The main focus of the thesis is two different approaches for establishing wireless communication, by means of electromagnetic fields, between an implanted glucose sensor and an external device in a glucose monitoring system for diabetics. In the first approach, called a passive system design, the implant is constructed without an internal energy source. Here the energy is transferred to the implant via an inductive link, which at the same time is used for communication. In the second approach, called an active system design the internal device is equipped with an internal energy source. The discussion focuses on limitations and ways of optimizing the performance of the two approaches for the application in question. The nature of the operating medium, the human body, is complex and this causes challenges not faced with short range systems in more traditional environments. An instrumental setup used to investigate the performance of the passive approach in air and in a sodium chloride solution, is also presented.
Although the discussion is based on the design of a communication system for a glucose monitoring system, it will be of relevance for other applications of short range communication systems on medical implants or with similar operating environments.