Reflectionless Sharp Bends and Corners in Waveguides Using Epsilon-Near-Zero Effects

Following our recent theoretical and experimental results that show how zero-permittivity metamaterials may provide anomalous tunneling and energy squeezing through ultranarrow waveguide channels, here we report an experimental investigation of the bending features relative to this counterintuitive resonant effect. We generate the required effectively zero permittivity using a waveguide operating at the cutoff of its dominant mode, and we show how sharp and narrow bends may be inserted within the propagation channel without causing any sensible reflection or loss and without affecting its tunneling properties. Disciplines Electrical and Computer Engineering | Engineering Comments Suggested Citation: Edwards, B., Alù, A., Silveirinha, M.G. and Engheta, N. (2009). "Reflectionless sharp bends and corners in waveguides using epsilon-near-zero effects." Journal of Applied Physics. 105, 044905. © 2009 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics and may be found at http://dx.doi.org/10.1063/1.3074506 This journal article is available at ScholarlyCommons: http://repository.upenn.edu/ese_papers/583 Reflectionless sharp bends and corners in waveguides using epsilon-near-zero effects B. Edwards, A. Alù, M. G. Silveirinha, and N. Engheta Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA Department of Electrical Engineering, Instituto de Telecomunicações, Universidade de Coimbra, 3030 Coimbra, Portugal Department of Electrical and Computer Engineering, University of Texas at Austin, 1 University Station, ENS 616, Austin, Texas 78712–0240, USA Received 25 July 2008; accepted 19 December 2008; published online 18 February 2009 Following our recent theoretical and experimental results that show how zero-permittivity metamaterials may provide anomalous tunneling and energy squeezing through ultranarrow waveguide channels, here we report an experimental investigation of the bending features relative to this counterintuitive resonant effect. We generate the required effectively zero permittivity using a waveguide operating at the cutoff of its dominant mode, and we show how sharp and narrow bends may be inserted within the propagation channel without causing any sensible reflection or loss and without affecting its tunneling properties. © 2009 American Institute of Physics. DOI: 10.1063/1.3074506