Roundabout tandem coil design for high performance magnetic sensing

The magnetic sensor based on micro/nano coil structure is widely used in modern power grid, automobile, communication, and other fields due to its wide frequency band, good linearity, and low saturation. The design and manufacture of high-quality metal micro/nano coil are crucial for this sensor. This paper proposes a design scheme of an external series island coil and ring in a planar spiral coil to address the issues of eddy current loss and resistance. By reducing the internal coil section and increasing the external coil section, the coil quality is improved. Additionally, a small spiral island coil is connected around the outside of the planar spiral coil to enhance the coil quality. By optimizing the cross-section, the number of external series coils, and the current direction, a high-performance ring-island series magnetic sensitive coil structure is designed, which shows excellent magnetic induction characteristics compared to traditional geometric spiral coils.