Performance analysis of fractal transformers fabricated by laser ablation on a flexible magnetic substrate

Abstract In this paper, performance analysis of bendable transformers with magnetic core is demonstrated. The transformers are fabricated by laser ablation. The fabrication method is green and on demand. Transformers are important components used for switched power supplies. Two different designs were fabricated and characterized. In the first design, the primary winding was Sierpinski fractal curve of the second iteration and the secondary winding was Sierpinski fractal curve of the third iteration. In the second design, both the primary and the secondary windings were of Sierpinski fractal curve of the third iteration. Commercially available copper adhesive tape was ablated by laser in order to produce Sierpinski windings. Windings were transferred to flexible magnetic substrate. High frequency parameters such as self-inductances of windings, resistances of windings and coupling coefficients were analyzed in the frequency range from 10 kHz to 1 GHz. The maximum coupling coefficient for the first design is approximately 0.45, whereas it is approximately 0.5 for the second design.