What are the advantages of common mode inductors wound with multi-strand twisted wires at high frequencies? ​

The advantage of common-mode inductors wound with multi-strand wires at high frequencies primarily stems from the suppression of skin and proximity effects. The single strand of multi-strand wire has a thin diameter (such as below 0.1mm). At high frequencies, the skin depth (δ=√(ρ/(πμf))) is comparable to the wire diameter, resulting in a larger total effective conductive area. The AC resistance is significantly lower than that of a single strand wire with the same cross-sectional area, reducing high-frequency loss. The twisted structure ensures that the strands are evenly and alternately positioned in the magnetic field, reducing uneven current distribution caused by proximity effects. This further reduces the equivalent resistance, ensuring a high impedance at high frequencies (such as above 100MHz), and enhancing the suppression capability of common-mode interference.