Terahertz signal propagation analysis inside the human skin

The paper presents an initial study of analyzing the propagation of electromagnetic waves at terahertz frequencies inside the human skin tissues in the frequency range 0.8-1.2 THz. The skin model is represented by three layers: stratum corneum (SC), epidermis, and dermis, and the effect of the presence of sweat ducts is also studied. The path loss resulting from the signal propagation between a transmitting antenna, located at the epidermis layer, and a receiving antenna, located at the dermis layer, is analyzed for different distances and different frequencies, in addition to changing the number of sweat ducts. Results show that the path loss through the skin tissues depends on the distance between the transmitter and the receiver, the frequency used, and the number of sweat ducts as the path loss decreases by approximately 1 dB for increasing the number of sweat duct from one duct to two ducts. Moreover, the path loss is statistically studied and its distribution is approximately Gaussian.