Miniaturized implantable patch antenna for near-field communication at ISM band

We present an implantable patch antenna designed for near-field communication with an external repeater device. The geometry is composed of a X-slot and four T-slots that increase the electric-length, thus miniaturizing the antenna, achieving a diameter of just 8 mm (0.064λ
₀
) for an antenna operation at 2.4 GHz. Moreover, the input reflection coefficient exhibits robust performance for different implantation depths. Lastly, we calculate a maximum input power imposed by Specific Absorption Rate regulation, according to Federal Communications Commission (FCC) and International Commission on Non-Ionizing Radiation Protection (ICNIRP).