Determination of Broadband Complex EM Parameters of Powdered Materials: 1. MCMC-Based Two-Port Transmission Line Measurements

We propose a Bayesian Markov Chain Monte Carlo parameter estimation technique to determine frequency-dependent complex dielectric permittivity and permeability of powdered planetary regolith analog materials from coaxial transmission line measurements. The technique uses either a flat (non-dispersive) or a generalized dielectric response model to simultaneously determine the complex permittivity and permeability from measured scattering parameters. By exploring the parameter space, the technique reduces the dependence on good initial model parameters required by typical optimization methods. The technique can be used with either two-port measurements or shorted measurements, where an additional one-port shorted sample is measured. We find the technique is able to accurately determine electromagnetic parameters of low-loss, high dielectric, and magnetic materials. The technique is also robust to half-wavelength resonances in the sample as well as the presence of higher order modes.