• Design of volumetric sub-THz negative refractive index metamaterial with gain

      Kantemur, A.; Tang, Q.; Xin, H.; Department of Electrical and Computer Engineering, University of Arizona; This work is supported in part by AFOSR grant under FA9550-13-1-0209 (IEEE, 2016-06)
      Conventional passive metamaterials always suffer from the limitation of loss and dispersion due to fundamental causality issue. Especially it becomes severe due to material loss at terahertz frequency. Our work resolves the loss problem by introducing gain device into the metamaterial structure. A passive volumetric metamaterial is firstly designed on the quartz substrate. A negative resistance is inserted into the wire of the structure to provide the gain. We have identified resonant tunneling diodes that work up into THz frequency and shown in simulation that simultaneous negative index and gain can be obtained.