We propose two models of composite left/right-handed NETLs consisting of a single line or two lines and show that they are multi pass-band filters exhibiting metamaterial behavior at low frequencies. By employing the standard linear stability analysis, the MI gain is derived as a function of the frequency and the wave number of perturbations. Using the numerical analysis, the regions of modulational instability are obtained. As a result, it comes out that the modulational instability is almost nonexistent in the metamaterial regime but appears preferably in high pass-band frequencies.

modulational instability gain, metamaterial, composite left/right-handed NETL, soliton.