SAR Analysis of Quad-Band PIFAs and Single-Band Loop Antennas Using a 7-Layer Head Model

We present the numerical analysis of specific absorption rate (SAR) and radiation performance of two brain-implantable planar inverted-F antennas (PIFAs) and two single-band loop antennas. The PIFAs operate in the Medical Device Radiocommunication Service (MedRadio) band (401–406 MHz), Wireless Medical Telemetry Service (WMTS) band (1427–1432), and Industrial, Scientific, and Medical (ISM) bands (902–928 MHz and 2400–2483.5 MHz). The central operating frequencies of loop antennas are 915 MHz and 2.45 GHz. All the antennas provide reflection coefficient below −10 dB and exhibit satisfactory gain and efficiency results. All the antennas displayed a similar radiation performance at 915 MHz. However, the loop antenna performed superior to the others in gain and efficiency at 2.45 GHz. SAR analysis was performed to evaluate the performance of all the antennas, prioritizing compliance with safety standards and minimizing potential health hazards.