Full-bridge structure corresponding to magnetoresistance sensor and magnetic field intensity measurement method

Abstract

The application relates to a full-bridge structure corresponding to a magnetic resistance sensor, a magnetic field intensity measurement method and device, computer equipment, a computer readable storage medium and a computer program product. The full-bridge structure comprises: a plurality of bridge arms, different types of tunnel junctions with the same initial magnetic resistance value are arranged on each bridge arm; the resistance value change amount of each tunnel junction is related to the temperature of the environment in which the magnetic resistance sensor is located; the different types of tunnel junctions comprise original tunnel junctions and compensation tunnel junctions, the sensitive axis directions of the original tunnel junctions and the compensation tunnel junctions are opposite; the compensation tunnel junctions are provided with a covering layer with a magnetic permeability higher than a magnetic permeability threshold value; the sensitive axis directions of the corresponding types of tunnel junctions in two bridge arms that are obliquely opposite are the same, the sensitive axis directions of the corresponding types of tunnel junctions in two adjacent bridge arms are opposite, and the two bridge arms that are obliquely opposite and the two adjacent bridge arms are determined from the plurality of bridge arms.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensors, in particular to a full-bridge structure corresponding to a magnetoresistance sensor, and a magnetic field strength measurement method and device, computer equipment, computer readable storage medium and computer program product. BACKGROUND

[0002] A magnetoresistance sensor is a device that converts the magnetic performance change of a sensitive element caused by external factors such as magnetic fields, currents, stress and strain, temperature, light, etc. into an electrical signal, in this way to detect the corresponding physical quantity. Tunnel magnetoresistance (TMR) sensors have higher sensitivity and linearity compared with anisotropic magnetoresistance sensors and giant magnetoresistance sensors, and have more advantages in practical applications. High-precision tunnel magnetoresistance sensors have wide application in power grids, non-destructive testing, and weak magnetic detection.

[0003] The temperature drift problem of a tunnel magnetoresistance sensor is an important factor limiting its practical application. The magnetoresistance of a high-sensitivity tunnel magnetoresistance sensor changes significantly with the ambient temperature, which seriously affects the output accuracy of the tunnel magnetoresistance sensor. Therefore, how to compensate for the magnetoresistance change caused by the temperature drift of the tunnel magnetoresistance sensor is a technical problem that needs to be solved. SUMMARY

[0004] Therefore, it is necessary to provide a full-bridge structure corresponding to a magnetoresistance sensor, and a magnetic field strength measurement method and device, computer equipment, computer readable storage medium and computer program product, which can compensate for the magnetoresistance change caused by the temperature drift of the tunnel magnetoresistance sensor.

[0005] In a first aspect, a full-bridge structure corresponding to a magnetoresistance sensor is provided, and the full-bridge structure comprises:

[0006] A plurality of bridge arms, each bridge arm is provided with different types of tunnel junctions with the same initial magnetoresistance value; the resistance change of each tunnel junction is related to the temperature of the environment in which the magnetoresistance sensor is located;

[0007] The different types of tunnel junctions include original tunnel junctions and compensation tunnel junctions, and the sensitive axis directions of the original tunnel junctions and the compensation tunnel junctions are opposite; the compensation tunnel junctions are provided with a covering layer with a magnetic permeability higher than a magnetic permeability threshold;

[0008] The sensitive axis directions of the corresponding types of tunnel junctions in the two bridge arms opposite to each other are the same, and the sensitive axis directions of the corresponding types of tunnel junctions in the two adjacent bridge arms are opposite, and the two bridge arms opposite to each other and the two adjacent bridge arms are determined from the plurality of bridge arms.

[0009] In one of the embodiments, the plurality of bridge arms comprises a first bridge arm, a second bridge arm, a third bridge arm and a fourth bridge arm;

[0010] One end of the first bridge arm is connected with one end of the second bridge arm, the other end of the second bridge arm is connected with one end of the fourth bridge arm, the other end of the tenth bridge arm is connected with one end of the third bridge arm, the other end of the third bridge arm is connected with the other end of the first bridge arm; the two bridge arms connected constitute the adjacent two bridge arms;

[0011] The first bridge arm and the fourth bridge arm constitute the diagonally opposite two bridge arms, and the second bridge arm and the third bridge arm constitute the diagonally opposite two bridge arms.

[0012] The second aspect of the present application provides a magnetic field strength measurement method, the method comprises:

[0013] Obtaining the bias voltage and the output voltage of the full-bridge structure of any one of the claims;

[0014] Based on the bias voltage and the output voltage, determining the magnetic resistance change amount of the magnetic resistance sensor; the magnetic resistance change amount of the magnetic resistance sensor is related to the resistance change amount of each tunnel junction;

[0015] Based on the magnetic resistance change amount, determining the magnetic field strength of the environment where the magnetic resistance sensor is located.

[0016] In one of the embodiments, based on the magnetic resistance change amount, determining the magnetic field strength of the environment where the magnetic resistance sensor is located, comprises:

[0017] Determining the positional relationship between the magnetic field lines of the magnetic field in the environment where the magnetic resistance sensor is located and the sensitive axis of each tunnel junction;

[0018] Based on the positional relationship and the magnetic resistance change amount, determining the magnetic field strength of the environment where the magnetic resistance sensor is located.

[0019] In one of the embodiments, based on the positional relationship and the magnetic resistance change amount, determining the magnetic field strength of the environment where the magnetic resistance sensor is located, comprises:

[0020] Based on the positional relationship, the ratio between the magnetic field component of the magnetic field in the corresponding direction of the target plane and the magnetic field;

[0021] Based on the magnetic resistance change amount, determining the initial magnetic field strength of the environment where the magnetic resistance sensor is located;

[0022] Based on the initial magnetic field strength and the ratio, determining the magnetic field strength of the environment where the magnetic resistance sensor is located.

[0023] In one of the embodiments, the determining the magnetic resistance change amount of the magnetic resistance sensor based on the bias voltage and the output voltage comprises:

[0024] determining a magnetic resistance change amount coefficient of the compensation tunnel junction based on the magnetic permeability of the cover layer and the position between the cover layer and the compensation tunnel junction;

[0025] determining the magnetic resistance change amount of the magnetic resistance sensor based on the bias voltage, the output voltage, the magnetic resistance change amount coefficient and the initial magnetic resistance value.

[0026] In a third aspect, the present application further provides a magnetic field strength measuring device, the device comprising:

[0027] an acquisition module configured to acquire the bias voltage and the output voltage of the full-bridge structure according to any one of the above;

[0028] a first determining module configured to determine the magnetic resistance change amount of the magnetic resistance sensor based on the bias voltage and the output voltage; the magnetic resistance change amount of the magnetic resistance sensor is related to the resistance change amount of each tunnel junction;

[0029] a second determining module configured to determine the magnetic field strength of the environment in which the magnetic resistance sensor is located based on the magnetic resistance change amount.

[0030] In a fourth aspect, the present application further provides a computer device comprising a memory and a processor, the memory storing a computer program, and the processor implementing the steps of the above-mentioned embodiments when executing the computer program.

[0031] In a fifth aspect, the present application further provides a computer readable storage medium having a computer program stored thereon, and the computer program implements the steps of the above-mentioned embodiments when executed by a processor.

[0032] In a sixth aspect, the present application further provides a computer program product comprising a computer program, and the computer program implements the steps of the above-mentioned embodiments when executed by a processor.

[0033] The full-bridge structure corresponding to the magnetoresistance sensor, and the magnetic field intensity measurement method, device, computer equipment, computer readable storage medium and computer program product, the full-bridge structure includes a plurality of bridge arms, different types of tunnel junctions with the same initial magnetic resistance value are arranged on each bridge arm, and the resistance value change of each tunnel junction is related to the temperature of the environment in which the magnetoresistance sensor is located, that is, the resistance value change of each tunnel junction changes with the change of temperature. The different types of tunnel junctions include original tunnel junctions and compensation tunnel junctions, the sensitive axis directions of the original tunnel junctions and the compensation tunnel junctions are opposite, and the compensation tunnel junctions are provided with a covering layer with a magnetic permeability higher than a magnetic permeability threshold. In this way, with the change of temperature, the corresponding magnetic resistance value changes of the original tunnel junctions and the compensation tunnel junctions on each bridge arm change in opposite directions with the change of temperature, the sensitive axis directions of the tunnel junctions of the corresponding types in the two bridge arms obliquely opposite to each other are the same, and the sensitive axis directions of the tunnel junctions of the corresponding types in the two adjacent bridge arms are opposite. By arranging the full-bridge structure, the resistance value changes of the plurality of bridge arms in the full-bridge structure are finally the same with the change of temperature, so that the magnetic resistance change of the magnetoresistance sensor as a whole is not affected by the change of temperature, the magnetic resistance change caused by the temperature drift of the magnetoresistance sensor is compensated, and the accuracy of the magnetic field detection of the magnetoresistance sensor is improved. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the drawings needed to be used in the description of the embodiments of the present application or the related art will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other related drawings can be obtained by those skilled in the art without creating any inventive labor.

[0035] Figure 1 It is a schematic diagram of the full-bridge structure corresponding to the magnetoresistance sensor in an embodiment;

[0036] Figure 2 It is a planar magnetic field distribution diagram of tunnel junctions with and without covering layers;

[0037] Figure 3 It is an out-of-plane magnetic field distribution diagram of tunnel junctions with covering layers;

[0038] Figure 4 It is a flowchart of the magnetic field intensity measurement method in an embodiment;

[0039] Figure 5 It is a structural block diagram of the magnetic field intensity measurement device in an embodiment;

[0040] Figure 6 It is an internal structure diagram of the computer equipment in an embodiment. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0042] The Wheatstone full bridge of the tunneling magnetoresistance sensor, also known as the Wheatstone bridge, is a bridge circuit composed of four resistors (or equivalent elements, such as tunneling magnetoresistance elements). The four resistors are connected to form a quadrilateral, forming two diagonal voltage measurement points. In the tunneling magnetoresistance sensor, the four resistors can be made of tunneling magnetoresistance material or combined with tunneling magnetoresistance elements to achieve sensitive measurement of magnetic field changes.

[0043] When the temperature rises, the magnetic resistance value of the tunnel junction (i.e. the resistor in the Wheatstone full bridge structure) in the tunneling magnetoresistance sensor changes under the joint action of multiple effects. Among them, the change of the magnetic resistance value caused by the magnetic domain disorder caused by thermal disturbance is related to the sensitive axis direction of the tunnel junction. The tunnel junctions with opposite sensitive axis directions change the magnetic resistance value in the opposite direction with the change of temperature, that is, the increase of temperature will cause the magnetic resistance value of the tunnel junction in the parallel state to increase, and the magnetic resistance value of the tunnel junction in the anti-parallel state to decrease, resulting in the change of the magnetic resistance of the tunnel junction on the bridge arm in the Wheatstone full bridge structure with the change of temperature. The relative (here, the relative is different from the following diagonal relative, for example Figure 1 , R1 and R2 are forward relative, R3 and R4 are diagonal relative, R1 and R4 are diagonal forward relative, and R2 and R3 are diagonal relative), the change amount of the magnetic resistance of the tunnel junction on the bridge arm with the change of temperature is inconsistent, thereby causing the tunneling magnetoresistance sensor to have a temperature drift problem. To solve this problem, the back-end hardware compensation and software compensation are based on the same temperature coefficient of the four bridge arms. Based on this idea, the present application can compensate the change amount of the magnetic resistance of the tunnel junction with the change of temperature, so that the change amount of the resistance value of the multiple bridge arms corresponding to the change of temperature is the same, and then the four bridge arms have a unified temperature coefficient, which compensates the magnetic resistance temperature drift error from the bottom structure. The specific implementation is as follows:

[0044] Referring to Figure 1 , the present application provides an embodiment, including a full bridge structure corresponding to a magnetoresistance sensor, the full bridge structure comprising: a plurality of bridge arms, different types of tunnel junctions with the same initial magnetic resistance value are arranged on each bridge arm; the resistance value change amount of each tunnel junction is related to the temperature of the environment in which the magnetoresistance sensor is located; the different types of tunnel junctions include original tunnel junctions and compensation tunnel junctions, the sensitive axis directions of the original tunnel junctions and the compensation tunnel junctions are opposite; the compensation tunnel junctions are provided with a covering layer with a magnetic permeability higher than a magnetic permeability threshold; the sensitive axis directions of the corresponding types of tunnel junctions in the two diagonal relative bridge arms are the same, the sensitive axis directions of the corresponding types of tunnel junctions in the two adjacent bridge arms are opposite, and the two diagonal relative bridge arms and the two adjacent bridge arms are determined from the plurality of bridge arms.

[0045] The conventional Wheatstone bridge structure includes four bridge arms, each of which is provided with a primitive tunnel junction. The four bridge arms are referred to as R1, R2, R3 and R4, respectively. R1 and R4 have the same sensitive axis direction, R2 and R3 have the same sensitive axis direction, R1 and R2 have opposite sensitive axis directions, and R3 and R4 have opposite sensitive axis directions. The sensitive axis of each primitive tunnel junction is parallel to the magnetic field line of the in-plane magnetic field.

[0046] The full bridge structure of the present application is a Wheatstone full bridge. Compared with the conventional Wheatstone bridge structure, the present application adds a compensation tunnel junction to each bridge arm. The compensation tunnel junction is used to compensate for the change in the magnetic resistance of the primitive tunnel junction on the same bridge arm due to temperature changes.

[0047] Specifically, the full bridge structure of the present application includes a plurality of bridge arms, typically four bridge arms. Each bridge arm is provided with a tunnel junction of different types, which specifically refers to a primitive tunnel junction and a compensation tunnel junction. The number of compensation tunnel junctions on each bridge arm is the same as the number of primitive tunnel junctions. Each bridge arm can be provided with one primitive tunnel junction and one compensation tunnel junction. The initial magnetic resistance value of the compensation tunnel junction on each bridge arm is the same as that of the primitive tunnel junction, and the initial magnetic resistance values of the primitive tunnel junctions on the plurality of bridge arms are also the same.

[0048] The resistance change (or magnetic resistance change) of each tunnel junction is related to the temperature of the environment in which the magnetic resistance sensor is located. As described above, the tunnel junctions with opposite sensitive axis directions have opposite magnetic resistance changes with temperature changes. The sensitive axis directions of the primitive tunnel junctions and the compensation tunnel junctions of each bridge arm of the present application are opposite. When the temperature rises, the magnetic resistance value of the tunnel junction parallel to the magnetic field line increases by a first magnetic resistance value, and the magnetic resistance value of the tunnel junction anti-parallel to the magnetic field line decreases by a first magnetic resistance value.

[0049] When the environment in which the magnetic resistance sensor is located has an in-plane magnetic field, the magnetic resistance value of the tunnel junction will also change. For tunnel junctions with opposite sensitive axis directions, the present application provides a cover layer with a magnetic permeability higher than a magnetic permeability threshold on each compensation tunnel junction. The in-plane magnetic field distribution of the tunnel junction with the cover layer and the in-plane magnetic field distribution of the tunnel junction without the cover layer are shown in FIGS. 1 and 2, respectively. Figure 2 When in the in-plane magnetic field, the cover layer guides the magnetic field lines to mainly pass through the cover layer, thereby reducing the magnetic field lines passing through the tunnel junction, and further reducing the change in the magnetic resistance of the tunnel junction with the in-plane magnetic field. If there is no cover layer, the magnetic field lines mainly pass through the tunnel junction. For example, the primitive tunnel junction without the cover layer has a magnetic resistance change of when the environment in which the magnetic resistance sensor is located has an in-plane magnetic field. The compensation tunnel junction has a magnetic resistance change of k , where k is a constant much smaller than 1.

[0050] In the embodiment, when the environment where the magnetic resistance sensor is located has an in-plane magnetic field, the tunnel junctions with opposite sensitive axis directions have opposite magnetic resistance change amounts, for example, the original tunnel junctions with opposite sensitive axis directions have magnetic resistance change amounts of and- , and the compensation tunnel junctions with opposite sensitive axis directions have magnetic resistance change amounts of k and-k .

[0051] In the embodiment, the two bridge arms diagonally opposite to each other at the bridge arm position determined from the plurality of bridge arms have the same sensitive axis direction of the corresponding type of tunnel junction, that is, the original tunnel junctions in the two bridge arms diagonally opposite to each other have the same sensitive axis direction, and the compensation tunnel junctions in the two bridge arms diagonally opposite to each other have the same sensitive axis direction.

[0052] The two bridge arms adjacent to each other at the bridge arm position determined from the plurality of bridge arms have opposite sensitive axis directions of the corresponding type of tunnel junction, that is, the original tunnel junctions in the two bridge arms adjacent to each other have opposite sensitive axis directions, and the compensation tunnel junctions in the two bridge arms adjacent to each other have opposite sensitive axis directions.

[0053] The full-bridge structure of the application includes a plurality of bridge arms, different types of tunnel junctions with the same initial magnetic resistance value are arranged on each bridge arm, and the resistance change amount of each tunnel junction is related to the temperature of the environment where the magnetic resistance sensor is located, that is, the temperature change will cause the resistance change amount of each tunnel junction to change, the different types of tunnel junctions include original tunnel junctions and compensation tunnel junctions, the sensitive axis directions of the original tunnel junctions and the compensation tunnel junctions are opposite, and the compensation tunnel junctions are provided with a covering layer with a magnetic permeability higher than a magnetic permeability threshold, so that with the change of temperature, the corresponding magnetic resistance change amounts of the original tunnel junctions and the compensation tunnel junctions on each bridge arm change in opposite directions, while the sensitive axis directions of the corresponding types of tunnel junctions in the two bridge arms diagonally opposite to each other are the same, and the sensitive axis directions of the corresponding types of tunnel junctions in the two bridge arms adjacent to each other are opposite. By arranging such a full-bridge structure, the resistance change amounts of the plurality of bridge arms in the full-bridge structure are ultimately the same (including the magnetic resistance change amounts of the tunnel junctions on the bridge arms diagonally opposite to each other in the full-bridge structure), so that the overall magnetic resistance change amount of the magnetic resistance sensor is not affected by the temperature change, the magnetic resistance change amount caused by the temperature drift of the magnetic resistance sensor is compensated, and the accuracy of the magnetic field detection of the magnetic resistance sensor is improved.

[0054] In one of the embodiments, the plurality of bridge arms comprises a first bridge arm, a second bridge arm, a third bridge arm and a fourth bridge arm; one end of the first bridge arm is connected with one end of the second bridge arm, the other end of the second bridge arm is connected with one end of the fourth bridge arm, the other end of the tenth bridge arm is connected with one end of the third bridge arm, and the other end of the third bridge arm is connected with the other end of the first bridge arm; the two bridge arms connected together constitute two adjacent bridge arms; the first bridge arm and the fourth bridge arm constitute two bridge arms opposite to each other in a diagonal direction, and the second bridge arm and the third bridge arm constitute two bridge arms opposite to each other in a diagonal direction.

[0055] The first bridge arm comprises a raw tunnel junction R1 and a compensation tunnel junction R5, the second bridge arm comprises a raw tunnel junction R3 and a compensation tunnel junction R7, the third bridge arm comprises a raw tunnel junction R2 and a compensation tunnel junction R6, and the fourth bridge arm comprises a raw tunnel junction R4 and a compensation tunnel junction R8; the initial magnetic resistance values of R1, R2, R3, R4, R5, R6, R7 and R8 are all R.

[0056] The two bridge arms connected together constitute two adjacent bridge arms means that the two bridge arms directly connected together constitute two adjacent bridge arms, for example, the first bridge arm and the second bridge arm constitute two adjacent bridge arms, the second bridge arm and the third bridge arm constitute two adjacent bridge arms, the third bridge arm and the fourth bridge arm constitute two adjacent bridge arms, and the fourth bridge arm and the first bridge arm constitute two adjacent bridge arms.

[0057] The sensitive axis directions of the raw tunnel junction and the compensation tunnel junction in the same bridge arm are opposite, that is, the sensitive axis directions of R1 and R5 are opposite, the sensitive axis directions of R3 and R7 are opposite, the sensitive axis directions of R2 and R6 are opposite, and the sensitive axis directions of R4 and R8 are opposite.

[0058] The sensitive axis directions of the tunnel junctions of the same type in the two adjacent bridge arms are opposite, that is, the sensitive axis directions of R1 and R3 are the same, the sensitive axis directions of R5 and R7 are opposite, the sensitive axis directions of R3 and R4 are opposite, the sensitive axis directions of R7 and R8 are opposite, the sensitive axis directions of R4 and R2 are opposite, the sensitive axis directions of R8 and R6 are opposite, the sensitive axis directions of R2 and R1 are opposite, and the sensitive axis directions of R6 and R5 are opposite.

[0059] In the first bridge arm and the fourth bridge arm, the sensitive axis directions of R1 and R4 are the same, and the sensitive axis directions of R5 and R4 are the same; in the second bridge arm and the third bridge arm, the sensitive axis directions of R2 and R3 are the same, and the sensitive axis directions of R6 and R7 are the same.

[0060] In one of the embodiments, as shown in Figure 3 A magnetic field strength measurement method is provided, and the embodiment takes the method applied to a terminal as an example. It can be understood that the method can also be applied to a server, and can also be applied to a system including a terminal and a server, and is realized through the interaction of the terminal and the server. In the embodiment, the method comprises the following steps:

[0061] Step 302, obtaining the bias voltage and the output voltage of the full-bridge structure.

[0062] The embodiment can be used for measuring the magnetic field strength of the environment where the magnetoresistive sensor is located, especially in the case where the temperature of the environment where the magnetoresistive sensor is located changes.

[0063] The bias voltage provided for the magnetoresistive sensor is VDD, and the output voltage is the differential voltage in the Wheatstone full-bridge circuit caused by the resistance change of the magnetoresistive sensor under the action of the applied magnetic field.

[0064] Step 304, determining the magnetoresistance change of the magnetoresistive sensor based on the bias voltage and the output voltage; the magnetoresistance change of the magnetoresistive sensor is related to the resistance change of each tunnel junction.

[0065] In the embodiment, the resistance change of each tunnel junction in the full-bridge structure determines the magnetoresistance change of the magnetoresistive sensor as a whole, so that in the full-bridge structure of the application, the resistance change of the compensation-type tunnel junction of each bridge arm can compensate for the resistance change of the original tunnel junction of the bridge arm, so that the magnetoresistance change of the four bridge arms affected by temperature is consistent.

[0066] Step 306, determining the magnetic field strength of the environment where the magnetoresistive sensor is located based on the magnetoresistance change.

[0067] After obtaining the bias voltage and the output voltage of the full-bridge structure, the magnetoresistance change of the magnetoresistive sensor can be determined based on the bias voltage and the output voltage. As described above, due to the opposite resistance change of the original tunnel junction and the compensation-type tunnel junction on each bridge arm with temperature change, the sensitive axis directions of the corresponding types of tunnel junctions in the two bridge arms that are diagonally opposite are the same, and the sensitive axis directions of the corresponding types of tunnel junctions in the two adjacent bridge arms are opposite, so that the resistance change of the multiple bridge arms in the full-bridge structure is the same with temperature change, and the magnetoresistance change of the magnetoresistive sensor as a whole is not affected by temperature change, which compensates for the magnetoresistance change caused by temperature drift of the magnetoresistive sensor and improves the accuracy of the magnetoresistive sensor in detecting the magnetic field.

[0068] In one embodiment, determining the magnetic field strength of the environment where the magnetoresistive sensor is located based on the magnetoresistance change includes: determining the positional relationship between the magnetic field lines of the magnetic field in the environment where the magnetoresistive sensor is located and the sensitive axes of each tunnel junction; and determining the magnetic field strength of the environment where the magnetoresistive sensor is located based on the positional relationship and the magnetoresistance change.

[0069] In the embodiment, the sensitive axes of the tunnel junctions in the full-bridge structure are parallel to each other, and the sensitive axes of the tunnel junctions are anti-parallel, and the directions of the sensitive axes of the tunnel junctions are opposite.

[0070] The tunneling magnetoresistance sensor can also be used for measuring the magnetic field strength of an in-plane magnetic field, in which case the positional relationship between the magnetic field lines and the sensitive axes of the tunnel junctions is parallel. If the magnetic field lines are parallel to the sensitive axes of the tunnel junctions, the change in the magnetic resistance is converted into a measurable electrical signal, and the magnetic field strength of the environment in which the tunneling magnetoresistance sensor is located is determined based on the electrical signal, and the direction of the magnetic field is determined to be the in-plane magnetic field direction.

[0071] The tunneling magnetoresistance sensor can also be used for measuring the magnetic field strength of an out-of-plane magnetic field, and the high magnetic permeability cover layer also has a magnetic aggregation effect on the out-of-plane magnetic field, as shown in FIG. 4. The magnetic aggregation effect of the high magnetic permeability cover layer affects the in-plane magnetic field component generated at the edge of the cover layer, and the direction of the magnetic field component is parallel to the sensitive axes of the tunnel junctions below. The directions of the in-plane magnetic field components at the left and right ends of the cover layer are opposite, and the left and right ends can form a push-pull structure of a Wheatstone bridge. In combination with the spatial relationship between the tunnel junctions and the cover layer, the design can realize the measurement of the out-of-plane magnetic field, in which case the positional relationship between the magnetic field lines and the sensitive axes of the tunnel junctions is perpendicular. In this case:

[0072] The magnetic field strength of the environment in which the tunneling magnetoresistance sensor is located is determined based on the positional relationship and the change in the magnetic resistance, including: determining the proportion between the out-of-plane magnetic field and the in-plane magnetic field component generated at the edge of the cover layer based on the positional relationship; determining the initial magnetic field strength of the environment in which the tunneling magnetoresistance sensor is located based on the change in the magnetic resistance; and determining the magnetic field strength of the environment in which the tunneling magnetoresistance sensor is located based on the initial magnetic field strength and the proportion.

[0073] First, the proportion between the out-of-plane magnetic field and the in-plane magnetic field component generated at the edge of the cover layer is determined, and the proportion can be obtained by calculating the angle between the magnetic field plane of the out-of-plane magnetic field and the plane in which the sensitive axes of the tunnel junctions are located.

[0074] The change in the magnetic resistance is converted into a measurable electrical signal, and the initial magnetic field strength of the environment in which the tunneling magnetoresistance sensor is located is determined based on the electrical signal.

[0075] Then, the initial magnetic field strength is divided by the proportion to obtain the magnetic field strength of the environment in which the tunneling magnetoresistance sensor is located, and the direction of the magnetic field is determined to be the out-of-plane magnetic field direction.

[0076] It can be seen that the tunneling magnetoresistance sensor can be used for measuring in-plane magnetic fields and out-of-plane magnetic fields. When the temperature changes, the change in the magnetic resistance of the tunneling magnetoresistance sensor will not be affected, so that the magnetic field strength of the in-plane magnetic field and the out-of-plane magnetic field can be accurately tested.

[0077] In one of the embodiments, determining the magnetic resistance change amount of the magnetic resistance sensor based on the bias voltage and the output voltage comprises: determining a magnetic resistance change amount coefficient of the compensation-type tunnel junction based on the magnetic permeability of the cover layer and the position between the cover layer and the compensation-type tunnel junction; and determining the magnetic resistance change amount of the magnetic resistance sensor based on the bias voltage, the output voltage, the magnetic resistance change amount coefficient, and the initial magnetic resistance value.

[0078] The magnetic resistance change amount coefficient k of the compensation-type tunnel junction is determined by the magnetic permeability of the cover layer and the position between the cover layer edge and the compensation-type tunnel junction, and can also be achieved by adjusting the cover layer to completely shield the magnetic field, at which time k is 0.

[0079] The magnetic permeability of the cover layer determines the degree of convergence of the magnetic lines of force (the degree of convergence of the magnetic lines of force affects the size of the horizontal component of the out-of-plane magnetic field), and the position between the cover layer edge and the compensation-type tunnel junction determines the position of the tunnel junction in the magnetic lines of force. Through the construction of a magnetic field simulation model, a qualitative analysis of the coefficient k and the above two related parameters can be obtained, and the specific coefficient k is generally obtained through actual measurement.

[0080] Based on the quotient value obtained by dividing the bias voltage by the output voltage, the magnetic resistance change amount of the magnetic resistance sensor is calculated based on the quotient value, the magnetic resistance change amount coefficient k, and the initial magnetic resistance value R. Specifically:

[0081] When the temperature rises, the change amount of the magnetic resistance with the change of the temperature for the tunnel junction with the sensitive axis parallel to the magnetic field lines is , and the change amount of the magnetic resistance with the change of the temperature for the tunnel junction with the sensitive axis anti-parallel to the magnetic field lines is When there is an in-plane magnetic field in the environment where the magnetic resistance sensor is located, for example, a magnetic field horizontally to the right relative to the sensitive axis direction, and in combination with the above Figure 1 , the sensor provides a bias voltage VDD. Since the tunnel junction magnetic resistance will change with the temperature, the calculation formula of the traditional TMR output voltage V12 is as follows:

[0082] ;

[0083] And the calculation formula of the output voltage of the TMR of the present application V12 is as follows:

[0084] ;

[0085] In the two formulas, R1 to R8 and and k are explained in the related description of the above embodiments, and will not be described here.

[0086] Therefore, it can be seen that, after the bias voltage VDD, the output voltage V12, the magnetic resistance change amount coefficient k, and the initial magnetic resistance value R are known, the magnetic resistance change amount of the magnetic resistance sensor can be calculated .

[0087] The TMR sensor of the present application can be used as a current sensor, and can be an effective tool for realizing distributed current detection of a power grid.

[0088] It should be understood that, although each step in the flowchart involved in each of the above-described embodiments is shown in sequence according to the arrow, these steps are not necessarily executed in the order indicated by the arrow. Unless otherwise specified herein, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other orders. Moreover, at least some of the steps in the flowchart involved in each of the above-described embodiments can include multiple steps or stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least some of the other steps or steps or stages in other steps.

[0089] Based on the same inventive concept, the embodiments of the present application also provide a magnetic field strength measurement device for implementing the above-mentioned magnetic field strength measurement method. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, so the specific limitations in one or more magnetic field strength measurement device embodiments provided below can refer to the limitations of the magnetic field strength measurement method described above, and will not be repeated here.

[0090] In one exemplary embodiment, as shown in Figure 5 A magnetic field strength measurement device 500 is provided, comprising:

[0091] The acquisition module 501 is configured to acquire the bias voltage and the output voltage of the full-bridge structure according to any one of the above-described embodiments.

[0092] The first determination module 502 is configured to determine the magnetic resistance change amount of the magnetic resistance sensor based on the bias voltage and the output voltage; the magnetic resistance change amount of the magnetic resistance sensor is related to the resistance change amount of each tunnel junction.

[0093] The second determination module 503 is configured to determine the magnetic field strength of the environment in which the magnetic resistance sensor is located based on the magnetic resistance change amount.

[0094] In one embodiment, the second determination module 503 is specifically configured to:

[0095] determine the positional relationship between the magnetic field lines of the magnetic field in the environment in which the magnetic resistance sensor is located and the sensitive axis of each tunnel junction.

[0096] determine the magnetic field strength of the environment in which the magnetic resistance sensor is located based on the positional relationship and the magnetic resistance change amount.

[0097] In one of the embodiments, the second determining module 503, when determining the magnetic field strength of the environment where the magneto-resistance sensor is located based on the position relationship and the magneto-resistance change amount, is specifically configured to:

[0098] a proportion between the magnetic field component of the magnetic field in the corresponding direction of the target plane and the magnetic field based on the position relationship;

[0099] determine the initial magnetic field strength of the environment where the magneto-resistance sensor is located based on the magneto-resistance change amount;

[0100] determine the magnetic field strength of the environment where the magneto-resistance sensor is located based on the initial magnetic field strength and the proportion.

[0101] In one of the embodiments, the first determining module 502 is specifically configured to:

[0102] determine the magneto-resistance change amount coefficient of the compensation tunnel junction based on the magnetic permeability of the cover layer and the position between the cover layer and the compensation tunnel junction;

[0103] determine the magneto-resistance change amount of the magneto-resistance sensor based on the bias voltage, the output voltage, the magneto-resistance change amount coefficient and the initial magneto-resistance value.

[0104] The above modules in the magnetic field strength measuring device can be realized by software, hardware and combinations thereof in whole or in part. The above modules can be embedded in or independent of the processor in the computer device in hardware form, or can be stored in the memory in the computer device in software form, so as to be called and executed by the processor to perform the operations corresponding to the above modules.

[0105] In one of the exemplary embodiments, a computer device is provided, which can be a terminal, and the internal structure diagram thereof can be as shown in Figure 6The computer device shown in the figure includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capability. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals in a wired or wireless manner. The wireless manner can be realized through WIFI, mobile cellular network, near field communication (NFC) or other technologies. The computer program is executed by the processor to realize a magnetic field strength measurement method. The display unit of the computer device is used to form a visually visible picture, which can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer overlaid on the display screen, or a key, trackball or touchpad arranged on the shell of the computer device, or an external keyboard, touchpad or mouse, etc.

[0106] Those skilled in the art can understand that, Figure 6 The skilled in the art can understand that,

[0107] In one exemplary embodiment, a computer device is provided, including a memory and a processor, the memory stores a computer program, and the processor executes the computer program to realize the steps in the above method embodiments.

[0108] In one embodiment, a computer readable storage medium is provided, which stores a computer program, and the computer program is executed by a processor to realize the steps in the above method embodiments.

[0109] In one embodiment, a computer program product is provided, including a computer program, and the computer program is executed by a processor to realize the steps in the above method embodiments.

[0110] It should be noted that the user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of related data need to comply with relevant regulations.

[0111] It can be understood by those skilled in the art that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing related hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments of each method. In the embodiments provided in the present application, any reference to memory, database or other medium can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., without being limited thereto.

[0112] Any technical features in the above embodiments can be combined, and for the sake of brevity, not all possible combinations are described above, however, any combination of these technical features is deemed to be within the scope of the present application.

[0113] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A full-bridge structure corresponding to a magnetoresistive sensor, characterized in that, The full-bridge structure includes: Multiple bridge arms, each with a different type of tunnel junction with the same initial magnetoresistive value; the resistance change of each tunnel junction is related to the temperature of the environment where the magnetoresistive sensor is located; The different types of tunnel junctions include original tunnel junctions and compensated tunnel junctions, and the sensitive axis directions of the original tunnel junctions and compensated tunnel junctions are opposite; the compensated tunnel junctions are provided with a capping layer with a magnetic permeability higher than the magnetic permeability threshold. The sensitive axis directions of the tunnel junctions of corresponding types in two obliquely opposite bridge arms are the same, and the sensitive axis directions of the tunnel junctions of corresponding types in two adjacent bridge arms are opposite. The two obliquely opposite bridge arms and the two adjacent bridge arms are determined from the plurality of bridge arms.

2. The full-bridge structure according to claim 1, characterized in that, The plurality of bridge arms includes a first bridge arm, a second bridge arm, a third bridge arm, and a fourth bridge arm; One end of the first bridge arm is connected to one end of the second bridge arm, the other end of the second bridge arm is connected to one end of the fourth arm, the other end of the fourth bridge arm is connected to one end of the third bridge arm, and the other end of the third bridge arm is connected to the other end of the first bridge arm; the two connected bridge arms form the two adjacent bridge arms. The first bridge arm and the fourth bridge arm form the two bridge arms that are diagonally opposite each other, and the second bridge arm and the third bridge arm form the two bridge arms that are diagonally opposite each other.

3. A method for measuring magnetic field strength, characterized in that, The method includes: Obtain the bias voltage and output voltage of the full-bridge structure according to any one of claims 1 or 2; Based on the bias voltage and the output voltage, the magnetoresistive change of the magnetoresistive sensor is determined; the magnetoresistive change of the magnetoresistive sensor is related to the resistance change of each tunnel junction. The positional relationship between the magnetic field lines of the magnetic field in the environment where the magnetoresistive sensor is located and the sensitive axis of each tunnel junction is determined; wherein, when measuring the magnetic field strength of an in-plane magnetic field, the positional relationship between the magnetic field lines of the magnetic field in the environment where the magnetoresistive sensor is located and the sensitive axis of each tunnel junction is parallel; when measuring the magnetic field strength of an out-of-plane magnetic field, the positional relationship between the magnetic field lines of the magnetic field in the environment where the magnetoresistive sensor is located and the sensitive axis of each tunnel junction is perpendicular. Based on the positional relationship, determine the ratio between the magnetic field component in the corresponding direction of the target plane and the magnetic field itself; Based on the change in magnetoresistive strength, the initial magnetic field strength of the environment in which the magnetoresistive sensor is located is determined. Based on the initial magnetic field strength and the ratio, the magnetic field strength of the environment in which the magnetoresistive sensor is located is determined.

4. The method according to claim 3, characterized in that, Determining the magnetoresistive change of the magnetoresistive sensor based on the bias voltage and the output voltage includes: Based on the magnetic permeability of the capping layer and the position between the capping layer and the compensation tunnel junction, the magnetic reluctance variation coefficient of the compensation tunnel junction is determined. The magnetoresistive change of the magnetoresistive sensor is determined based on the bias voltage, the output voltage, the magnetoresistive change coefficient, and the initial magnetoresistive value.

5. A magnetic field strength measuring device, characterized in that, The device includes: The acquisition module is used to acquire the bias voltage and output voltage of the full-bridge structure according to any one of claims 1 or 2; The first determining module is used to determine the magnetoresistive change of the magnetoresistive sensor based on the bias voltage and the output voltage; the magnetoresistive change of the magnetoresistive sensor is related to the resistance change of each tunnel junction. The second determining module is used to determine the positional relationship between the magnetic field lines of the magnetic field in the environment where the magnetoresistive sensor is located and the sensitive axes of each tunnel junction; wherein, when measuring the magnetic field strength of the in-plane magnetic field, the positional relationship between the magnetic field lines of the magnetic field in the environment where the magnetoresistive sensor is located and the sensitive axes of each tunnel junction is parallel; when measuring the magnetic field strength of the out-of-plane magnetic field, the positional relationship between the magnetic field lines of the magnetic field in the environment where the magnetoresistive sensor is located and the sensitive axes of each tunnel junction is perpendicular; based on the positional relationship, the module determines the ratio between the magnetic field component of the magnetic field in the corresponding direction of the target plane and the magnetic field; based on the magnetoresistive change, the module determines the initial magnetic field strength of the environment where the magnetoresistive sensor is located; and based on the initial magnetic field strength and the ratio, the module determines the magnetic field strength of the environment where the magnetoresistive sensor is located.

6. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 3 to 4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 3 to 4.

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 3 to 4.

Images