Effectiveness of shielded high frequency coaxial transformer for switching power supplies

The paper presents the configuration of a high frequency coaxial transformer with a Faraday shield and discusses the shielding effect and insertion loss at a high frequency range for the switch mode power supplies. The numerical computation and visualization results demonstrate the magnetic flux and eddy current distribution in the windings and Faraday shield. The shielding effectiveness of a Faraday shield in a high frequency coaxial transformer is also investigated by using a high frequency equivalent circuit model and Pspice simulation. The experimental results demonstrate the voltage ratio, coupling coefficient and load characteristic of the high frequency coaxial transformer with Faraday shield in the range up to 2 MHz.