Challenges in Realizing a Chronic High-Resolution Retinal Prosthesis - Artificial Sight: Basic Research, Biomedical Engineering, and Clinical Advances - page 145

Figure 7.9. Dual-band telemetry.
However, the dual-band approach faces the challenge of interference between
the power and the data link. As shown in Figure 7.10, the four coils have six
coupling coefficients, which make the design complicated. The power transmitter
generates a strong magnetic field in order to transmit power to the implant. This
magnetic field can generate a fairly high voltage on the data receiver coil, which
may corrupt the data signal completely. One way to tackle this problem is to
filter out the power interference before passing the data signal to the recovery
circuits. This filter may consume additional power in the implant, which is not
desirable. Another way is to minimize the coupling by relative positioning of
the power and data coils. For example, the data coils L 1_data and L 2_data can be
Figure 7.10. Interference between power and data telemetry.