Efficient on-chip wireless power transmission (invited paper)

In this work, an on-chip inductor was designed and fabricated for high efficiency miniaturized wireless power transfer. The on-chip power receiving inductor is based on above-CMOS integration (ACI) post processing technique. The fabricated 4.5×4.5 mm² ACI inductor achieved a large inductance of 4.24 μH and peak quality factor of 23 at 13.56 MHz frequency. The measurement of a wireless power transmission link with the ACI power receiving coil and a PCB based power transmitting coil renders a record-high efficiency of 37% and 8% at 5 mm and 10 mm transmission distances, respectively.