Dual band wireless power and bi-directional data link for implanted devices in 65 nm CMOS

Implantable neural recording and stimulation devices hold great promise in monitoring and treatment of neurological disorders, limb reanimation and, development of brain-computer interfaces among other applications. However, transcutaneous wires limit the lifetime of such devices and there is a need for self-contained fully implantable solutions. In this work, we propose a novel dual-frequency approach for simultaneous wireless power transfer and low-power communication for small form factor fully implantable neural devices. We deliver wireless power using efficient magnetically coupled resonators operating at 13.56MHz and communicate using ultra-low power backscatter communication at 915 MHz. We leverage the frequency separation to combine wireless power and communication resonators with minimal interference using a novel concentric design, which meets the stringent size restrictions. We implement the wireless power receiver and communication front end of the implanted device in 65 nm CMOS and demonstrate 25 mW power delivery and 6 Mbps communication link.