Jiang, Tao; Chang, Kihun; Si, Li-Ming; Ran, Lixin; Xin, Hao
Physical Review Letters. Volume: 107 Issue: 20 2011
The paper studied active metamaterial transmission line at microwave frequency designed with incorporating a Germanium tunnel diodes. Measurements of the fabricated planar transmission line structures with one, two and three unit cells showed that the addition of the DC pumped tunnel diodes not only provided gain but also maintained the left-handedness. This work demonstrated that negative index material (NIM) can be obtained with net gain when external source is incorporated.
