3D Printed Flexible Coreless Transformers

This report presents 3D printed flexible coreless transformers, which can be used in RF band for various applications such as voltage conversion and impedance matching for maximizing power transfer. Two types of transformers composed of a pair of coil inductors with opposing and complementary windings were printed on flexible polyimide film by using a 3D printer. Behaviors of printed transformers were simulated with parameters such as mutual inductance, coupling factor, power gain with 3D transformer models. And then, inductance value were compared with measured one.