Transmission through Single and Multiple Layers of Plant Leaves at THz Frequencies

By focusing on the diverse range of applications that THz communications/technology can offer, specifically in the domain of advanced agricultural systems, we define a theoretical model for an approximation of the transmitted/reflected electric fields for THz radiation through plant leaves. The provided model can be modified to accommodate scenarios with single or multiple layers of leaves, given the permittivity of specific leaf types. In addition, we provide measured results of the permittivity of coffee leaves in the range of 0.3-2 THz. Based on the measured data and the provided model, we analyse the effect of various parameters, e.g., the leaf thickness, the separation distance between leaves and the transmission frequency, on the total transmitted/reflected fields. The results indicate the significant impact of the transmission frequency and the leaf attributes on degrading the THz signal, which can challenge the feasibility of the mentioned applications.