A magnetic reluctance element for angle measurement and an angle sensor, electronic device

Abstract

The application discloses a magnetic resistance element for angle measurement, an angle sensor and electronic equipment. The magnetic resistance element comprises a substrate; a first cosine Wheatstone bridge comprising a first magnetic resistance, a second magnetic resistance, a third magnetic resistance and a fourth magnetic resistance which are sequentially coupled and whose preferred magnetic sensitive directions are alpha, 180 degrees-alpha, 360 degrees-alpha and 180 degrees+alpha respectively; and a first sine Wheatstone bridge comprising a fifth magnetic resistance, a sixth magnetic resistance, a seventh magnetic resistance and an eighth magnetic resistance which are sequentially coupled and whose preferred magnetic sensitive directions are 90 degrees+alpha, 270 degrees-alpha, 90 degrees-alpha and 270 degrees+alpha respectively. Wherein, cos alpha is not equal to 0 and cos(nalpha) is equal to 0, n is an odd number greater than 1. The magnetic resistance element for angle measurement can effectively eliminate odd harmonics, reduce measurement error and has the beneficial effect of being easy to implement.

Description

Technical Field

[0001] This invention relates to the field of angle sensor technology, and in particular to a magnetoresistive element for angle measurement, an angle sensor, and electronic equipment. Background Technology

[0002] Magnetoresistive angle sensors are typically configured as Wheatstone bridges to achieve temperature independence of the output signal.

[0003] To obtain precise angular information, it is typically necessary to configure two Wheatstone bridges with magnetic sensitivity directions orthogonal to each other, and obtain sine and cosine function signals at the bridge outputs. These two signals are used, for example, by the ARCTAN function to calculate precise angular orientation.

[0004] The higher the accuracy of angle measurement, the more sinusoidal the output signal of the Wheatstone bridge used to detect the angle of the magnetic field. However, due to factors such as the magnetic anisotropy of the magnetoresistive material, the tolerance of the sensor and magnet assembly, or the inaccuracy of the pole shoes or magnetic permeability elements, harmonics are often present in the output signal, leading to inaccurate measurements.

[0005] Therefore, it is necessary to improve the impact of harmonics on angle measurement by arranging magnetoresistive devices. Summary of the Invention

[0006] The purpose of this invention is to provide a magnetoresistive element, angle sensor, and electronic device that can reduce the influence of harmonics on angle measurement.

[0007] To achieve the above objectives, a first aspect of the present invention provides a magnetoresistive element.

[0008] The magnetoresistive element includes: a substrate; A first cosine Wheatstone bridge formed on the substrate includes a first magnetoresistive element, a second magnetoresistive element, a third magnetoresistive element, and a fourth magnetoresistive element, sequentially coupled with preferred magnetic susceptibility directions of α, 180°-α, 360°-α, and 180°+α, respectively. The first and second magnetoresistive elements are connected to a voltage source, and the third and fourth magnetoresistive elements are grounded. The preferred magnetic susceptibility direction α of the first magnetoresistive element satisfies cosα≠0 and cos(nα)=0, where n is an odd number greater than 1. The first sinusoidal Wheatstone bridge formed on the substrate includes a fifth magnetoresistive, a sixth magnetoresistive, a seventh magnetoresistive, and an eighth magnetoresistive, which are sequentially coupled and have preferred magnetic susceptibility directions of 90°+α, 270°-α, 90°-α, and 270°+α, respectively; the fifth and sixth magnetoresistives are connected to a voltage source, and the seventh and eighth magnetoresistives are grounded.

[0009] According to some embodiments of the present invention, the resistance characteristics of each arm of the first cosine Wheatstone bridge and the first sine Wheatstone bridge are substantially the same in terms of amplitude.

[0010] According to some embodiments of the present invention, each bridge arm is an AMR, GMR or TMR disposed on the substrate.

[0011] According to some embodiments of the present invention, when each bridge arm is an AMR arranged on the substrate, the magnetic susceptibility direction of each bridge arm is preferably its extension direction.

[0012] According to some embodiments of the present invention, when each bridge arm is a GMR or TMR arranged on the substrate, the preferred magnetic susceptibility direction of each bridge arm is the reference magnetization direction of its reference layer.

[0013] According to some embodiments of the present invention, the magnetic susceptibility of the first magnetoresistive element is preferably 30°, 18° or 54°.

[0014] According to some embodiments of the present invention, when used to eliminate the third harmonic, the magnetic susceptibility of the first magnetoresistive element is preferably 30°, 150°, 210° or 330°.

[0015] According to some embodiments of the present invention, when used to eliminate the 5th harmonic, the preferred magnetic susceptibility direction of the first magnetoresistive element is 18°, 54°, 126°, 162°, 198°, 234°, 306° or 342°.

[0016] According to some embodiments of the present invention, the magnetoresistive element further includes: a second cosine Wheatstone bridge formed on the substrate, comprising a ninth, tenth, eleventh, and twelfth magnetoresistive element sequentially coupled with magnetically responsive directions of β, 180°-β, 360°-β, and 180°+β, respectively; the ninth and tenth magnetoresistive elements are connected to a voltage source, and the eleventh and twelfth magnetoresistive elements are grounded; wherein cosβ≠0 and cos(nβ)=0, and n is an odd number greater than 1; and, The second sinusoidal Wheatstone bridge formed on the substrate includes a thirteenth magnetoresistive, a fourteenth magnetoresistive, a fifteenth magnetoresistive, and a sixteenth magnetoresistive, which are sequentially coupled and have preferred magnetic susceptibility directions of 90°+β, 270°-β, 90°-β, and 270°+β, respectively. The thirteenth and fourteenth magnetoresistives are connected to a voltage source, and the fifteenth and sixteenth magnetoresistives are grounded.

[0017] According to some embodiments of the present invention, α is 30°, 150°, 210° or 330°.

[0018] According to some embodiments of the present invention, β is 18°, 54°, 126°, 162°, 198°, 234°, 306° or 342°.

[0019] To achieve the above objectives, a second aspect of the present invention provides an angle sensor, the angle sensor including the aforementioned magnetoresistive element.

[0020] According to some embodiments of the present invention, the angle sensor further includes a signal processing unit; the signal processing unit is electrically coupled to the first cosine Wheatstone bridge and the first sine Wheatstone bridge respectively, and is used to determine the angular orientation of the magnetic field based on the differential signals of the first cosine Wheatstone bridge and the first sine Wheatstone bridge.

[0021] According to some embodiments of the present invention, the angle sensor further includes a signal processing unit; the signal processing unit is electrically coupled to the first cosine Wheatstone bridge, the second cosine Wheatstone bridge, the first sine Wheatstone bridge, and the second sine Wheatstone bridge, respectively, and is used to determine the angular orientation of the magnetic field based on the differential signals of the first cosine Wheatstone bridge, the second cosine Wheatstone bridge, the first sine Wheatstone bridge, and the second sine Wheatstone bridge.

[0022] To achieve the above objectives, a third aspect of the present invention provides an electronic device comprising the above-described magnetoresistive element or the above-described angle sensor.

[0023] Therefore, compared with the prior art, the present invention has the following beneficial effects: The magnetoresistive element disclosed in this invention includes a substrate; a first cosine Wheatstone bridge formed on the substrate, comprising a first magnetoresistive element, a second magnetoresistive element, a third magnetoresistive element, and a fourth magnetoresistive element, sequentially coupled with preferred magnetic susceptibility directions of α, 180°-α, 360°-α, and 180°+α, respectively; the first and second magnetoresistive elements are connected to a voltage source, and the third and fourth magnetoresistive elements are grounded; and a first sine Wheatstone bridge formed on the substrate, comprising a fifth magnetoresistive element, a sixth magnetoresistive element, a seventh magnetoresistive element, and an eighth magnetoresistive element, sequentially coupled with preferred magnetic susceptibility directions of 90°+α, 270°-α, 90°-α, and 270°+α, respectively; the fifth and sixth magnetoresistive elements are connected to a voltage source, and the seventh and eighth magnetoresistive elements are grounded, cosα≠0 and cos(nα)=0, where n is an odd number greater than 1. The magnetoresistive element of this invention, when used for angle measurement, can effectively eliminate odd harmonics, reduce measurement errors, and has the beneficial effect of being easily implemented. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the magnetoresistive element in the first embodiment of the invention; Figure 2 This is a schematic diagram of the structure of the magnetoresistive element according to the second embodiment of the invention; Figure 3 This is a schematic diagram of the structure of the magnetoresistive element according to the third embodiment of the invention; Figure 4 This is a schematic diagram of the structure of the magnetoresistive element in the fourth embodiment of the invention; Figure 5 A comparison diagram of simulated angle error curves of the magnetoresistive element in the first embodiment of the invention and the magnetoresistive element in the third comparative embodiment when used for angle measurement; Figure 6 A comparison diagram of the simulation curves of the first angle error of the magnetoresistive element in the second embodiment, the magnetoresistive element in the third embodiment, and the third comparative magnetoresistive element when used for angle measurement. Figure 7 This is a schematic diagram of the third parallel magnetoresistive element; Figure 8 This is a schematic diagram of the structure of the first comparative magnetoresistive element; Figure 9 This is a schematic diagram of the structure of the second parallel magnetoresistive element.

[0026] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0029] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0030] The Wheatstone bridge magnetoresistive sensor exhibits identical temperature dependence. Therefore, magnetoresistive angle sensors are typically configured as a Wheatstone bridge to achieve temperature independence of the output signal.

[0031] To obtain precise angular information, two Wheatstone bridges with magnetic sensitivity directions orthogonal to each other are typically needed. The sine and cosine functions are then obtained from the bridge outputs. These two signals are used, for example, by the ARCTAN function to calculate the precise angular orientation.

[0032] The higher the accuracy of angle measurement, the more sinusoidal the output signal of the Wheatstone bridge used to detect the angle of the magnetic field. However, due to factors such as the magnetic anisotropy of the magnetoresistive material, the tolerance of the sensor and magnet assembly, or the inaccuracy of the pole shoes or magnetic permeability elements, harmonics are often present in the output signal, leading to inaccurate measurements.

[0033] Therefore, it is necessary to improve the impact of harmonics on angle measurement.

[0034] The purpose of this invention is to provide a magnetoresistive element for angle measurement, which reduces the influence of harmonics on angle measurement through the arrangement of magnetoresistive devices.

[0035] Figure 1 This is a schematic diagram of the structure of the magnetoresistive element in the first embodiment of the invention.

[0036] like Figure 1 As shown, the magnetoresistive element of the first embodiment of the invention includes: a substrate 100 and a first cosine Wheatstone bridge 210 and a first sine Wheatstone bridge 220 formed on the substrate 100.

[0037] The first cosine Wheatstone bridge 210 includes a first magnetoresistive resistor R1, a second magnetoresistive resistor R2, a third magnetoresistive resistor R3, and a fourth magnetoresistive resistor R4 coupled in sequence, with their preferred magnetic susceptibility directions being 30°, 150°, 330°, and 210°, respectively. The first magnetoresistive resistor R1, the second magnetoresistive resistor R2, the third magnetoresistive resistor R3, and the fourth magnetoresistive resistor R4 are TMRs disposed on a substrate. The first magnetoresistive resistor R1 and the second magnetoresistive resistor R2 are connected to a voltage source Vcc, and the third magnetoresistive resistor R3 and the fourth magnetoresistive resistor R4 are grounded to GND. The first magnetoresistive resistor R1 and the fourth magnetoresistive resistor R4 form the first half-bridge, and the second magnetoresistive resistor R2 and the third magnetoresistive resistor R3 form the second half-bridge. The output signal of the first half-bridge is V. cos+ The output signal of the second half-bridge is V. cos- Furthermore, the cosine differential signal V of the first cosine Wheatstone bridge 210... cosdiff For V cos+ With V cos- The difference.

[0038] It should be noted that the first magnetoresistive element R1, the second magnetoresistive element R2, the third magnetoresistive element R3, and the fourth magnetoresistive element R4 are not limited to TMRs disposed on the substrate, but can also be AMRs, GMRs, or other elements with magnetoresistive effects disposed on the substrate. Specifically, when the first magnetoresistive element R1, the second magnetoresistive element R2, the third magnetoresistive element R3, and the fourth magnetoresistive element R4 are AMRs, the preferred magnetic sensing direction refers to the extension direction of each bridge arm; when the first magnetoresistive element R1, the second magnetoresistive element R2, the third magnetoresistive element R3, and the fourth magnetoresistive element R4 are GMRs or TMRs, the preferred magnetic sensing direction refers to the reference magnetization direction of the reference layer in each bridge arm or its pinning direction.

[0039] It should be understood that the preferred magnetic sensing directions of the first magnetoresistive R1, the second magnetoresistive R2, the third magnetoresistive R3, and the fourth magnetoresistive R4 in the embodiments of the present invention are determined by the reference magnetization direction of the reference layer in each bridge arm. The first magnetoresistive R1, the second magnetoresistive R2, the third magnetoresistive R3, and the fourth magnetoresistive R4 can be adjusted by using magnetic track-changing elements and high-temperature magnetic field annealing after integral molding to adjust the magnetization direction of the reference layer in each bridge arm.

[0040] It should be understood that, in the embodiments of the present invention, the preferred magnetic sensing direction α of the first magnetoresistive R1 is 30°, the sum of the preferred magnetic sensing directions of the first magnetoresistive R1 and the second magnetoresistive R2 is 180°, the difference between the preferred magnetic sensing directions of the first magnetoresistive R1 and the fourth magnetoresistive R4 is 180°, and the difference between the preferred magnetic sensing directions of the second magnetoresistive R2 and the third magnetoresistive R3 is 180°.

[0041] It should be understood that the resistance characteristics of the first magnetoresistive R1, the second magnetoresistive R2, the third magnetoresistive R3, and the fourth magnetoresistive R4, which are the bridge arms of the first cosine Wheatstone bridge 210, are basically the same in terms of amplitude.

[0042] The first sinusoidal Wheatstone bridge 220 includes a fifth magnetoresistor R5, a sixth magnetoresistor R6, a seventh magnetoresistor R7, and an eighth magnetoresistor R8 coupled in sequence, with their preferred magnetic susceptibility directions being 120°, 240°, 60°, and 300°, respectively. The fifth magnetoresistor R5, the sixth magnetoresistor R6, the seventh magnetoresistor R7, and the eighth magnetoresistor R8 are TMRs disposed on a substrate. The fifth magnetoresistor R5 and the sixth magnetoresistor R6 are connected to a voltage source Vcc, and the seventh magnetoresistor R7 and the eighth magnetoresistor R8 are grounded to GND. The fifth magnetoresistor R5 and the eighth magnetoresistor R8 form the third half-bridge, and the sixth magnetoresistor R6 and the seventh magnetoresistor R7 form the fourth half-bridge. The output signal of the third half-bridge is V. sin+ The output signal of the fourth half-bridge is V. sin- Furthermore, the sinusoidal differential signal V of the first sinusoidal Wheatstone bridge 220... sindiff For V sin+ With V sin- The difference.

[0043] It should be understood that the angles between the preferred magnetic sensing directions of the fifth magnetoresistive R5 and the first magnetoresistive R1, the sixth magnetoresistive R6 and the second magnetoresistive R2, the seventh magnetoresistive R7 and the third magnetoresistive R3, and the eighth magnetoresistive R8 and the fourth magnetoresistive R4 are all 90°.

[0044] It should be understood that the preferred magnetic sensing directions of the fifth magnetoresistive element R5, the sixth magnetoresistive element R6, the seventh magnetoresistive element R7, and the eighth magnetoresistive element R8 in this embodiment of the invention are determined by the reference magnetization direction of the reference layer in each bridge arm. The magnetization direction of the reference layer in each bridge arm can be adjusted by using magnetic track-changing elements and high-temperature magnetic field annealing after integral molding.

[0045] Figure 2 This is a schematic diagram of the structure of the magnetoresistive element in the second embodiment of the invention.

[0046] like Figure 2 As shown, the magnetoresistive element of the second embodiment of the invention includes: a substrate 100 and a first cosine Wheatstone bridge 210 and a first sine Wheatstone bridge 220 formed on the substrate 100.

[0047] The first cosine Wheatstone bridge 210 includes a first magnetoresistive resistor R1, a second magnetoresistive resistor R2, a third magnetoresistive resistor R3, and a fourth magnetoresistive resistor R4 coupled in sequence, with preferred magnetic susceptibility directions of 18°, 162°, 342°, and 198°, respectively. The first magnetoresistive resistor R1, the second magnetoresistive resistor R2, the third magnetoresistive resistor R3, and the fourth magnetoresistive resistor R4 are TMRs disposed on a substrate. The first magnetoresistive resistor R1 and the second magnetoresistive resistor R2 are connected to a voltage source Vcc, and the third magnetoresistive resistor R3 and the fourth magnetoresistive resistor R4 are grounded to GND. The first magnetoresistive resistor R1 and the fourth magnetoresistive resistor R4 form the first half-bridge, and the second magnetoresistive resistor R2 and the third magnetoresistive resistor R3 form the second half-bridge. The output signal of the first half-bridge is V. cos+ The output signal of the second half-bridge is V. cos- Furthermore, the cosine differential signal V of the first cosine Wheatstone bridge 210... cosdiff For V cos+ With V cos- The difference.

[0048] It should be understood that the preferred magnetic direction α of the first magnetoresistive R1 is 18°, the sum of the preferred magnetic directions of the first magnetoresistive R1 and the second magnetoresistive R2 is 180°, the difference between the preferred magnetic directions of the first magnetoresistive R1 and the fourth magnetoresistive R4 is 180°, and the difference between the preferred magnetic directions of the second magnetoresistive R2 and the third magnetoresistive R3 is 180°.

[0049] The first sinusoidal Wheatstone bridge 220 includes a fifth magnetoresistor R5, a sixth magnetoresistor R6, a seventh magnetoresistor R7, and an eighth magnetoresistor R8 coupled in sequence, with their preferred magnetic susceptibility directions being 108°, 252°, 72°, and 288°, respectively. The fifth magnetoresistor R5, the sixth magnetoresistor R6, the seventh magnetoresistor R7, and the eighth magnetoresistor R8 are TMRs disposed on a substrate. The fifth magnetoresistor R5 and the sixth magnetoresistor R6 are connected to a voltage source Vcc, and the seventh magnetoresistor R7 and the eighth magnetoresistor R8 are grounded to GND. The fifth magnetoresistor R5 and the eighth magnetoresistor R8 form a third half-bridge, and the output signal of the third half-bridge is V. sin+ The sixth magnetoresistor R6 and the seventh magnetoresistor R7 form the fourth half-bridge, and the output signal of the fourth half-bridge is V. sin- Furthermore, the sinusoidal differential signal V of the first sinusoidal Wheatstone bridge 220... sindiff For V sin+ With V sin- The difference.

[0050] It should be understood that the angles between the preferred magnetic sensing directions of the fifth magnetoresistive R5 and the first magnetoresistive R1, the sixth magnetoresistive R6 and the second magnetoresistive R2, the seventh magnetoresistive R7 and the third magnetoresistive R3, and the eighth magnetoresistive R8 and the fourth magnetoresistive R4 are all 90°.

[0051] Figure 3 This is a schematic diagram of the structure of the magnetoresistive element in the third embodiment of the invention.

[0052] like Figure 3 As shown, the magnetoresistive element of the third embodiment of the invention includes: a substrate 100 and a first cosine Wheatstone bridge 210 and a first sine Wheatstone bridge 220 formed on the substrate 100.

[0053] The first cosine Wheatstone bridge 210 includes a first magnetoresistive resistor R1, a second magnetoresistive resistor R2, a third magnetoresistive resistor R3, and a fourth magnetoresistive resistor R4 coupled in sequence, with preferred magnetic susceptibility directions of 54°, 126°, 306°, and 234°, respectively. The first magnetoresistive resistor R1, the second magnetoresistive resistor R2, the third magnetoresistive resistor R3, and the fourth magnetoresistive resistor R4 are TMRs disposed on a substrate. The first magnetoresistive resistor R1 and the second magnetoresistive resistor R2 are connected to a voltage source Vcc, and the third magnetoresistive resistor R3 and the fourth magnetoresistive resistor R4 are grounded to GND. The first magnetoresistive resistor R1 and the fourth magnetoresistive resistor R4 form the first half-bridge, and the second magnetoresistive resistor R2 and the third magnetoresistive resistor R3 form the second half-bridge. The output signal of the first half-bridge is V. cos+ The output signal of the second half-bridge is V. cos- Furthermore, the cosine differential signal V of the first cosine Wheatstone bridge 210... cosdiff For V cos+ With V cos- The difference.

[0054] It should be understood that the preferred magnetic direction α of the first magnetoresistive R1 is 54°, the sum of the preferred magnetic directions of the first magnetoresistive R1 and the second magnetoresistive R2 is 180°, the difference between the preferred magnetic directions of the first magnetoresistive R1 and the fourth magnetoresistive R4 is 180°, and the difference between the preferred magnetic directions of the second magnetoresistive R2 and the third magnetoresistive R3 is 180°.

[0055] The first sinusoidal Wheatstone bridge 220 includes a fifth magnetoresistor R5, a sixth magnetoresistor R6, a seventh magnetoresistor R7, and an eighth magnetoresistor R8 coupled in sequence, with their preferred magnetic susceptibility directions being 144°, 216°, 36°, and 324°, respectively. The fifth magnetoresistor R5, the sixth magnetoresistor R6, the seventh magnetoresistor R7, and the eighth magnetoresistor R8 are TMRs disposed on a substrate. The fifth magnetoresistor R5 and the sixth magnetoresistor R6 are connected to a voltage source Vcc, and the seventh magnetoresistor R7 and the eighth magnetoresistor R8 are grounded GND. The fifth magnetoresistor R5 and the eighth magnetoresistor R8 form the third half-bridge, and the sixth magnetoresistor R6 and the seventh magnetoresistor R7 form the fourth half-bridge. The output signal of the third half-bridge is V. sin+ The output signal of the fourth half-bridge is V. sin- Furthermore, the sinusoidal differential signal V of the first sinusoidal Wheatstone bridge 220... sindiff For V sin+ With V sin- The difference.

[0056] It should be understood that the angles between the preferred magnetic sensing directions of the fifth magnetoresistive R5 and the first magnetoresistive R1, the sixth magnetoresistive R6 and the second magnetoresistive R2, the seventh magnetoresistive R7 and the third magnetoresistive R3, and the eighth magnetoresistive R8 and the fourth magnetoresistive R4 are all 90°.

[0057] In summary, the magnetoresistive element disclosed in the embodiments of the present invention includes a substrate 100 and a first cosine Wheatstone bridge 210 and a first sine Wheatstone bridge 220 formed on the substrate.

[0058] The first cosine Wheatstone bridge 210 includes a first magnetoresistive resistor R1, a second magnetoresistive resistor R2, a third magnetoresistive resistor R3, and a fourth magnetoresistive resistor R4 coupled in sequence, with their preferred magnetic susceptibility directions being α, 180°-α, 360°-α, and 180°+α, respectively. The first magnetoresistive resistor R1 and the second magnetoresistive resistor R2 are connected to a voltage source Vcc, and the third magnetoresistive resistor R3 and the fourth magnetoresistive resistor R4 are grounded to GND. The first magnetoresistive resistor R1 and the fourth magnetoresistive resistor R4 form the first half-bridge, and the second magnetoresistive resistor R2 and the third magnetoresistive resistor R3 form the second half-bridge. The output signal of the first half-bridge is V. cos+ The output signal of the second half-bridge is V. cos- Furthermore, the cosine differential signal V of the first cosine Wheatstone bridge 210... cosdiff For V cos+ With V cos- The difference.

[0059] The first sinusoidal Wheatstone bridge 220 includes a fifth magnetoresistor R5, a sixth magnetoresistor R6, a seventh magnetoresistor R7, and an eighth magnetoresistor R8 coupled sequentially, with their preferred magnetic susceptibility directions being 90°+α, 270°-α, 90°-α, and 270°+α, respectively. The fifth magnetoresistor R5, the sixth magnetoresistor R6, the seventh magnetoresistor R7, and the eighth magnetoresistor R8 are TMRs disposed on a substrate. The fifth magnetoresistor R5 and the sixth magnetoresistor R6 are connected to a voltage source Vcc, and the seventh magnetoresistor R7 and the eighth magnetoresistor R8 are grounded GND. The fifth magnetoresistor R5 and the eighth magnetoresistor R8 form the third half-bridge, and the sixth magnetoresistor R6 and the seventh magnetoresistor R7 form the fourth half-bridge. The output signal of the third half-bridge is V. sin+ The output signal of the fourth half-bridge is V. sin- Furthermore, the sinusoidal differential signal V of the first sinusoidal Wheatstone bridge 220... sindiff For V sin+ With V sin- The difference.

[0060] In the first embodiment of the invention, α is 30°; in the second embodiment, α is 18°; and in the third embodiment, α is 54°.

[0061] When only the fundamental frequency and the third harmonic exist, the output signal V of the first half-bridge is...cos+ conform to: V cos+ =A1cos(θ-α)+ A3cos[3(θ-α)], Where A1 is the amplitude of the fundamental wave, A3 is the amplitude of the third harmonic; α is the preferred magnetic sensing direction of the first magnetoresistive R1, and θ is the angular orientation; The output signal V of the second half-bridge cos- conform to: V cos- =A1cos(θ-180°+α)+ A3cos[3(θ-180°+α)]; The output signal V of the third half-bridge sin+ conform to: V sin+ =A1cos(θ-90°-α)+ A3cos[3(θ-90°-α)]; The output signal V of the fourth half-bridge sin- conform to: V sin- =A1cos(θ-270°+α)+ A3cos[3(θ-270°+α)]; Furthermore, the cosine differential signal V of the first cosine Wheatstone bridge 210 cosdiff That is, V cos+ With V cos- The difference conforms to: V cosdiff =2A1cosαcosθ+2A3cos(3α)cos(3θ); The sinusoidal differential signal V of the first sinusoidal Wheatstone bridge 220 sindiff That is, V sin+ With V sin- The difference conforms to: V sindiff =2A1cosαsinθ-2A3cos(3α)sin(3θ).

[0062] Therefore, V can be achieved when cos(3α) is 0 and cosα is not 0 (i.e., α is 30°, 150°, 210° or 330°). cosdiff =2A1cosαcosθ and V sindiff =2A1cosαsinθ,V cosdiff With V sindiff All of them are independent of the third harmonic, thus eliminating the third harmonic; at the same time, their amplitudes are all |2A1cosα|.

[0063] Therefore, the magnetoresistive element in the first embodiment of the invention can eliminate harmonic errors caused by the third harmonic and can be directly passed through Simply obtain the angular orientation.

[0064] When only the fundamental frequency and the 5th harmonic exist, the output signal V of the first half-bridge is... cos+ conform to: V cos+ =A1cos(θ-α)+ A5cos[5(θ-α)], where A1 is the amplitude of the fundamental wave, A5 is the amplitude of the 5th harmonic; α is the preferred magnetic direction of the first magnetoresistive R1, and θ is the angular orientation; The output signal V of the second half-bridge cos- conform to: V cos- =A1cos(θ-180°+α)+A5cos[5(θ-180°+α)]; The output signal V of the third half-bridge sin+ conform to: V sin+ =A1cos(θ-90°-α)+A5cos[5(θ-90°-α)]; The output signal V of the fourth half-bridge sin- conform to: V sin- =A1cos(θ-270°+α)+A5cos[5(θ-270°+α)]; Furthermore, the cosine differential signal V of the first cosine Wheatstone bridge 210 cosdiff That is, V cos+ With V cos- The difference conforms to: V cosdiff =2A1cosαcosθ+2A5cos(5α)cos(5θ); The differential signal V of the first sinusoidal Wheatstone bridge 220 sindiff That is, V sin+ With V sin- The difference conforms to: V sindiff =2A1cosαsinθ+2A5cos(5α)sin(5θ).

[0065] Therefore, V can be realized when cos(5α) is 0 and cosα is not 0 (i.e., α is 18°, 54°, 126°, 162°, 198°, 234°, 306°, 342°). cosdiff =2A1cosαcosθ and V sindiff =2A1cosαsinθ. Here, V cosdiff With V sindiff All of them are independent of the 5th harmonic, thus eliminating the 5th harmonic; at the same time, their amplitudes are all |2A1cosα|.

[0066] Therefore, the magnetoresistive elements in the second and third embodiments of the invention can eliminate the influence of the fifth harmonic on angle measurement and can be directly passed through... Simply obtain the angular orientation.

[0067] Therefore, the magnetoresistive element of the present invention can be used for angle measurement, and the accuracy of angle measurement can be easily improved by eliminating harmonics.

[0068] Figure 8 This is a schematic diagram of the structure of the first proportional magnetoresistive element.

[0069] like Figure 8 As shown, the first comparative magnetoresistive element includes a substrate 100 and a first cosine Wheatstone bridge 210 and a first sine Wheatstone bridge 220 deposited on the substrate. The preferred magnetic susceptibility directions of the first magnetoresistive element R1, the second magnetoresistive element R2, the third magnetoresistive element R3, and the fourth magnetoresistive element R4 connected in sequence in the first cosine Wheatstone bridge 210 are 60°, -60°, 120°, and 240°, respectively. The first magnetoresistive element R1 and the second magnetoresistive element R2 are connected to the voltage source Vcc, and the third magnetoresistive element R3 and the fourth magnetoresistive element R4 are grounded to GND. The first magnetoresistive element R1 and the fourth magnetoresistive element R4 form the first half-bridge, and the second magnetoresistive element R2 and the third magnetoresistive element R3 form the second half-bridge. In the first sinusoidal Wheatstone bridge 220, the preferred magnetic susceptibility directions of the fifth magnetor R5, the sixth magnetor R6, the seventh magnetor R7, and the eighth magnetor R8 are 150°, 30°, 210°, and 330°, respectively. The fifth magnetor R5 and the sixth magnetor R6 are connected to the voltage source Vcc, and the seventh magnetor R7 and the eighth magnetor R8 are grounded. The fifth magnetor R5 and the eighth magnetor R8 form the third half-bridge, and the sixth magnetor R6 and the seventh magnetor R7 form the fourth half-bridge.

[0070] It should be understood that the first pair of proportional magnetoresistive elements conform to the following: the corresponding magnetoresistive elements in the same bridge branch have an angular offset of 180°, and the magnetoresistive elements in the same bridge branch that are opposite to each other have an angular offset of 120° (i.e., 180° - 60°).

[0071] Figure 9 This is a schematic diagram of the second proportional magnetoresistive element. (See attached diagram.) Figure 9As shown, the second comparative magnetoresistive element includes a substrate 100 and a first cosine Wheatstone bridge 210 and a first sine Wheatstone bridge 220 deposited thereon. The preferred magnetic susceptibility directions of the first magnetoresistive element R1, the second magnetoresistive element R2, the third magnetoresistive element R3, and the fourth magnetoresistive element R4 connected in sequence in the first cosine Wheatstone bridge 210 are 36°, -108°, 72°, and 216°, respectively. The first and second magnetoresistive elements are connected to a voltage source Vcc, and the third and fourth magnetoresistive elements are grounded. The first magnetoresistive element R1 and the fourth magnetoresistive element R4 form a first half-bridge, and the second magnetoresistive element R2 and the third magnetoresistive element R3 form a second half-bridge. In the first sinusoidal Wheatstone bridge 220, the preferred magnetic susceptibility directions of the fifth magnetor R5, the sixth magnetor R6, the seventh magnetor R7, and the eighth magnetor R8 are 126°, -18°, 162°, and 306°, respectively. The fifth magnetor R5 and the sixth magnetor R6 are connected to the voltage source Vcc, and the seventh magnetor R7 and the eighth magnetor R8 are grounded. The fifth magnetor R5 and the eighth magnetor R8 form the third half-bridge, and the sixth magnetor R6 and the seventh magnetor R7 form the fourth half-bridge.

[0072] It should be understood that the second pair of proportional magnetoresistive elements conform to the following: the corresponding magnetoresistive elements in the same bridge branch have an angular offset of 180°, and the magnetoresistive elements in the same bridge branch that are opposite to each other have an angular offset of 144° (i.e., 180° - 36°).

[0073] In summary, the comparative magnetoresistive element includes a substrate 100 and a first cosine Wheatstone bridge 210 and a first sine Wheatstone bridge 220 deposited on the substrate. The preferred magnetic susceptibility directions of the first magnetoresistive element R1, the second magnetoresistive element R2, the third magnetoresistive element R3, and the fourth magnetoresistive element R4, connected sequentially in the first cosine Wheatstone bridge 210, are α, α+β-180° and α+β, α+180°, respectively. The first and second magnetoresistive elements are connected to a voltage source Vcc, while the third and fourth magnetoresistive elements are grounded. The first magnetoresistive element R1 and the fourth magnetoresistive element R4 form a first half-bridge, and the second magnetoresistive element R2 and the third magnetoresistive element R3 form a second half-bridge. In the first sinusoidal Wheatstone bridge, the preferred magnetic susceptibility directions of the fifth magnetor R5, the sixth magnetor R6, the seventh magnetor R7, and the eighth magnetor R8 are 90°+α, α+β-90°, α+β+90°, and 270°+α, respectively. The fifth and sixth magnetors are connected to the voltage source Vcc, and the seventh and eighth magnetors are grounded. The fifth magnetor R5 and the eighth magnetor R8 form the third half-bridge, and the sixth magnetor R6 and the seventh magnetor R7 form the fourth half-bridge.

[0074] In the comparative magnetoresistive elements, the corresponding magnetoresistances in the same bridge branch have an angular offset of 180°, and the magnetoresistances opposite each other in the same bridge branch have an angular offset of 180°-β. Specifically, β is 60° in the first comparative magnetoresistive element and 36° in the second comparative magnetoresistive element.

[0075] When only the fundamental frequency and the third harmonic exist, the output signal V of the first half-bridge is... cos+ conform to: V cos+ =A1cos(θ-α)+ A3cos[3(θ-α)], Where A1 is the amplitude of the fundamental wave, A3 is the amplitude of the third harmonic; α is the preferred magnetic sensing direction of the first magnetoresistive R1, and θ is the angular orientation; The output signal V of the second half-bridge cos- conform to: V cos- =A1cos(θ-180°-β+α)+ A3cos[3(θ-180°-β+α)]; The output signal V of the third half-bridge sin+ conform to: V sin+ =A1cos(θ-90°-α)+ A3cos[3(θ-90°-α)]; The output signal V of the fourth half-bridge sin- conform to: V sin- =A1cos(θ-β-α+90°)+ A3cos[3(θ-β-α+90°)]; and then, The cosine differential signal V of the first cosine Wheatstone bridge 210 cosdiff That is, V cos+ With V cos- The difference conforms to: V cosdiff =2A1cos(θ- cos(α- )+2A3cos(3θ- cos(3α- ); The sinusoidal differential signal V of the first sinusoidal Wheatstone bridge 220 sindiff That is, V sin+ With V sin- The difference conforms to: V sindiff =2A1sin(θ-α- cos( )-2A3sin(3θ-3α- cos( ); Therefore, in cos(3α- ) and cos( When both are 0 (e.g., α=60°, β=60°), the third harmonic component in the output signal of both Wheatstone bridges can be eliminated simultaneously.

[0076] When α = 60°, β = 60° V cosdiff = A1cos(θ-30°); V sindiff = A1cosθ; and then, .

[0077] Therefore, when α=60° and β=60°, the output signals of these two Wheatstone bridges can eliminate the third harmonic, and they cannot be directly passed through. Simply obtaining angular orientation requires processing through a certain algorithm.

[0078] When only the fundamental frequency and the 5th harmonic exist, the output signal V of the first half-bridge is... cos+ conform to: V cos+ =A1cos(θ-α)+ A5cos[5(θ-α)], Where A1 is the amplitude of the fundamental wave, A5 is the amplitude of the 5th harmonic; α is the preferred magnetic sensing direction of the first magnetoresistive R1, and θ is the angular orientation; The output signal V of the second half-bridge cos- conform to: V cos- =A1cos(θ-180°-β+α)+A5cos[5(θ-180°-β+α)]; The output signal V of the third half-bridge sin+ conform to: V sin+ =A1cos(θ-90°-α)+A5cos[5(θ-90°-α)]; The output signal V of the fourth half-bridge sin- conform to: V sin- =A1cos(θ-β-α+90°)+A5cos[5(θ-β-α+90°)]; Furthermore, the cosine differential signal V of the first cosine Wheatstone bridge 210 cosdiff That is, V cos+ With V cos- The difference conforms to: V cosdiff =2A1cos(θ- cos(α- )+2A5cos(5θ- cos(5α- ); The differential signal V of the first sinusoidal Wheatstone bridge 220sindiff That is, V sin+ With V sin- The difference conforms to: V sindiff =2A1sin(θ-α- cos( )+2A5sin(5θ-5α- cos( ); Therefore, in cos(5α- ) and cos( When both are 0 (e.g., α=36°, β=36°), the 5th harmonic component in the output signal of both Wheatstone bridges can be eliminated simultaneously.

[0079] When α=36°, β=36° V cosdiff =2A1cos(θ-18°)cos(18°); V sindiff =2A1sin(θ-54°)cos(18°); and then, .

[0080] Therefore, when α=36° and β=36°, the output signals of these two Wheatstone bridges can eliminate the 5th harmonic component, which cannot be directly passed through... Simply obtaining angular orientation requires processing through a certain algorithm.

[0081] Therefore, compared with the comparative magnetoresistive element, the magnetoresistive element of the present invention can effectively eliminate odd harmonics, reduce measurement errors, and has the beneficial effect of being easy to implement when used for angle measurement.

[0082] The following demonstrates the simulation effect of the magnetoresistive element used for angle measurement in the embodiments of the present invention.

[0083] Figure 7 This is a schematic diagram of the third comparative magnetoresistive element. The third comparative magnetoresistive element differs from the magnetoresistive element in the first embodiment only in that: the preferred magnetic susceptibility directions of the first magnetoresistive R1, second magnetoresistive R2, third magnetoresistive R3, and fourth magnetoresistive R4, sequentially coupled in the first cosine Wheatstone bridge 210, are 0°, 180°, 180°, and 0°, respectively; and the preferred magnetic susceptibility directions of the fifth magnetoresistive R5, sixth magnetoresistive R6, seventh magnetoresistive R7, and eighth magnetoresistive R8, sequentially coupled in the second sine Wheatstone bridge 220, are 90°, 270°, 270°, and 90°, respectively.

[0084] Angle measurement simulations were performed by placing the third comparative magnetoresistive element, the magnetoresistive element of the first embodiment, the magnetoresistive element of the second embodiment, and the magnetoresistive element of the third embodiment in an environment where fundamental, third, fifth, seventh, and ninth harmonics coexisted. The simulation results are as follows. Figure 5-6 As shown in the figure, the curve corresponding to 120° is the simulation curve of the angle error of the magnetoresistive element in the first embodiment, the curve corresponding to 180° is the simulation curve of the angle error of the magnetoresistive element in the third comparative embodiment, the curve corresponding to 72° is the simulation curve of the angle error of the magnetoresistive element in the third embodiment, and the curve corresponding to 144° is the simulation curve of the angle error of the magnetoresistive element in the second embodiment.

[0085] Based on simulation results, the output signal of the third parallel-mode magnetoresistive element contains a 3rd harmonic residual error of 1.3922 × 10⁻² (i.e., the ratio of the residual amplitude of the 3rd harmonic to the fundamental amplitude) and a 1.7697 × 10⁻² error. ⁻3 The residual error of the 5th harmonic (i.e., the ratio of the residual amplitude of the 5th harmonic to the amplitude of the fundamental wave) is 7.5792 × 10⁻⁶. ⁻5 The 7th harmonic residual error (i.e., the ratio of the residual amplitude of the 7th harmonic to the fundamental amplitude); the output signal of the magnetoresistive element in the first embodiment of the invention contains only 1.6170 × 10⁻⁶. ⁻8 The third harmonic and 1.7697×10 ⁻3 The 5th harmonic, 7.5815 × 10 ⁻5 The 7th harmonic; in the second embodiment of the invention, the output signal of the magnetoresistive element contains only 3.1285 × 10⁻ 8 The 5th harmonic, and 8.6042×10⁻ 3 The third harmonic, 4.6847 × 10 ⁻5 The 7th harmonic; in the third embodiment of the invention, the output signal of the magnetoresistive element contains only 3.1285 × 10⁻⁶. ⁻8 The 5th harmonic, and 8.6042 × 10 ⁻3 The third harmonic, 4.6847 × 10⁻ 5 The 7th harmonic indicates that the magnetoresistive element in the first embodiment can effectively eliminate the 3rd harmonic, and the magnetoresistive elements in the second and third embodiments can effectively eliminate the 5th harmonic.

[0086] Based on simulation results, the angle information output by the third comparative magnetoresistive element exhibits a peak angle error of 0.6958° and a root mean square error of 0.4924°; the angle information output by the magnetoresistive element in the first embodiment exhibits a peak angle error of 0.1017° and a root mean square error of 0.0718°; the angle information output by the magnetoresistive element in the second embodiment exhibits a peak angle error of 0.4924° and a root mean square error of 0.3486°; and the angle information output by the magnetoresistive element in the third embodiment exhibits a peak angle error of 1.2903° and a root mean square error of 0.9126°. This demonstrates that the magnetoresistive elements in the first and second embodiments of the invention have lower angle errors when used for angle measurement.

[0087] In summary, the magnetoresistive element of the present invention has the following advantages compared with the prior art: The magnetoresistive element of this invention includes a substrate; a first cosine Wheatstone bridge formed on the substrate, comprising a first magnetoresistive element, a second magnetoresistive element, a third magnetoresistive element, and a fourth magnetoresistive element, sequentially coupled with preferred magnetic susceptibility directions of α, 180°-α, 360°-α, and 180°+α, respectively; the first and second magnetoresistive elements are connected to a voltage source Vcc, and the third and fourth magnetoresistive elements are grounded; and a first sine Wheatstone bridge formed on the substrate, comprising a fifth magnetoresistive element, a sixth magnetoresistive element, a seventh magnetoresistive element, and an eighth magnetoresistive element, sequentially coupled with preferred magnetic susceptibility directions of 90°+α, 270°-α, 90°-α, and 270°+α, respectively. The fifth and sixth magnetoresistive elements are connected to the voltage source Vcc, and the seventh and eighth magnetoresistive elements are grounded, cosα≠0 and cos(nα)=0, where n is an odd number greater than 1. The magnetoresistive element of this invention, when used for angle measurement, can effectively eliminate odd harmonics, reduce measurement errors, and has the beneficial effect of being easily implemented.

[0088] Figure 4 This is a schematic diagram of the structure of the magnetoresistive element in the fourth embodiment of the invention.

[0089] like Figure 4 As shown, the magnetoresistive element of the fourth embodiment of the invention includes: a substrate 100 and a first cosine Wheatstone bridge 210, a first sine Wheatstone bridge 220, a second cosine Wheatstone bridge 230, and a second sine Wheatstone bridge 240 formed on the substrate 100.

[0090] The first cosine Wheatstone bridge 210 includes a first magnetoresistive resistor R1, a second magnetoresistive resistor R2, a third magnetoresistive resistor R3, and a fourth magnetoresistive resistor R4 coupled in sequence, with their preferred magnetic susceptibility directions being 30°, 150°, 330°, and 210°, respectively. The first magnetoresistive resistor R1, the second magnetoresistive resistor R2, the third magnetoresistive resistor R3, and the fourth magnetoresistive resistor R4 are TMRs disposed on a substrate. The first magnetoresistive resistor R1 and the second magnetoresistive resistor R2 are connected to a voltage source Vcc, and the third magnetoresistive resistor R3 and the fourth magnetoresistive resistor R4 are grounded to GND. The first magnetoresistive resistor R1 and the fourth magnetoresistive resistor R4 form the first half-bridge, and the second magnetoresistive resistor R2 and the third magnetoresistive resistor R3 form the second half-bridge. The output signal of the first half-bridge is V. 1cos+ The output signal of the second half-bridge is V. 1cos- Furthermore, the cosine differential signal V of the first cosine Wheatstone bridge 210... 1cosdiff For V 1cos+ With V 1cos- The difference.

[0091] The first sinusoidal Wheatstone bridge 220 includes a fifth magnetoresistor R5, a sixth magnetoresistor R6, a seventh magnetoresistor R7, and an eighth magnetoresistor R8 coupled in sequence, with their preferred magnetic susceptibility directions being 120°, 240°, 60°, and 300°, respectively. The fifth magnetoresistor R5, the sixth magnetoresistor R6, the seventh magnetoresistor R7, and the eighth magnetoresistor R8 are TMRs disposed on a substrate. The fifth magnetoresistor R5 and the sixth magnetoresistor R6 are connected to a voltage source Vcc, and the seventh magnetoresistor R7 and the eighth magnetoresistor R8 are grounded to GND. The fifth magnetoresistor R5 and the eighth magnetoresistor R8 form the third half-bridge, and the sixth magnetoresistor R6 and the seventh magnetoresistor R7 form the fourth half-bridge. The output signal of the third half-bridge is V. 1sin+ The output signal of the fourth half-bridge is V. 1sin- Furthermore, the sinusoidal differential signal V of the first sinusoidal Wheatstone bridge 220... 1sindiff For V 1sin+ With V 1sin- The difference.

[0092] The second cosine Wheatstone bridge 230 includes a ninth magnetoresistive resistor R9 and a tenth magnetoresistive resistor R1, which are coupled in sequence. 10 Eleventh magnetoresistive R 11 12th magnetoresistive R 12 Furthermore, their preferred magnetic sensing directions are 18°, 162°, 342°, and 198°, respectively. The ninth magnetoresistive R9 and the tenth magnetoresistive R... 10 Eleventh magnetoresistive R 11 12th magnetoresistive R 12 The TMR is arranged on the substrate. Ninth magnetoresistive R9 and tenth magnetoresistive R... 10 Connected to voltage source Vcc, eleventh magnetoresistive R 11 and the twelfth magnetoresistive R 12 Ground GND, ninth magnetoresistive R9 and twelfth magnetoresistive R 12Forming the fifth half-bridge, the tenth magnetoresistive R 10 and the eleventh magnetoresistive R 11 This forms the sixth half-bridge, and the output signal of the fifth half-bridge is V. 2cos+ The output signal of the sixth half-bridge is V. 2cos- Furthermore, the cosine differential signal V of the second cosine Wheatstone bridge 230... 2cosdiff For V 2cos+ With V 2cos- The difference.

[0093] The second sinusoidal Wheatstone bridge 240 includes a thirteenth magnetoresistor R coupled in sequence. 13 Fourteenth magnetoresistive R 14 The fifteenth magnetoresistive R 15 The sixteenth magnetoresistive R 16 Furthermore, their preferred magnetic sensing directions are 108°, 252°, 72°, and 288°, respectively. The thirteenth magnetoresistive R... 13 and the fourteenth magnetoresistive R 14 Connected to voltage source Vcc, fifteenth magnetoresistive R 15 and the sixteenth magnetoresistive R 16 Ground (GND), thirteenth magnetoresistive resistor (R) 13 and the sixteenth magnetoresistive R 16 Forming the seventh half-bridge, the fourteenth magnetoresistive R 14 and the fifteenth magnetoresistive R 15 This forms the eighth half-bridge, with the output signal of the seventh half-bridge being V. 2sin+ The output signal of the eighth half-bridge is V. 2sin- Furthermore, the sinusoidal differential signal V of the second sinusoidal Wheatstone bridge 240... 2sindiff For V 2sin+ With V 2sin- The difference.

[0094] When the fundamental frequency, the third harmonic, and the fifth harmonic are present simultaneously, the output signal V of the first half-bridge is... 1cos+ conform to: V 1cos+ =A1cos(θ-30°)+ A3cos[3(θ-30°)]+ A5cos[5(θ-30°)], The output signal V of the second half-bridge 1cos- (conform to: V 1cos- =A1cos(θ-150°)+ A3cos[3(θ-150°)] +A5cos[5(θ-180°+30°)]; The output signal V of the third half-bridge 1sin+ conform to: V 1sin+=A1cos(θ-120°)+A3cos[3(θ-120°)]+ A5cos[5(θ-120°)]; The output signal V of the fourth half-bridge 1sin- conform to: V 1sin- =A1cos(θ-240°)+A3cos[3(θ-240°)]+ A5cos[5(θ-240°)]; The output signal V of the fifth half-bridge 2cos+ conform to: V 2cos+ =A1cos(θ-18°)+A3cos[3(θ-18°)]+ A5cos[5(θ-18°)], The output signal V of the sixth half-bridge 2cos- conform to: V 2cos- =A1cos(θ-162°)+A3cos[3(θ-162°)] +A5cos[5(θ-162°)]; The output signal V of the seventh half-bridge 2sin+ conform to: V 2sin+ =A1cos(θ-108°)+A3cos[3(θ-108°)]+ A5cos[5(θ-108°)]; The output signal V of the eighth half-bridge 2sin- conform to: V 2sin- =A1cos(θ-252°)+A3cos[3(θ-252°)]+A5cos[5(θ-252°)]; Furthermore, the cosine differential signal V of the first cosine Wheatstone bridge 210 1cosdiff That is, V 1cos+ With V 1cos- The difference conforms to: ; The sinusoidal differential signal V of the first sinusoidal Wheatstone bridge 220 1sindiff That is, V 1sin+ With V 1sin- The difference conforms to: ; The cosine differential signal V of the second cosine Wheatstone bridge 230 2cosdiff That is, V 2cos+ With V 2cos- The difference conforms to: ; The sinusoidal differential signal V of the second sinusoidal Wheatstone bridge 2402sindiff That is, V 2sin+ With V 2sin- The difference conforms to: ; When the fundamental frequency, the third harmonic, and the fifth harmonic are present simultaneously, the differential signals of the first sine Wheatstone bridge and the first cosine Wheatstone bridge can eliminate the influence of the third harmonic, and the differential signals of the second sine Wheatstone bridge and the second cosine Wheatstone bridge can eliminate the influence of the fifth harmonic.

[0095] The first prediction angle can be obtained based on the sinusoidal differential signal of the first sine Wheatstone bridge and the cosine differential signal of the first cosine Wheatstone bridge. The first prediction angle... conform to: .

[0096] The second prediction angle can be obtained based on the sinusoidal differential signal of the second sine Wheatstone bridge and the cosine differential signal of the second cosine Wheatstone bridge. The second prediction angle... conform to: .

[0097] make , Angular orientation conform to: .

[0098] Therefore, when the fundamental wave, the third harmonic, and the fifth harmonic are present simultaneously, the magnetoresistive element of this embodiment can achieve a smaller angle measurement error.

[0099] The fifth embodiment of the invention is an angle sensor, which includes the aforementioned magnetoresistive element and a signal processing unit. The signal processing unit is electrically coupled to a first cosine Wheatstone bridge and a first sine Wheatstone bridge in the magnetoresistive element, respectively, and is used to determine the angular orientation of the magnetic field based on the differential signals of the first cosine Wheatstone bridge and the first sine Wheatstone bridge.

[0100] It should be understood that the signal processing unit can be an ASIC, DSP, or MCU integrated on the same chip, or it can be a physically separate but circuitically coupled processing chip.

[0101] The sixth embodiment of the invention is another angle sensor, which includes a magnetoresistive element and a signal processing unit as described in the fourth embodiment of the invention. The signal processing unit is electrically coupled to the first cosine Wheatstone bridge, the second cosine Wheatstone bridge, the first sine Wheatstone bridge, and the second sine Wheatstone bridge in the magnetoresistive element, respectively, and is used to determine the angular orientation of the magnetic field based on the differential signals of the first cosine Wheatstone bridge, the second cosine Wheatstone bridge, the first sine Wheatstone bridge, and the second sine Wheatstone bridge.

[0102] It should be understood that the signal processing unit can be an ASIC, DSP, or MCU integrated on the same chip, or it can be a physically separate but circuitically coupled processing chip.

[0103] The signal processing unit can obtain the harmonic components based on the differential signals of the first cosine Wheatstone bridge, the second cosine Wheatstone bridge, the first sine Wheatstone bridge, and the second sine Wheatstone bridge.

[0104] When the third harmonic is dominant, the signal processing unit can determine the angular orientation based on the quotient of the differential signals of the first sine Wheatstone bridge and the first cosine Wheatstone bridge.

[0105] When the fifth harmonic is dominant, the signal processing unit can determine the angular orientation based on the quotient of the differential signals of the second sine Wheatstone bridge and the second cosine Wheatstone bridge.

[0106] The signal processing unit includes a first determining unit, a second determining unit, and a third determining unit. The first determining unit is used to determine a first prediction angle 1 based on the quotient of the differential signals of the first sine Wheatstone bridge and the first cosine Wheatstone bridge; the second determining unit is used to determine a second prediction angle 2 based on the quotient of the differential signals of the second sine Wheatstone bridge and the second cosine Wheatstone bridge; the third determining unit is used based on the relationship between the first prediction angle 1, the second prediction angle 2, and the angle orientation. Determine angular orientation , where E1 and E2 are constants.

[0107] The seventh embodiment of the invention is an electronic device that includes the aforementioned magnetoresistive element or angle sensor. This electronic device can perform angle measurement based on the magnetoresistive element or angle sensor.

[0108] The specific structure of the magnetoresistive element and the angle sensor will not be described in detail here.

[0109] The above are merely exemplary embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of this specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A magnetoresistive element for angle measurement, characterized in that, include: Substrate; A first cosine Wheatstone bridge formed on the substrate includes a first magnetoresistive element, a second magnetoresistive element, a third magnetoresistive element, and a fourth magnetoresistive element, sequentially coupled with preferred magnetic susceptibility directions of α, 180°-α, 360°-α, and 180°+α, respectively. The first and second magnetoresistive elements are connected to a voltage source, and the third and fourth magnetoresistive elements are grounded. Wherein, cosα ≠ 0, cos(nα) = 0, and n is an odd number greater than 1. The first sinusoidal Wheatstone bridge formed on the substrate includes a fifth magnetoresistive, a sixth magnetoresistive, a seventh magnetoresistive, and an eighth magnetoresistive, which are sequentially coupled and have preferred magnetic susceptibility directions of 90°+α, 270°-α, 90°-α, and 270°+α, respectively; the fifth and sixth magnetoresistives are connected to a voltage source, and the seventh and eighth magnetoresistives are grounded.

2. The magnetoresistive element according to claim 1, characterized in that, The resistance characteristics of each arm in the first cosine Wheatstone bridge and the first sine Wheatstone bridge are basically the same in terms of amplitude.

3. The magnetoresistive element according to claim 2, characterized in that, Each bridge arm is an AMR, GMR, or TMR arranged on the substrate.

4. The magnetoresistive element according to claim 3, characterized in that, When each bridge arm is an AMR arranged on the substrate, the preferred magnetic sensing direction of each bridge arm is its extension direction; and, When each bridge arm is a GMR or TMR arranged on the substrate, the preferred magnetic sensing direction of each bridge arm is the reference magnetization direction of its reference layer.

5. The magnetoresistive element according to claim 1, characterized in that, When used to eliminate the third harmonic, α is 30°, 150°, 210° or 330°; When used to eliminate the 5th harmonic, α is 18°, 54°, 126°, 162°, 198°, 234°, 306°, or 342°.

6. The magnetoresistive element according to any one of claims 1-5, characterized in that, Also includes: A second cosine Wheatstone bridge formed on the substrate includes a ninth, tenth, eleventh, and twelfth magnetoresistive resistors sequentially coupled with preferred magnetic susceptibility directions of β, 180°-β, 360°-β, and 180°+β, respectively. The ninth and tenth magnetoresistive resistors are connected to a voltage source, and the eleventh and twelfth magnetoresistive resistors are grounded. Wherein, cosβ ≠ 0, cos(nβ) = 0, and n is an odd number greater than 1. The second sinusoidal Wheatstone bridge formed on the substrate includes a thirteenth magnetoresistive, a fourteenth magnetoresistive, a fifteenth magnetoresistive, and a sixteenth magnetoresistive, which are sequentially coupled and have preferred magnetic susceptibility directions of 90°+β, 270°-β, 90°-β, and 270°+β, respectively. The thirteenth and fourteenth magnetoresistives are connected to a voltage source, and the fifteenth and sixteenth magnetoresistives are grounded.

7. The magnetoresistive element according to claim 6, characterized in that, α can be 30°, 150°, 210°, or 330°. β can be 18°, 54°, 126°, 162°, 198°, 234°, 306° or 342°.

8. An angle sensor, characterized in that, The angle sensor includes the magnetoresistive element as described in any one of claims 1-5; The angle sensor further includes a signal processing unit; the signal processing unit is electrically coupled to the first cosine Wheatstone bridge and the first sine Wheatstone bridge respectively, and is used to determine the angular orientation of the magnetic field based on the differential signals of the first cosine Wheatstone bridge and the first sine Wheatstone bridge.

9. An angle sensor, characterized in that, The angle sensor includes the magnetoresistive element as described in any one of claims 6-7; The angle sensor further includes a signal processing unit; the signal processing unit is electrically coupled to the first cosine Wheatstone bridge, the second cosine Wheatstone bridge, the first sine Wheatstone bridge, and the second sine Wheatstone bridge, respectively, and is used to determine the angular orientation of the magnetic field based on the differential signals of the first cosine Wheatstone bridge, the second cosine Wheatstone bridge, the first sine Wheatstone bridge, and the second sine Wheatstone bridge.

10. An electronic device, characterized in that, It includes the magnetoresistive element according to any one of claims 1-7 or the angle sensor according to any one of claims 8-9.

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