Implant-to-Implant Communications using Quad-Band PIFAs for Intracranial Applications

In this paper, we study the feasibility of implant-to-implant (121) communications with quad-band implantable planar inverted-F (PIFA) antennas through numerical simulations. The four frequency bands included are the Medical Device Radiocommunication Service (MedRadio) band (401–406 MHz), the Wireless Medical Telemetry Service (WMTS) band (1427–1432 MHz), and the Industrial, Scientific, and Medical (ISM) bands (902.8-928 MHz and 2400-2483.5 MHz), where the antenna's reflection coefficient (18<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</inf>1) is better than -10 dB. The two implant antennas are positioned 14.8 mm deep in the CSF layer and 75 mm deep in the brain of the ellipsoid human head model. The relationship between the mutual coupling (18<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</inf>1) and the far-field gain products of the antennas is analyzed to understand the electromagnetic coupling mechanism between the antennas.