Amplifier design for a biomedical inductive power system

The use of switching power amplifiers in the driver stage of a biomedical inductive power system is investigated. The main emphasis is on miniature biomedical implant systems where the receiver coils are very small compared to the transmitter coil and where magnetic coupling is very weak. Because of the weak coupling the driver circuit is almost independent of the load variation in the secondary coil. This makes it possible to design the driver circuit for a fixed primary coil parasitic resistance, which acts as an effective load. The goal is to design a primary coil driver circuit for a specified current level determined by field regulations for biomedical devices, by using parameters determined by the coupled electromagnetic system.