Low frequency lumped element-based negative index metamaterial

Abstract
A lumped element-based negative index metamaterial (NIM) was designed, fabricated, and tested for operation at 400MHz in the ultrahigh frequency (UHF) band. At 400MHz the measured real part of the index of refraction of this NIM was nreal=−3.11 with a loss that was less than 1dB∕cm using unit cells whose overall size d was λ∕d∼75. The NIM bandwidth was >10% in the neighborhood of 400MHz.