Multiple-folded antenna design for maximizing power transfer efficiency at 6.78 MHz

In this paper, we present the transmitter and receiver multiple-folded design for maximizing power transfer efficiency (PTE) for wireless power transfer (WPT) systems at 6.78 MHz. Using this design, it is possible to achieve higher PTE than the one obtained with square loops provided in the standard. The multiple-folded antennas are designed and tested with numerical electromagnetic software in free space, their quality factors are calculated and compared, and the problem of transmitter and receiver misalignment is investigated. The proposed transmitter and receiver are fabricated and proof-of-concept WPT measurements are performed using vector network analyzer.