Quad-Band Meandered Implantable Planar Inverted-F Antenna for Wireless Brain Health Monitoring

We present the development and optimization of a quad-band meandered implantable Planar Inverted-F Antenna (PIFA) for wireless brain health monitoring. The design of an implantable antenna is of prime importance in implantable wireless biomedical telemetry systems for establishing wireless data connection. Through numerical optimization based on the full-wave EM simulations, we have achieved operation on four central wireless communication bands for healthcare systems: Medical Device Radiocommunication Service (MedRadio) band (401-406 MHz), Wireless Medical Telemetry Service (WMTS) band (1427-1432 MHz), and Industrial, Scientific, and Medical (ISM) bands (902.8-928 MHz, 2400-2483.5 MHz), with reflection coefficient below −10 dB. The meandered miniaturizing technique is deployed to compact the size of the antenna. A shorting pin is introduced for shorting the radiating part to the ground plane, the biocompatible silicone coating is used to prevent the direct contact of the antenna with the body, and the high-permittivity substrate Rogers RO3210 is used. For the full-wave electromagnetic field simulation, the 7-layer human head model is utilized, and the antenna is implanted at the depth of 13.25 mm of the cranial cavity in the cerebrospinal fluid (CSF) layer. The antenna volume is 11×19.8×1.8 mm³ including the silicone coating.