to 20VPP, providing low-jitter and low-distortion signal output to ensure the accuracy of the test results; the power amplifier uses a broadband linear amplifier design, which can provide stable power output over the entire frequency range, with a maximum output power of up to 100W; the current probe is a non-contact current probe (based on a Hall effect sensor) with a bandwidth of up to 100Mhz and a sensitivity of up to 10 mA / div, and has an AC accuracy of ±3%; the voltage probe has a bandwidth of up to 200Mhz, high input impedance (10MΩ) and low parasitic capacitance (15pF); the oscilloscope uses a high-speed and high-precision ADC chip, with a sampling rate of up to 1GS / s and a resolution of 16 bits, which can accurately capture the details of high-frequency signals; in order to reduce the influence of parasitic parameters in the test system, a number of measures have been taken in hardware design; first, the entire test process is completed on a designed PCB circuit board, and coaxial cables and SMA connectors are used to connect the modules to reduce losses and reflections during signal transmission; secondly, a high-input impedance buffer amplifier is added to the front end of the data acquisition module to reduce the impact on the circuit under test.

[0042] Further, combined with Figure 2 The principle of the PCB test board shown in the figure, where SMA1 is the excitation source. The high-frequency signal generated by the signal generator is amplified by the broadband amplifier and connected to the test system by SMA1. Pins 1, 2, 3, and 4 of SMA1 are connected and grounded by a metal shell on the outside. Pin 5 is the positive input and output connected to the left side of the DC blocking 10μF capacitor C1, and the right side of C1 is connected to pad P5. The middle of pads P5 and P6 is connected by a copper wire. The current probe is connected here to extract the current waveform in the loop. Pad P6 is connected to P8, and it is also connected to the positive input 5 pin of SMA2. The PCB inductor to be tested is welded in pads P7 and P8, and pad P7 is grounded. The same as above, SMA2, the metal shell of pins 1, 2, 3, and 4 is connected to the ground, and SMA2 is the voltage waveform acquisition interface of the inductor to be tested.

[0043] In this embodiment, combined with Figure 3 As shown, signal processing and data analysis are the key links to obtain accurate test results. Therefore, the large signal impedance test of the inductor at high frequency is a method for characterizing the high-frequency characteristics of magnetic passive devices based on the application of the test system: the method specifically includes the following steps:

[0044] Step S1: De-noising, DC isolation and Fourier transformation are performed on the collected voltage and current signals to obtain the spectrum information of the signals;

[0045] Exemplarily, during the signal acquisition process, the collected voltage and current signals often contain a lot of noise due to environmental noise, equipment noise and interference during signal transmission. Therefore, signal preprocessing is a key step to ensure the accuracy of subsequent analysis. Therefore, the collected voltage and current signals are subjected to preprocessing steps including denoising, filtering and baseline correction, wherein high-frequency noise is removed by adopting a wavelet transform method, specifically including:

[0046] S101: Select a wavelet basis suitable for high-frequency signal processing; since the Daubechies wavelet basis (db4) has good localization characteristics, this wavelet basis is selected to perform denoising on the high-frequency signal.

[0047] S102: Determine the number of wavelet decomposition layers according to the signal frequency range. In this embodiment, the number of decomposition layers is determined to be 5.

[0048] S103: using a soft threshold method to perform threshold processing on the wavelet coefficients to remove high-frequency noise components;

[0049] S104: Perform wavelet reconstruction on the processed wavelet coefficients to obtain a denoised signal.

[0050] In order to further remove the spurious frequency components in the signal, a digital filter is used for processing: that is, a bandpass filter is selected with a passband range of 10MHz to 70MHz and a stopband attenuation greater than 60dB. By adopting an FIR filter and using the window function method to design it, the window function selects the Hamming window for filtering, and the denoised signal is filtered to remove out-of-band noise and achieve filtering processing.

[0051] For example, since there may be a DC bias that is not completely filtered out by the capacitor during the signal acquisition process, a baseline correction is required:

[0052] Baseline estimation: Calculate the mean of the signal as the baseline estimate;

[0053] Baseline Correction: Subtract the baseline estimate from the raw signal to obtain the corrected signal.

[0054] Furthermore, in order to obtain the spectrum information of the signal, the preprocessed signal is subjected to Fourier transform:

[0055] Windowing: Use Blackman-Harris window to reduce spectrum leakage.

[0056] FFT calculation: Perform fast Fourier transform (FFT) on the windowed signal to obtain the signal's spectrum.

[0057] Spectrum interpolation: Use interpolation FFT algorithm to improve spectrum resolution, and the interpolation multiple is selected as 4 times.

[0058] Step S2: Obtaining impedance data of the inductor at different frequencies by calculating the ratio of the voltage spectrum to the current spectrum;

[0059] In this embodiment, before calculating the impedance of the magnetic core inductor, a preliminary experiment is performed using an air core inductor to obtain a delay of the test system in the range of 5.2-7ns (10M-70Mhz). Figure 1 The resistance and inductance introduced by the copper winding are obtained with the help of finite element simulation software. The simulation model is as follows: Figure 4 As shown; the present invention believes that the winding resistance here may change with the change of the magnetic permeability of the magnetic core, so the finite element simulation is also used to simulate the copper loss under different magnetic permeabilities. The results show that within the magnetic permeability range of 1-1000, the change of copper loss is within 5%.

[0060] For example, the inductor impedance is accurately obtained by numerically calculating the voltage waveform and the current waveform: Figure 1 The equivalent circuit of the input The expressions for output I are:

[0061]

[0062]

[0063] in, is the voltage peak value, is the peak current, , are the initial phases of voltage and current respectively, is the angular frequency, , complex domain expression of I , for:

[0064]

[0065]

[0066] So the circuit impedance The expression is:

[0067]

[0068] Right now:

[0069]

[0070] in, is the phase difference between input and output (the phase angle of the inductor itself). It can be seen that the real part To test the equivalent resistance of the inductor loss , imaginary part Inductive reactance L, and the probe mismatch during the test and the phase shift of the test system itself It will affect the calculation of the equivalent resistance and inductance of the inductor, resulting in deviation in the loss calculation. After considering the phase shift, the actual output current Complex Field Expressions for:

[0071]

[0072] in, is the phase shift caused by the probe mismatch mentioned above and the test system.

[0073] According to the above formula, the actual impedance for:

[0074]

[0075] Among them, the real part The resistance of the test circuit after phase shift is , according to the loss calculation formula, the error formula can be derived as follows:

[0076]

[0077] in, , They represent the resistance of the test circuit before and after considering the phase shift, , They represent the test circuit losses before and after considering the phase shift, Error factor representing the effect of phase shift on loss calculations.

[0078] Step S3: synchronously calibrating and compensating for parasitic parameters and test system delay in the test system;

[0079] In this implementation, the system calibration is performed by using three standard states: open circuit, short circuit and load, and the compensation calculation is based on the calibration results to compensate the measured impedance data to eliminate the influence of system delay and parasitic parameters;

[0080] For example, open circuit calibration: measures the parasitic capacitance in the open circuit state; short circuit calibration: measures the parasitic inductance in the short circuit state; load calibration: uses a standard load (50Ω) for calibration to measure the transmission characteristics of the system.

[0081] Furthermore, considering the internal parasitics of the voltage probe and the inductor, the measured circuit impedance The expression is:

[0082]

[0083] in, is the inductor resistance, is the inductor reactance, The capacitive reactance of the circuit is introduced as parasitic. is the parasitic parameter, is the inductor inductance. In the inductance test circuit, , so the formula is further deduced as:

[0084]

[0085] The real part is expressed as:

[0086] This is the resistance of the test circuit after considering parasitic parameters. , according to the formula derived above:

[0087]

[0088] Step S4: fitting calculation and analysis are performed on the obtained impedance data to obtain an impedance characteristic curve of the inductor under high frequency and large signal.

[0089] In this embodiment, the compensated impedance data is finally fitted and analyzed: the least squares method is used to fit and calculate the impedance data to obtain the impedance characteristic curve of the inductor under high frequency and large signal. By analyzing the shape and characteristic points of the curve, the key parameters of the inductor, such as the inductance value, quality factor, and loss density, can be evaluated. At the same time, the nonlinear characteristics of the inductor under large signal conditions can be studied by comparing the impedance characteristics under different signal strengths.

[0090] In this implementation, in order to verify the effectiveness and accuracy of this method, a series of experimental tests were carried out:

[0091] Test object: Select inductors with different magnetic cores, including ferrite, film and air core inductors in the present invention (preliminary experiment);

[0092] Test frequency range: 10MHz to 70MHz;

[0093] Excitation signal range: 50mA to 200mA;

[0094] Test environment: carried out in a shielded room, the ambient temperature is controlled at 25±1℃;

[0095] For example, in order to further verify the reliability of the test results, we used two methods for comparative verification, namely, comparing with the impedance analyzer test and finite element simulation data respectively. The test results show that the method of the present invention can accurately measure the impedance characteristics of the inductor under high-frequency large signals, and the measurement results are in good agreement with the theoretical calculation values. The specific results are as follows:

[0096] Ferrite inductor: In the range of 10MHz to 70MHz, the impedance measurement error is less than 8%;

[0097] Air core inductor: impedance measurement error is less than 2% in the range of 10MHz to 70MHz;

[0098] Film inductors: Impedance measurement error is less than 6% in the range of 10MHz to 70MHz.

[0099] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0100] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-frequency characteristic characterization system for magnetic passive devices, characterized by: The test system includes the following functional modules: a signal generating module, a data acquisition module, and a data processing module. The signal generating module is used to generate a large signal at a high frequency. The data acquisition module is used to collect the voltage signal at both ends of the inductor and the current signal flowing through the inductor. The data processing module is used to denoise, isolate DC, and Fourier transform the collected voltage and current signals to obtain the spectrum information of the signal.

2. A magnetic passive device high frequency characteristic characterization system according to claim 1, characterized in that: The signal generating module comprises a signal generator and a power amplifier. The signal generator is used to generate a large signal at a high frequency, and the power amplifier is used to amplify the signal to meet the test requirements and apply it to the inductor to be tested; the data acquisition module comprises a voltage probe, a current probe, a coaxial cable, and an oscilloscope. The voltage probe and the current probe are used to collect the voltage signal at both ends of the inductor and the current signal flowing through the inductor. The coaxial cable is used to transmit the signal to the oscilloscope, and the oscilloscope is used to capture the details of the high-frequency signal through a high-precision ADC chip.

3. A magnetic passive device high frequency characteristic characterization system according to claim 2, characterized in that: The signal generator adopts direct digital frequency synthesis technology to generate high-frequency signals with a frequency range from 1μHz to 150MHz and an amplitude from 1mVPP to 20VPP; the power amplifier adopts a broadband linear amplifier to provide power output in the entire frequency range, with a maximum output power of 100W; the current probe is a non-contact current probe based on a Hall effect sensor, with a bandwidth of up to 100MHz, a sensitivity of up to 10mA / div, and an AC accuracy of ±3%; the voltage probe has a bandwidth of up to 200MHz, a high input impedance of 10MΩ and a low parasitic capacitance of 15pF.

4. A magnetic passive device high frequency characteristic characterization system according to claim 1, using a magnetic passive device high frequency characteristic characterization method, characterized in that: The method comprises the following steps: Step S1: performing denoising, filtering and baseline correction preprocessing on the collected voltage and current signals, and performing Fourier transform on the preprocessed signals to obtain the spectrum information of the signals; Step S2: Obtaining impedance data of the inductor at different frequencies by calculating the ratio of the voltage spectrum to the current spectrum; Step S3: synchronously calibrating and compensating for parasitic parameters and test system delay in the test system; Step S4: fitting calculation and analysis are performed on the obtained impedance data to obtain an impedance characteristic curve of the inductor under high frequency and large signal.

5. A method for characterizing high-frequency characteristics of a magnetic passive device according to claim 4, characterized in that: The denoising specifically includes: S101: Select Daubechies wavelet basis as the wavelet basis for high frequency signal denoising; S102: Determine the number of wavelet decomposition layers according to the signal frequency range; S103: using a soft threshold method to perform threshold processing on the wavelet coefficients to remove high-frequency noise components; S104: performing wavelet reconstruction on the processed wavelet coefficients to obtain a denoised signal; The filtering specifically includes: using a digital filter for filtering: that is, selecting a bandpass filter with a passband range of 10MHz to 70MHz and a stopband attenuation greater than 60dB, and filtering the denoised signal by using a FIR filter and a window function method to remove out-of-band noise; The baseline correction specifically includes: calculating the mean value of the signal as a baseline estimation value, subtracting the baseline estimation value from the original signal to obtain a corrected signal, wherein the baseline correction is used to eliminate a DC bias in the signal; The Fourier transform comprises: performing windowing processing using a Blackman-Harris window, performing a fast Fourier transform (FFT) on the windowed signal to obtain a spectrum of the signal, and finally improving the spectrum resolution by an interpolation FFT algorithm.

6. A method and system for characterizing high-frequency characteristics of a magnetic passive device according to claim 5, characterized in that: The calculating the ratio of the voltage spectrum to the current spectrum to obtain the impedance data of the inductor at different frequencies includes: Defining input based on equivalent circuit and output The expressions are: ； ； in, is the voltage peak value, is the peak current, , are the initial phases of voltage and current respectively, is the angular frequency, , The complex domain expression of , for: ； ； in, is an imaginary unit; So the circuit impedance The expression is: ； Right now: ； in, is the phase difference between input and output, that is, the phase angle of the inductor itself, where the real part To test the equivalent resistance of the inductor loss , imaginary part Inductive reactance L, probe mismatch during the test and phase shift of the test system itself It will affect the calculation of the equivalent resistance and inductance of the inductor, resulting in deviation in the loss calculation. After considering the phase shift, the actual output current Complex Field Expressions for: ； in, The phase shift caused by the above-mentioned probe mismatch and the test system; According to the above formula, the actual impedance for: ； Among them, the real part The resistance of the test circuit after phase shift is , according to the loss calculation formula, the error formula can be derived as follows: ； ； ； in, , They represent the resistance of the test circuit before and after considering the phase shift, , They represent the test circuit losses before and after considering the phase shift, Error factor representing the effect of phase shift on loss calculations.

7. A method for characterizing high-frequency characteristics of a magnetic passive device according to claim 6, characterized in that: The calibration includes: performing system calibration by adopting three standard states of open circuit, short circuit and load, and the compensation includes: compensating the measured impedance data according to the system calibration result to eliminate the influence of system delay and parasitic parameters.

8. A method for characterizing high-frequency characteristics of a magnetic passive device according to claim 7, characterized in that: The step S3 also includes: measuring the circuit impedance for the voltage probe and the internal parasitics of the inductor. The expression is: ； in, is the inductor resistance, is the inductor reactance, The capacitive reactance of the circuit is introduced as parasitic. is the parasitic parameter, is the inductor inductance. In the inductance test circuit, , so the formula is further deduced as: ； The real part is expressed as: ; This is the resistance of the test circuit after considering parasitic parameters. , according to the formula derived above: 。 9. A method and system for characterizing high-frequency characteristics of a magnetic passive device according to claim 8, characterized in that: The fitting, calculation and analysis of the impedance data include: using the least squares method to perform curve fitting and calculation on the impedance data to obtain the impedance characteristic curve of the inductor with a large signal at a high frequency, and by analyzing the shape and characteristic points of the curve, evaluating the key parameters of the inductor's inductance value, quality factor, and loss density, and by comparing the impedance characteristics under different signal strengths, outputting the nonlinear characteristics of the inductor under large signal conditions, that is, outputting the impedance characteristic curve of the inductor with a large signal at a high frequency.

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