Study on dielectric properties of electromagnetic wave oblique incidence on sandwich hole-core structure wave-transmitting materials

The variation law of equivalent dielectric properties of sandwich hole-core structure materials are investigated based on the analysis method, where the hole-core structure can be three kinds of structures, such as square, hexagon, and circle. Considering the hole-core structure is anisotropic, the calculation method of the electromagnetic parameters on the sandwich hole-core structure wave-transmitting materials are first derived. The accuracy of this method is validated by a numerical example of a plane wave incidence on a sandwich hole-core structure materials in free space. In addition, an S-parameter inversion method is proposed to calculate the equivalent dielectric and the results using phase-compensated to solve the inaccurate calculation of the dielectric around the S-parameter half-wavelength resonance. Finally, according to this model, the equivalent dielectric constant increases with increasing the incident angle for transverse electric (TE) polarized wave incidence and transverse magnetic (TM) polarized wave incidence, while an opposite phenomenon occurs for TE polarized wave incidence and TM polarized wave incidence on equivalent loss tangent.