WO2018184565A1 - 一种预调制磁电阻传感器 - Google Patents

一种预调制磁电阻传感器 Download PDF

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Publication number
WO2018184565A1
WO2018184565A1 PCT/CN2018/081914 CN2018081914W WO2018184565A1 WO 2018184565 A1 WO2018184565 A1 WO 2018184565A1 CN 2018081914 W CN2018081914 W CN 2018081914W WO 2018184565 A1 WO2018184565 A1 WO 2018184565A1
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layer
modulator
magnetoresistive
sensor
modulated
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English (en)
French (fr)
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迪克詹姆斯•G
周志敏
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MultiDimension Technology Co Ltd
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MultiDimension Technology Co Ltd
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Priority to US16/500,912 priority Critical patent/US11287491B2/en
Priority to JP2019554724A priority patent/JP7105497B2/ja
Priority to EP18781732.5A priority patent/EP3608680A4/en
Publication of WO2018184565A1 publication Critical patent/WO2018184565A1/zh
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
    • G01R33/06—Measuring direction or magnitude of magnetic fields or magnetic flux using galvano-magnetic devices
    • G01R33/09—Magnetoresistive devices
    • G01R33/093—Magnetoresistive devices using multilayer structures, e.g. giant magnetoresistance sensors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/0011—Arrangements or instruments for measuring magnetic variables comprising means, e.g. flux concentrators, flux guides, for guiding or concentrating the magnetic flux, e.g. to the magnetic sensor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
    • G01R33/06—Measuring direction or magnitude of magnetic fields or magnetic flux using galvano-magnetic devices
    • G01R33/09—Magnetoresistive devices
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/0023—Electronic aspects, e.g. circuits for stimulation, evaluation, control; Treating the measured signals; calibration
    • G01R33/0041—Electronic aspects, e.g. circuits for stimulation, evaluation, control; Treating the measured signals; calibration using feed-back or modulation techniques
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
    • G01R33/06—Measuring direction or magnitude of magnetic fields or magnetic flux using galvano-magnetic devices
    • G01R33/09—Magnetoresistive devices
    • G01R33/096—Magnetoresistive devices anisotropic magnetoresistance sensors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/0052—Manufacturing aspects; Manufacturing of single devices, i.e. of semiconductor magnetic sensor chips

Definitions

  • the present invention relates to a magnetoresistive sensor, and more particularly to a pre-modulated magnetoresistive sensor.
  • Magnetoresistive sensors are limited by 1/f noise, limiting resolution at a low frequency.
  • Techniques for modulating magnetic field sensors have evolved to convert measurement signals to higher frequencies relative to the inherent noise of the sensor, which can bypass the 1/f noise of the sensor.
  • the prior art includes the use of a flux concentrator, further, by moving the sensor and the flux concentrator in an oscillating manner relative to each other using MEMS, providing a larger volume flux concentrator on the outside of the sensor, and using one The coils disposed around the flux concentrator are periodically infiltrated.
  • the purpose is to periodically change the magnetic field to be measured, which is induced by the sensor, a method called pre-modulation, which can be subsequently modulated by the output of the sensor signal, which converts the sensor signal
  • pre-modulation a method called pre-modulation
  • the modulating magnetic field must be small enough so as not to cause noise in the sensor element. Modulating the sensor itself with a more periodic magnetic field can cause Barkhausen noise, and if the amplitude is large enough, it will also produce a nonlinear modulation of the sensor sensitivity, while nonlinear modulation mixes the low frequency thermomagnetic noise of the sensor. Enter the sideband of the modulated signal. When the smallest modulating magnetic field is present in the sensor, the best noise reduction and hence the best signal to noise ratio is produced, which also corresponds to the peak amplitude of the detected signal.
  • noise reduction is beneficial for reducing sensor 1/f noise based on the following factors: proper sensor bias; appropriate sensor material; adequate sensor size.
  • the input signal occurs in the white noise region of the sensor; the resistance of the sensor is low, so Johnson's noise is low; the sensitivity of the sensor is high, so the equivalent input noise is small; according to a certain voltage or The current biases the sensor so that it does not cause scatter noise, which exceeds the thermal Johnson noise of the sensor and maximizes noise reduction.
  • the modulation method in the prior art is: moving the magnetic flux concentrator or moving the sensor relative to the magnetic flux concentrator, the two methods are too complicated and costly; placing the sensor in a large shield, the shield periodically The penetration, however, in this method the shield is on the outside of the sensor, so the volume can become very large and expensive.
  • the present invention proposes a pre-modulated magnetoresistive sensor.
  • the invention is implemented according to the following technical solutions:
  • a pre-modulated magnetoresistive sensor having a substrate disposed on an XY plane, a magnetoresistive sensing element, a modulator, an electrical connector, an electrically insulating layer, and a bonding pad deposited on the substrate, the magnetoresistive The sensing direction of the sensing element is parallel to the X axis;
  • the magnetoresistive sensing elements are connected in series to form a series of magnetoresistive sensing elements, the series of magnetoresistive sensing elements being electrically connected into a sensor bridge, the sensor bridge being a push-pull half-bridge circuit or a push-pull full-bridge circuit
  • the magnetic resistance sensing element string is electrically connected to the bonding pad such that a bias voltage or current flows through the magnetoresistive sensing element and detects a voltage or current on the magnetoresistive sensing element;
  • the modulator is electrically connected to the bonding pad, and a modulation current is obtained from the bonding pad, the direction of the modulation current is parallel to a direction of a Y-axis, and the modulator causes a modulation current to pass a conductor around the soft ferromagnetic flux concentrator that generates a magnetic field around the soft ferromagnetic flux concentrator to modulate the magnetic permeability of the soft magnetic flux concentrator, the modulator and the magnetoresistive sensing element being provided with an electrically insulating layer, An electrically insulating layer separates the modulator from the magnetoresistive sensing element.
  • the magnetoresistive sensing element is an AMR, GMR or TMR magnetic sensing element
  • the modulator is composed of a plurality of modulator bars, and the modulator bar has a rectangular strip shape with a long axis parallel to a Y-axis direction having a short axis parallel to the X-axis direction, a plurality of the modulator bars being arranged in an array, a gap between the modulator bars, and a spacing distance of the gaps extending in an X-axis direction,
  • the ends of the modulator bars are connected by a electrical connector into a snake-shaped current path.
  • the modulator bar is composed of a three-layer structure of an FM1 layer, an NM layer and an FM2 layer, wherein the FM1 layer and the FM2 layer are soft ferromagnetic layers, and the NM layer is a common metal layer;
  • the material of the NM layer is tantalum or copper, the thickness of the NM layer is less than 5 nm, and there is antiferromagnetic RKKY coupling between the FM1 layer and the FM2 layer.
  • the electrical connector is metal, and the electrical connector is connected to an upper surface, a lower surface or a side surface of the modulator;
  • the electrical connector is etched from a three-layer structure of the FM1 layer, the NM layer, and the FM2 layer.
  • the modulator comprises a current carrying coil and a ferromagnetic rectangular body, the current carrying coil is located above the ferromagnetic rectangular body, and the current carrying coil is connected to the bonding pad.
  • the sensor further includes an AC reference power source that periodically drives the modulator bar of the sensor, the analog front end circuit, the low pass filter, and the mixer at a frequency f
  • the analog front end circuit includes a front end processor and an amplifier, the front end processor being capacitively coupled to an output of the magnetoresistive sensor, the input end of the mixer being electrically coupled to the alternating reference power supply and the front end processing
  • the output of the low-pass filter is electrically connected to the output of the mixer, the output of the low-pass filter provides an output signal, and the output signal is The magnitude and polarity of the magnetic field detected by the magnetoresistive sensing element correspond.
  • the optimization filter electrically connected to the AC reference power signal or an input signal of the mixer; the optimization filter entering the mixing circuit by the AC reference power signal
  • the partial power component is previously removed, and the reference power signal is adjusted by converting the AC reference power signal to an AC voltage signal.
  • said AC reference power signal is unipolar
  • said low pass filter is coupled to an output of said mixer, said low pass filter having a low frequency cutoff frequency of frequency F .
  • the AC reference power signal is bipolar
  • the magnetoresistive sensor further comprises a frequency multiplier, the frequency multiplier and the AC reference power source and the input of the mixer
  • the terminal is electrically connected
  • the low pass filter is connected to the output of the mixer, and the low pass filter has a low frequency cutoff frequency of 2F.
  • the sensor bridge comprises a single chip, a bridge arm constituting the sensor bridge is deposited on the single chip; or the sensor bridge comprises two or more interconnected chips, each independent chip Each includes a string of magnetoresistive sensing elements that are electrically coupled into a bridge arm of one or more sensor bridges.
  • the magnetoresistive sensor element produces a white noise frequency that is much greater than a 1/f noise frequency when the AC reference power signal is in the operating frequency range.
  • the FM1 layer and the FM2 layer have different remanence thickness products Mrt.
  • the modulation current generates a minimum magnetic field at the sensor position.
  • a pre-modulated magnetoresistive sensor of the present invention has the following technical effects:
  • the present invention uses an RKKY coupled FM stack form to change the magnetic permeability of the magnetoresistive sensor by a modulation current from the modulator, and thereby modulate the magnetic field; the present invention is capable of signal modulation prior to detection by the sensor element, and the modulation The current ensures that the modulated signal operates within the corresponding linear range of the magnetoresistive sensor; further magnetic field modulation and noise suppression are achieved by varying the magnetic permeability.
  • Figure 1 is a schematic diagram showing the relationship between the frequency of a modulated signal and sensor noise
  • Figure 2 is a schematic diagram of a standard signal modulation technique
  • Figure 3 is a schematic diagram showing the variation of Johnson noise and 1/f noise with frequency
  • Figure 4 is a schematic diagram of signal modulation and noise offset
  • FIG. 5 is a schematic structural view of a pre-modulated magnetoresistive sensor of the present invention.
  • Figure 6 is a cross-sectional view showing a pre-modulated magnetoresistive sensor of the present invention.
  • Figure 7 is a schematic view showing the structure of a modulator rod of the present invention.
  • Figure 8 is a schematic view showing the structure of another modulator rod of the present invention.
  • Figure 9 is a schematic view showing the magnetic field distribution of the modulatorless current-free modulator bar of the present invention.
  • Figure 10 is a schematic view showing the magnetic field distribution of a modulator bar having a modulated current according to the present invention.
  • FIG. 11 is a schematic structural view of a modulator of a pre-modulated magnetoresistive sensor of the present invention.
  • Figure 12 is a schematic view showing the relationship between the magnetic permeability of the sensor shaft and the modulation current
  • Figure 13 is a waveform diagram of an applied modulation current
  • Figure 14 is a waveform diagram of a change in magnetic permeability
  • Figure 15 is a waveform diagram of sensor gain
  • Figure 16 is a schematic diagram of input and output of a modulated magnetoresistive sensor
  • 17 is a schematic diagram of a first harmonic application of a unipolar circuit of a single magnetoresistive circuit of the present invention.
  • FIG. 18 is a schematic diagram of a bipolar second harmonic application of a single magnetoresistive circuit of the present invention.
  • FIG. 19 is a schematic diagram of a first harmonic application of a unipolar circuit of a half bridge circuit of the present invention.
  • 20 is a schematic diagram of a bipolar second harmonic application of the half bridge circuit of the present invention.
  • 21 is a schematic diagram of a first harmonic application of a unipolar circuit of a full bridge circuit of the present invention.
  • Figure 22 is a schematic diagram of the application of the second harmonic of the bipolar of the full bridge circuit of the present invention.
  • Figure 1 is a schematic diagram of the relationship between the frequency of the modulated signal and the sensor noise; specifically, at position 1, the low frequency signal has greater noise, in which case the DC signal has a very low resolution; at position 2, if It is a very ideal state that the DC signal is shifted to a white noise range at a certain frequency.
  • Figure 2 is a schematic diagram of a standard modulation technique that ideally eliminates noise from noise amplifiers, mixers, and low-pass filters that require modulation of low-noise circuit components by applying AC voltage bias or
  • the alternating magnetic field signal is applied to the sensor to modulate the sensor, which can be used as a method to separate the desired signal from the noise of the sensor, but this method cannot achieve sensor noise removal.
  • the resistance noise refers to the random and irregular fluctuation of the resistance in a device.
  • R noise ( ⁇ ) when a current flows through a device, the resistance noise will appear as voltage noise.
  • voltage noise refers to a random and irregular fluctuation of the voltage in a device, which is defined as V noise ( ⁇ ) in the present application.
  • a device For a device, it is very likely that there is only voltage noise and no current flowing. Therefore, a device can have a balanced voltage without resistance noise. Johnson noise is an example; it is also possible to have voltage noise independent of the bias current, Johnson noise. It is also an example.
  • Figure 3 is a graph showing the variation of Johnson noise and 1/f noise with frequency. The magnitude of the Johnson noise does not change as the bias current changes, and the 1/f voltage noise changes with the bias current.
  • Johnson spectral noise density is It is worth noting that this is voltage noise, which is independent of the frequency in the drawing, where the resistance R of the sensor is 5K ohms, corresponding to 10 nV/rtHz.
  • 1/f noise is large at low frequencies, and the amplitude of 1/f noise is determined by the bias voltage, and Johnson noise is independent of it; wherein 1/f noise appears in the form of resistance fluctuations, There are many possible mechanisms of action; but for sensor design, it is the resistance fluctuation that determines how it is suppressed, and the specific mechanism of action is not important.
  • H is the measured magnetic field
  • S is the sensitivity
  • V noise ( ⁇ ) is the random sensor noise
  • ⁇ 1 is the signal nonlinear coefficient
  • i is a positive number ⁇ 1.
  • the modulation sensor bias cannot reduce the 1/f noise, so the sensor generates resistance noise.
  • the modulation is performed in a pre-modulation manner, assuming that the sensor output is a nonlinear combination of noise of the signal, and the sensor is DC biased.
  • H is the measured magnetic field
  • S is the sensitivity
  • V noise ( ⁇ ) is the random sensor noise
  • ⁇ 1 is the signal nonlinear coefficient
  • i is a positive number ⁇ 1.
  • the noise and magnetic field that can be measured are independent of each other.
  • the magnetic field is input at ⁇ c , which can be obtained.
  • the noise is turned to a negative frequency with respect to the detection signal.
  • Figure 4 is a schematic diagram of signal modulation and noise offset, with the modulated spectral offset shifted to a low frequency at frequency ⁇ c , resulting in a reduction in low frequency noise. If a high modulation magnetic field is used, nonlinearity causes sensor noise to mix into the modulated sideband, which reduces the amount of noise reduction.
  • the modulator modulates the signal to be measured without necessarily modulating the 1/f noise of the sensor, still achieving a frequency offset between the signal and the noise, reducing the 1/f noise of the system output.
  • FIG. 5 is a schematic structural view of a pre-modulated magnetoresistive sensor of the present invention.
  • a substrate 1 is disposed on an XY plane, a magnetoresistive sensing element 3, a modulator bar 2, an electrical connector 4, and a sensor.
  • a connector 5, a bonding pad 6, a bonding pad 7, a bonding pad 8, a bonding pad 9 and the like are deposited on the substrate 1, and the sensing direction of the magnetoresistive sensing element 3 is parallel to the X-axis;
  • the magnetoresistive sensing elements 3 are connected in series to form a series of magnetoresistive sensing elements, the series of magnetoresistive sensing elements being electrically connected into a sensor bridge; the string of magnetoresistive sensing elements passing through the sensor connector 5, and the bonding
  • the pad 7 and the bonding pad 8 are electrically connected such that a bias voltage or current flows through the magnetoresistive sensing element 3 and detects a voltage or current on the magnetoresistive sensing element 3, and the plurality of modulator bars 2 Arranging in an array form, there is a gap between the modulator bars 2, the gap distance of the gap is extended in the X-axis direction, and the modulator bar 2 is electrically connected to the bonding pad to modulate current from
  • the bond pads pass through, the modulation current is parallel to the direction of the Y-axis, and the ends of the modulator bars 2 are connected by a electrical connector 4 into a serpentine current path.
  • the magnetoresistive sensing element 3 is an AMR, GMR or TMR magnetic sensing element.
  • the magnetoresistive sensing elements are electrically connected in series to a push-pull half-bridge circuit, or the magnetoresistive sensing elements are electrically connected in series to a push-pull full-bridge circuit.
  • FIG. 6 is a cross-sectional view of a pre-modulated magnetoresistive sensor of the present invention, with a passivation protective layer 16 deposited over the modulator bar 2, an upper electrode 15 deposited over the magnetoresistive sensing element 3, and a bottom deposited below the magnetoresistive sensing element 3.
  • the electrode 14, the bottom electrode 14 is connected to the substrate 1, and an electrically insulating layer is disposed between the modulator bar 2 and the magnetoresistive sensing element 3.
  • the electrically insulating layer 13 senses the modulator bar 2 and the magnetoresistance The elements 3 are separated.
  • an electrically insulating layer is also disposed between the magnetoresistive sensing element 3 and the substrate 1, and 17 in the figure is a bonding pad.
  • FIG. 7 is a schematic structural view of a modulator bar
  • FIG. 8 is a schematic structural view of another modulator bar.
  • the modulator bar 2 is composed of a three-layer structure of an FM1 layer 21, an NM layer 22, and an FM2 layer 23, wherein the FM1 layer
  • the FM2 layer is a soft ferromagnetic layer
  • the NM layer is a common metal layer
  • the modulator rod 2 has a rectangular strip shape with a long axis parallel to the Y-axis direction and a short axis parallel to the X-axis direction.
  • the modulator bars 2 are arranged in an array with gaps between the modulator bars, the gaps being spaced apart by the X-axis direction. Arrows 74 and 75 in the figure indicate the inflow and outflow of current, respectively.
  • the material of the NM layer of the modulator rod 2 is tantalum or copper, the thickness of the NM layer is less than 5 nm, and there is an antiferromagnetic RKKY coupling between the FM1 layer and the FM2 layer.
  • the electrical connector of FIG. 7 is preferably a metal conductor element connected to the upper surface, the lower surface or the side surface of the modulator rod 2, and
  • the electrical connector 4 of Figure 8 is etched from a three layer structure of FM1 layer, NM layer and FM2 layer.
  • the current in the modulator bar is concentrated in the middle layer of the modulator bar; when the current is large, the FM1 layer and the FM2 layer lower the modulator in parallel
  • the magnetic permeability in the direction of sensing of the sensor element high magnetic permeability means that the concentrated magnetic flux content on the sensor string is high, and conversely, low magnetic permeability means that the concentrated magnetic flux content on the sensor string is low. Therefore, by passing an alternating current through the modulator, the external magnetic field can be modulated by a change in magnetic permeability.
  • the FM1 and FM2 layers of the modulator require the same remanence thickness product (Mrt) so that they can compensate each other between the modulators.
  • Mrt remanence thickness product
  • the top layer FM2 layer of the modulator rod is close to the magnetoresistive sensing element
  • the top layer The remanent thickness of the FM1 layer is higher than that of the underlying FM2 layer.
  • the ends of the modulator rods are electrically connected to each other, and the modulation current can flow through the modulator rod in a serpentine manner, and the unevenness caused by the mismatch between FM1 and FM2 can be compensated for in the entire magnetoresistive sensing element region.
  • Figure 9 is a schematic diagram showing the magnetic field distribution of a modulator bar without modulation current, and the magnetic field generated by the modulator bar is concentrated at the magnetoresistive sensing element.
  • Fig. 10 is a schematic view showing the magnetic field distribution of a modulator rod having a modulated current. As is apparent from the figure, when a modulation current is applied, there is no concentration of a magnetic field in the magnetoresistive sensing element.
  • the modulator of the pre-modulated magnetoresistive sensor includes a current-carrying coil 11 and a ferromagnetic rectangular body 18, The current-carrying coil 11 is located above the ferromagnetic rectangular body 18, and the current-carrying coil 11 is connected to the bonding pad 12.
  • Figure 12 is a schematic diagram of the magnetic permeability of the sensor shaft as a function of the modulation current; as the modulation current increases, the magnetic permeability of the magnetic sensor shaft decreases, applying an alternating current modulation current, and Figure 13 is a waveform diagram of the applied modulation current.
  • the applied current is a sinusoidal signal; the magnitude of the magnetic permeability is exactly opposite to the current, as shown in Figure 14,
  • Figure 14 is a waveform diagram of the change in magnetic permeability; due to the change in magnetic field gain with magnetic permeability The change, and thus the sensor gain waveform, is shown in Figure 15.
  • the modulated magnetoresistive sensor includes a modulation current input terminal, a modulation current output terminal, a sensor current input terminal, and a sensor current output terminal.
  • the direction of the arrow in the figure is the direction of the pinning layer.
  • the present invention also includes an AC reference power supply that periodically drives a modulator bar, an analog front end circuit, a low pass filter, and a mixer of the sensor at a frequency f, the analog front end circuit including a front end a processor and an amplifier, the front end processor being capacitively coupled to an output of the magnetoresistive sensor, the input of the mixer being electrically coupled to the AC reference power supply and the front end processor output;
  • the input end of the low pass filter is electrically connected to the output end of the mixer, the output end of the low pass filter provides an output signal, and the output signal and the magnetoresistive sensing element are The magnitude and polarity of the detected magnetic field correspond.
  • FIG. 17 is a schematic diagram of a unipolar first harmonic application of a single magnetoresistive circuit
  • FIG. 18 is a bipolar second harmonic application diagram of a single magnetoresistive circuit
  • FIG. 19 is a unipolar phase of a half bridge circuit.
  • Schematic diagram of a harmonic application Figure 20 is a schematic diagram of the application of the second harmonic of the bipolar circuit
  • Figure 21 is a schematic diagram of the application of the first harmonic of the full-bridge circuit
  • Figure 22 is the double of the full-bridge circuit
  • a schematic diagram of the second harmonic application of polarity is a schematic diagram of the second harmonic application of polarity.
  • the AC reference power signal described in Figure 17 is unipolar.
  • the low pass filter is coupled to the output of the mixer, and the low pass filter is a first harmonic low pass filter having a low frequency cutoff frequency of frequency F.
  • an optimization filter electrically coupled to the AC reference power supply or an input signal of the mixer, the optimized filter being removed by the AC reference power signal before entering the mixing circuit Part of the frequency component, and adjusting the reference power signal by converting the AC reference power signal to an AC voltage signal.
  • the AC reference power signal is bipolar
  • the magnetoresistive sensor further includes a frequency multiplier, the frequency multiplier and the AC reference power source and the mixer
  • the input terminal is electrically connected
  • a low pass filter is connected to the output of the mixer.
  • the low pass filter is a second harmonic low pass filter having a low frequency cutoff frequency of 2F.
  • the sensor bridge includes two or more interconnected chips, each of which includes a magnetoresistive sensing element string, and the magnetoresistive sensing element is electrically connected in series to one or more sensor bridge circuits.
  • the bridge arm; or the sensor bridge includes a single chip on which the bridge arms that make up the sensor bridge are deposited.
  • the FM1 layer and the FM2 layer have different remanence thickness products Mrt; wherein, when no external magnetic field is applied, even if the AC reference power signal is the largest, the modulation current is generated at the sensor position.
  • the magnetic field is also minimal, and the magnetic field generated by the modulation current at the sensor location is unaffected by the AC reference power supply.
  • the magneto-resistive sensor element when the AC reference power signal is in the operating frequency range, the magneto-resistive sensor element generates a white noise frequency that is much larger than the 1/f noise frequency. Among them, by increasing the size of the sensor, the area can be reduced to reduce the 1/f noise.
  • the present invention uses an RKKY coupled FM stack form in which the modulation current output by the modulator changes the magnetic permeability of the magnetoresistive sensor and thus modulates the magnetic field. Moreover, the present invention is capable of modulating prior to detection by the sensor element, ensuring that the modulated signal is within a respective linear region of the magnetoresistive sensor.

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Abstract

一种预调制磁电阻传感器，在XY平面上设置有一衬底(1)，磁电阻感应元件(3)、调制器、电连接器(4)、电绝缘层(13)和键合焊盘(6,7,8,9)均沉积在衬底(1)上，磁电阻感应元件(3)的感应方向平行于X轴，磁电阻感应元件(3)串连连接成磁电阻感应元件串，调制器由多个调制器棒(2)构成，调制器棒(2)由FM1层(21)、NM层(22)和FM2层(23)三层结构构成，调制器棒(2)的端部之间电连接形成蛇形状的电流路径，调制器棒(2)与磁电阻感应元件(3)之间设置有一层电绝缘层(13)，电绝缘层(13)将调制器棒(2)与磁电阻感应元件(3)隔开。通过调制电流确保调制信号工作在磁场传感器的线性区域，进一步通过调制磁场改变磁导率，进而实现噪声的抑制。

Description

一种预调制磁电阻传感器 技术领域
本发明涉及一种磁电阻传感器，尤其涉及一种预调制磁电阻传感器。
背景技术
磁电阻传感器受到1/f噪声的限制，限制分辨率在一个低的频率。调制磁场传感器的技术已经发展到将测量信号转换为相对于传感器固有噪声的更高频率，这样可以绕过传感器的1/f噪声。
现有技术中包括使用磁通集中器，进一步地，通过使用MEMS相对于彼此以摆动的方式移动传感器和磁通集中器，在传感器的外部提供体积更大些的通量集中器，并且使用一种设置在磁通集中器周围的线圈进行周期性地渗透。
在上述两种情况中，目的是为了周期性地改变将要测量到的磁场，该磁场通过传感器感应，称之为预调制的一种方法可以通过传感器信号的输出随后进行调制，这将传感器信号转换为更高的频率，而此时，传感器的噪声变得更小。
调制磁场必须足够的小，这样才不引起传感器元件的噪声。通过更大地周期性的磁场对传感器本身进行调制既可引起巴克豪森噪声，并且如果振幅足够大时，它还将产生传感器灵敏度的非线性调制，而非线性调制混合了传感器的低频热磁性噪声进入到调制信号的边频带。当最小的调制磁场出现在传感器中，最佳的降噪并因此最佳信噪比就产生了，这些也正对应于被检测信号的峰值幅度。
此外，降噪有益于降低传感器1/f噪声，这是基于下述因素实现的：适当的传感器偏置；适当的传感器材料；足够的传感器的尺寸。
最终，且当在足够高的频率调制，这样使得输入信号发生在传感器的白噪声区域；传感器的电阻低，这样约翰逊噪声低；传感器的灵敏度高， 这样等效输入噪声小；按照一定的电压或者电流偏置传感器，这样不会引起散射噪声，散射噪声超过了传感器的热约翰逊噪声，降噪达到了最大化。
现有技术中的调制方法为：移动磁通集中器或者相对于磁通集中器移动传感器，这两种方法太复杂，花费费用很高；放置传感器在一个大的屏蔽罩中，屏蔽罩周期性的渗透，然而，该方法中屏蔽罩是在传感器的外部，这样体积会变得很大，也很昂贵。
发明内容
为了解决上述技术问题，本发明提出了一种预调制磁电阻传感器。本发明是根据以下技术方案实现的：
一种预调制磁电阻传感器，在XY平面上设置有一衬底，磁电阻感应元件、调制器、电连接器、电绝缘层和键合焊盘均沉积在所述衬底上，所述磁电阻感应元件的感应方向平行于X轴；
所述磁电阻感应元件串连连接成磁电阻感应元件串，所述的磁电阻感应元件串电连接成传感器电桥，所述传感器电桥为推挽式半桥电路或推挽式全桥电路；所述的磁电阻感应元件串与所述的键合焊盘电连接，使得偏置电压或者电流流过所述的磁电阻感应元件并探测所述磁电阻感应元件上的电压或电流；
所述的调制器与所述的键合焊盘电连接，从所述的键合焊盘得到调制电流，所述调制电流的方向平行于Y轴的方向，所述的调制器使得调制电流通过软铁磁通量集中器周围的导体，在软铁磁通量集中器周围产生磁场来调制软磁通量集中器的磁导率，所述的调制器与磁电阻感应元件之间设置有一层电绝缘层，所述的电绝缘层将所述的调制器与所述的磁电阻感应元件隔开。
优选地，所述的磁电阻感应元件为AMR、GMR或者TMR磁感应元件；所述的调制器由多个调制器棒构成，所述的调制器棒的结构为矩形条状，其长轴平行于Y轴方向，其短轴平行于X轴方向，多个所述的调制器棒以阵列形式设置，所述调制器棒之间有间隙，所述间隙的间隔距离方向延X轴方向，所述的调制器棒的端部之间通过电连接器连接成蛇形状的电流路径。
优选地，所述的调制器棒是由FM1层、NM层和FM2层三层结构构成，其中FM1层和FM2层是软铁磁体层，NM层是普通金属层；
所述NM层的材料为钌或铜，所述NM层的厚度小于5nm，所述FM1层和所述FM2层之间存在反铁磁RKKY耦合作用。
优选地，所述的电连接器为金属，所述的电连接器与所述的调制器的上表面、下表面或者侧表面相连；
或者，所述的电连接器从FM1层、NM层和FM2层的三层结构中刻蚀。
优选地，所述的调制器包括载流线圈和铁磁性矩形体，所述的载流线圈位于铁磁性矩形体的上方，所述的载流线圈与所述的键合焊盘连接。
优选地，所述的传感器还包括交流基准电源，所述的交流基准电源以频率f周期性地驱动所述传感器的调制器棒、模拟前端电路、低通滤波器以及混频器，所述的模拟前端电路包括前端处理器和放大器，所述的前端处理器与磁电阻传感器的输出端电容耦合，所述的混频器的输入端电连接到所述的交流基准电源和所述的前端处理器输出端，所述的低通滤波器的输入端电连接所述的混频器的输出端，所述的低通滤波器的输出端提供一个输出信号，所述的输出信号与所述的磁电阻感应元件所检测的磁场的幅值和极性对应。
优选地，还包括有优化滤波器，所述优化滤波器与交流基准电源信号或者所述的混频器的一个输入信号电连接；所述优化滤波器通过在交流基准电源信号进入到混频电路之前去除部分频率分量，以及通过转换交流基准电源信号为交流电压信号的方式来调节所述基准电源信号。
优选地，所述的交流基准电源信号是单极性的，所述的低通滤波器与所述的混频器的输出端连接，所述的低通滤波器具有频率为F的低频截止频率。
优选地，所述的交流基准电源信号是双极性的，所述的磁电阻传感器还包括倍频器，所述的倍频器与所述的交流基准电源以及所述的混频器的输入端电连接，所述的低通滤波器与所述的混频器的输出端连接，所述的低通滤波器具有频率为2F的低频截止频率。
优选地，所述传感器电桥包括单一芯片，构成传感器电桥的桥臂沉积在所述单一芯片上；或者所述传感器电桥包括两个或者两个以上互连的芯片， 每个独立的芯片均包括磁电阻感应元件串，所述的磁电阻感应元件串电连接成一个或多个传感器电桥的桥臂。
优选地，在所述交流基准电源信号位于工作频率范围时，所述的磁电阻传感器元件产生白噪声频率远大于1/f噪声频率。
优选地，所述的FM1层和所述的FM2层有不同的剩磁厚度积Mrt，在无外加磁场时，即使交流基准电源信号最大，所述调制电流在传感器位置产生的磁场也为最小。
本发明的一种预调制磁电阻传感器与现有技术相比，本发明具有以下技术效果：
本发明使用RKKY耦合的FM堆栈形式，通过来自于调制器的调制电流改变所述磁电阻传感器的磁导率，并因此调制磁场；本发明能够在传感器元件探测之前进行信号调制，且所述调制电流能够确保调制信号工作在磁电阻传感器的相应线性范围内；进一步通过改变磁导率实现磁场调制和噪声抑制。
附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其它附图。
图1为调制信号的频率和传感器噪声的关系示意图；
图2为标准的信号调制技术示意图；
图3为约翰逊噪声和1/f噪声随频率变化示意图；
图4为信号调制和噪声的偏移示意图；
图5为本发明的一种预调制磁电阻传感器的结构示意图；
图6为本发明的一种预调制磁电阻传感器的剖视图；
图7为本发明的一种调制器棒的结构示意图；
图8为本发明的另一种调制器棒的结构示意图；
图9为本发明的无调制电流的调制器棒的磁场分布示意图；
图10为本发明的有调制电流的调制器棒的磁场分布示意图；
图11为本发明的预调制磁电阻传感器的一种调制器的结构示意图；
图12为传感器轴的磁导率与调制电流关系的示意图；
图13为施加的调制电流的波形图；
图14为磁导率变化的波形图；
图15为传感器增益的波形图；
图16为调制磁电阻传感器的输入输出示意图；
图17为本发明的单磁电阻电路的单极性的第一谐波应用示意图；
图18为本发明的单磁电阻电路的双极性的第二谐波应用示意图；
图19为本发明的半桥电路的单极性的第一谐波应用示意图；
图20为本发明的半桥电路的双极性的第二谐波应用示意图；
图21为本发明的全桥电路的单极性的第一谐波应用示意图；
图22为本发明的全桥电路的双极性的第二谐波应用示意图。
具体实施方式
为使本发明实施例的目的、技术方案和优点更加清楚，下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其它实施例，都属于本发明保护的范围。
图1为调制信号的频率与传感器噪声的关系示意图；具体地，在位置1处，低频信号具有更大的噪声，这种情况下，直流信号具有很低的分辨率；在位置2处，如果直流信号以一定的频率偏移到白色噪声范围，将是一种非常理想的状态。
图2为标准的调制技术的示意图，理想情况下，可以消除来自于噪声放大器、混频器以及低通滤波器的噪声，这个调制器需要先调制低噪声电路元件，通过施加交流电压偏置或者交流磁场信号给传感器来调制传感器，这可作为将所希望得到的信号从传感器的噪声中分离开的一个方法，但是该方法 不能实现传感器噪声的去除。
其中，电阻噪声是指一个装置中的电阻随机且没有规律的波动。在本申请中，定义为R noise(ω)，当一个电流流过一个装置时，电阻噪声将以电压噪声的形式出现。进一步地，电压噪声是指一个装置中的电压随机且没有规律的波动，在本申请中定义为V noise(ω)。
对于一个装置，很有可能只有电压噪声而没有流过的电流，因此，一个装置可以有平衡电压而没有电阻噪声，约翰逊噪声就是一个例子；也有可能具有独立于偏置电流的电压噪声，约翰逊噪声也是一个例子。
图3为约翰逊噪声和1/f噪声随频率变化示意图。约翰逊噪声的幅度没有随着偏置电流改变而改变，1/f电压噪声随着偏置电流而改变。
约翰逊光谱噪声密度为
Figure PCTCN2018081914-appb-000001
值得注意的是，这是电压噪声，它与附图中的频率无关，其中，传感器的电阻R为5K欧姆，对应于10nV/rtHz。
所述的1/f噪声在低频率时是很大的，1/f噪声的幅值由偏置电压决定，约翰逊噪声与之是独立的；其中，1/f噪声以电阻波动的形式出现，其中有很多种可能的作用机制；但是对于传感器设计而言，它是电阻波动决定了它是如何被抑制，具体的作用机制并不重要。
下面给出分析，证明传感器偏置调制是不起作用的：假设，传感器的输出是信号与噪声的结合：
Figure PCTCN2018081914-appb-000002
其中，H表示测量的磁场，S表示灵敏度，V noise(ω)表示随机的传感器噪声，α 1表示信号非线性系数，i为≥1的正数，
在一个极限下，V out(ω)≈H(ω)S+V noise(ω)；
可以考虑调制传感器偏置来改变灵敏度，
则，V out(ω)≈H(ω)S(I bias(ω c))+V noise(ω,I bias(ω c))
然而，1/f噪声以电阻噪声的形式出现，电阻噪声的幅值取决于流过传感器元件的偏置电流：
V out(ω)≈H(ω)S(I bias(ω c))+R noise(ω)I bias(ω c)+....
因此，当以ω c来调制传感器时，可以得到：
V out(ω-ω c)-V out(ω+ω c)≈H(ω){S(I bias(0))-S(I bias(2ω c))}+R noise(ω){I bias(0)-I bias(2ω c)}+....然后以ω c通过低通滤波器，我们没有看到1/f噪声的减小，
V out(ω-ω c)≈H(ω)S(I bias(0))+R noise(ω)I bias(0)+....
V out(ω-ω c)≈H(ω)S+V noise(ω)+....
因此，可以看到调制传感器偏置不能够减小1/f噪声，这样传感器会产生电阻噪声。
下面采用预调制的方式进行调制，假设传感器输出是信号的噪声的非线性结合，所述传感器是采用直流偏置，
Figure PCTCN2018081914-appb-000003
其中，H表示测量的磁场，S表示灵敏度，V noise(ω)表示随机的传感器噪声，α 1表示信号非线性系数，i为≥1的正数，
在极限下，可以测量到的噪声和磁场相互是独立的，
V out(ω)≈H(ω)S+V noise(ω)
假设在传感器探测磁场之前，在ω c调制磁场输入，这样可以得到
V out(ω)≈H(ω+ω c)S+V noise(ω)，
通过ω c进行对V out进行混频，可以得到：
V out(ω-ω c)-V out(ω+ω c)≈{-H(2ω c)+H(ω)}S-V noise(ω+ω c)+V noise(ω-ω c)+...最终通过低通滤波器，可以得到：
V out(ω-ω c)≈H(ω)S+V noise(ω-ω c)+...
这样噪声相对于探测信号就转向负频率。
图4为信号调制和噪声的偏移示意图，调制的频谱偏移以频率ω c移到低频率，造成低频率噪声的降低。如果使用高的调制磁场，非线性会造成传感器噪声混合到调制的边频带上，这将降低噪声消减的数量。
为了任何调制结构能够工作，调制器调制待测量的信号而不一定非要调制传感器的1/f噪声，仍然可以实现信号和噪声之间的频率偏移，降低系统输出的1/f噪声。
图5为本发明的一种预调制磁电阻传感器的结构示意图，如图5所示，在XY平面上设置有一衬底1，磁电阻感应元件3、调制器棒2、电连接器4、 传感器连接件5、键合焊盘6、键合焊盘7、键合焊盘8、键合焊盘9等沉积在所述衬底1上，磁电阻感应元件3的感应方向平行于X轴；
磁电阻感应元件3串连连接成磁电阻感应元件串，所述的磁电阻感应元件串电连接成传感器电桥；所述的磁电阻感应元件串通过传感器连接件5，与所述的键合焊盘7和键合焊盘8电连接，使得偏置电压或者电流流过所述的磁电阻感应元件3并探测磁电阻感应元件3上的电压或电流，多个所述的调制器棒2以阵列形式设置，所述调制器棒2之间有间隙，所述间隙的间隔距离的方向延X轴方向，所述的调制器棒2与所述的键合焊盘电连接，调制电流从所述键合焊盘穿过，所述调制电流平行于Y轴的方向，所述的调制器棒2的端部之间通过电连接器4连接成蛇形状的电流路径。
其中，所述的磁电阻感应元件3为AMR、GMR或者TMR磁感应元件。所述的磁电阻感应元件串电连接成推挽式半桥电路，或者所述的磁电阻感应元件串电连接成推挽式全桥电路。
图6为本发明的预调制磁电阻传感器的剖视图，在调制器棒2上方沉积一层钝化保护层16，在磁电阻感应元件3上方沉积上部电极15，在磁电阻感应元件3下方沉积底部电极14，底部电极14与衬底1连接，调制器棒2与磁电阻感应元件3之间设置有一层电绝缘层，电绝缘层13将所述的调制器棒2与所述的磁电阻感应元件3隔开。其中，磁电阻感应元件3与衬底1之间也设置一层电绝缘层，图中的17为键合焊盘。
图7为一种调制器棒的结构示意图，图8为另一种调制器棒的结构示意图，调制器棒2是由FM1层21、NM层22和FM2层23三层结构构成，其中FM1层和FM2层是软铁磁体层，NM层是普通金属层，所述的调制器棒2的结构为矩形条状，其长轴平行于Y轴方向，其短轴平行于X轴方向，多个所述的调制器棒2以阵列形式设置，调制器棒之间有间隙，所述间隙的间隔距离延X轴方向。图中箭头74和75分别表示电流的流进和流出。
优选地，所述的调制器棒2的NM层的材料为钌或铜，所述NM层的厚度小于5nm，所述FM1层和所述FM2层之间存在反铁磁RKKY耦合。
图7和图8的差别在于：图7中电连接器优选地，所述的电连接器4为 金属导体元件，与所述的调制器棒2的上表面、下表面或者侧表面相连，而图8中的电连接器4是从FM1层、NM层和FM2层三层结构中刻蚀。
由于金属层比FM1层和FM2层具有更高的导电性，所以，调制器棒中的电流聚集在调制器棒的中间层；当电流很大时，FM1层和FM2层降低了调制器在平行于传感器元件感应方向上的磁导率。其中，高的磁导率意味着传感器串上集中的磁通量含量高，相反地，低的磁导率意味着传感器串上的集中的磁通量含量低。因此，通过交流电流穿过调制器，外部磁场可以通过磁导率的改变来调制。
调制器的FM1层和FM2层需要相同的剩磁厚度积(Mrt)，这样它们可以在调制器间进行相互补偿，然而，因为调制器棒的底层FM2层接近于磁电阻感应元件，因此，顶层的FM1层的剩磁厚度积比底层的FM2层要高一些。并且，调制器棒端部之间相互电连接，调制电流可以以蛇形的方式流过调制器棒，在整个的磁电阻感应元件区域可以弥补由于FM1和FM2不匹配而造成的不均匀。
图9为无调制电流的调制器棒的磁场分布示意图，调制器棒产生的磁场集中在磁电阻感应元件处。图10为有调制电流的调制器棒的磁场分布示意图，从图中可知，当施加调制电流时，在磁电阻感应元件没有磁场的集中。
图11本发明的预调制磁电阻传感器的调制器的另一种结构示意图，如图11所示，所述的预调制磁电阻传感器的调制器包括载流线圈11和铁磁性矩形体18，所述的载流线圈11位于铁磁性矩形体18的上方，所述的载流线圈11与所述的键合焊盘12连接。
图12为传感器轴的磁导率随调制电流变化的示意图；随着调制电流的增加，磁传感器轴的磁导率减小，施加交流调制电流，图13为施加的调制电流的波形图，从图13看出中，施加电流为正弦信号；其中的磁导率的大小与电流刚好相反，如图14所示，图14为磁导率变化的波形图；因磁场增益随磁导率的变化而变化，进而得到了传感器增益波形图，如图15所示。
图16为调制磁电阻传感器的输入输出示意图，调制磁电阻传感器包括调制电流输入端、调制电流输出端、传感器电流输入端和传感器电流输出端， 图中的箭头方向为钉扎层方向。
本发明还包括交流基准电源，所述的交流基准电源以频率f周期性地驱动所述传感器的调制器棒、模拟前端电路、低通滤波器以及混频器，所述的模拟前端电路包括前端处理器和放大器，所述的前端处理器与磁电阻传感器的输出端电容耦合，所述的混频器的输入端电连接到所述的交流基准电源和所述的前端处理器输出端；所述的低通滤波器的输入端电连接所述的混频器的输出端，所述的低通滤波器的输出端提供一个输出信号，所述的输出信号与所述的磁电阻感应元件所检测的磁场的幅值和极性对应。
图17为单个磁电阻电路的单极性的第一谐波应用示意图，图18为单个磁电阻电路的双极性的第二谐波应用示意图，图19为半桥电路的单极性的第一谐波应用示意图，图20为半桥电路的双极性的第二谐波应用示意图；图21为全桥电路的单极性的第一谐波应用示意图；图22为全桥电路的双极性的第二谐波应用示意图。
图17中所述的交流基准电源信号是单极性的。所述的低通滤波器与所述的混频器的输出端连接，所述的低通滤波器为一次谐波低通滤波器，具有频率为F的低频截止频率。
图17中还包括有一个优化滤波器，与所述的交流基准电源或者所述的混频器的一个输入信号电连接，所述优化滤波器通过在交流基准电源信号进入到混频电路之前去除部分频率分量，以及通过转换交流基准电源信号为交流电压信号的方式来调节所述基准电源信号。
图18中，所述的交流基准电源信号是双极性的，所述的磁电阻传感器还包括倍频器，所述的倍频器与所述的交流基准电源以及所述的混频器的输入端电连接，低通滤波器与所述的混频器的输出端连接，所述的低通滤波器为二次谐波低通滤波器，具有频率为2F的低频截止频率。
图19和图20分别采用两个磁电阻电路元件构成半桥电路。图21和图22分别采用四个磁电阻电路元件构成全桥电路，具体工作原理与上述类似。所述的传感器电桥包括两个或者两个以上互连的芯片，每个独立的芯片包括磁电阻感应元件串，所述的磁电阻感应元件串电连接成一个或多个传感器电 桥电路的桥臂；或者所述传感器电桥包括单一芯片，构成传感器电桥的桥臂沉积在所述单一芯片上。
需要说明的是，所述的FM1层和所述的FM2层有不同的剩磁厚度积Mrt；其中，在无外加磁场时，即使交流基准电源信号最大，此时所述调制电流在传感器位置产生的磁场也为最小，所述调制电流在传感器位置产生的磁场不受交流基准电源的影响。
需要说明的是，在所述交流基准电源信号位于工作频率范围时，所述的磁电阻传感器元件产生白噪声频率是远大于1/f噪声频率的。其中，通过增加传感器的尺寸，扩大面积能够减小1/f噪声。
本发明使用RKKY耦合的FM堆栈形式，通过调制器输出的调制电流改变所述磁电阻传感器的磁导率，并因此调制磁场。并且，本发明能够在被传感器元件探测之前进行调制，确保调制信号位于所述磁电阻传感器的相应线性区域范围内。
以上实施例仅说明本发明的技术方案，而非对其限制；尽管参照前述实施例对本发明进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本发明各实施例技术方案的精神和范围。

Claims (12)

  1. 一种预调制磁电阻传感器，其特征在于：
    在XY平面上设置有一衬底，磁电阻感应元件、调制器、电连接器、电绝缘层和键合焊盘均沉积在所述衬底上，所述磁电阻感应元件的感应方向平行于X轴；
    所述磁电阻感应元件串联连接成磁电阻感应元件串，所述的磁电阻感应元件串电连接成传感器电桥，所述传感器电桥为推挽式半桥电路或者推挽式全桥电路；所述的磁电阻感应元件串与所述的键合焊盘电连接，使得偏置电压或者电流流过所述的磁电阻感应元件并探测所述磁电阻感应元件上的电压或电流；
    所述调制器与所述的键合焊盘电连接，从所述键合焊盘得到调制电流，所述调制电流的方向平行于Y轴的方向，所述调制器使得调制电流通过软铁磁通量集中器周围的导体，在软铁磁通量集中器周围产生磁场来调制软铁磁通量集中器的磁导率，所述调制器与磁电阻感应元件之间设置有一层电绝缘层，所述的电绝缘层将所述调制器与所述磁电阻感应元件隔开。
  2. 根据权利要求1所述的一种预调制磁电阻传感器，其特征在于：
    所述的磁电阻感应元件为AMR、GMR或者TMR磁感应元件；所述的调制器由多个调制器棒构成，所述的调制器棒的结构为矩形条状，其长轴平行于Y轴方向，其短轴平行于X轴方向，多个所述的调制器棒以阵列形式设置，所述调制器棒之间有间隙，所述间隙的间隔距离的方向延X轴方向，所述的调制器棒的端部之间通过电连接器连接成蛇形状的电流路径。
  3. 根据权利要求2所述的一种预调制磁电阻传感器，其特征在于：所述的调制器棒是由FM1层、NM层和FM2层三层结构构成，其中FM1层和FM2层是软铁磁体层，NM层是普通金属层；
    所述NM层的材料为钌或铜，所述NM层的厚度小于5nm，所述FM1层和所述FM2层之间存在RKKY耦合作用。
  4. 根据权利要求3所述的一种预调制磁电阻传感器，其特征在于：所述电连接器为金属，所述的电连接器与所述的调制器的上表面、下表面或者侧表面相连；
    或者所述电连接器从FM1层、NM层和FM2层的三层结构中刻蚀。
  5. 根据权利要求1所述的一种预调制磁电阻传感器，其特征在于：所述调制器包括载流线圈和铁磁性矩形体，所述的载流线圈位于铁磁性矩形体的上方，所述载流线圈与所述的键合焊盘连接。
  6. 根据权利要求3所述的一种预调制磁电阻传感器，其特征在于：所述的传感器还包括交流基准电源，所述的交流基准电源以频率f周期性地驱动所述的传感器中的调制器棒、模拟前端电路、低通滤波器以及混频器，所述模拟前端电路包括前端处理器和放大器，所述的前端处理器与磁电阻传感器的输出端电容耦合，
    所述的混频器的输入端电连接到所述的交流基准电源和所述的前端处理器输出端，
    所述的低通滤波器的输入端电连接所述的混频器的输出端，所述的低通滤波器的输出端提供一个输出信号，所述的输出信号与所述的磁电阻感应元件所检测的磁场的幅值和极性相对应。
  7. 根据权利要求6所述的一种预调制磁电阻传感器，其特征在于：还包括有优化滤波器，所述优化滤波器与交流基准电源信号以及所述的混频器的一个输入信号电连接，
    所述优化滤波器通过在交流基准电源信号进入到混频电路之前去除部分频率分量，以及通过转换交流基准电源信号为交流电压信号的方式来调节所述基准电源信号。
  8. 根据权利要求6的一种预调制磁电阻传感器，其特征在于：所述的交流基准电源信号是单极性的，所述的低通滤波器与所述的混频器的输出端连接，所述的低通滤波器具有频率为F的低频截止频率。
  9. 根据权利要求7所述的一种预调制磁电阻传感器，其特征在于：所述的交流基准电源信号是双极性的，所述的磁电阻传感器还包括倍频器，所述 的倍频器与所述的交流基准电源以及所述的混频器的输入端电连接，所述的低通滤波器与所述的混频器的输出端连接，所述的低通滤波器具有频率为2F的低频截止频率。
  10. 根据权利要求1所述的一种预调制磁电阻传感器，其特征在于：所述传感器电桥包括单一芯片，构成传感器电桥的桥臂沉积在所述单一芯片上；
    或者所述传感器电桥包括两个或者两个以上互连的芯片，每个独立的芯片均包括磁电阻感应元件串，所述的磁电阻感应元件串电连接成一个或多个传感器电桥的桥臂。
  11. 根据权利要求7所述的一种预调制磁电阻传感器，其特征在于：在所述交流基准电源信号位于工作频率范围时，所述的磁电阻传感器元件产生白噪声频率远大于1/f噪声频率。
  12. 根据权利要求6所述的一种预调制磁电阻传感器，其特征在于：所述的FM1层和所述的FM2层有不同的剩磁厚度积Mrt，在无外加磁场时，即使交流基准电源信号最大，所述调制电流在传感器位置产生的磁场也为最小。
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021150680A1 (en) * 2020-01-21 2021-07-29 Spincoil Systems, Inc. Apparatus and method for improving the sensitivity of magnetic field sensors
US11287491B2 (en) 2017-04-05 2022-03-29 MultiDimension Technology Co., Ltd. Modulated magnetoresistive sensor

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106160670B (zh) * 2016-08-18 2023-05-30 江苏多维科技有限公司 一种平衡磁电阻混频器
CN109473545A (zh) * 2017-09-08 2019-03-15 Tdk株式会社 磁阻效应器件及高频器件
CN108413992A (zh) * 2018-01-30 2018-08-17 江苏多维科技有限公司 一种三轴预调制低噪声磁电阻传感器
CN108318838B (zh) * 2018-03-06 2024-06-04 美新半导体（无锡）有限公司 设置有自检线圈的磁电阻传感器
CN109212440B (zh) * 2018-10-31 2020-12-25 中国科学技术大学 一种基于固态自旋的磁场测量方法及装置和磁场测量系统
CN111198342B (zh) * 2020-01-10 2021-07-06 江苏多维科技有限公司 一种谐波增宽线性范围的磁电阻传感器
CN111505545B (zh) 2020-04-30 2022-02-18 江苏多维科技有限公司 一种机电调制磁阻旋转式磁场强探头
DE102021120034A1 (de) 2021-08-02 2023-02-02 Infineon Technologies Ag Redundanter stromsensor
EP4394418A1 (en) * 2022-12-31 2024-07-03 Melexis Technologies SA Semiconductor device with integrated soft-magnetic component, and method of producing same
CN117936515B (zh) * 2023-12-08 2024-09-17 中国工程物理研究院电子工程研究所 含磁阻电流传感的三维集成tsv转接板及制备方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101680740A (zh) * 2007-05-29 2010-03-24 Nxp股份有限公司 外部磁场角度确定
JP2010078401A (ja) * 2008-09-25 2010-04-08 Koichi Egashira 非接触磁気変調型信号増幅器。
CN101896976A (zh) * 2007-10-31 2010-11-24 纽约大学 基于电流感应自旋动量转移的高速低功率磁性装置
CN103645449A (zh) * 2013-12-24 2014-03-19 江苏多维科技有限公司 一种用于高强度磁场的单芯片参考桥式磁传感器
CN103675756A (zh) * 2012-09-13 2014-03-26 伯恩斯公司 使用通量调制和角度感测的位置测量
CN107037382A (zh) * 2017-04-05 2017-08-11 江苏多维科技有限公司 一种预调制磁电阻传感器
CN207081821U (zh) * 2017-04-05 2018-03-09 江苏多维科技有限公司 一种预调制磁电阻传感器

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04191685A (ja) * 1990-11-26 1992-07-09 Fujitsu Ltd 磁界センサ
US6129957A (en) * 1999-10-12 2000-10-10 Headway Technologies, Inc. Method of forming a second antiferromagnetic exchange-coupling layer for magnetoresistive (MR) and giant MR (GMR) applications
US7195945B1 (en) * 2004-09-15 2007-03-27 United States Of America As Represented By The Secretary Of The Army Minimizing the effect of 1/ƒ noise with a MEMS flux concentrator
US8331064B2 (en) * 2008-04-18 2012-12-11 International Business Machines Corporation System having a TMR sensor with leads configured for providing joule heating
US7915890B2 (en) * 2008-06-23 2011-03-29 Seagate Technology Llc High sensitivity magnetic sensor
CN101969098B (zh) * 2010-08-11 2012-10-17 上海腾怡半导体有限公司 一种磁阻传感器的制造方法
US8222898B1 (en) * 2011-04-15 2012-07-17 The United States Of America As Represented By The Secretary Of The Army Method and apparatus for utilizing magnetic field modulation to increase the operating frequency of sensors
US9341684B2 (en) * 2013-03-13 2016-05-17 Plures Technologies, Inc. Magnetic field sensing apparatus and methods
CN103267955B (zh) * 2013-05-28 2016-07-27 江苏多维科技有限公司 单芯片桥式磁场传感器
US10495699B2 (en) * 2013-07-19 2019-12-03 Allegro Microsystems, Llc Methods and apparatus for magnetic sensor having an integrated coil or magnet to detect a non-ferromagnetic target
CN103630855B (zh) * 2013-12-24 2016-04-13 江苏多维科技有限公司 一种高灵敏度推挽桥式磁传感器
JP2015197388A (ja) * 2014-04-02 2015-11-09 アルプス電気株式会社 フラックスゲート型磁気センサ
CN104569870B (zh) * 2015-01-07 2017-07-21 江苏多维科技有限公司 一种单芯片具有校准/重置线圈的z轴线性磁电阻传感器
CN105093139B (zh) * 2015-06-09 2017-11-24 江苏多维科技有限公司 一种推挽式x轴磁电阻传感器
CN104880682B (zh) * 2015-06-09 2018-01-26 江苏多维科技有限公司 一种交叉指状y轴磁电阻传感器
CN105185655B (zh) * 2015-08-12 2017-08-29 江苏多维科技有限公司 一种磁电阻继电器
JP6529885B2 (ja) * 2015-10-19 2019-06-12 アルプスアルパイン株式会社 磁気センサ、磁界の測定方法、電流センサ、および電流の測定方法
CN105259518A (zh) * 2015-11-03 2016-01-20 江苏多维科技有限公司 一种高灵敏度单芯片推挽式tmr磁场传感器
CN107479010B (zh) * 2016-06-07 2019-06-04 江苏多维科技有限公司 一种具有补偿线圈的磁电阻传感器

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101680740A (zh) * 2007-05-29 2010-03-24 Nxp股份有限公司 外部磁场角度确定
CN101896976A (zh) * 2007-10-31 2010-11-24 纽约大学 基于电流感应自旋动量转移的高速低功率磁性装置
JP2010078401A (ja) * 2008-09-25 2010-04-08 Koichi Egashira 非接触磁気変調型信号増幅器。
CN103675756A (zh) * 2012-09-13 2014-03-26 伯恩斯公司 使用通量调制和角度感测的位置测量
CN103645449A (zh) * 2013-12-24 2014-03-19 江苏多维科技有限公司 一种用于高强度磁场的单芯片参考桥式磁传感器
CN107037382A (zh) * 2017-04-05 2017-08-11 江苏多维科技有限公司 一种预调制磁电阻传感器
CN207081821U (zh) * 2017-04-05 2018-03-09 江苏多维科技有限公司 一种预调制磁电阻传感器

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3608680A4 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11287491B2 (en) 2017-04-05 2022-03-29 MultiDimension Technology Co., Ltd. Modulated magnetoresistive sensor
WO2021150680A1 (en) * 2020-01-21 2021-07-29 Spincoil Systems, Inc. Apparatus and method for improving the sensitivity of magnetic field sensors

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