Planar Resonance Reactive Shield for Reducing the EMI in Portable WPT Device Application

Abstract

Nowadays, the demand in wireless power transfer (WPT) technology has increased due to the battery problems of portable devices such as heavy weight and inconvenience of battery charging devices. However, wireless charging portable devices radiate the magnetic field which has high chance to cause the malfunction of electric devices. Therefore, the interest and demand of research about suppression of radiated EMI are increased. The planar resonant reactive shield employs coil for power transfer, and closed loop and capacitor to reduce the EMI. The planar resonant reactive shield dramatically reduces the radiated magnetic field from WPT system. The shielding performance is compared using analytical method and measurement. The analytical solution and measurement show good agreement.