Short Range Wireless Power Transmission Using Radio-frequency Loop Resonators

A microstrip loop resonator structure is proposed for short range wireless power transmission around 1 GHz. Physical dimensions of the proposed structure are as small as 3 cm by 3 cm. Power transmission efficiency greater than 80% is achieved with power transmission distance smaller than 5 mm via the strong coupling between two loop resonators, as demonstrated by experimental results. Experimental data also show that, the power transmission performance is insensitive to various geometrical misalignments.