Dispersion inherent to TLM nodes for modelling of metamaterials

The transmission line modelling (TLM) numerical approach to simulate metamaterials includes the assumption of a working frequency at which the required permittivity and permeability are adjusted; both are altered at any other value. Controlling the behaviour of the simulated metamaterial in a given frequency range is crucial. The dispersion relation of the TLM node for metamaterials is derived. It is found that such a node disperses according to the Drude model.