title: Spiral-type terahertz antennas and the manifestation of the Mushiake principle.
abstract: We report on the experimental and theoretical study of the resonant eigenmodes of spiral-type terahertz antennas. The analysis is carried out for a varying number of spiral windings. For larger numbers the structure possesses a self-complementary property which allows the application of the Mushiake principle predicting that the impedance of such structures is half the impedance of free space. This permits to observe an equal and frequency independent reflection and transmission coefficient. This property makes the spiral-type terahertz antenna not only a fascinating example of a medium supporting strong resonances in the long wavelength limit but also a medium which can be easily and reasonably homogenized at higher frequencies. This is in stark contrast to most of the existing metamaterials.
authors.affiliation: School of Electrical and Computer Engineering, Oklahoma State University, Stillwater, Oklahoma 74078, USA.
authors.forename: Ranjan
authors.initials: R
authors.lastname: Singh
authors.forename: Carsten
authors.initials: C
authors.lastname: Rockstuhl
authors.forename: Christoph
authors.initials: C
authors.lastname: Menzel
authors.forename: Todd P
authors.initials: TP
authors.lastname: Meyrath
authors.forename: Mingxia
authors.initials: M
authors.lastname: He
authors.forename: Harald
authors.initials: H
authors.lastname: Giessen
authors.forename: Falk
authors.initials: F
authors.lastname: Lederer
authors.forename: Weili
authors.initials: W
authors.lastname: Zhang
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008962:Models, Theoretical; D055096:Optical Devices; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055053:Terahertz Radiation