SAR Evaluation of Microwave UWB Antenna Array for Real Time Fetus Monitoring

This study focuses on the safety and efficacy of using a microwave Ultra-Wideband (UWB) antenna for fetus monitoring by evaluating the Specific Absorption Rate (SAR) and power absorbed in fetus tissues. The proposed UWB antenna, designed with FR-4 substrates (ϵ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</inf> = 4.3, tanδ =0.02) and dimensions of 50 × 42 × 1.6 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>, operates within the 3.1 - 10 GHz range. simulations performed in CST Studio Suite with a human voxel female model (Katja), the antenna array placed at 10 mm and 15 mm distances from the abdomen was analyzed. The results showed that a 15 mm distance maintained SAR levels below the 2 W/kg limit for safety, making the system suitable for fetus monitoring and imaging during the gestation period. This work demonstrates the potential of UWB antennas for prenatal care, ensuring compliance with Federal Communications Commission (FCC) regulations while optimizing safety and performance.