Improving the Coupling Efficiency of the WPT System and Miniaturized Implantable Resonator using Circle Shaped Defected Ground Structure

In this research, we propose a new structure of resonators built on a Rogers RO3010 substrate for wireless power transfer (WPT) implant. The resonator’s transmitter (TX) and receiver (RX) are both utilized for the stimulation. The design operates at 0.685 GHz at a transmission distance of 20 mm with a size of (18 mm × 18 mm). The size of the resonator is greatly reduced by considering a high dielectric constant. From literature, it is found that this proposed WPT system design is the smallest in comparison to a similar type of resonator and it achieves strong power transmission efficiency. The coupled resonators are optimized and loaded with defected ground structure (DGS) and integrated with a lumped capacitor. This proposed WPT system can be minimized to a small size, in addition to increasing the transmission distances and improved efficiency. Results indicate that the maximum lg average SAR level is about 1.22 W/kg in agreement with IEEE standard C95.1-1999 for maintaining standard SAR levels. This increases the overall performance efficiency of the WPT system. Also, the WPT system using DGS attains a power transfer efficiency of 98 %. There is a good agreement between the simulated, theoretical, and measured results that have been obtained. All the simulations of the circle-shaped DGS resonator and resonator systems are done in computer software technology (CST) and advanced digital system (ADS).