Comparative analysis of the electric permittivity for some HF board materials with PTFE base

A parametrical analysis of the electric permittivity evolution with frequency was performed in this paper. We have considered a board material class with PTFE (polytetrafluoroethylene) base and different reinforcement materials, for comparison. Characteristics of each material are different, considering their internal geometry and reinforcing fibers nature. Materials structures were simulated using the HFSS (3D Full-wave Electromagnetic Field Simulation) program, considering exposure field with linear variations after the coordinate axes. The results represent the effective permittivity evolution over a frequency range of 2.45 to 12.4 GHz, considering the thermal shift. Conclusions illustrate the resonant behavior of the permittivity and the thermal resonances shift in function of the material components properties.