  Human exposure to electromagnetic fields produced by two wearable antennas
operating in the 2.4 GHz frequency band was assessed by computational tools.
Both antennas were designed to be attached to the skin, but they were intended
for different applications. The first antenna was designed for off-body
applications, i.e. to communicate with a device placed outside the body, while
the second antenna model was optimized to communicate with a device located
inside the body. The power absorption in human tissues was determined at
several locations of adult male and female body models. The maximum specific
absorption rate (SAR) value obtained with the off-body antenna was found on the
torso of the woman model and was equal to 0.037 W/kg at 2.45 GHz. SAR levels
increased significantly for the antenna transmitting inside the body. In this
case, SAR values ranged between 0.23 and 0.45 W/kg at the same body location.
The power absorbed in different body tissues and total power absorbed in the
body were also calculated; the maximum total power absorbed was equal to 5.2 mW
for an antenna input power equal to 10 mW.
