In this article, redefined antenna parameters regarding the additional effects occurring with on-body propagation are derived to enable a standardized characterization of on-body antennas. A model for the on-body propagation… Click to show full abstract
In this article, redefined antenna parameters regarding the additional effects occurring with on-body propagation are derived to enable a standardized characterization of on-body antennas. A model for the on-body propagation of arbitrary wearable and implantable antennas using Green’s functions based on the Norton surface wave theory and the surface equivalence principle is presented, which subsequently is used as an on-body near-field-to-far-field transformation. The defined on-body far-field enables the redefinition of the antenna parameters (gain, effective area, and efficiency) for the on-body case. Based thereon, the antennas can be deembedded from the on-body channel and the on-body link between two antennas can be calculated by an adapted Friis transmission equation similar to free-space propagation. It is demonstrated by two examples, one of a hearing aid antenna and another of an antenna of an implantable pacemaker, that the on-body antenna parameters allow for an educated design of the antennas without the necessity of electromagnetic modeling of the entire system.
               
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