Low Magnetic Loss Metamaterial Based Miniaturized WPT System for Biomedical Implants

We propose a low magnetic loss multi-ring resonator (MRR) metamaterial. Then, we utilize this MRR metamaterial in a stacked configuration as the WPT transmitter (TX) for a miniaturized receiver (RX) embedded in biomedical tissue. A prototype is fabricated, and the measurement shows an efficiency of 51% at 50 MHz when the TX/RX separation distance is 9 mm. The TX/RX sizes are 20 mm × 20 mm and 7 mm × 7 mm, respectively. Hence, the proposed system has a figure-of-merit of 0.42, which is a significant improvement over the previously reported WPT systems. Also, the simulated specific absorption rate is within the recommended level when the input power is 21 dBm.