Investigation of Scattering Invariant Modes for Electromagnetic Wave Propagation in Random Vegetation Models

Scattering invariant modes (SIM) are investigated in random media for the microwave regime, resulting in low-loss propagation. A 2D model of an agroforest, constructed of long cylinders, is utilized for radio link or radar use cases in rural areas. The robustness of the constructed scattering invariant mode is quantified by the invariance to the properties of the forest (material parameter, trunk position, and diameter). The statistical characterization method of Polynomial Chaos Expansion is used, providing sensitivity to the forest parameters. In this work, a numerical model is established based on the transfer matrix theory in order to prove, for the first time, that scattering invariant modes can be generated for radio-wave propagation through random vegetation. It is also illustrated by investigating a random 2D forest model that a robust SIM persists through an ensemble of forest configurations with realistic distributions of forest parameters.