The application of high impedance surface for noise reduction inside the package

In this paper, a slot type high impedance surface and a mushroom type high impedance surface are applied respectively for the noise reduction inside the shielded package. A simple and efficient modelling method is proposed for the high impedance surface design. A commercial chip with its package is employed to show the performance of the proposed high impedance surface. Both simulation and measurement results show that the proposed high impedance surfaces can greatly reduce the induced currents flowing on the surfaces of the shielding box and keep the enclosed chip working on its normal condition.