A double-carrier wireless power and data telemetry for implantable biomedical systems

In this paper a double-carrier simultaneous power and data telemetry system with just one internal coil for biomedical implantable devices is presented. In the proposed system, back-telemetry data is transmitted by the capacitor switching at the secondary side in two-level. As a result, the secondary side resonates at two different resonant frequencies in different periods of time. To hold the power transfer efficiency (PTE) and the power delivered to the load (PDL) almost constant, a double-carrier technique is introduced. In this method, two external power transmitters are employed, each at different times, such that the power carrier frequency is equal to the frequency at which the secondary side is tuned. Also, the forward data is modulated in PSK modulation on both carrier frequencies. The implemented full-duplex data and power telemetry prototype has delivered 60 mW power to 270 Ohm load with 36% efficiency and data rates of 50 kbps and 10 kbps have been achieved for forward and backward telemetry, respectively.