Impact of Multi-Path Wave Propagation on Specific Absorption Rate in Layered Dielectrics

Correctly characterizing the power dissipated in the body, and subsequently, the specific absorption rate (SAR), is critical for compliance with electromagnetic radiation safety regulations and link budget analysis. Before building a system, electromagnetic simulations estimate the power requirements. However, geometrical simplifications are often necessary to reduce the computational complexity of simulations. When tissue layers are not electrically small, omitting explicitly defined layer boundaries fails to capture multi-path behavior contributing to the total electric field and, subsequently, the SAR. This paper studies the relationship between multi-path interference within biological tissue layers and the corresponding SAR values.