title: Loss compensation in metamaterials through embedding of active transistor based negative differential resistance circuits.
abstract: Dielectric and ohmic losses in metamaterials are known to limit their practical use. In this paper, an all-electronic approach for loss compensation in metamaterials is presented. Each unit cell of the meta-material is embedded with a cross-coupled transistor pair based negative differential resistance circuit to cancel these losses. Design, simulation and experimental results for Split Ring Resonator (SRR) metamaterials with and without loss compensation are presented. Results indicate that the quality factor (Q) of the SRR improves by over 400% at 1.6 GHz, showing the effectiveness of the approach. The proposed technique is scalable over a broad frequency range and is limited only by the maximum operating frequency of transistors, which is reaching terahertz in today's semiconductor technologies.
authors.affiliation: NanoLab, Department of Electrical and Computer Engineering, Tufts University, 161 College Ave, Medford, MA 02155, USA.
authors.forename: Wangren
authors.initials: W
authors.lastname: Xu
authors.forename: Willie J
authors.initials: WJ
authors.lastname: Padilla
authors.forename: Sameer
authors.initials: S
authors.lastname: Sonkusale
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D017097:Electric Impedance; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008962:Models, Theoretical; D014173:Transistors, Electronic