Investigation of electrically small monofilar spherical helical antenna used for mid-range wireless power transfer

This study is focused on electrically small monofilar spherical helical antenna for wireless power transfer (WPT) based on resonant coupling. WPT systems with different antenna geometry and loads at the receiving antenna are simulated and compared. The simulation results demonstrate some key WPT concepts including: the frequency splitting, critical coupling, impedance mismatch and the performance of electrically small antennas in WPT system design. By varying the spherical helical antenna geometry (diameter and number of turns) it is possible to achieve an efficient mid-range WPT at different frequencies. The antennas that best utilize the same physical volume achieve better power transfer efficiency over distance.