Low-loss left-handed metamaterials at millimeter waves

An omega-type multilayered metamaterial aimed at operating at millimeter wavelengths was characterized between 75 and 110 GHz (⁠$W$-band). The fabrication involves a monolithic integration of planar arrays of broad-side coupled microresonators with a benzocyclobutene spacing layer printed onto quartz substrates. The frequency dependence of the transmittance shows a well-resolved transmission window centered around 80 GHz with a 10% fractional bandwidth and another one starting from 100 GHz, both displaying comparable high transmission levels. The left- or right-handed behavior is assessed by the comparison of the phase delay between two devices of different lengths and by tilted-incidence transmission experiments.