Analysis and Experimental Validation of Circularly Slotted Near-Field WPT Systems

An analysis of circular-type slots on the performance of defected ground structure-based wireless power transfer (WPT) systems is presented in this paper. This entails the development of transmitting and receiving resonators with various circular-type defects. The analysis is carried out and compared in terms of the quality factor and generated magnetic field. Owing to its superior performance the Archimedean coil is selected for further development of WPT. The J-inverters transform is used to extract the WPT parameters. For the validation purpose of the developed WPT concept, a prototype on a 20-by-20 sq. mm resonator area is fabricated. Subsequently, WPT operating at 433 MHz shows a power transfer efficiency of 72% at 20 mm.