The Analysis and Design of an Inter-Winding Shielding Structure of a High Frequency Transformer

Generally planar transformers experience significant capacitive coupling between the primary and secondary windings. A novel shielding configuration which overcomes the problems of conventional electrostatic shields is presented While the technique is focused on planar transformers, it is shown that similar benefits may be obtained with conventional transformers. The operation of the new shield relies on the principle of charge balancing to eliminate the flow of capacitive currents. The design of the structures as well as experimental verification thereof is presented. The occurrence of common mode displacement currents in the transformer is shown to be greatly reduced.