| 摘要 |
PROBLEM TO BE SOLVED: To detect a high frequency magnetic field such as gigahertz which was unmeasurable in the past. SOLUTION: Output voltage of a magnetic sensor 10 is received by a high-speed amplifier 1, and output signal of the high-speed amplifier is used as a signal voltage corresponding to a magnetic field of a measuring object. According to the output signal of the high-speed amplifier, a negative feedback magnetic field is generated by a negative feedback circuit including an integrator 14, a feedback resistance element 15 and a modulation coil 16 and supplied to the magnetic sensor 10. The operation point of the magnetic sensor is set to a point with where its voltage-field characteristic is largest by an operation point setting circuit 2. COPYRIGHT: (C)2005,JPO&NCIPI
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