WO2014075407A1

WO2014075407A1 - Micromechanical magnetic field sensor and application thereof

Info

Publication number: WO2014075407A1
Application number: PCT/CN2013/071864
Authority: WO
Inventors: 熊斌; 吴国强; 徐德辉; 王跃林
Original assignee: 中国科学院上海微系统与信息技术研究所
Priority date: 2012-11-19
Filing date: 2013-02-26
Publication date: 2014-05-22
Also published as: CN102914750A; CN102914750B

Abstract

A micromechanical magnetic field sensor and application thereof. The micromechanical magnetic field sensor at least comprises a resonant oscillator pair, and insulating layers (6) and metal wire coils (7) that are sequentially formed on the surfaces of the resonant oscillator pair. The micromechanical magnetic field sensor utilizes the differential capacitor excitation and electromagnetic induction to measure the size of a magnetic field, two resonant oscillator structures (1) forming the resonant oscillator pair work in a same phase mode, the winding directions of the metal induction coils (7) on the resonant oscillator structures (1) are opposite, and induced electromotive forces generated by the metal induction coils (7) on the two resonant oscillator structures (1) are connected with each other in series. As differential mode output is adopted, a capacitive coupling signal in an output signal is eliminated to acquire a simplex magnetic field output signal. Meanwhile, the two resonant oscillator structures are coupled through a coupling structure, so that the two resonant oscillator structures act in an integrally connected manner. Further, the micromechanical magnetic field sensor has the advantages of simple structure, less temperature influence, large output signal, high sensitivity, high detection accuracy and suitability for high working frequency.

Description

Micromechanical magnetic field sensor and its application

Technical field

The invention belongs to the technical field of design and detection of micro-mechanical magnetic field sensors, and relates to a magnetic field sensor, in particular to a micro-mechanical magnetic field sensor and its circuit structure working in an expanded mode. Background technique

By sensing the direction of the Earth's magnetic field or navigating the ship, especially in the fields of navigation, aerospace, automation, military, and consumer electronics, magnetic field sensors are becoming more widely used. Magnetic field sensing technology is moving toward miniaturization, low power consumption, high sensitivity, high resolution, and compatibility with electronic devices. According to the working principle, the magnetic field sensor can be divided into: superconducting quantum interference magnetic field sensor, Hall magnetic field sensor, fluxgate magnetometer, giant magnetoresistive magnetic field sensor and induction coil magnetic field sensor.

The superconducting quantum interference magnetic field sensor has the highest sensitivity among all magnetic field sensors, but its structure is complex, bulky, expensive, and needs to work in a low temperature environment. The Hall magnetic field sensor has low power consumption and small size, and can measure static or dynamic magnetic fields. However, its sensitivity is low, noise level and static offset are large; fluxgate magnetometer is used to measure static or slowly changing magnetic field, high resolution, low power consumption, but large volume and low frequency response; giant magnetoresistance Magnetic field sensors are highly sensitive, but cannot measure large magnetic fields. Inductive coil magnetic field sensors are based on Faraday's law of electromagnetic induction to detect changing magnetic fields. They have low power consumption and simple structure (AL Herrera-May, LA Aguilera-Corts, PJ Garca- Ramrez and E. Manjarrez, "Resonant magnetic field sensors based on MEMS technology", Sensors, vol. 9, no. 10, pp. 7875-7813, 2009. ).

Induction coils fabricated by MEMS (Micro Electro Mechanical System) technology Magnetic field sensors are simple in structure and easy to process, and are compatible with CMOS IC (Complementary Metal Oxide Semiconductor Integrated Circuit) technology. MEMS magnetic field sensors have the advantages of small size, light weight, low power consumption, low cost, high reliability, excellent performance and powerful functions that are unmatched by traditional sensors. The development of MEMS technology has enabled micro-structure processing on the chip, while reducing the cost of MEMS, and can also accomplish tasks that many large-scale electromechanical systems cannot perform, thus promoting the development of magnetic field sensors.

At present, the main working principle of the magnetic field sensor of the MEMS structure is: After the Lorentz force of the induction coil of the current is subjected to the magnetic field, the structure of the support coil is bent or twisted, and the method of capacitance detection or piezoresistive detection, optical detection, etc. The magnitude of the magnetic field signal can be detected by measuring the amount of torsional deformation or the amount of bending deformation of the supporting coil structure. These devices typically have inductive coils fabricated on cantilever beams, U-beams, or plates that can be bent or twisted. Device When working, place the device in a magnetic field and apply current to the induction coil. The induction coil is subjected to Lorentz forces, which cause bending or torsion of the cantilever beam, U-beam or plate. By measuring the amount of bending or the amount of twist of the cantilever beam, U-beam or plate, the magnitude of the magnetic field can be detected. However, since these devices all need to pass current to the induction coil, their power consumption is relatively large; in addition, these devices generally operate in a bending mode or a torsional mode, and thus they operate at a lower resonance frequency.

Further, in order to reduce power consumption and structural complexity, the MEMS-structured magnetic field sensor can also be implemented by loading a metal coil on a resonant oscillator structure operating in an expanded mode (in the case of a bulk mode). The resonant resonator may be a square plate, a circular plate or a circular plate structure. Figures la to lc are modal diagrams of several resonant oscillator structures operating in a bulk mode, where the dashed line indicates the deformation trend of the outer contour of the resonant oscillator structure during operation (resonant state), and Figure la is for operation at the Square Extensional ( SE) modal square plate resonant oscillator structure, Figure lb is a circular plate resonant oscillator structure operating in the Radial Extensional (RE) mode, and Figure lc is a circular plate resonant oscillator structure operating in the Radial Extensional (RE) mode . However, the micromechanical magnetic field sensor in the magnetic field sensor is an electrostatically driven device. Due to the parasitic capacitance between the input signal and the output port, the measured output signal contains a capacitive coupling signal caused by capacitive coupling. In the prior art, the effect of capacitive coupling is generally reduced by reducing the parasitic capacitance between the input signal and the output port. However, this method can only reduce the capacitive coupling signal and cannot completely eliminate it. In other words, there is still a capacitive coupling signal in the output signal, and a simple magnetic field output signal cannot be obtained. Summary of the invention

In view of the above-discussed shortcomings of the prior art, it is an object of the present invention to provide a micromechanical magnetic field sensor for solving the problem that the output signal of the micromechanical magnetic field sensor of the prior art cannot eliminate the influence of the capacitive coupling signal.

In order to achieve the above and other related objects, the present invention provides a micro-mechanical magnetic field sensor, the micro-mechanical magnetic field sensor comprising: a pair of resonant oscillators and an insulating layer and a metal coil sequentially formed on a surface thereof;

The resonant oscillator pair includes:

Two resonant oscillator structures having an axisymmetric structure, each of the resonant axes of the resonant oscillator structure includes at least a first axis of symmetry and a second axis of symmetry, and the first axis of symmetry is perpendicular to the second axis of symmetry;

a main support beam on the first axis of symmetry, and two resonant oscillator structures are coupled to each other through respective main support beams;

a first anchor point, connected to the free end of the main support beam, wherein the first anchor point of the two resonant oscillator structure is respectively connected to the output end through a pad formed thereon;

Driving electrodes are respectively distributed on opposite sides of each of the resonant oscillator structures, and between the resonant resonator structures Forming a driving gap, the driving electrode is connected to the DC power source through a resistor, and the driving electrode is connected to the AC power source through a capacitor;

The insulating layer is formed on the resonant oscillator structure of the pair of resonant oscillators and the upper surface of the main supporting beam, and an insulating layer is formed between the first anchor point and the pad formed thereon;

The metal coils are respectively formed on the insulating layer on each of the resonant oscillator structures, and the metal coil is a metal coil surrounded by the center of the corresponding insulating layer from the center of the insulating layer, wherein a resonant oscillator structure is The metal coil is surrounded by clockwise, and the metal coil on the other vibrator structure is surrounded by a counterclockwise; the beginning of each metal coil is connected to the pad on the corresponding first anchor point through the first connecting bridge, and each of the The ends of the metal coils are connected to each other on the first insulating layer on the coupled main support beam by a second connecting bridge, or the ends of the metal coils are connected to the corresponding first anchor points through the second connecting bridge. And a starting end of each of the metal coils is connected to the first insulating layer on the main supporting beam of the coupled connection through a first connecting bridge; and each of the first connecting bridge and each of the metal coils located therebelow is formed Insulation.

Optionally, the resonant oscillator pair further includes a first coupling beam connected at one end to the main supporting beam coupled to each other, and a second anchor point connected to the other end of the first coupling beam, where The second anchor point is grounded through a pad formed thereon, and an insulating layer is formed between the upper surface of the first coupling beam and the pad formed on the second anchor point and the pad formed thereon.

Optionally, the end of each of the metal coils is connected to the pad on the second anchor point through a second connecting bridge via a main support beam coupled to each other and a first insulating layer on the first coupling beam; or The beginning of the metal coil is connected to the pad on the second anchor point through the first connecting bridge via the main support beam coupled to each other and the first insulating layer on the first coupling beam.

Optionally, the resonant oscillator structure is a rectangular plate, a circular plate or a circular annular plate.

Optionally, the first coupling beam is a straight beam or a curved folding beam.

Optionally, the resonant oscillator pair further includes a second coupling beam, and the second coupling beam is also connected to the main supporting beam on the first symmetry axis and connected to each other, and the second coupling beam is connected There is a third anchor point; wherein the second coupling beam and the first coupling beam are respectively distributed on two sides of the first symmetry axis.

Optionally, the second coupling beam is a straight beam or a curved folding beam.

Optionally, when the resonant oscillator structure is a rectangular plate, the first axis of symmetry is parallel to a long side or a wide side of the rectangular plate. Optionally, when the resonant oscillator structure is a square plate, the first symmetry axis and the second symmetry axis are respectively extension lines of two diagonal lines of the square plate.

Optionally, the resonant oscillator pair further includes a side support beam on the second symmetry axis and one end connected to the resonant oscillator structure, and a fourth anchor point connected to the other end of the side support beam.

Optionally, the metal coil is a plurality of layers, and the metal coils of each layer are connected in series, and the metal coils of each layer have the same winding direction, and an insulating layer is formed between the metal coils of each layer. Optionally, the metal coils are connected in series by a continuous even-numbered layer and an odd-numbered layer, the ends of the metal coils are connected, and the continuous odd-numbered layer and the even-numbered layer are connected to the beginning of the metal coil, and each of the The metal coils connected in series have an insulating layer in addition to the joint.

Optionally, a metal support post supporting the metal coil to hang over the insulating layer is formed between the metal coil and the insulating layer under the metal coil.

Optionally, the metal coil is a circle, and the metal coil is circular or rectangular.

Optionally, the metal coil is a plurality of turns, and the metal coil is a circular spiral or a rectangular spiral.

The present invention also provides a circuit structure of a micro-mechanical magnetic field sensor, the circuit structure including at least: a phase-locked loop circuit, the micro-mechanical magnetic field sensor, a differential voltage amplifier, and a voltage follower, wherein the phase-locked loop circuit Including a voltage controlled oscillator, a phase detector and a low pass filter;

An output of the voltage controlled oscillator for generating an alternating current signal having the same resonant frequency as the micromechanical magnetic field sensor is respectively connected to an alternating current power input end of the micromechanical magnetic field sensor and an input end of the phase detector, The AC signal outputted by the voltage controlled oscillator is used as a reference signal of the phase detector, and a DC voltage is connected to the DC power input end of the micromechanical magnetic field sensor;

An output of the micromechanical magnetic field sensor for generating an induced voltage is coupled to an input of the differential voltage amplifier for connecting an output of the differential voltage amplifier that amplifies the induced voltage to another phase detector An input terminal, wherein the amplified induced voltage signal output by the differential voltage amplifier is used as a measurement signal;

An output of the phase detector for identifying a phase difference between the measurement signal and the reference signal is coupled to an input of the low pass filter;

An output of the low pass filter for filtering an alternating current portion of the phase detector output signal is connected to a control end of the voltage controlled oscillator and an input end of the voltage follower, wherein the low pass The DC signal outputted by the filter is used as a control voltage signal of the voltage controlled oscillator to ensure that the entire phase locked loop circuit is in a stable working state;

The output of the voltage follower is connected to an external measuring device, wherein the magnitude of the DC voltage signal output by the voltage follower characterizes the magnitude of the magnetic field to be measured of the micromechanical magnetic field sensor. As described above, the micromechanical magnetic field sensor of the present invention has the following advantageous effects:

1) The present invention uses a coupling beam to couple two resonant oscillator structures to form a resonant oscillator pair, and uses single-ended capacitive excitation and electromagnetic induction to measure the magnitude of the magnetic field, wherein the two resonant oscillator structures operate in the same phase mode, and each of the resonant oscillators The metal coils on the structure are wound in opposite directions, and the induced electromotive forces generated by the metal coils on the two resonant oscillator structures are mutually stringed. Because the differential mode output is used, two capacitive coupling signals are formed between the two differential output signals and the input driving signal, and since the two capacitive coupling signals are equal in magnitude, the differential mode output eliminates the output signal. The capacitive coupling signal, thereby obtaining a simple magnetic field output signal, realizes the detection of a simple magnetic field output signal of the micromechanical magnetic field sensor;

2) The invention couples two resonant oscillator structures by using a coupling structure, and the two resonant resonator structures are integrally connected by the coupling structure, thereby ensuring that the entire micro-mechanical magnetic field sensor has a single resonant frequency;

3) The resonant oscillator of the micromechanical magnetic field sensor proposed by the invention operates in an expanding mode, so that each small metal cutting magnetic line on the metal coil generates an induced electromotive force which is superposed in series with each other to enhance the intensity of the output signal; the metal coil of the present invention It can be one or more layers of spiral coils, which is beneficial to further increase the intensity of the output signal and improve the sensitivity of detection;

4) The present invention can also suspend the metal coil over the resonant oscillator through the metal support column, thereby reducing the problem of crosstalk between the resonant oscillator structure and the metal coil at high frequencies;

5) The invention has a simple structure, does not need to pass current on the metal coil, and reduces the power consumption of the device; at the same time, the magnitude of the magnetic field is measured by measuring the induced electromotive force at both ends of the metal coil, so that the temperature is less affected; and since the invention adopts The two resonant oscillator structures further enhance the strength of the output signal and also increase the sensitivity of the output signal. DRAWINGS

Figures la to lc show schematic diagrams of modalities of several resonant oscillator structures operating in bulk mode in the prior art, wherein Figure la is a square plate resonant oscillator structure operating in the Square Extensional (SE) mode, Figure Lb is a circular plate resonant oscillator structure operating in the Radial Extensional (RE) mode, and Figure lc is a circular plate resonant oscillator structure operating in the Radial Extensional (RE) mode.

2a is a schematic view showing a test circuit of the micromechanical magnetic field sensor of the present invention in the first embodiment, wherein the resonant oscillator structure is a SE modal square plate.

Fig. 2b is a schematic view showing a related structure of a resonator pair of a micromechanical magnetic field sensor of the present invention.

Fig. 2c is a schematic view showing the structure of a pair of resonant oscillators of the micromechanical magnetic field sensor of the present invention in the first embodiment.

Fig. 2d is a schematic view showing the circuit structure of the micromechanical magnetic field sensor of the present invention in the first embodiment.

Fig. 3a is a schematic view showing the test circuit of the micromechanical magnetic field sensor of the present invention in the second embodiment, wherein the resonant oscillator structure is a Width Extensional (WE) mode rectangular plate.

FIG. 3b is a schematic diagram showing the related structure of the resonant oscillator pair in the second embodiment of the micromechanical magnetic field sensor of the present invention. Figure.

Fig. 4a is a schematic view showing the test circuit of the micromechanical magnetic field sensor of the present invention in the third embodiment, wherein the resonant oscillator structure is a RE mode circular plate.

Fig. 4b is a schematic view showing the structure of a pair of resonant oscillators of the micromechanical magnetic field sensor of the present invention in the third embodiment. Component label description

1 resonant oscillator structure

21 main support beam

22 side support beam

31 first coupling beam

32 second coupling beam

41 first anchor point

42 second anchor point

43 third anchor point

44 fourth anchor point

5 drive electrode

6 insulation

7 metal coil

81 first connecting bridge

82 second connecting bridge

P DC power supply

v _in AC power

V _out voltage output

R resistance

C capacitor

91 voltage controlled oscillator

93 Micro-Mechanical Magnetic Field Sensor

94 differential voltage amplifier

95 phase detector 96 low pass filter

97 voltage follower

The embodiments of the present invention are described in the following specific embodiments, and those skilled in the art can readily appreciate the other advantages and effects of the present invention from the disclosure.

Please refer to Figures 2a to 4b. It is to be understood that the structures, the proportions, the dimensions, and the like of the drawings are only used to facilitate the understanding and reading of those skilled in the art, and are not intended to limit the practice of the present invention. The conditions are limited, so it is not technically meaningful. Any modification of the structure, change of the proportional relationship or adjustment of the size should remain in the present invention without affecting the effects and the achievable objectives of the present invention. The disclosed technical content is within the scope of the disclosure. At the same time, terms such as "upper", "lower", "left", "right", "intermediate" and "one" as used in this specification are also for convenience of description, and are not intended to limit the present. The scope of the invention, the change or adjustment of the relative relationship, is also considered to be within the scope of the invention. Embodiment 1

As shown in FIGS. 2a to 2c, the present invention provides a micro-mechanical magnetic field sensor, the micro-mechanical magnetic field sensor comprising: a pair of resonant oscillators and an insulating layer 6 and a metal coil 7 sequentially formed on a surface thereof, wherein The resonant oscillator pair includes: a resonant oscillator structure 1, a main support beam 21, a first anchor point 41, and a drive electrode 5. In the first embodiment, the harmonic oscillator pair further includes a first coupling beam 31 and a second anchor point 42.

The resonant oscillator structure 1 is two and both axisymmetric structures, and the axis of symmetry of each of the resonant oscillator structures 1 includes at least a first axis of symmetry and a second axis of symmetry, and the first axis of symmetry is perpendicular to the second symmetry. axis. The material of the resonant oscillator structure 1 is monocrystalline silicon, polycrystalline silicon, amorphous silicon or silicon carbide. It should be noted that the resonant oscillator structure 1 is a rectangular plate, a circular plate or a circular annular plate. When the resonant oscillator structure 1 is a rectangular plate, the first axis of symmetry is parallel to a long side or a wide side of the rectangular plate. Preferably, the resonant oscillator structure 1 is a square plate; further, the resonant oscillator structure 1 In the case of a square plate, the first axis of symmetry and the second axis of symmetry may also be extension lines of two diagonal lines of the square plate, specifically, in the first embodiment, as shown in FIG. 2c, two The resonant oscillator structure 1 is a single crystal silicon square plate, and the first symmetry axis and the second symmetry axis of the square plate resonant oscillator structure 1 are respectively an extension line of two diagonal lines of the square plate, that is, the main support beam 21 is connected to the square plate. The corners of the resonant oscillator structure 1 and the dashed lines of each of the resonant oscillator structures 1 in Fig. 2c indicate the deformation tendency of the external profile of each of the resonant oscillator structures 1 during operation (resonant state).

The main support beam 21 is located on the first axis of symmetry, and the two resonant resonator structures 1 are coupled to each other by respective main support beams 21. Specifically, in the first embodiment, the main support beam 21 is two, and each of the single crystal silicon is positive. The square plate resonant oscillator structures 1 are coupled to each other by a respective one of the main support beams 21.

It should be noted that, in the first embodiment, the resonant oscillator pair further includes a first coupling beam 31 and a second anchor point 42, but is not limited thereto. In another embodiment, the resonant oscillator pair may The first coupling beam 31 and the second anchor point 42 are not included (see Figure 2b). One end of the first coupling beam 31 is connected to the main supporting beam 21 connected to each other, wherein the first coupling beam 31 is a straight beam or a curved folding beam. Specifically, in the first embodiment, as shown in FIG. 2c, the first coupling beam 31 is a curved folded beam.

The second anchor point 42 is connected to the other end of the first coupling beam 31, wherein the second anchor point 42 is formed with a pad (as shown in FIG. 2a, the first anchor point is filled with a cross grid place) And the second anchor point 42 is grounded through the pad.

The first anchor point 41 is connected to the free end of the main support beam 21, wherein the first anchor point 41 is formed with a pad (as shown in FIG. 2a, the second anchor point is filled with a cross-grid space) The first anchor point 41 of the two resonant resonator structure 1 is respectively connected to the voltage output terminal V through pads formed thereon. _ut, i.e. differentially detected output V _out of the induced electromotive force is measured and further test field magnitude.

The driving electrodes 5 are respectively disposed on opposite sides of each of the resonant oscillator structures 1 , and a driving gap is formed between each of the resonant oscillator nodes 1 , and the driving electrode 5 is connected to the DC power source V _p through the resistor R, and The driving electrode 5 is connected to the AC power source V _in through the capacitor C, so that the two resonant oscillator structures are single-ended capacitive excitation driving mode (refer to FIG. 2a), then the two resonant oscillator structures 1 operate in the same phase mode. At the same time, due to the differential mode output, two capacitive coupling signals are formed between the two differential output signals and the input driving signal, and since the two capacitive coupling signals are equal in size, the differential mode output will eliminate the output signal. The capacitive coupling signal, in order to obtain a simple magnetic field output signal, realizes the detection of a simple magnetic field output signal of the micromechanical magnetic field sensor.

Preferably, in the first embodiment, as shown in FIG. 2a, the driving electrodes 5 are located on opposite sides of each of the square plate resonant oscillator structures 1, and between the driving electrodes 5 and the resonant oscillator structure 1. A driving gap is formed. As shown in FIG. 2c, the driving electrodes 5 are two pairs, and each pair is symmetrically distributed on opposite sides of each of the square plate resonant oscillator structures 1, that is, each pair of the driving electrodes 5 is symmetrically distributed. On the side opposite to the side of each of the square plate resonant oscillator structures 1, but is not limited thereto, in another embodiment, the driving electrodes may be only a pair and distributed in the opposite direction of each of the square plate resonant oscillator structures 1. side.

It should be noted that, as shown in FIG. 2c, in the first embodiment, the resonant oscillator pair further includes a second coupling beam 32, and the second coupling beam 32 is also connected to the first symmetry axis. And connected to the main support beam 21, and the second coupling beam 32 is connected with a third anchor point 43, preferably, as shown in FIG. 2c, the second coupling beam 32 and the first coupling beam 31 Symmetrically distributed on both sides of the first axis of symmetry. It should be further noted that, in the first embodiment, as shown in FIGS. 2a and 2c, the resonant oscillator pair further includes a side support beam 22 and a fourth anchor point 44, wherein the side support beam 22 is located in the a second axis of symmetry, one end of which is connected to the resonant oscillator structure 1 and the other end of which is connected to the fourth anchor point 44, that is, the side support beam 22 is connected to the corner of the square plate resonant oscillator structure 1, but is not limited thereto. Therefore, in another embodiment, the resonant oscillator pair may also be free of the side support beam and the fourth anchor point. Further, as shown in FIGS. 2a and 2c, in the first embodiment, the four anchor points 44 are grounded through the pads located thereon, but are not limited thereto, and the pads on the fourth anchor point are shown. It can also be ungrounded.

The insulating layer 6 is formed on the upper surface of the resonant oscillator structure 1 and the main support beam 21 of the pair of resonant resonators, and an insulating layer 6 is formed between the first anchor point 41 and the pad formed thereon. Specifically, in the first embodiment, the upper surface of the first coupling beam 31 is also formed with an insulating layer 6, and the insulating layer 6 is formed between the second anchor point 42 and the pad formed thereon. Preferably, the resonant oscillator structure 1, the main support beam 21, the first coupling beam 31, the first anchor point 41 and the second anchor point 42 are formed in the same plane, and the insulating layer is formed on the upper surface of the plane. on. Further, in the first embodiment, the resonant oscillator pair further includes a second coupling beam 32, a third anchor point 43, a side support beam 22, and a fourth anchor point 44, as shown in FIG. 2a, the second coupling There is no insulating layer 6 on the beam 32, the third anchor point 43, and the side support beam 22. The insulating layer 6 is formed between the fourth anchor point 44 and the pad formed thereon, but is not limited thereto. In another embodiment, the second coupling beam 32, the third anchor point 43, and the side support beam 22 may also have an insulating layer 6. When the fourth anchor point 44 has no pad, there may be no insulation. Layer 6.

The metal coils 7 are respectively formed on the insulating layer 6 on each of the resonant oscillator structures 1 , wherein the metal coils are metal coils whose inner ends are surrounded by the center of the insulating layer 6 . The metal coil 7 on one resonant resonator structure 1 is clockwise, and the metal coil 7 on the other oscillator structure 1 is surrounded by counterclockwise. Since the metal coils on the resonant resonator structure 1 are in the opposite direction; and since the two resonant resonator structures 1 are excited by the single-ended capacitor and operate in the in-phase mode, the induced electromotive force generated by the metal coils 7 on the two resonant oscillator structures 1 Connected in series.

In the first embodiment, as shown in FIG. 2a, the metal coil 7 on a resonant oscillator structure 1 is clockwise, and the metal coil turns on the other vibrator structure 1 are counterclockwise; each of the metal coils is The end is connected to the pad on the corresponding first anchor point 41 through the second connecting bridge 82, and the main support beam 21 and the first coupling beam which are coupled to each other through the first connecting bridge 81 through the first connecting bridge 81 The insulating layer 6 on the 31 is connected to the pad on the second anchor point 42. At this time, the second connecting bridge 82 is located on the insulating layer 6 on the main supporting beam 21 connected to the first anchor point 41. At the same time, an insulating layer 6 is formed between each of the first connecting bridges 81 and each of the metal coils located thereunder, wherein the first connecting bridge 81-end is connected to the insulating layer 6 located therebelow to The beginning end of the metal coil ,, the other end of the first connecting bridge 81 is connected to the pad on the second anchor point 42. At this time, the first connecting bridge 81 is located at the metal coil 7, and is coupled to each other. Supporting the beam 21 and the insulating layer 6 on the first coupling beam 31; the metal coil 7, A connecting bridge 81 The material of the second connecting bridge 82 is gold, but it is not limited thereto. The materials of the three connecting materials may be the same or different from each other, but the materials of the three are selected from gold, copper or copper to ensure good electrical connection. aluminum.

It should be noted that the manner in which the metal coil is connected to the pads on the first anchor point and the second anchor point is not limited thereto. In another embodiment (not shown), the beginning of each of the metal coils is connected to the pads on its corresponding first anchor point through the first connecting bridge, and the ends of the metal coils pass through the second connecting bridge. The main support beam and the insulating layer on the first coupling beam are connected to the pad on the second anchor point; at the same time, each of the first connecting bridge and each of the metal coils located under the same is formed An insulating layer, wherein one end of the first connecting bridge is connected to a beginning end of the metal coil through an insulating layer located under the first connecting bridge, and the other end of the first connecting bridge is connected to a pad on the first anchor point.

It should be noted that the metal coil may be a layer or a plurality of layers; when the metal coil is a plurality of layers, the metal coils of each layer are connected in series, and the metal coils of each layer have the same winding direction. An insulating layer is further formed between the metal coils of each layer, wherein the metal coils are connected in series by continuous even-numbered layers and odd-numbered layers are connected to ends of the metal coils, and continuous odd-numbered layers and even-numbered layers The starting ends of the metal coils are connected to ensure that the layers are in the same winding direction, and each of the metal coils connected in series has an insulating layer except for the joint. Taking the three-layer metal coils as clockwise surrounds as an example: the first layer of metal coils is clockwise surrounded from the inside to the outside with the center as the beginning, and the second layer of metal coils is connected to the ends of the first layer of metal coils, and the The two-layer metal coil is surrounded by the end from the outside to the clockwise direction. At this time, the first layer of the metal coil and the second layer of the metal coil are wound in the same direction, and then the third layer of the metal coil is connected to the center of the second layer of the metal coil. And the third layer of metal coils is clockwisely surrounded from the inside to the outside with the center as the starting end. At this time, the winding directions of the metal coils of the first layer, the second layer and the third layer are the same.

It should be further noted that the metal coil may be directly formed on the insulating layer, or a metal coil may be suspended between the metal coil and the insulating layer underneath. The metal support column, wherein the support column and the coil are of the same material, and are all selected from the group consisting of gold, copper or aluminum. When the metal coil is suspended above the resonant vibrator by the metal support post, the problem of signal crosstalk between the resonant vibrator structure and the metal coil at a high frequency can be reduced.

It should be noted that the number of turns of the metal coil is one turn (unclosed), the metal coil is circular or rectangular; the metal coil may also be multiple turns, and the metal coil is circular spiral or The rectangle is spiral, but it is necessary to ensure that the shape of each of the resonant oscillator structures 1 is consistent with the shape of the metal coil located thereon.

Specifically, as shown in FIG. 2a, in the first embodiment, the metal coil is a layer of a square spiral metal coil 7 formed directly on the insulating layer 6.

In order to further understand the embodiments of the micromechanical magnetic field sensor of the present invention, the specific working steps and working principles of the micromechanical magnetic field sensor of the present invention will be described in detail below. The working principle of the invention is as follows:

The micromechanical magnetic field sensor proposed by the present invention is realized by loading a metal coil on two resonant oscillator structures forming a pair of resonant oscillators. The invention utilizes a single-ended capacitor excitation to drive the two resonant oscillator structures into a resonant state. When the sensor is located in the measured magnetic field, the resonant oscillator vibration will drive the metal coil to move, the metal coil cuts the magnetic induction line, and generates an induced electromotive force at both ends of the metal coil. The differential mode output method is used to measure the induced electromotive force at both ends of the metal coil to measure the magnitude of the measured magnetic field.

The working steps of the present invention are:

a) placing the micromechanical magnetic field sensor in the magnetic field to be measured;

b) simultaneously applying a superimposed driving signal provided by the direct current power source V _p and the alternating current power source V _in the driving electrode 5 of the micromechanical magnetic field sensor, so that the two resonant oscillator structures are single-ended capacitive excitation driving mode; c) When the frequency of the applied alternating signal is equal to the resonant frequency of the micromechanical magnetic field sensor itself, the micromechanical magnetic field sensor is in a resonant working state, the resonant vibrator vibrates to move the metal coil located thereon, and the metal coil cuts the magnetic induction line, at this time, the measurement The induced electromotive force generated at both ends of the metal coil leads to the magnitude of the measured magnetic field. The present invention also provides a circuit structure of a micromechanical magnetic field sensor. In the first embodiment, as shown in FIG. 2d, the circuit structure includes at least: a phase locked loop circuit, a micromechanical magnetic field sensor 93, and a differential voltage amplifier 94. And a voltage follower 97, wherein the phase locked loop circuit comprises a voltage controlled oscillator 91, a phase detector 95 and a low pass filter 96.

An output end of the voltage controlled oscillator 91 for generating an alternating current signal having the same resonant frequency as the micromechanical magnetic field sensor 93 is respectively connected to an alternating current power input end (V _in ) of the micro mechanical magnetic field sensor 93 and the An input terminal of the phase detector 95, wherein the AC signal outputted by the voltage controlled oscillator 91 is used as a reference signal of the phase detector 95, and a DC voltage input terminal of the micro-mechanical magnetic field sensor 93 is further connected with a DC voltage. V _p .

An output of the micro-mechanical magnetic field sensor 93 for generating an induced voltage is coupled to an input of the differential voltage amplifier 94.

An output of the differential voltage amplifier 94 for amplifying the induced voltage is coupled to another input of the phase detector 95, wherein the amplified induced voltage signal output by the differential voltage amplifier 94 is used as Measurement signal.

An output of the phase detector 95 for discriminating the phase difference between the measurement signal and the reference signal is coupled to the input of the low pass filter 96.

An output of the low-pass filter 96 for filtering an alternating current portion of the output signal of the phase detector 95 is connected to a control end of the voltage controlled oscillator 91 and an input end of the voltage follower 97, wherein The output of the low pass filter 96 is straight The stream signal is used as a control voltage signal of the voltage controlled oscillator 91 to ensure that the entire phase locked loop circuit is in a stable operating state.

The output of the voltage follower 97 is connected to an external measuring device (not shown), wherein the magnitude of the DC voltage signal output by the voltage follower 97 characterizes the magnitude of the magnetic field to be measured of the micro-mechanical magnetic field sensor 93.

The specific working principle of the circuit structure of the micro-mechanical magnetic field sensor is as follows: an AC signal having the same resonant frequency as the micro-mechanical magnetic field sensor 93 is generated by a voltage-controlled oscillator (VCO) 91 in the phase-locked loop circuit; The output AC signal is superimposed with the DC voltage V _p to excite the micro-mechanical magnetic field sensor 93 to operate; the induced voltage of the micro-mechanical magnetic field sensor 93 is amplified by a differential voltage amplifier (Amplifier) 94; the frequency signal output by the voltage-controlled oscillator 91 As the reference frequency, the output of the differential voltage amplifier 94 is used as a measurement signal, and the phase difference between the measurement signal and the reference signal is discriminated by the phase detector 95; the output signal of the phase detector 95 is connected to the low-pass filter (Low-pass Filter) 96, filtering out the alternating part of the signal to obtain a direct current signal related to the amplitude of the magnetic field signal to be measured; using the direct current signal outputted by the low pass filter 96 as the control voltage signal of the voltage controlled oscillator 91, thereby ensuring the entire phase lock The loop circuit is in a stable working state; the DC signal output by the low-pass filter 96 reflecting the magnitude of the signal of the magnetic field to be measured The number is connected to an external measuring device via a Buffer Amplifier 97, which is the DC voltage signal V of the final output. The size of _ut characterizes the magnitude of the magnetic field to be measured by the micromechanical magnetic field sensor 93. Compared with the conventional micro-mechanical magnetic field sensor, the micro-mechanical magnetic field sensor of the present invention has the following beneficial effects:

1) The present invention uses a coupling beam to couple two resonant oscillator structures to form a resonant oscillator pair, and uses single-ended capacitive excitation and electromagnetic induction to measure the magnitude of the magnetic field, wherein the two resonant oscillator structures operate in the same phase mode, and each of the resonant oscillators The structural metal coils are wound in opposite directions, and the induced electromotive forces generated by the metal coils on the two resonant oscillator structures are connected in series; due to the differential mode output, two capacitive couplings are formed between the two differential output signals and the input drive signals. The signal, and because the two capacitive coupling signals are equal in magnitude, the differential mode output eliminates the capacitive coupling signal in the output signal, thereby obtaining a simple magnetic field output signal and realizing a simple magnetic field of the micromechanical magnetic field sensor. Output signal detection;

3) The resonant oscillator of the micromechanical magnetic field sensor proposed by the invention operates in an expanding mode, so that each small metal cutting magnetic line on the metal coil generates an induced electromotive force which is superposed in series with each other to enhance the intensity of the output signal; the metal coil of the present invention It can be one or more layers of spiral coils, which is beneficial to further increase the intensity of the output signal and improve the sensitivity of detection; 4) The present invention can also suspend the metal coil over the resonant oscillator through the metal support column, thereby reducing the problem of crosstalk between the resonant oscillator structure and the metal coil at high frequencies;

5) The invention has a simple structure, does not need to pass current on the metal coil, and reduces the power consumption of the device; at the same time, the magnitude of the magnetic field is measured by measuring the induced electromotive force at both ends of the metal coil, so that the temperature is less affected; and since the invention adopts The two resonant oscillator structures further enhance the strength of the output signal and also increase the sensitivity of the output signal. Embodiment 2

The second embodiment is basically the same as the technical solution of the first embodiment, and the difference is mainly as follows: The resonant oscillator structure in the first embodiment is a square plate, and the resonant oscillator pair includes a first coupling beam, a second anchor point, and a first The second coupling beam and the third anchor point; in the second embodiment, the resonant oscillator structure is a rectangular plate, and the resonant oscillator pair does not include the first coupling beam, the second anchor point, the second coupling beam and the third anchor For the rest of the resonance oscillator pairing (structure, manufacturing method, and working principle), refer to the related description of the first embodiment, and details are not described herein again.

As shown in FIG. 3a and FIG. 3b, the second embodiment provides a micro-mechanical magnetic field sensor. The micro-mechanical magnetic field sensor includes at least: a pair of resonant oscillators and an insulating layer 6 and a metal coil 7 sequentially formed on a surface thereof, wherein The resonant oscillator pair includes: a rectangular plate resonant oscillator structure 1, a main support beam 21, a first anchor point 41, and a driving electrode 5, but is not limited thereto. In another embodiment, each of the resonant oscillator pairs is also The first coupling beam connected to the interconnected main support beam and the second anchor point connected to the other end of the first coupling beam may be further included, and each of the resonant oscillator pairs may further include a connection The second coupling beam on the main support beam on the first axis of symmetry and connected to each other and the third anchor point connecting the second coupling beam.

The rectangular plate resonant oscillator structure 1 is silicon carbide, and its first axis of symmetry is parallel to the long side or wide side of the rectangular plate. In the second embodiment, as shown in Fig. 3b, the first axis of symmetry is parallel to the long side of the rectangular plate, i.e., the main support beam 21 is connected to the wide side of the rectangular plate resonator structure 1.

The first anchor point 41 is connected to the free end of the main support beam 21, wherein the first anchor point 41 is formed with a pad (as shown in FIG. 3a, the second anchor point is filled with a cross-grid space) The first anchor point 41 of the two resonant resonator structure 1 is respectively connected to the voltage output terminal V through pads formed thereon. _Ut (as shown in Figure 3a), that is, the induced electromotive force V is measured by a differential mode output method. _{Ut in} turn measures the size of the magnetic field to be measured.

The driving electrodes 5 are respectively disposed on opposite sides of each of the rectangular plate resonator structure 1 and the driving motor 5 and the resonant oscillator structure 1 are formed with a driving gap. In the second embodiment, as shown in FIG. 3a, The driving electrodes 5 are two and symmetrically distributed on both sides of the first symmetry axis of each of the rectangular plate resonant oscillator structures 1, that is, the driving electrodes 5 are symmetrically distributed on the long sides of the rectangular plate resonant oscillator structures 1 side. It should be noted that, in another embodiment, the moment The plate resonant resonator structure may also preferably be a square plate.

The insulating layer 6 is formed on the upper surface of the resonant oscillator structure 1 and the main support beam 21 of the pair of resonant resonators, and an insulating layer 6 is formed between the first anchor point 41 and the pad formed thereon. . Preferably, the resonant oscillator structure 1, the main support beam 21 and the first anchor point 41 are formed in the same plane, and the insulating layer is formed on the upper surface of the plane. Further, in another embodiment, when the second coupling beam 32 and the third anchor point 43 are included in each of the resonant oscillator pairs, the second coupling beam 32 and the third anchor point 43 may be formed on the second coupling beam 32 and the third anchor point 43. The insulating layer 6 may also have no insulating layer 6.

For a description of the metal coil 7, please refer to the first embodiment, except that the metal coil 7 has a rectangular spiral shape as shown in Fig. 3a.

The circuit structure (not shown) of the micro-mechanical magnetic field sensor of the second embodiment is basically the same as that of the first embodiment, except that the structure of the micro-mechanical magnetic field sensor of the second embodiment is different from that of the first embodiment. See the related description in the first embodiment.

Compared with the conventional micro-mechanical magnetic field sensor, the micro-mechanical magnetic field sensor of the present invention has the following beneficial effects:

5) The invention has a simple structure, does not need to pass current on the metal coil, and reduces the power consumption of the device; at the same time, the magnitude of the magnetic field is measured by measuring the induced electromotive force at both ends of the metal coil, so that the temperature is less affected; and since the invention adopts The two resonant oscillator structures further enhance the strength of the output signal and also increase the sensitivity of the output signal. Embodiment 3

The third embodiment is basically the same as the technical solution of the first embodiment, and the difference is mainly as follows: The resonant oscillator structure in the first embodiment is a square plate; in the third embodiment, the resonant oscillator structure is a circular plate, and the resonant oscillator For the other aspects of the structure (structure, manufacturing method, and working principle), refer to the related description of the first embodiment, and details are not described herein again.

As shown in FIG. 4a and FIG. 4b, the third embodiment provides a micro-mechanical magnetic field sensor. The micro-mechanical magnetic field sensor includes at least: a pair of resonant oscillators and an insulating layer 6 and a metal coil 7 sequentially formed on a surface thereof, wherein The resonant oscillator pair includes: a circular plate resonant oscillator structure 1, a main support beam 21, a first coupling beam 31, a first anchor point 41, a second anchor point 42, and a driving electrode 5, wherein the first axis of symmetry An extension of the diameter of the circular plate.

It should be noted that the resonant oscillator structure 1 is not limited to a circular plate, and the resonant oscillator structure 1 may also be a circular plate or a circular ring plate, wherein the first symmetry axis is a circular plate or a circle. An extension of the major or minor axis of the circle in the ring plate. Further, the annular plate is a preferred embodiment of the annular plate, and the first axis of symmetry is an extension of the diameter of the annular plate.

It should be further noted that, as shown in FIG. 4b, the resonant oscillator pair further includes a second coupling beam 32 connected to the main support beam 21 and a third anchor point 43 connected to the second coupling beam 32, wherein The main support beam 21 is a main support beam that is located on the first axis of symmetry and is connected to each other, but is not limited thereto. In another embodiment, the pair of resonant beams may not have the second coupling beam and A third anchor point connected to the second coupling beam.

The driving electrodes 5 are respectively disposed on opposite sides of each of the square plate resonant oscillator structures 1, and the driving motor 5 and the resonant oscillator structure 1 are formed with a driving gap. In the third embodiment, as shown in FIG. 4b, The driving electrodes are two arc-shaped driving electrodes matched with the circular plate, and are symmetrically distributed on opposite sides of each of the circular plate resonant oscillator structures 1.

The insulating layer 6 is formed on the resonant oscillator structure 1 of the resonant oscillator pair, the main support beam 21, and the upper surface of the first coupling beam 31, and between the first anchor point 41 and the pad formed thereon An insulating layer 6 is formed, and an insulating layer 6 is formed between the second anchor 42 and a pad formed thereon. Preferably, the resonant oscillator structure 1, the main support beam 21, the first coupling beam 31, the first anchor point 41 and the second anchor point 42 are formed in the same plane, and the insulating layer is formed on the upper surface of the plane. on. Further, in the second embodiment, the resonant oscillator pair further includes a second coupling beam 32 connected to the main support beam 21 and a third anchor point 43 connected to the second coupling beam 32, as shown in FIG. 4a. The second coupling beam 32 and the third anchor point 43 are not provided with the insulating layer 6, but are not limited thereto. In another embodiment, the second coupling beam 32 and the third anchor point 43 are also There may be an insulating layer 6.

For a description of the metal coil 7, please refer to the first embodiment, except that the metal coil 7 has a circular spiral shape as shown in Fig. 4a.

The circuit structure (not shown) of the micro-mechanical magnetic field sensor of the third embodiment is basically the same as that of the first embodiment, and the difference is only in The structure of the micro-mechanical magnetic field sensor of the third embodiment is different from that of the first embodiment. For the rest of the similarities, refer to the related description in the first embodiment.

In summary, the micro-mechanical magnetic field sensor of the present invention has the following beneficial effects as compared with the conventional micro-mechanical magnetic field sensor:

5) The invention has a simple structure, does not need to pass current on the metal coil, and reduces the power consumption of the device; at the same time, the magnitude of the magnetic field is measured by measuring the induced electromotive force at both ends of the metal coil, so that the temperature is less affected; and since the invention adopts The two resonant oscillator structures further enhance the strength of the output signal and also increase the sensitivity of the output signal.

Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

The above-described embodiments are merely illustrative of the principles of the invention and its advantages, and are not intended to limit the invention. Modifications or variations of the above-described embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and scope of the inventions are still to be covered by the appended claims.

Claims

The present invention provides a micromechanical magnetic field sensor, wherein the micromechanical magnetic field sensor comprises: a pair of resonant oscillators and an insulating layer and a metal coil sequentially formed on a surface thereof;

The resonant oscillator pair includes:

a main support beam, located on the first symmetry axis, and two resonant oscillator structures are coupled to each other through respective main support beams;

a first anchor point connected to the free end of the main support beam, wherein the first anchor point of the two resonant oscillator structure is respectively connected to the output end or a first anchor point output end through a pad formed thereon Another first anchor point is grounded;

Driving electrodes are respectively disposed on opposite sides of each of the resonant oscillator structures, and a driving gap is formed between each of the resonant oscillator structures, the driving electrode is connected to a DC power source through a resistor, and the driving electrode is connected to the AC through a capacitor a power source, wherein the driving electrodes of each of the resonant oscillator structures are respectively connected to an alternating current power source having opposite phase amplitudes;

The insulating layer is formed on the resonant oscillator structure of the pair of resonant resonators and the upper surface of the main supporting beam, and an insulating layer is formed between the first anchor point and the pad formed thereon;

The metal coils are respectively formed on the insulating layer on each of the resonant oscillator structures, and the metal coils are metal coils whose inner ends are surrounded by the center of the insulating layer, wherein the two resonant resonator structures are The metal coils are in the same direction; the beginning ends of the metal coils are connected to the pads on the corresponding first anchor points through the first connecting bridge, and the ends of the metal coils are connected to each other through the second connecting bridge. On the first insulating layer on the main support beam, or the end of each metal coil is connected to the pad on the corresponding first anchor point through the second connecting bridge, and the beginning end of each metal coil passes through the first connecting bridge Connected to the first insulating layer on the main supporting beam of the coupled connection; an insulating layer is formed between each of the first connecting bridge and each of the metal coils located under the connecting bridge. The micromechanical magnetic field sensor according to claim 1, wherein: the resonant oscillator pair further includes a first coupling beam connected at one end to the main supporting beam coupled to each other, and connected to the first a second anchor point at the other end of the coupling beam, wherein the second anchor point is grounded through a pad formed thereon, the first coupling beam upper surface, and the second anchor point and the second anchor point formed thereon An insulating layer is formed between the pads. The micromechanical magnetic field sensor according to claim 2, wherein: the end of each of the metal coils is connected to the main support beam coupled to each other via the second connecting bridge and the first insulating layer on the first coupling beam a pad on the second anchor point; or a start end of each of the metal coils is connected to the second anchor point via a first connecting bridge via a main support beam coupled to each other and a first insulating layer on the first coupling beam Pad. The micromechanical magnetic field sensor according to claim 1, wherein the resonant oscillator structure is a rectangular plate, a circular plate or a circular annular plate. The micromechanical magnetic field sensor according to claim 1, wherein: the first coupling beam is a straight beam or a curved folded beam. The micromechanical magnetic field sensor according to claim 1, wherein: the resonant oscillator pair further includes a second coupling beam, and the second coupling beam is also connected to the first symmetry axis and connected to each other. And a second anchor point is connected to the second coupling beam; wherein the second coupling beam and the first coupling beam are respectively disposed on two sides of the first symmetry axis. The micromechanical magnetic field sensor according to claim 6, wherein: the second coupling beam is a straight beam or a curved folded beam. The micromechanical magnetic field sensor according to claim 4, wherein when the resonant oscillator structure is a rectangular plate, the first axis of symmetry is parallel to a long side or a wide side of the rectangular plate. The micromechanical magnetic field sensor according to claim 4, wherein when the resonant oscillator structure is a square plate, the first symmetry axis and the second symmetry axis are respectively extension lines of two diagonal lines of the square plate. The micromechanical magnetic field sensor according to claim 9, wherein: the resonant oscillator pair further includes a side support beam on the second symmetry axis and one end connected to the resonant oscillator structure, and is connected to a fourth anchor point of the other end of the side support beam. 1. The micromachined magnetic field sensor according to claim 1, wherein: said metal coil is a plurality of layers, each

18 The metal coils of the layer are connected in series, and the metal coils of each layer have the same winding direction, and an insulating layer is formed between the metal coils of each layer. The micromechanical magnetic field sensor according to claim 11, wherein: said metal coils are connected in series by continuous even-numbered layers and odd-numbered layers are connected to ends of said metal coils, and continuous odd-numbered layers and The even ends of the metal coils are connected to each other, and each of the metal coils connected in series has an insulating layer except for the joint. The micromechanical magnetic field sensor according to claim 1, wherein a metal support post supporting the metal coil suspended above the insulating layer is formed between the metal coil and the insulating layer located thereunder. The micromechanical magnetic field sensor according to claim 1, wherein: the metal coil is one turn, and the metal coil is circular or rectangular. The micromechanical magnetic field sensor according to claim 1, wherein the metal coil has a plurality of turns, and the metal coil has a circular spiral shape or a rectangular spiral shape. A circuit structure of a micro-mechanical magnetic field sensor, characterized in that the circuit structure comprises at least: a phase-locked loop circuit, a differential operational amplifier, the micro-mechanical magnetic field sensor according to any one of claims 1 to 15, a voltage amplifier and a voltage a follower loop circuit, wherein the phase locked loop circuit comprises a voltage controlled oscillator, a phase detector and a low pass filter; and the voltage controlled oscillator for generating an alternating current signal having the same resonant frequency as the micromechanical magnetic field sensor An output terminal is respectively connected to an input end of the differential operational amplifier and an input end of the phase detector, wherein an AC signal output by the voltage controlled oscillator is used as a reference signal of the phase detector;

An output terminal of the differential operational amplifier for converting an AC signal output by the voltage controlled oscillator into a differential voltage signal, and an AC power input terminal of the micromechanical magnetic field sensor, a DC power supply of the micromachine magnetic field sensor A DC voltage is also connected to the input terminal;

An output of the micromechanical magnetic field sensor for generating an induced voltage is coupled to an input of the voltage amplifier for connecting an output of the voltage amplifier that amplifies the induced voltage to another input of the phase detector End, wherein the amplified induced voltage signal output by the voltage amplifier is used as a measurement signal;

An output of the phase detector for identifying a phase difference between the measurement signal and the reference signal is coupled to the low pass The input of the filter;

The output of the voltage follower is connected to an external measuring device, wherein the magnitude of the DC voltage signal output by the voltage follower characterizes the magnitude of the magnetic field to be measured of the micromechanical magnetic field sensor. The circuit structure of the micromechanical magnetic field sensor according to claim 16, wherein: when the first anchor point of the two resonant resonator structure is respectively connected to the output end through the pads formed thereon, the voltage amplifier has A differential voltage amplifier at two inputs; when one first anchor of the two resonant oscillator structure is connected to the output and the other first anchor is grounded, the voltage amplifier is a conventional voltage amplifier having one input.

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