Abstract: A magnetoresistive audio pickup comprises an audio detection circuit. The audio detection circuit comprises at least one linear magnetoresistive sensor, a coupling capacitance, an AC amplifier, and a signal processing circuit comprising an additional amplifier. The linear magnetoresistive sensor comprises at least one single-axis linear magnetoresistive sensor unit. The linear magnetoresistive sensors are placed in a measurement plane above a speaker's voice coil, the signal output end of each single-axis linear magnetoresistive sensor unit is capacitively coupled to the AC amplifier which provides AC signals through electrical connection to the amplifier, these signals are combined within the signal processing unit into an audio signal, and the audio signal is output from the circuit; each single-axis linear sensor unit is located in the linear response area of the measurement plane.

Abstract: A dual Z-axis magnetoresistive angle sensor comprising a circular permanent magnet encoding disc, two Z-axis magnetoresistive senor chips, and a PCB, two Z-axis magnetoresistive sensors are placed on the PCB. The magnetic sensing directions of the Z-axis magnetoresistive sensors are orthogonal to the substrate. Each Z-axis magnetoresistive sensor chip comprises a substrate and at least one magnetoresistive sensor located on the substrate. The magnetic field sensitive direction of the magnetoresistive sensor is perpendicular to the substrate. The magnetoresistive sensor comprises a flux concentrator and a magnetoresistive sensor unit. The magnetoresistive sensor unit is connected electrically into a push-pull structure. The push arm and pull arm of the magnetoresistive sensor are respectively located at two side positions equidistant from Y-axis central line and above or below the flux concentrator. The circular permanent magnet encoding disc has a magnetization direction parallel to the diameter direction.

Abstract: A three-axis digital compass comprising two X-axis magnetic sensors, two Y-axis magnetic sensors, a flux concentrator, a signal sampling unit, a signal processing unit, and a signal output unit is disclosed. The X-axis and Y-axis magnetic sensors are arranged along a periphery of the flux concentrator. An external magnetic field is distorted when passing through the flux concentrator. An Z axis component of the external magnetic field is converted into X-axis or Y-axis magnetic field components when passing through the flux concentrator, and the so converted components of the external magnetic field act on the X-axis and Y-axis magnetic sensitive sensors. An output signal of the X-axis and Y-axis magnetic sensitive sensors is sent to the signal processing unit through the signal sampling unit, and it is used to calculate the three orthogonal components of the external magnetic field. These calculated external magnetic field components are output in a digital format through the signal output unit.

Abstract: A single-chip off-axis magnetoresistive Z-X angle sensor and measuring instrument. The single-chip off-axis magnetoresistive Z-X angle sensor comprises a substrate located on an X-Y plane, at least one X-axis magnetoresistive sensor and at least one Z-axis magnetoresistive sensor, the X-axis magnetoresistive sensor and the Z-axis magnetoresistive sensor being located on the substrate. The X-axis magnetoresistive sensor and the Z-axis magnetoresistive sensor each comprise magnetoresistive sensing units and a flux concentrator, the magnetoresistive sensing units being electrically connected into a magnetoresistive bridge comprising at least two bridge arms. The Z-axis magnetoresistive sensor is a push-pull bridge structure, a push arm and a pull arm of the push-pull bridge structure being respectively located at positions equidistant from a Y-axis central line of the flux concentrator.

Abstract: A magnetoresistive mixer, comprising a spiral coil, a bridge-type magnetoresistive sensor and a magnetic shielding layer, wherein the spiral coil is located between the bridge-type magnetoresistive sensor and the magnetic shielding layer. Four tunnel magnetoresistive sensor units forming the bridge-type magnetoresistive sensor respectively contain N array-type magnetic tunnel junction rows. The magnetic tunnel junction rows are connected in series, parallel, or combination of series and parallel connections to form two port structures.

Abstract: A magnetoresistive current limiter, comprising a substrate, a magnetoresistive sensor layer, a first insulating layer, a coil, a second insulating layer, a magnetic shield layer, and an input electrode and output electrode. The coil is located between the magnetic shield layer and the magnetoresistive sensor layer. The first and second insulating layers are isolated from the magnetoresistive sensor layer and the coil, and from the coil and the magnetic shield layer, respectively; the magnetoresistive sensor layer and the coil are connected in series, and are connected to the input electrode and the output electrode.

Abstract: Disclosed are a magnetic bar code chip and a reading method thereof. The magnetic bar code chip comprises binary information bits formed by N rows and M columns of permanent magnet bars and/or null bits, and information identification bits that are peripheral to the binary information bits. The information identification bits are composed of permanent magnet bar identifiers and used for representing a position and a state of the magnetic bar code chip. The permanent magnet bars and the null bits represent 1 and 0 or 0 and 1 respectively.

Abstract: Provided are a single-chip differential free layer push-pull magnetic field sensor bridge and preparation method, the magnetic field sensor bridge comprising: a substrate, a staggered soft magnetic flux concentrator array, and a GMR spin valve or a TMR magnetoresistance sensing unit array having a magnetic sensing axis in an X-direction on the substrate. A soft magnetic flux concentrator comprises sides parallel to an X-axis and a Y-axis, and four corners sequentially labeled as A, B, C and D clockwise from an upper left position. Magnetoresistive sensing units are located at gaps between the soft magnetic flux concentrators. Additionally, the magnetoresistive sensing units corresponding to the A and C corner positions and B and D corner positions of the soft flux concentrators are defined as push magnetoresistive sensing units and pull magnetoresistive sensing units respectively.

Abstract: The present invention relates to a permanent magnet suitable for a magnetic angle encoder. The permanent magnet has an annular cylindrical structure and comprises a first permanent magnet unit and a second permanent magnet unit. The first permanent magnet unit and the second permanent magnet unit are geometrically symmetrical with respect to a diametral cross section. The magnetization intensity of the first permanent magnet unit and the magnetization intensity of the second permanent magnet unit are parallel to the axial direction of the annular cylinder and are in opposite directions, or the magnetization intensity of the first permanent magnet unit and the magnetization intensity of the second permanent magnet unit are perpendicular to the diametral cross section and are parallel to one another and in the same direction.

Abstract: A magnetoresistive Z-axis gradient sensor chip, which is used to detect the gradient in the XY plane of a Z-axis magnetic field component generated by a magnetic medium; the sensor chip comprises a Si substrate, a collection of two or two groups of flux guide devices separated a distance Lg and an arrangement of electrically interconnected magnetoresistive sensor units. The magnetoresistive sensor units are located on the Si substrate and located above or below the edge of the flux guide devices as well; the flux guide devices convert the component of the Z-axis magnetic field into the direction parallel to the surface of the Si substrate along the sensing axis direction of the magnetoresistive sensing units. The magnetoresistive sensor units are electrically interconnected into a half bridge or a full bridge gradiometer arrangement, wherein the opposite bridge arms are separated by distance Lg. This sensor chip can be utilized with a PCB or in combination with a PCB plus back-bias magnet with casing.

Abstract: Disclosed is a low fly height in-plane magnetic image sensor chip. This sensor chip comprises a Si substrate with a pit on the surface, a magnetoresistive sensor, and an insulating layer. The magnetoresistive sensor is located on the bottom surface of the pit in the Si substrate. The insulating layer is located above the magnetoresistive sensor. The magnetic image surface detected during operation is coplaner or parallel with the surface of the Si substrate surface. The input and output ends of the magnetoresistive sensor are connected with leads directly, or bonded with leads through pads, or through a conducting post and pads to form connections. And the flying height of the leads is lower than the height of the surface of the Si substrate. This technical solution has several advantages, such as compact structure, high output signal, and direct contact with the magnetic image.

Abstract: A magnetic angle encoder comprising counting wheels, with columnar ring-shaped permanent magnets coaxially mounted to the counting wheels, tunneling magnetoresistive angular displacement sensors, and a digital processing circuit. In the magnetic angle encoder, the tunneling magnetoresistive angular displacement sensors are located in a region within detection planes of the permanent magnets with an axial distance and a specific radial distance from the permanent magnets. Within this specific radius range, the rotating magnetic field angle (?) of the component of the magnetic field generated by the permanent magnets in the detection planes varies linearly with the rotation phase angle (?) of the permanent magnets. An electronic water meter is also disclosed, and it comprises a plurality of counting units and a digital processing circuit. The counting units contain counting wheels, permanent magnets, and tunneling magnetoresistive angular displacement sensors.

Abstract: Disclosed are a magnetic bar code chip and a reading method thereof. The magnetic bar code chip comprises binary information bits formed by N rows and M columns of permanent magnet bars and/or null bits, and information identification bits that are peripheral to the binary information bits. The information identification bits are composed of permanent magnet bar identifiers and used for representing a position and a state of the magnetic bar code chip. The permanent magnet bars and the null bits represent 1 and 0 or 0 and 1 respectively.

Abstract: A multi-turn absolute magnetic encoder, comprising (M+1) counting units, a single-turn signal processing unit, and a multi-turn signal processing unit. Each counting unit comprises counting wheels with a cylindrical ring permanent magnet fixed thereon, and a tunneling magnetoresistive angular displacement sensor. The magnetoresistive angular displacement sensor is located within a region in a detection plane of the permanent magnet at within a specific radius range from the axis of the cylindrical ring permanent magnet, within the detection plane the angle of a component of a magnetic field generated by the permanent magnet is linearly proportional to the rotation angle of the cylindrical ring permanent magnet.

Abstract: A magnetoresistive mixer, comprising a spiral coil, a bridge-type magnetoresistive sensor and a magnetic shielding layer, wherein the spiral coil is located between the bridge-type magnetoresistive sensor and the magnetic shielding layer. Four tunnel magnetoresistive sensor units forming the bridge-type magnetoresistive sensor respectively contain N array-type magnetic tunnel junction rows. The magnetic tunnel junction rows are connected in series, parallel, or combination of series and parallel connections to form two port structures.

Abstract: A magnetoresistive current limiter, comprising a substrate, a magnetoresistive sensor layer, a first insulating layer, a coil, a second insulating layer, a magnetic shield layer, and an input electrode and output electrode. The coil is located between the magnetic shield layer and the magnetoresistive sensor layer. The first and second insulating layers are isolated from the magnetoresistive sensor layer and the coil, and from the coil and the magnetic shield layer, respectively; the magnetoresistive sensor layer and the coil are connected in series, and are connected to the input electrode and the output electrode.

Abstract: A three-axis digital compass comprising two X-axis magnetic sensors, two Y-axis magnetic sensors, a flux concentrator, a signal sampling unit, a signal processing unit, and a signal output unit is disclosed. The X-axis and Y-axis magnetic sensors are arranged along a periphery of the flux concentrator. An external magnetic field is distorted when passing through the flux concentrator. An Z axis component of the external magnetic field is converted into X-axis or Y-axis magnetic field components when passing through the flux concentrator, and the so converted components of the external magnetic field act on the X-axis and Y-axis magnetic sensitive sensors. An output signal of the X-axis and Y-axis magnetic sensitive sensors is sent to the signal processing unit through the signal sampling unit, and it is used to calculate the three orthogonal components of the external magnetic field. These calculated external magnetic field components are output in a digital format through the signal output unit.

Abstract: A multi-turn absolute magnetic encoder, comprising (M+1) counting units, a single-turn signal processing unit, and a multi-turn signal processing unit. Each counting unit comprises counting wheels with a cylindrical ring permanent magnet fixed thereon, and a tunneling magnetoresistive angular displacement sensor. The magnetoresistive angular displacement sensor is located within a region in a detection plane of the permanent magnet at within a specific radius range from the axis of the cylindrical ring permanent magnet, within the detection plane the angle of a component of a magnetic field generated by the permanent magnet is linearly proportional to the rotation angle of the cylindrical ring permanent magnet.

Abstract: A magnetic angle encoder comprising counting wheels, with columnar ring-shaped permanent magnets coaxially mounted to the counting wheels, tunneling magnetoresistive angular displacement sensors, and a digital processing circuit. In the magnetic angle encoder, the tunneling magnetoresistive angular displacement sensors are located in a region within detection planes of the permanent magnets with an axial distance and a specific radial distance from the permanent magnets. Within this specific radius range, the rotating magnetic field angle (?) of the component of the magnetic field generated by the permanent magnets in the detection planes varies linearly with the rotation phase angle (?) of the permanent magnets. An electronic water meter is also disclosed, and it comprises a plurality of counting units and a digital processing circuit. The counting units contain counting wheels, permanent magnets, and tunneling magnetoresistive angular displacement sensors.

Abstract: The present invention relates to a permanent magnet suitable for a magnetic angle encoder. The permanent magnet has an annular cylindrical structure and comprises a first permanent magnet unit and a second permanent magnet unit. The first permanent magnet unit and the second permanent magnet unit are geometrically symmetrical with respect to a diametral cross section. The magnetisation intensity of the first permanent magnet unit and the magnetisation intensity of the second permanent magnet unit are parallel to the axial direction of the annular cylinder and are in opposite directions, or the magnetisation intensity of the first permanent magnet unit and the magnetisation intensity of the second permanent magnet unit are perpendicular to the diametral cross section and are parallel to one another and in the same direction.