Complex Permittivity Extraction of Typical Wooden Furniture Materials Based on Multi-Objective Particle Swarm Optimization Over 40-50 GHz

In order to facilitate the study of indoor propagation characteristics of millimeter waves, it is necessary to extract electromagnetic parameters of indoor materials in the millimeter wave frequency band. It is understood that there is currently limited research on the electromagnetic characteristics of materials with the same material and different internal structures. In the 40–50 GHz frequency band, the free-space method is used to measure three types of materials: plywood, particle wood, and solid wood. To avoid the ripples and ambiguity problems in the common methods, we propose a multi-objective particle swarm optimization scheme to extract the dielectric constant and conductivity of the materials using the measured values and formula calculated values at 30° incidence angle. Comparing with measurements at other incidence angles, the extraction results are validated and analyzed, and the fitting curve shows good results.