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In this work, we study the properties of slow electromagnetic surface TM-waves propagating along the planar waveguide structure involving the mu-negative metamaterial slab. The planar mu-negative metamaterial layer separates two semi-infinite regions: the plasma and the conventional dielectric. All media are assumed to be linear, homogeneous, and isotropic. The dispersion properties, the phase and group velocities, the spatial distribution of the electromagnetic fields of the TM mode in frequency range where the metamaterial has a negative permeability are under the consideration. The properties of this TM-eigenwave of the structure and two other TE modes are compared. It is studied the TM-eigenwave properties variation with metamaterail and plasma-like media properties changing. It is shown that for the considered structure, the properties of the TM mode depend significantly on the parameters of the plasma-like medium.

We have considered the refraction of surface electromagnetic waves (SEW) at the heterogeneous metasurface. The considered structure consists of three regions: mu-negative metamaterial, ordinary magnetic, and vacuum. The boundaries between considered media are planar. A phenomenological approach was used; media were assumed to be lossless and isotropic. In this paper, we show the possibility of total internal reflection effect for SEW of TE-polarization that can propagate along such heterogeneous metasurface. The value of the angle of total internal reflection decreases for higher frequency waves from the interval under consideration. The presented result may help design both research and industry complex systems.

The paper presents the results of the study of slow surface electromagnetic waves directed along the flat mu-negative metamaterial slab surrounded by ordinary dielectric material. It is considered the case of isotropic and homogeneous metamaterial without losses. This metamaterial possesses the positive permittivity and the negative permeability over a definite frequency band. It is found that two surface modes of TE polarization can propagate along such waveguide structure. The dispersion properties, the spatial distribution of the electromagnetic field, as well as the phase and group velocities of these slow modes are studied. The first mode is a conventional forward wave, and has a lower frequency and lower phase velocity than the second mode. The second mode may have zero group velocity at a certain frequency. Characteristics of these surface modes for different values of the mu-negative slab parameters have been studied. The studied surface electromagnetic waves can be used for practical applications as in laboratory experiments, as in various technologies.

In this paper, a novel terahertz (THz) spectroscopy technique and a new graphene-based sensor is proposed. The proposed sensor consists of a graphene-based metasurface (MS) that operates in reflection mode over a broad range of frequency band (0.2 – 6 THz) and can detect relative permittivity of up to 4 with a resolution of 0.1 and a thickness ranging from 5 μm to 600 μm with a resolution of 0.5 μm. To the best of author’s knowledge, such a THz sensor with such capabilities has not been reported yet. Additionally, an equivalent circuit of the novel unit cell is derived and compared with two conventional grooved structures to showcase the superiority of the proposed unit cell. The proposed spectroscopy technique utilizes some unique spectral features of a broadband reflection wave including Accumulated Spectral power (ASP) and Averaged Group Delay (AGD), which are independent to resonance frequencies and can operate over a broad range of spectrum. ASP and AGD can be combined to analyse the magnitude and phase of the reflection diagram as a coherent technique for sensing purposes. This enables the capability to distinguish between different analytes with high precision which, to the best of author’s knowledge, has been accomplished for the first time. [ABSTRACT FROM AUTHOR]

This paper investigates coupling between electromagnetic surface waves on parallel wires. Finite-element method (FEM)-based and analytic models are developed for single- and double-wire Sommerfeld and Goubau lines. Models are validated via measurements for Goubau lines and a comparison between the analytic and the FEM-based computations for coupled Sommerfeld- and Goubau-type lines is carried out. The measurements and calculations show remarkable agreement. The FEM-based and analytic models match remarkably well too. The results exhibit new favourable effects for surface waves propagation over multiple conductors. The short-range behaviour of the coupled wires and, consequently, the existence of an optimum separation of coupled wires is one of the most significant findings of this paper. We comment on the relevance of our results, particularly in relation to applications of high bandwidth demands and cross-coupling effects. [ABSTRACT FROM AUTHOR]

• A novel antenna is designed for plasma current drive using lower hybrid wave. • The antenna consists of a periodic fin array and was named finline antenna. • The wave propagation on fin array is used the electromagnetic surface wave. • The propagation wave on the fin array and radiation wave in the plasm is simulated by the COMSOL simulation code. • At perform the antenna operation test to the TST-2 plasma, increase of the X-ray was confirmed. A novel "finline" antenna was designed to excite lower-hybrid waves (LHWs) for plasma current drive at 2.45 GHz in the TST-2 spherical tokamak. A periodic fin array acts as a transmission line for electromagnetic surface waves. Cold tests confirmed propagation of the electromagnetic surface wave on the fin array which was dominantly Transverse Magnetic (TM). Unlike the conventional waveguide array "grill" antenna, the finline antenna requires only two ports to feed all the elements, and calculations show that there is little reflection regardless of the plasma conditions in front of the antenna. Characteristics of the microwave transmission on the fin array were investigated using a three-dimensional full-wave simulation and the fin geometry was tuned to achieve the desired refractive index. Coupling to LHWs under typical TST-2 scrape-off layer conditions was confirmed by the simulation. To demonstrate LHW excitation, the finline antenna was energized in the presence of a plasma generated by another 200 MHz LH antenna. The x-ray radiation showed strong enhancement during the finline antenna pulse which indicated successful generation of fast electrons by LHWs. [ABSTRACT FROM AUTHOR]

Electromagnetic surface wave propagation on a corrugated metal plate is confirmed by a cold test in the X-band. The measured cut-off frequency is almost in agreement with the theoretical cut-off frequency. The propagation is damped at a frequency region higher than the cut-off frequency. The periodicity of the propagation power to the frequency is confirmed. For the confirmation of these characteristics, it is necessary that the corrugated metal plate is enclosed within a microwave absorber. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes the exploration of a sensor concept for use in structural health monitoring. The sensor is based on the principle of electromagnetic (EM) surface wave propagation, and consists of a thin-layer of wave-guiding media attached to a metal base (e.g., steel bridge elements) and an EM wave emitter and receiver. Targeting at a low-cost and practical solution, various dielectric materials that facilitate EM wave propagation were examined. Low-density polyethylene was determined to have the most suitable dielectric properties and was selected for laboratory tests using tension coupon specimens. The tests of steel coupons with a low-density polyethylene strip indicated that the parameters of an EM wave (e.g., amplitude and phase) changed as the coupon specimens deformed. Therefore, the proposed sensor concept based on EM surface wave propagation can be a viable option for monitoring steel bridges. [Copyright &y& Elsevier]

The tangential component of the electric field of a surface wave at any distance from the transmitting antenna lying in the interface plane of two homogeneous media can be represented in terms of a function of two complex variables Ŵ( q,ξ) for arbitrary parameters of the interface. In this paper, representations of the function Ŵ( q,ξ) in the form of series are given that allow one to quickly calculate the values of Ŵ( q,ξ) and to investigate the analytic properties of this function. The dependence of the field of the surface wave on time is determined using the inverse Laplace transform, where the path of integration is chosen in such a way that the integrand rapidly decreases at infinity, which drastically improves the computation speed compared with the method based on the Fourier transform. [ABSTRACT FROM AUTHOR]

Fundamental wave propagation mechanisms for intra-chip communications in a multilayered IC chip structure are studied theoretically and numerically. The well-known Green's function representation in terms of branch cuts (continuous spectrum), residues (discrete spectrum), and direct source-receiver radiation is used to clarify important wave processes for typical intra-chip antenna structures. It is found that surface waves may or may not provide the dominant propagation channel contribution, depending on frequency and chip structure. We generalize the concept of multipath to include multiple spectral (e.g., discrete and continuous) wave components, appropriate for the near- and intermediate-field problems of interest for chip-scale propagation. The effect of a guiding layer placed either below or above the silicon substrate is considered. It is found that a guiding layer can provide enhanced single-channel signal transmission via the surface wave channel, and thereby reduce dispersion associated with multi wave component effects. [ABSTRACT FROM AUTHOR]