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A 3-Axis Miniature Magnetic Sensor Based on a Planar Fluxgate Magnetometer with an Orthogonal Fluxguide.

Lu CC, Huang J - Sensors (Basel) (2015)

Bottom Line: Experimental characterization of the miniature fluxgate device demonstrates satisfactory spatial magnetic field detection results in terms of responsivity and noise spectrum.As a result, at an excitation frequency of 50 kHz, a maximum in-plane responsivity of 122.4 V/T appears and a maximum out-of-plane responsivity of 11.6 V/T is obtained as well.The minimum field noise spectra are found to be 0.11 nT/√Hz and 6.29 nT/√Hz, respectively, in X- and Z-axis at 1 Hz under the same excitation frequency.

View Article: PubMed Central - PubMed

Affiliation: Institute of Mechatronic Engineering, National Taipei University of Technology, Taipei 106, Taiwan. cclu23@ntut.edu.tw.

ABSTRACT
A new class of tri-axial miniature magnetometer consisting of a planar fluxgate structure with an orthogonal ferromagnetic fluxguide centrally situated over the magnetic cores is presented. The magnetic sensor possesses a cruciform ferromagnetic core placed diagonally upon the square excitation coil under which two pairs of pick-up coils for in-plane field detection are allocated. Effective principles and analysis of the magnetometer for 3-D field vectors are described and verified by numerically electromagnetic simulation for the excitation and magnetization of the ferromagnetic cores. The sensor is operated by applying the second-harmonic detection technique that can verify V-B relationship and device responsivity. Experimental characterization of the miniature fluxgate device demonstrates satisfactory spatial magnetic field detection results in terms of responsivity and noise spectrum. As a result, at an excitation frequency of 50 kHz, a maximum in-plane responsivity of 122.4 V/T appears and a maximum out-of-plane responsivity of 11.6 V/T is obtained as well. The minimum field noise spectra are found to be 0.11 nT/√Hz and 6.29 nT/√Hz, respectively, in X- and Z-axis at 1 Hz under the same excitation frequency. Compared with the previous tri-axis fluxgate devices, this planar magnetic sensor with an orthogonal fluxguide provides beneficial enhancement in both sensory functionality and manufacturing simplicity. More importantly, this novel device concept is considered highly suitable for the extension to a silicon sensor made by the current CMOS-MEMS technologies, thus emphasizing its emerging applications of field detection in portable industrial electronics.

No MeSH data available.


Related in: MedlinePlus

The theoretical magnetic flux density along the longitudinal core vs. the distance from the core junction with respect to various core width.
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sensors-15-14727-f005: The theoretical magnetic flux density along the longitudinal core vs. the distance from the core junction with respect to various core width.

Mentions: Also, based on the resultant parametric settings, we survey magnetic flux density along the longitudinal distance of the magnetic core vs. various ferromagnetic core width designs. Therefore, as shown in Figure 5, its shown that the theoretical magnetic flux density in the interior of core along the longitudinal direction is relatively decreased when the core width is increased from 2 mm to 5 mm. Apparently, the variation of core width is related to the cross-sectional area and demagnetization effect of the core geometry, and by referring to Equation (1), the simulation results also make it evident that the demagnetization factor is probably more dominant in improving the device responsivity.


A 3-Axis Miniature Magnetic Sensor Based on a Planar Fluxgate Magnetometer with an Orthogonal Fluxguide.

Lu CC, Huang J - Sensors (Basel) (2015)

The theoretical magnetic flux density along the longitudinal core vs. the distance from the core junction with respect to various core width.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507702&req=5

sensors-15-14727-f005: The theoretical magnetic flux density along the longitudinal core vs. the distance from the core junction with respect to various core width.
Mentions: Also, based on the resultant parametric settings, we survey magnetic flux density along the longitudinal distance of the magnetic core vs. various ferromagnetic core width designs. Therefore, as shown in Figure 5, its shown that the theoretical magnetic flux density in the interior of core along the longitudinal direction is relatively decreased when the core width is increased from 2 mm to 5 mm. Apparently, the variation of core width is related to the cross-sectional area and demagnetization effect of the core geometry, and by referring to Equation (1), the simulation results also make it evident that the demagnetization factor is probably more dominant in improving the device responsivity.

Bottom Line: Experimental characterization of the miniature fluxgate device demonstrates satisfactory spatial magnetic field detection results in terms of responsivity and noise spectrum.As a result, at an excitation frequency of 50 kHz, a maximum in-plane responsivity of 122.4 V/T appears and a maximum out-of-plane responsivity of 11.6 V/T is obtained as well.The minimum field noise spectra are found to be 0.11 nT/√Hz and 6.29 nT/√Hz, respectively, in X- and Z-axis at 1 Hz under the same excitation frequency.

View Article: PubMed Central - PubMed

Affiliation: Institute of Mechatronic Engineering, National Taipei University of Technology, Taipei 106, Taiwan. cclu23@ntut.edu.tw.

ABSTRACT
A new class of tri-axial miniature magnetometer consisting of a planar fluxgate structure with an orthogonal ferromagnetic fluxguide centrally situated over the magnetic cores is presented. The magnetic sensor possesses a cruciform ferromagnetic core placed diagonally upon the square excitation coil under which two pairs of pick-up coils for in-plane field detection are allocated. Effective principles and analysis of the magnetometer for 3-D field vectors are described and verified by numerically electromagnetic simulation for the excitation and magnetization of the ferromagnetic cores. The sensor is operated by applying the second-harmonic detection technique that can verify V-B relationship and device responsivity. Experimental characterization of the miniature fluxgate device demonstrates satisfactory spatial magnetic field detection results in terms of responsivity and noise spectrum. As a result, at an excitation frequency of 50 kHz, a maximum in-plane responsivity of 122.4 V/T appears and a maximum out-of-plane responsivity of 11.6 V/T is obtained as well. The minimum field noise spectra are found to be 0.11 nT/√Hz and 6.29 nT/√Hz, respectively, in X- and Z-axis at 1 Hz under the same excitation frequency. Compared with the previous tri-axis fluxgate devices, this planar magnetic sensor with an orthogonal fluxguide provides beneficial enhancement in both sensory functionality and manufacturing simplicity. More importantly, this novel device concept is considered highly suitable for the extension to a silicon sensor made by the current CMOS-MEMS technologies, thus emphasizing its emerging applications of field detection in portable industrial electronics.

No MeSH data available.


Related in: MedlinePlus