Hybrid power transfer and wireless antenna system design for biomedical implanted devices

In this paper, we present a hybrid system consisting of a high frequency (HF) coil (13.56 MHz), and an ultra-high frequency (UHF) antenna (905 MHz), integrated on an FR-4 substrate that provides a compact solution for simultaneous wireless power transfer and wireless communication for implanted medical devices. The challenge of minimizing the coupling effect between the coil and the antenna is addressed by optimizing their dimensions. The hybrid system was numerically modeled and the performance was tested at different depths inside a layered body tissue model. It is shown that the antennas' resonance frequencies of the external and implanted antennas, frex and frim, respectively, are stable and do not change by the depth of implanted antenna inside the tissue. Furthermore, transmission efficiency (η) at different distances is calculated. The system provides a good solution for the combination of power transfer and signal communication in a compact design.