Novel Frequency-Selective Surfaces for Printed Circuit Board-Based Wireless Power Resonators with High Quality Factors

The conventional printed circuit board (PCB)-based wireless power resonator with the single layer structure is criticized by its low quality (Q) factor for high-frequency operations. Recently, a double-layer PCB-based resonator with much a higher Q factor is proposed. However, the newly designed PCB-based resonators suffer from the electromagnetic interference (EMI) issue. Traditional passive EMI filtering schemes can effectively address the EMI issue, but simultaneously degrade the Q factor. To maintain the high Q factor while mitigate the EMI, two active shields (i.e., Shield-1 and Shield-2) are presented in this paper. Both shields exhibit good shielding performance and much better Q degradation than the passive ferrite and aluminium shielding. In comparison, the Q degradation of the Shield-2 with Jerusalem cross is better than that of the Shield-1 with square spiral.