Effective permittivity of artificial material composed of metal particles — A generalized picture

A generalized formulism has been derived from an equivalent circuit model for describing the effective permittivity of an artificial material composed of dumbbell-shaped metal particles embedded periodically in a host dielectric medium. Theoretical value of effective permittivity compare well with numerical results obtained from HFSS simulation. The work shows that artificial material can achieve high material constant by controlling the size and shape of its constituent particles, a fact verified by the simulation. The simulation also shows that the proposed material has a cut off frequency, below which the material is transparent, that depends mainly on the particle gaps. In its special case, the generalized model reduces to Pendry´s model for thin wire medium.