Abstract: A printed circuit board integrated with a two-axis fluxgate sensor includes a first soft magnetic core formed lengthwise in a first axial direction, a first excitation coil formed of a metal film and wound around the first soft magnetic core, a first pick-up coil formed of a metal film and wound around the first soft magnetic core and the first excitation coil, a second soft magnetic core formed lengthwise in a second axial direction, the second axial direction being perpendicular to the first axial direction, a second excitation coil formed of a metal film and wound around the second soft magnetic core, a second pick-up coil formed of a metal film and wound around the second soft magnetic core and the second excitation coil, and a pad for establishing conductivity between the first and second excitation coils and the first and second pick-up coils and an external circuit.

Abstract: A magnetic element in a flat-plate shape includes a linearly-extending first flat plate being made of one of a magnetic material and a conductive material and a helical second flat plate being made of the other of the magnetic material and the conductive material, and the first flat plate is inserted into the helical structure of the second flat plate so as to alternatively weave front and back surfaces of the second flat plate.

Abstract: Two coil forming elements (12, 14) formed of conductor layers and a contact means (19), which is formed in an interlayer dielectric film (13) interposed between the conductor layers and brings the upper and lower coil forming elements into contact with each other through a via hole form a stacked coil (10). One end of the stacked coil is connected to an upper grounding layer (27) of a strip line (20), and the other end of the stacked coil is connected to a strip conductor (23) of the strip line. The number of turns of the stacked coil is larger than 1. A magnetic flux penetrating through the stacked coil increases to be able to induce a relatively large electromotive force. Thus, a high spatial resolution can be obtained easily.

Abstract: What is described is a magnetoresistive sensor for operation with a magnetized encoder, which is equipped with a zone with magnetic north and south poles arranged alternately along a direction of motion, comprising a Wheatstone bridge configuration with a first bridge arm between a first supply terminal and a first signal output terminal of the Wheatstone bridge configuration, a second bridge arm between the first supply terminal and a second signal output terminal of the Wheatstone bridge configuration, a third bridge arm between a second supply terminal and the first signal output terminal of the Wheatstone bridge configuration, and a fourth bridge arm between the second supply terminal and the second signal output terminal of the Wheatstone bridge configuration, wherein each of the bridge arms comprises an ohmic resistance element with a resistance-value dependence on the magnetic field strength of a magnetic field influencing the ohmic resistance element in accordance with a defined characteristic.

Abstract: Described herein is a magnetoresistive network responsive to a magnetic field of the type comprising a plurality of magnetoresistive elements. According to the invention, the one or more magnetoresistive elements comprise at least one magnetoresistive element in the form of nanoconstriction, the nanoconstriction comprising at least two pads made of magnetic material, associated to which are respective magnetizations oriented in directions substantially opposite to one another and connected through a nanochannel, the nanochannel being able to set up a domain wall that determines an electrical resistance of the nanoconstriction as a function of the position, with respect to said nanochannel, of said domain wall formed in said sensor device.

Abstract: A Printed Circuit Board (PCB) having a weak magnetic field sensor of the present invention includes a base plate on which a first excitation circuit and a first detection circuit are formed on each of the sides thereof, soft magnetic core bodies laminated on the top and bottom of the base plate, respectively, and formed of a plurality of soft magnetic cores, and outer layers that are laminated on the soft magnetic core bodies, respectively, and on which a second excitation circuit and a second detection circuit connected to the first excitation circuit and the first detection circuit through via holes are formed so as to surround the soft magnetic cores, respectively. The present invention is characterized in that the soft magnetic cores, the excitation circuit and the detection circuit formed on one side of the base plate are perpendicular to the soft magnetic cores, the excitation circuit and the detection circuit formed on the other side of the base plate.

Abstract: In a magnetic detection device for obtaining an output from between a variable resistance element using the magnetoresistance effect and a reference resistance element, a balance between resistance values in the device can be easily adjusted in a wide range. A voltage is applied to a resistance adjusting unit, a reference resistance element, and a variable resistance element, which are serially connected, and is also applied to another variable resistance element, another reference resistance element, and another resistance adjusting unit, which are serially connected. When subjected to a magnetic field of a predetermined size, resistance values of the variable resistance elements change, and as a result, the potentials of output terminals change. Each of the resistance adjusting units includes serially connected parallel portions each including a plurality of parallel connected resistance elements.

Abstract: An ultrasensitive room temperature magnetoelectric thin film magnetometer is fabricated on a cantilever beam and includes an active magnetoelectric multilayer structure having a plurality of thin films formed at a region defined on the cantilever beam. Upon application of a magnetic field, the active magnetoelectric structure generates a corresponding response of an electrical nature which is a measure of a value of the applied magnetic field. The material of the cantilever beam may be removed beneath the active magnetoelectric multilayer structure to form a freestanding modification of the magnetometer with superior sensitivity. The active magnetoelectric multilayer structure is either a bi-layer structure which includes a piezoactive (piezoelectric and/or piezoresistive) thin film deposited in contact with a magnetostrictive thin film or a tri-layer active structure (in the free-standing implementation) including a piezoactive thin film sandwiched between a pair of magnetostrictive thin films.

Abstract: The application provides a magnetic sensor which can suppress an irregularity of a central potential due to a change in a temperature, decrease size of the sensor, and lower the manufacturing cost of the sensor. A magneto-resistive element and fixed resister are provided on an element base and have the same configuration elements. A second magnetic layer and non-magnetic layer in the fixed resistor are reversely laminated on each other in a manner different from the magneto-resistive element, and the second magnetic layer is formed in contact with the first magnetic layer, thereby fixing the magnetization directions of the first magnetic layer and the second magnetic layer in the same direction. In this manner, the irregularity of the temperature coefficient between the magneto-resistive element and the fixed resistor is suppressed, and the irregularity of the central potential due to the change in the temperature is suppressed.

Abstract: A GMR sensor element is proposed, having a rotationally symmetrical positioning of especially eight GMR resistor elements which are connected to each other to form two Wheatstone's full bridges. This GMR sensor element is especially suitable for use in an angle sensor for the detection of the absolute position of the camshaft or the crankshaft in a motor vehicle, particularly in the case of a camshaft-free engine having electrical or electrohydraulic valve timing, of a motor position of an electrically commutated motor, or of detection of a windshield wiper position, or in the steering angle sensor system in motor vehicles.

Abstract: A thin film sensing device operates based on a spin polarized current. The spin device includes ferromagnetic layers characterized by different coercivities and/or magnetization states, and one or more low transmission barriers in between. The device is further configured so that the spin polarized current flows at least in part in a direction perpendicular to the aforementioned layers.

Abstract: A three-dimensional magnetic bearing sensor 10a includes a first sensor 101, a second sensor 102, and a third sensor 103 each constituted by a magneto-impedance sensor element 10 comprising a magnetic sensitive member 2 having a characteristic changed responsive to an external magnetic field, an insulator 4 formed to allow penetration of the magnetic sensitive member 2 therethrough, and an electromagnetic coil 3 made up of foil-like conductive patterns 31, 32 arranged in adjacent relation on an outer surface of the insulator 4. The first sensor 101, the second sensor 102, and the third sensor 103 are disposed such that directions in which the magnetic sensitive members 2 in respective sensors have maximum magnetic field detection sensitivities are substantially orthogonal to each other.

Abstract: A device for detecting magnetic fields, of the type comprising at least one element made of hard 5 magnetic material (12) and an element made of soft magnetic material (13) associated an element made of semiconductor material (11), electrodes (15) for forcing a current (I) in the semiconductor material (11), characterised in that the element made of hard magnetic material (12) and element made of soft magnetic material (13) are positioned in planar fashion on the element made of semiconductor material (11).

Abstract: A magnetic-sensing apparatus and methods of making and using thereof are disclosed. The sensing apparatus may have one or more magneto-resistive-sensing elements, one ore more reorientation elements for adjusting the magneto-resistive-sensing elements, and semiconductor circuitry having driver circuitry for controlling the reorientation elements. The magneto-resistive-sensing elements, reorientation elements and semiconductor circuitry may be disposed in single package and/or monolithically formed on a single chip. Alternatively, some of the semiconductor circuitry may be monolithically formed on a first chip with the magneto-resistive-sensing elements, while a second portion of the semiconductor circuitry may be formed on a second chip. The first and second chips may be placed in close proximity and electrically connected together. Alternatively the chips may have no intentional electrical interaction.

Abstract: The present invention provides an integrated circuit and a method for noise removal in a magnetic nano-particle sensor device. The method of the present invention comprises the steps of sending a conductor current through a conductor to generate a first horizontal magnetic field component at the location of a magneto-resistive sensor. In a further step the optimal operation point of the magneto-resistive sensor is determined by minimizing the noise at the output of the magneto-resistive sensor by means of a noise optimization circuit. By applying an external magnetic field such that nano-particles in the vicinity of the sensor are vertically magnetized, a second horizontal magnetic field component is generated at the location of the sensor. Then, the conductor current is adjusted such that the first horizontal magnetic field component compensates for the second horizontal magnetic field component.

Abstract: A ferromagnetic thin-film based magnetic field detection system used for detecting the presence of selected molecular species. A magnetic field sensor supported on a substrate has a binding molecule layer positioned on a side thereof capable of selectively binding to the selected molecular species held on a magnetic particle. The magnetic field sensor can be substantially covered by an electrical insulating layer having a recess therein adjacent to the sensor in which the binding molecule layer is provided. A thin-film channel structure to the sensor is supported on the substrate that can be accompanied by a reservoir structure, and an electrical interconnection conductor is supported on the substrate at least in part between the sensor and the substrate, and is electrically connected to the sensor. The magnetic field sensor can be provided in a bridge circuit, and can be formed by a number of interconnected individual sensors.

Abstract: A magneto impedance sensor element with electromagnetic coil comprised of: a terminal board on which an extended groove which extends in one direction has been formed; an electromagnetic coil, made with one part of the coil formed in a spiral shape inside the extended groove in the terminal board, and joined to each tip of that coil the other part of the coil placed across the top of the groove; insulating material placed in the extended groove on the terminal board; and a magnetic sensitive body inserted within the insulating material, to which either high frequency or pulse electic current is applied. When either high frequency or pulse electrical current is applied to the magnetic sensitive body, voltage is output from the above electromagnetic coil in response to the intensity of the external magnetic field which is generated in the electromagnetic coil.

Abstract: A fluxgate sensor is integrated in a printed circuit board. The fluxgate sensor has two bar-type(or rectangular-ring shaped) soft magnetic cores to form a closed magnetic path on a printed circuit board and an excitation coil in the form of a metal film is wound around the two bar-type soft magnetic cores either in a united structure that winds the two bar-type soft magnetic cores altogether, or in a separated structure that winds the two bar-type soft magnetic cores respectively, both in a pattern of number ‘8’. A pick-up coil is mounted on the excitation coil, either winding the two bars altogether, or respectively, in a solenoid pattern. The fluxgate sensor integrated in the printed circuit board can be mass-produced at a cheap manufacturing cost. The fluxgate sensor also can be made compact-sized, and at the same time, is capable of forming a closed-magnetic path.

Abstract: In a fluxgate sensor integrated in a semiconductor substrate and a method for manufacturing the same, the fluxgate sensor includes a soft magnetic core formed on the semiconductor substrate, an excitation coil winding the soft magnetic core and being insulated by first and second insulating layers deposited above and below the soft magnetic core, respectively, and a pick-up coil, winding the soft magnetic core and being insulated by third and fourth insulating layers deposited above and below the excitation coil, respectively.

Abstract: A magnetic field sensor relies on variations in permeability of magnetic material to detect an external field. An exemplary magnetic field sensor includes a lengthwise extending sensing element, and a coil wound about the sensing element. The sensing element may be formed as a number of geometrically and magnetically similar or identical conductive cores that are ferromagnetic, driven by an AC magnetic field. The multiple conductive cores are connected in parallel. An external magnetic field changes the magnetic characteristics of the sensing element and induces a change in electric potential of the induction coil. The sensor output is proportional to the number of conductive cores.

Abstract: On a single chip are formed a plurality of magnetoresistance effect elements provided with pinned layers having fixed magnetization axes in the directions that cross each other. On a substrate 10 are formed magnetic layers that will become two magnetic tunnel effect elements 11, 21 as magnetoresistance effect elements. Magnetic-field-applying magnetic layers made of NiCo are formed to sandwich the magnetic layers in plan view. A magnetic field is applied to the magnetic-field-applying magnetic layers. The magnetic field is removed after the magnetic-field-applying magnetic layers are magnetized in the direction shown by arrow A.

Abstract: The present invention relates to an ultra sensitive in-situ magnetometer system, and more particularly to an ultra sensitive in-situ magnetometer system that can in-situ monitor a magnetic moment of a magnetic thin film with sub-monolayer precision while depositing and growing the magnetic thin film in an ultra high vacuum (UHV) chamber.

Abstract: A magnetic sensor assembly comprising magnetic detection elements is provided. In a magnetic sensor assembly 100 according to the present invention, a magnetic detection element 140 is fixed to a base member 110 and, by having the base member 110 stand upright, it is possible to stand the magnetic detection element 140 upright. Thereby, it becomes easy to manufacture magnetic detection devices which detect three-axis components of terrestrial magnetism vector. In the base member 110, first terminals 120 are provided on a first surface 112 whereas second terminals 124 are provided on a second surface 114. The first terminals 120 are electrically connected with electrodes of the magnetic detection element 140 whereas the second terminals 124 are electrically connected to external wires.

Abstract: In order to obtain a magneto-impedance type magnetic sensor having a soft magnetic film facing to a conductive nonmagnetic film, and available a large impedance change with a carrier signal at a relatively low frequency, the magnetic sensor comprises a meander type conductive nonmagnetic thin film of zigzag shape formed with at least one pair of electrode terminals at both ends and a soft magnetic film which is strip-shaped so as to face thereto at a plurality of regions and has an easy axis of magnetization in a width direction of the strip shape, a high frequency carrier signal is applied to the above-mentioned electrode terminals and further a direct current bias magnetic field is applied. By performing AM detection of an AM modulation signal output from the above-mentioned electrode terminals, an impedance change of the conductive nonmagnetic film which is changed by external magnetic field is detected as a change of the high frequency carrier signal, thereby the external magnetic field can be detected.

Abstract: Disclosed is a magnetic field sensor of high sensitivity, and which is power-saving and can be manufactured with low cost in a very small size. The magnetic field sensor includes a soft magnetic core formed to construct a closed-magnetic circuit on a semiconductor substrate, a magnetic field sensing coil formed by a metal film in a shape that winds the soft magnetic core, and a drive line for exciting the soft magnetic core by directly applying an electric current thereto. The drive line is formed in a rectangular angle to the magnetic field sensing coil, and connected to the both ends of the soft magnetic core in a length direction.

Abstract: An azimuth meter using spin-valve giant magneto-resistive elements, which is simple in manufacturing process, can be made compact in size and contribute to power saving, is disclosed. The azimuth meter comprises a quadrilateral plane coil having two pairs of parallel opposed sides and four spin-valve giant magneto-resistive element pairs, each pair of the elements disposed on a plane parallel to the coil. The longitudinal directions of two elements of each pair orthogonally cross each other, and cross only a respective side or only the same side of a pair of the opposed sides of the plane coil at substantially 45 degrees. The pinned layer of one of the two elements is magnetized in its longitudinal direction, and that of the other element is magnetized in the same direction as the pinned layer of that one element. The paired elements are connected to each other at one end.

Abstract: A magnetic sensing method and system include a die comprising a central location thereof. A group of magnetoresistive bridge circuits are located and configured upon the die. A magnetic biasing component is then utilized to bias the plurality of magnetoresistive bridge circuits with a magnetic field rotating about an axis of the central location of the die in order to generate a plurality of bridge output signals thereof. Finally, the plurality of bridge output signals are processed in order to determine position data thereof.

Abstract: Disclosed are a spin injection device applicable as a memory and a logical device using a spin valve effect obtained by injecting a carrier spin-polarized from a ferromagnet into a semiconductor at an ordinary temperature, and a spin-polarized field effect transistor.

Abstract: Disclosed is a magnetic field sensor of high sensitivity, and which is power-saving and can be manufactured with low cost in a very small size. The magnetic field sensor includes a soft magnetic core formed to construct a closed-magnetic circuit on a semiconductor substrate, a magnetic field sensing coil formed by a metal film in a shape that winds the soft magnetic core, and a drive line for exciting the soft magnetic core by directly applying an electric current thereto. The drive line is formed in a rectangular angle to the magnetic field sensing coil, and connected to the both ends of the soft magnetic core in a length direction.

Abstract: A sensor circuit includes a sensor element, a current source for supplying an operating current for the sensor element and an amplifier circuit for amplifying a sensor voltage produced by the sensor element when applying the operating current, wherein the amplifier circuit has a resistor influencing the amplification of it. The resistor of the amplifier current and the sensor element are formed equally as regards technology so that variations, due to technology, of the sensor sensitivity of the sensor element are counteracted by an amplification factor of the amplifier circuit changing in the opposite way.

Abstract: A magnetoelectric magnetic field sensor has one or more laminated magnetostrictive layers and piezoelectric layers. The magnetostrictive layers are magnetized by a bias magnetic field in a longitudinal, in-plane direction. The piezoelectric layers can be poled in the longitudinal direction or perpendicular direction. The longitudinal magnetization of the magnetostrictive layers provides greatly increased sensitivity at lower bias fields compared to other magnetoelectric sensors. Perpendicular poling of the piezoelectric layers tends to provide higher sensitivity at lower detection frequency (e.g. less than 1 Hz). Longitudinal poling tends to provide higher sensitivity at high detection frequency (e.g. above 10 Hz). Also included are embodiments having relative thicknesses for the magnetostrictive layers that are optimized for sensitivity. Equations are provided for calculating the best relative thickness for the magnetostrictive layer for maximum sensitivity.

Abstract: In a weak-magnetic field sensor a rectangular ring-shaped magnetic core is wound by exciting circuit patterns and detecting circuit patterns, and weak-magnetic field sensors are implemented in x-axis and y-axis directions, respectively, to precisely calculate azimuth, thereby sensing a weak-magnetic field having a strength similar to that of earth's magnetic field. The sensor includes a magnetic core having first and second cores connected in parallel to each other; exciting coils wound around the first and second cores, respectively, to supply alternating excitation current to the magnetic core; and a detecting coil alternately arranged together with the exciting coils on the same surfaces on which the exciting coils are formed, and wound around the first and second cores, in order to detect variation of magnetic fluxes generated in the magnetic core.

Abstract: A method of orienting the axis of magnetization of a first magnetic element with respect to a second magnetic element uses a first element and a second element lying on a substrate. Each of the elements has a magnetic layer with an axis of magnetization. The method includes depositing a pattern of flux-concentrating material close to the first element and subsequently orienting the axis of magnetization of the first element in an applied magnetic field. The semi-finished article for measuring a magnetic field includes a substrate, a first magnetic element, a second magnetic element, a third magnetic element and a fourth magnetic element on the substrate in a bridge configuration. A first bridge portion is provided wherein the first element and the second element are electrically connected in series. A second bridge portion is provided wherein the third element and the fourth element are electrically connected in series.

Abstract: The present invention is a magnetic field detection device that makes use of a frequency characteristic affording circuit in order to selectively detect magnetic signals from a frequency domain accurately at a high level of sensitivity. The present invention has a magneto-impedance element, a detector coil and a negative feedback coil which is wound around the magneto-impedance element, and a frequency characteristic affording circuit which affords a frequency characteristics on the negative feedback signal of a negative feedback connecting an output terminal thereof with the negative feedback coil. Using filters as the frequency characteristic affording circuit, the following are possible uses of this magnetic field detection device: a geomagnet detection device for earthquake prediction (using a high-pass filter), a bill validation apparatus for vending machines, etc. (using a low-pass filter), and a magnetic oscillation detection device for a magnetic gate system (using a band-reject filter).

Abstract: A magnetic field detection circuit comprises a magnetic impedance device, a detection coil wound around or arranged close to the impedance device, an electric current application circuit for applying a pulse-shaped high frequency electric current substantially equally swinging to the positive side and the negative side to the magnetic impedance device, and a detection circuit for detecting a voltage generated in the detection coil in response to rises and falls of the applied pulse-shaped electric current and outputting a signal corresponding to the intensity of the external magnetic field on the basis of the outcome of the detection. The magnetic field detection circuit can provide nil-point setting on a stable basis by means of a simple circuit arrangement at low cost.

Abstract: A magnetic detection element suitable for detecting a strength of an external magnetic field, has a magnetic thin film formed on a single non-magnetic substrate, a circuit that applies a high-frequency current to the magnetic thin film, and a spiral-type planar coil that is stacked on the magnetic thin film with an insulating layer, in between. The magnetic thin film is formed in a longitudinal shape, and magnetic anisotropy is provided such that the direction of easy magnetization is orthogonal to the longitudinal direction of the longitudinal shape.

Abstract: A magnetic field sensor relies on variations in permeability of magnetic material to detect an external field. An exemplary magnetic field sensor includes a magnetic material and two or more conductors, at least one of which is connected to an electrical energy source. Current flowing through at least one of the conductors establishes a magnetic field in die magnetic material at a magnitude at which there is a generally linear relationship between the magnetic field and the permeability of the material. An external field to be sensed influences the permeability of the material. Sensing variations in the permeability of the magnetic material allows the external magnetic field to be sensed.

Abstract: The present invention is a two-dimensional magnetic sensor having a first magneto-impedance sensor element including a first magneto-sensitive element and a first electro-magnetic coil which is wound around said first magneto-sensitive element; a second magneto-impedance sensor element including a second magneto-sensitive element and a second electro-magnetic coil which is wound around said second magneto-sensitive element; and an integrated circuit including an oscillator, a current switching element, a voltage detector, and an amplifier.

Abstract: A thin film magnetic sensor comprises a pair of thin film yokes each formed of a soft magnetic material, the thin film yokes being arranged to face each other with a gap interposed therebetween; a GMR film electrically connected to the pair of the thin film yokes and having an electrical resistivity higher than that of the soft magnetic material; and an insulating substrate supporting the thin film yokes and the GMR film and formed of an insulating nonmagnetic material. A gap column of a multilayer structure including a layer formed of an insulating nonmagnetic material and a layer of the GMR film is arranged within the gap, and the thickness of the GMR film is uniform over the gap length.

Abstract: A thin film magnetic sensor comprises a pair of first thin film yoke and second thin film yoke each formed of a soft magnetic material, the first and second thin film yokes being positioned to face each other with a gap interposed therebetween; a GMR film having an electrical resistivity higher than that of the soft magnetic material and formed in the gap so as to be electrically connected to the first thin film yoke and the second thin film yoke; and an insulating substrate made of an insulating nonmagnetic material and serving to support the first thin film yoke, the second thin film yoke and the GMR film. The GMR film is formed on a facing surface of the first thin film yoke positioned to face the second thin film yoke, and the length of the gap is defined by the thickness of the GMR film positioned on the facing surface of the first thin film yoke.

Abstract: To provide a magnetism detection apparatus that is small and low in cost and power consumption, a biasing coil 4 and a negative-feedback coil are integrated with a magnetic impedance element having a magnetic impedance effect in a resinous structure. The magnetism detection apparatus has a reduced magnetic resistance between the magnetic impedance element and the coil, thereby making it possible to apply a bias magnetic field and a negative-feedback magnetic field to the magnetic impedance element with a reduced power consumption.

Abstract: A differential magnetometer consisting of at least one active coil (4, 5) and a receiver coil (10) for which the windings are installed differentially, is provided with a measurement circuit (14) with a slaving device that corrects dissymmetry appearing between windings (11, 12) to eliminate residual induction at the frequency of the magnetic excitation field, intended to make the measurement coil (10) more sensitive without applying a voltage to it.

Abstract: In a high-frequency impedance type magnetic head having high impedance and capable of efficiently detecting a change in impedance, an electrically conductive metal film is sandwiched between two soft magnetic films, and the two soft magnetic films form a portion of a magnetic path. The thickness of one soft magnetic film is smaller than the thickness of the other soft magnetic film. The electrically conductive metal thin film has a pair of electrodes at respective ends thereof, to which are connected an oscillator for applying a high frequency carrier signal to the electrodes and a high frequency amplifier having a demodulator circuit. Further, an electrically conductive metal film winding is provided, and a DC current is applied to the electrically conductive metal film winding at the time of reproduction, while on the other hand, a signal current is applied to the electrically conductive metal film winding at the time of recording.

Abstract: In order to obtain a magneto-impedance type magnetic sensor having a soft magnetic film facing to a conductive nonmagnetic film, and available a large impedance change with a carrier signal at a relatively low frequency, the magnetic sensor comprises a meander type conductive nonmagnetic thin film of zigzag shape formed with at least one pair of electrode terminals at both ends and a soft magnetic film which is strip-shaped so as to face thereto at a plurality of regions and has an easy axis of magnetization in a width direction of the strip shape, a high frequency carrier signal is applied to the above-mentioned electrode terminals and further a direct current bias magnetic field is applied. By performing AM detection of an AM modulation signal output from the above-mentioned electrode terminals, an impedance change of the conductive nonmagnetic film which is changed by external magnetic field is detected as a change of the high frequency carrier signal, thereby the external magnetic field can be detected.

Abstract: A printed circuit fluxgate sensor for use in magnetic gradient detection devices and the like includes a highly magnetically saturable core formed as a flat, closed loop that is bonded between two planar substrate members. An excitation coil is formed on the outer surfaces of the substrate members by masking and etching a layer of a conductive metal in a pattern of tracks that extend across the core. Each track end is connected through a metal plated bore hole through the substrates from one track end to the next adjacent track end on the opposite substrate to form a current path circling the core in a toroidal fashion. Indicia are provided on the sensor that define the mechanical axis and the magnetic axis of the sensor.

Abstract: An MI sensor is miniaturized while maintaining high sensitivity. At least one MI element detects an external magnetic field and outputs a sense signal. The sense signal is supplied to a rectangular IC chip. The IC chip is provided with an MI element connection electrode connected to the MI element and a switching circuit controlled by a pulse signal so as to supply a pulsed magnetizing current to the MI element through the MI element connection electrode. The MI element connection electrode is located near a side of the rectangular IC chip.

Abstract: An integrated circuit signal isolator includes a magnetic field sensor in a first metal layer formed over a semiconductor substrate. A first dielectric layer is formed over the first metal layer, and an input coil in a second metal layer is formed over the first dielectric layer. Additionally, a second dielectric layer is formed over the second metal layer, and a feedback coil in a third metal layer is formed over the second dielectric layer. The feedback coil is coupled to an output of the magnetic field sensor.

Abstract: A modified hybrid Hall effect device is provided which is the combination of a conventional Hall effect device and a second Hall effect device having a Hall plate coupled to a ferromagnetic layer. The hybrid Hall effect device can be used to determine the independent magnetic field vector components comprising a vector magnetic field, such as for determining the {circumflex over (x)} and the {circumflex over (z)} components of a magnetic field, or for measuring the total magnitude of a vector magnetic field of any orientation. The modified Hall Effect device can be adapted for use as a magnetic field sensor for the detection of macroscopic objects that have associated magnetic fields, or for microscopic objects that have been tagged by microscopic magnetic particles.

Abstract: A high sensitivity magnetic field sensor is described. The sensing element is a stress-sensitive, negative-magnetostriction, melt-extracted amorphous wire, in which a strong magneto-impendance effect develops when the wire is connected to conventional electronic circuitry, which can be an impedance-meter. An a.c. current is provided to the wire and its relative change in impedance is measured. Simultaneously, the wire is submitted to a longitudinal d.c. magnetic field, H. A saturating d.c. field pulse is also applied to this wire at the beginning of the operating cycle. Tensile stress is further generated in the wire by pulling one end of the wire with a given force. This stress can be fine-tuned for sensitivity and bias with the help of a suitable mechanism. All these elements are packaged in a rugged non-magnetic enclosure, which permits easy and reliable connection of the sensor to said conventional electronic circuitry.

Abstract: A magnetic head includes a GMR read head that is protected from electrostatic discharge (ESD) on a slider by a silicon germanium (SiGe) integrated circuit device. In a preferred embodiment the SiGe circuit device includes one or more silicon germanium heterojunction bipolar transistors (SiGe HBT) or silicon germanium carbon heterojunction bipolar transistors (SiGeC HBT) that is electrically connected across the electrical leads of the GMR read head. Particular electrical connection configurations with the SiGe circuit devices include diodic modes, npn modes, series cascade modes and two stage ESD network configurations. The silicon chip may be sandwiched between the slider body and the read/write head or the read/write head may be sandwiched between the slider body and the silicon chip.