Design of a Novel Miniaturized Implantable PIFA for Biomedical Telemetry

A broadband, circular, double-stacked, implantable planar inverted-F antenna (PIFA) is proposed for biomedical telemetry at f0= 402 MHz. Both patches are meandered and a high permittivity substrate material is used to limit the radius and height of the antenna to 3.6 mm and 0.7 mm, respectively. The tuning and radiation characteristics as well as the specific absorption rate (SAR) distribution induced by the proposed antenna implanted inside a skin-tissue simulating box and inside the skin layer of a three-layer spherical human head model are evaluated. Simulations based on both finite-difference time-domain (FDTD) method and finite-element-method (FEM) are carried out. The feasibility of the communication link between the proposed antenna implanted in the spherical head model and an exterior λ0/2 dipole antenna is also examined.