Wearable Monopole Antennas for Microwave Stroke Imaging

Three compact wearable monopole antennas are proposed for stroke imaging applications. First, three different antenna geometries are developed based on a 1.6-mm-thick FR4 substrate. Then, a number of efforts are investigated and parametric studies are performed to reduce the antennas sizes. The measured and simulated results show that the antennas achieve wideband and ultra wideband (UWB) characteristics, partially covering the range of frequencies that can efficiently penetrate through the human head. These frequencies are from 0.6 GHz to 1.5 GHz both in free space and inside a matching medium. Simulations also show that the proposed antennas can achieve an omnidirectional radiation pattern and gains between 5 and 6 dBi, allowing for a good reception of signals being back-scattered from the human head. In addition, the omnidirectional radiation patterns provide flexibility to the antennas' orientation when placed on the interior surface of the helmet worn by patients.