Lumped element-based, highly sub-wavelength, negative index metamaterials at UHF frequencies

Several lumped element-based epsilon-negative (ENG), mu-negative (MNG), and double-negative (DNG) metamaterial designs have been developed for operation at 400 MHz in the UHF frequency band. The use of lumped elements enabled the creation of highly sub-wavelength unit cells whose overall size was ${\lambda }_0/d\sim 75$ at 400 MHz. The measured negative index material (NIM) showed an effective real index of refraction $n_{\text{real}}=-3.11$ with a total loss that was less than 1 dB/cm. The NIM bandwidth was $>10\%$ in the neighborhood of 400 MHz.