A planar coil fluxgate magnetometer using multi-core configuration

This paper presents our proposed design for a multi-core planar fluxgate sensor for low magnetic field measurements. It stands out from other fluxgate designs by using three core layers. This will increase flux concentration in the pickup coil and thus improve field sensitivity. The basic structure of the multi core fluxgate magnetic sensor is shown in Fig. 1. It consists of three-core flux concentrators, an excitation coil and a sensing coil. The actual implementation of the structure in PCB technology is shown in Fig. 1. The 20 turn planar excitation coil was constructed with a thickness of 30μm and sandwiched between the three-cores. The magnetic components were measured from the sensing coil, 400μm wide with 20 turns. The excitation and sensing coils were on separate PCB layers separated by a distance of 50 μm from each other.