An inductive-link with a regulated secondary voltage based on frequency adjustment

This paper shows a wireless powering system for implantable biomedical devices that does not need a voltage regulator inside the body. The regulated voltage is obtained in the secondary of an inductive link and is controlled by varying the operating frequency of the inductive link. This frequency operation varies between 950 kHz and 1.2 MHz when the distance between the coils varies between 0mm and 40mm. The results show that it is not necessary to elevate the supply voltage of the external circuit to regulate the internal voltage. This scheme eliminates the necessity of a voltage regulator inside the body, reducing the implant operating temperature.