35 research outputs found
Characteristics of bound modes in coupled dielectric waveguides containing negative index media
We investigate the characteristics of guided wave modes in planar coupled
waveguides. In particular, we calculate the dispersion relations for TM modes
in which one or both of the guiding layers consists of negative index media
(NIM)-where the permittivity and permeability are both negative. We find that
the Poynting vector within the NIM waveguide axis can change sign and
magnitude, a feature that is reflected in the dispersion curves
Mode Bifurcation and Fold Points of Complex Dispersion Curves for the Metamaterial Goubau Line
In this paper the complex dispersion curves of the four lowest-order
transverse magnetic modes of a dielectric Goubau line () are
compared with those of a dispersive metamaterial Goubau line. The vastly
different dispersion curve structure for the metamaterial Goubau line is
characterized by unusual features such as mode bifurcation, complex fold
points, both proper and improper complex modes, and merging of complex and real
modes
Guided Modes of Elliptical Metamaterial Waveguides
The propagation of guided electromagnetic waves in open elliptical
metamaterial waveguide structures is investigated. The waveguide contains a
negative-index media core, where the permittivity, and permeability
are negative over a given bandwidth. The allowed mode spectrum for these
structures is numerically calculated by solving a dispersion relation that is
expressed in terms of Mathieu functions. By probing certain regions of
parameter space, we find the possibility exists to have extremely localized
waves that transmit along the surface of the waveguide
Improved analysis of antenna radiation from a circular aperture covered by a dielectric hemispherical radome shell
10.1049/ip-map:20000217IEE Proceedings: Microwaves, Antennas and Propagation1472144-150IMIP