Design, simulation and fabrication of non-spiral based fluxgate sensor on printed circuit board (PCB)

This paper presents performance characteristics of non-spiral planar excitation and pick-up micro-coils implemented for a fluxgate sensor with a NiFe magnetic rod core. Using Ansys Maxwell's software, the sensor performance is simulated. Magnetic flux [phi], magnetic flux density [B], magnetic field intensity [H], coupling coefficient, inductance [L] and magnetic energy [E] of the coils are simulated for a set of excitation currents. A simple, cost-effective and less complex fabrication method is implemented to fabricate the sensor using Printed Circuit Board (PCB) technology. Non-spiral 5-turn fluxgate sensor of dimensions 50mmx 20mmx 0.5 mm [length x breadth x width] is fabricated and analysed at an excitation current with a fundamental frequency of 500 kHz. Two excitation coils and one pick-up coil are deposited on a horizontal PCB plane and NiFe rod type material is placed on it, which acts as the core. Synthetic glue is spread on the coils; it acts a insulator between the coils and the core. Copper is used for deposition of the both the excitation and pick-up coils. On applying different excitation current, the frequency response of the non-spiral fluxgate sensor is plotted. The sensor demonstrated earth magnetic field strength detection (similar to 25 mu T).