Proposed module integrated wireless power transfer antenna with a metal plate inside the loop improves transmission efficiency by reducing the change of mutual inductance caused by the change of distance between two antennas. The antenna was designed and implemented on a 1 mm FR-4 substrate.

[System specification]

Operating Frequency : 6.78 MHz

Transmission Coefficient : -0.72 dB (Max. at 50 mm), -6.34 dB (Min. at 1 mm)

Physical Size : 110 × 140  mm​^​2 

Metal Plate Size : 55 × 55  mm​^​2