Low Energy Wireless Electricity Transmission Using Resonant Magnetic Coupling

This paper presents a novel framework for low-energy wireless electricity transmission based on resonant magnetic coupling between tuned LC circuits. Unlike conventional inductive power transfer which suffers from rapid efficiency degradation beyond a few centimetres, the proposed system exploits strongly coupled magnetic resonances to achieve efficient power transfer at distances exceeding the coil diameter. We derive analytical expressions for the coupling coefficient and power transfer efficiency as functions of coil geometry, operating frequency, and load impedance. A key contribution is the development of a self-tuning algorithm that automatically adjusts the operating frequency to maintain resonance as environmental conditions change, thereby maximising transfer efficiency without manual intervention. Experimental validation using custom-wound coils operating at 1.2 MHz demonstrates power transfer efficiencies of 67% at a distance of 30 cm and 41% at 60 cm, representing a significant improvement over conventional loosely-coupled inductive systems. The system successfully powers a 5W LED array and charges a mobile telephone battery at distances impractical for standard inductive chargers. Analysis of the electromagnetic field distribution confirms compliance with ICNIRP safety guidelines for human exposure. The findings suggest that resonant wireless power transfer offers a promising pathway toward eliminating power cables in consumer electronics, medical implants, and industrial automation applications.