Magnetic field amplification by slender cuboid-shaped magnetic concentrators with a single gap

Brugger, S.; Oliver, Paul

doi:10.1016/j.sna.2009.11.009

Cited by 18 publications

(3 citation statements)

References 10 publications

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“…For a magnetic field of 1 mT, a typical Hall sensor with a biasing current of 1 mA can only produce an output signal of 100 -400 μV. At the expense of extra fabrication cost, the limited sensitivity of Hall sensors can be improved by an order of magnitude with the help of flux concentrators, which can be realized by depositing a ferromagnetic layer above the sensor [20] [21]. However, spread in concentrator geometry results in extra sensitivity spread [22].…”

mentioning

confidence: 99%

Multipath Wide-Bandwidth CMOS Magnetic Sensors

Jiang

Makinwa

2017

IEEE J. Solid-State Circuits

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This paper proposes a multi-path multi-sensor architecture for CMOS magnetic sensors, which effectively extends their bandwidth without compromising either their offset or resolution. Two designs utilizing the proposed architecture were fabricated in a 0.18 μm standard CMOS process. In the first, the combination of spinning-current Hall sensors and non-spun Hall sensors achieves an offset of 40 μT, and a resolution of 272 μTrms in a bandwidth of 400 kHz, which is 40x more than previous low-offset CMOS Hall sensors. In the second, the combination of spinning-current Hall sensors and pick-up coils achieves the same offset, with a resolution of 210 μTrms in a further extended bandwidth of 3 MHz, which is the widest bandwidth ever reported for a CMOS magnetic sensor.

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confidence: 99%

Multipath Wide-Bandwidth CMOS Magnetic Sensors

Jiang

Makinwa

2017

IEEE J. Solid-State Circuits

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“…There are two main factors affecting magnetic field gain, i.e., structural shape and soft magnetic material permeability. Magnetic concentrators with different shapes such as a T-shape, bar shape and triangle shape, etc., but which are processed by the same materials have different collecting efficiency in the detection of external magnetic fields [9,10,11,12,13,14]. Moreover, typical soft magnetic materials such as Ni, Co and their alloys, have been adopted to fabricate concentrators because of their excellent saturation magnetic flux density ( B s ), high relative permeability ( μ r ), low coercivity ( H c ) and remanence magnetic flux density ( B r ).…”

Section: Introductionmentioning

confidence: 99%

Characteristics of a Magnetic Field Sensor with a Concentrating-Conducting Magnetic Flux Structure

Zhao

2019

Sensors

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A magnetic field sensor with a new concentrating-conducting magnetic flux structure (CCMFS) is proposed in this paper, using a silicon-on insulator (SOI) Hall element fabricated by complementary metal oxide semiconductor (CMOS) technology as a magnetic sensitive unit. By fixing the CCMFS above the Hall element packaged on a printed circuit board (PCB) based on inner-connect wire bonding technology, a non-magnetized package can subsequently be obtained. To analyze the inner magnetic field vector distribution of the CCMFS, a simulation model was built based on a finite element software, where the CCMFS was processed using Ni-Fe alloys material by a low speed wire-cut electric discharge technology. The test results showed that the measurement of magnetic fields along a sensitive and a non-sensitive axis can be achieved when VDD = 5.0 V at room temperature, with magnetic sensitivities of 122 mV/T and 132 mV/T in a testing range from −30 mT to 30 mT, respectively. This study makes it possible to not only realize the detection of magnetic field, but also to significantly improve the sensitivity of the sensor along a non-sensitive axis.

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“…It is reasonable to integrate the flux guides with GMR sensor via MEMS technologies. The sensitivity of magnetic sensors can be improved by several orders of magnitude by implementing them into especially tailored magnetic flux guides [3], [4], and the magnetic flux guides are well studied and widely used [5]- [8]. The GMR sensors are intrinsically sensitive to the magnetic field along the direction in-plane of the sensor substrate, and it is relatively easier to fabricate a magnetic sensor sensing the in-plane magnetic components.…”

Section: Introductionmentioning

confidence: 99%

Designs of Novel Magnetic Flux Guides for Three-Axis Magnetic Sensor

Zhao

Pan

2015

IEEE Trans. Magn.

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In general, giant magnetoresistance (GMR) sensors are only sensitive to the magnetic field in the plane of the substrate due to fabrication restraints. Then, a three-axis magnetic sensor based on GMR sensors has to be assembled to obtain three magnetic field components. Novel magnetic flux guides for three-axis magnetic sensor are described in this paper. These novel flux guides are designed with flux conversion structure and are able to bring magnetic flux out-of-plane to in-plane. With these flux guides, the magnetic field perpendicular to the chip surface can be detected with the GMR sensors in-plane. Then, numerical simulations are performed to validate the designs, and optimizations are made to improve the flux guides' performance. Based on these works, a three-axis magnetic sensor based on the in-plane GMR sensors is proposed. Without assembling the z-axis sensor, the integrated three-axis magnetic sensor is expected to have better angular position. According to the designs, the flux guides can be deposited with good symmetry. Therefore, Wheatstone bridges are configured to deduce a differential voltage, only relative to a certain component of the magnetic field. In addition, the magnetic field at the active region of the GMR sensor would be intensified. In addition, the sensitivity of the sensor can be improved due to the amplification ability of the flux guides.

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Magnetic field amplification by slender cuboid-shaped magnetic concentrators with a single gap

Cited by 18 publications

References 10 publications

Multipath Wide-Bandwidth CMOS Magnetic Sensors

Multipath Wide-Bandwidth CMOS Magnetic Sensors

Characteristics of a Magnetic Field Sensor with a Concentrating-Conducting Magnetic Flux Structure

Designs of Novel Magnetic Flux Guides for Three-Axis Magnetic Sensor

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