A novel iterative method to estimate the soil complex permittivity from measurement and simulation modeling

This paper introduces a new strategy to determine the soil permittivity and its loss tangent which uses simulation and measurement result for comparison. The setup of the measurement system includes a high frequency connector and a two-rod transmission line (TRTL) where one of the rods is embedded in an unknown-permittivity soil. In order to validate the simulation model by optimizing the complex permittivity of the soil from the measurement result a smart searching tool performed by the PSO (Particle Swarm Optimization) algorithm is applied. The measurements were carried out by a VNA (Vector Network Analyzer) to obtain the reflected signals from the TRTL for a non-parameterized soil. The effectiveness of the PSO algorithm is demonstrated by equalizing both simulated and measurement results of the soil complex permittivity in the simulation model.