A Transcutaneous Data Telemetry System Tolerant to Power Telemetry Interference

Minimally-invasive implanted devices usually transmit both power and data through inductive coupling. By separating power and data carriers into different frequency bands, a high data rate can be transmitted without affecting power link efficiency. However in a dual band approach, the electromagnetic field from the power link interferes with data transmission. This paper presents a high data rate Differential Phase Shift Keying (DPSK) telemetry designed to tolerate interference without electromagnetic shielding or a high-order filter. On the transmitter side, by analyzing the nature of the interference, "frequency pre-distortion" is introduced to maintain the maximum efficiency. On the receiver side, a differential scheme is employed to provide inherent interference rejection. Using subsampling and novel analog demodulation, the scheme also eliminates the requirement of carrier recovery, thus reducing circuit complexity. The receiver achieves a 1 Mbps data rate and can be upgraded to 2 Mbps