Towards an implantable wireless module with a bandwidth-enhanced antenna manufactured using inkjet-printing technology

Intra-body electromagnetic propagation through dispersive tissue and studies of wireless power transmission have tended to focus on MHz frequencies due to relatively lower tissue absorption loss in this frequency range. Other studies have focused on the 2.4GHz frequency. The Medical Implant Communication Service, a standard specified by the U.S. Federal Communications Commission, allows bi-directional radio communication between implantable devices using 401 and 406 MHz. Recent studies, however, have shown that frequencies in the low GHz range can be used for both bi-directional communication and wireless power transfer with the lowest absorption loss. This paper presents a preliminary study towards the development of an implantable module at 1.86 GHz. A Planar Inverted-F Antenna (PIFA) has been considered as the modules' antenna and in order to increase the inherently narrow bandwidth, a ground slot is used. The module demonstrates omni-directional radiation pattern, it is well matched at 1.86 GHz and it has 1.5 dBi gain. The module's antenna can be easily inkjet-printed on conformal materials such as paper and bio-compatible LCP.