Effective permittivity of dielectric honeycombs

摘要

The effective permittivity of a dielectric honeycomb can be represented by a diagonal permittivity tensor. In the paper, an empirical equation is derived using the FD-TD (finite difference-time domain) method, which defines the diagonal components of the complex permittivity in terms of the honeycomb material permittivity and the fraction of honeycomb material per unit cell. The impact is investigated of electrically large honeycomb cells on effective permittivity failure. The manner in which the effective permittivity fails proves to favour a honeycomb orientation such that the direction of an incident plane wave's Poynting vector is parallel with the honeycomb's axis. The consequences are considered of an invalid effective permittivity on radar cross-section and planar reflectivity.