Design of a Low Loss Metallo-Dielectric EBG Waveguide at Submillimeter Wavelengths

Abstract

Abstract-In this letter we show the viability of using concentric cylindrically-periodic (CP) dielectrics to realize low-loss propagation at submillimeter wavelengths. Most of the power in the CP Waveguide (WG) is confined to an air core propagating a TE 01 mode. The TM 11 mode degeneracy is removed over a very wide bandwidth by a series of periodically spaced dielectric rings that are optimized in thickness and spacing. The new waveguide differs from classical Bragg fibers in that we use only a small number of dielectric layers (2-4), and terminate the outer layer with an external metal coating. We include several designs and describe the optimization procedure that was used to realize structures with low propagation and bend loss.Index Terms-Bragg fibers, electromagnetic bandgap (EBG), optimization, THz waveguide.

Optimization of the E-Plane Loaded Rectangular Waveguide for Low-Loss Propagation

“…The dispersion diagram of the optimal E-plane loaded rectangular waveguide has been computed with (11) and (12). The result is shown in Fig.…”

“…Taking advantage of this confinement, this paper shows that the proposed waveguide also presents low losses on curves [11,16], and can be used to design efficient devices.…”

“…Once the propagation constant of each mode is determined, constants A e, o(r) and B e, o(r) on each region can be easily obtained by solving (11) and (12). To do so, one column of the matrices is placed as an independent term and one row must be removed due to redundancy.…”

“…E-plane loaded rectangular waveguide fabricated in the Ka-band. (b) (a) (b) (a) 29 and dielectrics have a high power absorption [11], which increases the attenuation of any waveguide [12]. This makes common waveguides, e.g., the metallic rectangular or circular waveguides, impractical.…”

“…This characteristic is specially important at high frequencies, e.g., submillimeter-wave or THz frequencies. At these frequencies, waveguides are affected by severe conductor skin-depth losses and dielectric absorption [11], which considerably increases the attenuation of the waveguides [12]. Hence, the confinement of power in a region of air by non-conducting materials may decrease noticeably the attenuation of the waveguide.…”