Design of a Miniaturized Circular Implantable Antenna

The design of a new miniaturized circular implantable antenna at 1 GHz is presented along with the near-field radiation performance inside the human skin. For minimally invasive antenna inside the human head, the skin has been selected as the implantation tissue. To effectively miniaturize the antenna, unequal cross slots with shortening pin have been added to achieve a total volume of 185mm(3). The antenna is encapsulated in a cylindrical biocompatible alumina substrate and superstrate. The proposed antenna is designed to operate at frequency around 1GHz to achieve good penetration in the human head with low signal attenuation. E-field distribution in the reactive near- field infront of the surface of the antenna has been assessed at different radial distance to investigate the strength with distance variation. To abide with IEEE standards for specific absorption rate (SAR), the maximum input power has been derived along with SAR simulation in xy, xz and yz planes.