High-frequency Inductors Using an Air Gap Fringing Shield: Cost-effective Approach and Compact Design without Litz Wire

Abstract:
In converter systems with inductors carrying a current waveform with non-negligible high-frequency components, increased HF losses occur. In case of gapped inductors, this increase is mainly due to the impact of the magnetic fringing field emanating from the air gap. Recently, a conductive shield to reduce these losses has been proposed. While losses in the shield itself occur, the HF winding losses are reduced significantly. This article compares the concept based on a conductive shield in various application scenarios with conventional inductor designs. The designs are compared regarding overall losses, temperature rise, volume & weight, and costs.