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In this study, we investigate the output properties of the orthogonal fluxgate sensor fabricated with a cylinder-shaped ferrite core, and examine whether it could show both high sensitivity and wide measurement range for the application of magnetic treatment facility for surface vessels and submarines. The excitation coil and pickup coil are 10 turns and 280 turns respectively. To gain the wide measurement range over 30 Oe, we design the shape of magnetic core through FEM analysis. It is found that a stable fundamental mode operation would be possible when an adequate DC bias is adding to alternating excitation current. There is a resonant peak in the operation frequency dependence of output voltage, which is caused by LC resonance of pickup coil and coaxial cable. The maximum sensitivity was \sim2 V/Oe at 870 kHz, and the output increased almost linearly by external magnetic field to reach \sim30 Oe. [ABSTRACT FROM AUTHOR]

The orthogonal fluxgate sensor with a novel structure is presented in this paper for the first time. To overcome a weakness (tiny and flexible) of an amorphous wire in mass production, the sensor proposed in this study is composed of a pickup coil and a CoFeSiB amorphous wire which was embedded onto the surface of alumina substrate. We demonstrate that the fundamental mode operation can be achieved, and the sensitivity is enhanced by adding a suitable bias to excitation current. We present there is a close correspondence between the impedance resonance frequency and the optimal frequency of the sensor output. This can be explained with the equivalent circuit of the pickup coil and the maximum power transfer theorem. The experimental result says the operation frequency has to be decided by measuring the impedance of the pickup coil. The maximum sensitivity of the fabricated sensor at the optimal operation frequency is 0.8 V/Oe with the excitation current of 25 mA and DC bias of 15 mA. [ABSTRACT FROM AUTHOR]