Statistical modeling of a shielded wireless charging device

In this paper, a geometrical propagation model for a wireless powering channel in an over-moded cavity loaded with conductive objects is presented. The cavity is designed for wireless charging of multiple objects simultaneously in a shielded environment. A conductive resonator approximately 50 cm × 28 cm × 18 cm in size is excited by a 10-GHz probe and the power distribution inside the charging box is measured using a rectenna and power management circuit for various positions of other conductive objects within the resonator. Based on the geometrical model, a simulation model for multipath fading in this cavity is developed and compared with measured statistical data with 2000 samples. The results show good agreement between measured and simulated received power levels and distributions.