Microwave Brightness Temperature in S-Band of Human Head with Incidence Angle and Polarization

Microwave radiometers have received extensive attention due to their passive and non-intrusive ability to measure the internal temperature of the human body. In this paper, the brightness temperature (TB) characteristics of a human head in S-band are modeled and analyzed in depth. Initially, we employ the finite element method to model the 1D temperature profile within the head. Subsequently, an incoherent radiation model is applied to a five-layer head structure, consisting of the skin, skull, cerebrospinal fluid, grey matter, and white matter to simulate the emitted TB. The simulation focuses on the angular variations in TB as a function of incidence angles spanning both horizontal and vertical polarizations. The results indicate significant discrepancies that are dependent on polarization, as well as a pronounced angular dependency. This underscores the intricate electromagnetic interactions present within the layered head model. This work contributes critical insights into the thermal-radiative characteristics of human head tissues, with implications for advanced medical diagnostic techniques.