Design of miniaturized and biocompatible implant antenna for retinal prosthesis systems

In this paper, the combination of Hilbert fractal geometry and rectangular shape based microstrip implant antenna design for retinal prosthesis systems is presented. The proposed antenna is miniaturized 5.8 × 6.5 × 2 mm³ (width × height × thickness mm³) and operates in the ISM band (2.4-2.48 GHz). PDMS superstrate is applied on top of the antenna to avoid a direct contact with the metallization and achieve biocompatibility. Implant antenna is simulated at the size of the eyeball (12.5 mm) which is filled with vitreous humor liquid model. Simulation results show that the presented antenna has a reflection coefficient characteristic <; -15dB and axial ratio of 1.08 dB for circular polarization. Designed antenna has acceptable specific absorption rate values for eye implantation at 2.4 GHz.