Magnetic field sensor and apparatus for measuring magnetic field

A magnetic field measurement device comprising:

• at least one magnetic field sensor configured to measure a capacitance depending on a change of a magnetic field;
• and
• a signal processor configured to receive the capacitance and measure the magnetic field,
• wherein each of the at least one magnetic field sensor comprises:
• a first electrode comprising a magnetic material at least partially;
• a second electrode comprising a non-magnetic material at least partially;
• a common electrode disposed between the first electrode and the second electrode and connected to a ground terminal;
• a power supplier of which one end is connected to the first electrode and the second electrode and of which another end is connected to the common electrode to supply power of a frequency band required;
• a variable resistor configured to control at least one of a resistance value between the first electrode and the power supplier or a resistance value between the second electrode and the power supplier;
• and
• a differential amplifier connected to the first electrode through a positive terminal and connected to the second electrode through a negative terminal to output a difference value between a first capacitance generated by the first electrode and a second capacitance generated by the second electrode in response to external application of a magnetic field,
• wherein a distance between the first and common electrodes changes by the external application of a magnetic field and a distance between the second and common electrodes does not change by the external application of a magnetic field.

A magnetic field sensor comprising:

• a first electrode comprising a magnetic material at least partially;
• a second electrode comprising a non-magnetic material at least partially;
• a common electrode disposed between the first electrode and the second electrode and connected to a ground terminal;
• a first power supplier connected to the first electrode and the common electrode to supply first power of a frequency band for which measurement is required;
• a second power supplier connected to the second electrode and the common electrode to supply second power of a frequency band for which measurement is required;
• and
• a differential amplifier connected to the first electrode through a positive terminal and connected to the second electrode through a negative terminal to output a difference value between a first capacitance generated by the first electrode and a second capacitance generated by the second electrode in response to external application of a magnetic field,
• wherein a distance between the first and common electrodes changes by the external application of a magnetic field and a distance between the second and common electrodes does not change by the external application of a magnetic field.