The structure and analysis of coreless printed circuit board transformers

The coreless printed circuit board (PCB) transformers have good characteristics at high-frequency. They have the advantages of low costs, very high power density, no magnetic loss. Their structures are simple and easy to be integrated for manufactures. This paper introduces the structure of the coreless PCB transformers; especially an improved calculation of the self and mutual impedances in coreless PCB transformers is given. An experiment proved that the theory calculation is closely coincident with the testing results.