In this article, a new wireless power transfer (WPT) design is proposed for improving the efficiency of the system. The suggested system contains two spiral defected ground structure (DGS) resonators coupled back-toback. A band-pass filter is then to be designed for the wireless power to be transferred from the transmitter unit to the receiver unit. The DGS resonators are loaded through chip capacitors for miniaturization. The proposed structures are fabricated and tested. The proposed system has the highest efficiency of 97.7% at a transmission distance of 10 mm which is suitable for biomedical applications. Both simulated and experimental results are in good concurrence.

No abstract

This work introduces a novel design for high efficiency and compact size dual‐frequency wireless power transfer (DF‐WPT) systems. The proposed design is composed of two identical transmitting (Tx) and receiving (Rx) substrates. Each substrate has a microstrip feed line, a C‐shaped coupled resonator on the top layer and a spiral coupled defected ground structure on the bottom layer. The system is analysed using J‐inverters for the dual‐frequencies (DFs) operation. The measured results show that the proposed DF‐WPT system with a compact size of 20 × 20 mm2 is able to provide a stable WPT characteristic with total efficiencies of 91.2 and 79.4% at 0.28 and 0.49 GHz, respectively with a transmission distance of 6 mm. The proposed system achieved good agreements between the analytical design procedure, the circuit model, the electromagnetic simulations, and the measurements.

In this work, the wireless power transfer system employing nested open loop ring resonators at the ground plane is proposed. In the suggested design both the transmitter and the receiver are symmetric. The forward‐facing view contains the transmission line. The ground plane contains number of 33 open loop ring resonators which are nested together. The system has a size of 40 × 40 mm2 with a transmission distance of 15 mm. The proposed design is investigated in two cases with and without the loading capacitor. Comparisons between the resonance frequency and the power transfer efficiency of the proposed design with and without the loading capacitor are presented. The coupled resonator system achieved an efficiency of 97% at 1.35 GHz while the system with the loading capacitor achieved an efficiency of 98.8% at 1 GHz. The proposed system is designed, simulated, and measured.

No abstract