A Simple Equivalent Circuit Model for Shielding Analysis of Magnetic Sheets Based on Microstrip Line Measurement

This paper presents a simple equivalent circuit model for estimating shielding performance of thin and flexible magnetic sheets or films, which are commonly used in modern mobile devices, such as smartphones. The proposed equivalent circuit model can accurately and effectively represent the measurement setup using a microstrip line and a loop probe that are typically employed to evaluate a near-field shielding effectiveness (SE) of commercial magnetic absorbing sheets or films. The calculated SEs of magnetic sheets using the proposed equivalent circuit model are validated by 3-D electromagnetic simulation and experiment, and show good agreement with measurement results in the frequency range up to 0.5 GHz.