Perfect Electromagnetic Conductor Research Articles

The study of the radar cross section of perfect electromagnetic conductor strip

In this article, we study the radar cross section (RCS) of a perfect electromagnetic conductor (PEMC) strip which is supposed to be placed in the four different soil materials respectively. Using the duality transformation introduced by Lindell and Sihvola, an analytic theory is developed and the radar cross section of the PEMC strip is evaluated. PEC and PMC are the limiting cases of PEMC, where there is no cross-polarized component. Finally the numerical results of RCS of the PEMC Strip are discussed and compared with the standard graphs.

Investigation of uniaxial anisotropic chiral metamaterial waveguide with perfect electromagnetic conductor loading

The paper presents investigations of the electromagnetic characteristics of circular waveguides made of uniaxial anisotropic chiral medium; the outer surface of the guide being coated with a PEMC (perfect electromagnetic conductor) medium. The emphasis is given on the energy flux density patterns of such guides with varieties of anisotropic chiral materials. Dispersion relation of the guide is developed, and followed by the evaluation of sustained modes, which determine the energy flux density patterns corresponding to different low-order hybrid modes. The flux density characteristics provide the evidence of existing backward waves in uniaxial anisotropic mediums, contributing more to the phenomenon of slow light in chiral metamaterials.

Numerical analysis of scattering from cylindrical structures coated by layers having inhomogeneity in both radial and azimuthal directions

In this study, the problem of electromagnetic scattering from cylindrical structures with multi-layered coating having inhomogeneity in both radial and azimuthal directions is investigated. The core of the structure may be perfect electric conductor, perfect magnetic conductor, perfect electromagnetic conductor, impedance surface, dielectric or metamaterial. The previous investigations have been restricted to a special case, for example, coatings with only radial inhomogeneity, normal incidence etc. Moreover, in these investigations only single layer coatings are considered and the analysis is based on modelling inhomogeneous coating by homogeneous layers. However, in this study, for the first time, electromagnetic scattering from cylindrical structures coated by multilayered inhomogeneous coating is considered in the most general case for any arbitrary number of layers, incident angle and polarisation. The analysis is based on finite difference method which is a common method in solving engineering electromagnetic problems and the inhomogeneous coating is not approximated by homogeneous layers. The validity of the proposed method is verified through some comprehensive examples. Comparing the results of the proposed method with exact solutions and the results obtained from other commonly used methods in the literature, it is confirmed that the method is simple, fast, accurate and valid for all inhomogeneous layers with continuous electromagnetic profiles.

Perfect Co-Circular Polarization Reflector: A Class of Reciprocal Perfect Conductors With Total Co-Circular Polarization Reflection

We establish a general class of reciprocal perfect conductors, namely perfect co-circular polarization (CP) reflector, from which the reflected waves are completely co-polarized when a circularly polarized electromagnetic (EM) wave impinges on it, in contrast to a conventional perfect conductor like a perfect electric conductor (PEC), a perfect magnetic conductor (PMC) or their interpolated version as a perfect electromagnetic conductor (PEMC). We discuss the impedance boundary conditions and the reflection characteristics of the perfect conductors, including perfect co-CP reflectors and perfect cross-CP reflectors, in terms of a circularly polarized EM wave. We also discuss the realization of one of the perfect co-CP reflectors approximated by coating a layer of anisotropic, yet lossless and reciprocal, material on a PEC. In addition, we discuss its realization using metamaterial structures.

Dispersion characteristics of optical fibers under PEMC twists

Electromagnetic behavior of twisted clad optical fibers is investigated under the situation of sheath helix of perfect electromagnetic (PEMC) conductor introduced at the core–clad interface. The eigenvalue equation for the structure is deduced by applying suitable boundary conditions, and the dispersion behavior of the fiber is analyzed considering the cases of non-dispersive as well as dispersive core with the sustainment of a few low-order modes. The effect on dispersion properties is observed due to alterations in the pitch angle of helical twists as well as the admittance value of the PEMC material. It has been found that the pitch angle and the admittance values can be properly adjusted to attain the degenerate properties of modes which would find many applications in optics industry.

Mimicking the Perfect Electromagnetic Conducting Scattering Mechanisms with Suitable Bi-Isotropic Media

The perfect electromagnetic conducting boundary is an intriguing conception with multiple potential applications; however, the physical mechanisms that can simulate a similar behavior is not yet completely identified. This work considers an electrically small cylindrical perfect electromagnetic conducting boundary for which the scattering effect is mimicked by suitable bi-isotropic media. The derivation of their optimal parameters is based on the Taylor expansion of the omni-directional terms; nonetheless, a post-correction is required to obtain reliable results for any kind of excitation and for any spatial harmonic. However, the advantage of this optimal solution is its non-extremal magnitudes, which render the practical realization more feasible. The present study, which is valid only for a thin perfect electromagnetic conducting wire, could play the role of the unit cell when treating more sizable perfect electromagnetic conducting configurations of arbitrary shape and curvature.

Magnetic line source diffraction by a perfect electromagnetic conductor (PEMC) step

In this paper, an analytic theory for the magnetic line source diffraction by a perfect electromagnetic conductor (PEMC) step is developed. Using the duality transformation, introduced by Lindell and Sihvola, transformations have been made from the diffraction of a magnetic line source by a perfect electric conductor (PEC) step. As an application, plane wave diffracted from a planar interface of air and PEMC media is studied. PEC and PMC are the limiting cases, while there is no cross-polarized component.

Scattering of electromagnetic wave from perfect electromagnetic conductor cylinders placed in un-magnetized isotropic plasma medium

The two dimensional analytical formulation of scattering of electromagnetic wave from a perfect electromagnetic conductor (PEMC) cylinder placed in un-magnetized isotropic plasma medium is presented. The extended classical scattering theory is used. The incident wave is taken as linearly polarized wave. The analytical theory is formulated for parallel polarization (TM) and also for perpendicular polarization (TE). The numerical computation results show that backscattering and forward scattering are sensitive to electron density and effective collision frequency of plasma medium. We placed different types of cylinders (PEC, PMC and PEMC) in un-magnetized plasma medium and concluded that stealth capability of plasma increases with the placement of PEMC cylinder in plasma medium.

Analysis of waveguides containing EMCs (electromagnetic conductors) or PEMCs (perfect electromagnetic conductors)

The concept of a perfect electromagnetic conductor (PEMC) was introduced to generalize and unify two well-known and apparently disjoint concepts in electromagnetics: the perfect electric conductor (PEC) and the perfect magnetic conductor (PMC). Although the PEMC has proven a fertile tool in electromagnetic analyses dealing with new and complex boundaries, its corresponding definition as a medium has, nevertheless, raised several problems. In fact, according to its initial 3D definition, the PEMC cannot be considered a unique and well-defined medium: it leads to extraneous fields without physical meaning. By using a previously published generalization of a PEMC that regards this concept both as a boundary and as a medium – which was dubbed an MIM (Minkowskian isotropic medium) and acts, in practice, as an actual electromagnetic conductor (EMC) – it is herein presented a straightforward analysis of waveguides containing PEMCs that readily and systematically follows from the general framework of waveguides containing EMCs.

Frictionless contact of a functionally graded magneto-electro-elastic layered half-plane under a conducting punch

This paper investigates the two-dimensional frictionless contact problem of a functionally graded magneto-electro-elastic materials (FGMEEMs) layered half-plane under a rigid flat or a cylindrical punch. It is assumed that the punch is a perfect electro-magnetic conductor with a constant electric potential and a constant magnetic potential. The magneto-electro-elastic (MEE) properties of the FGMEEM layer vary exponentially along the thickness direction. Using the Fourier transform technique, the contact problem can be reduced to Cauchy singular integral equations, which are then solved numerically to determine the normal contact stress, electric displacement and magnetic induction on the contact surface. Numerical results show that the gradient index, punch geometry and magneto-electro-mechanical loads have a significant effect on the contact behavior of FGMEEMs.

Electromagnetic scattering from anisotropic plasma-coated perfect electromagnetic conductor cylinders

The scattering of electromagnetic waves by a perfect electromagnetic conductor (PEMC) cylinder coated with a homogeneous plasma anisotropic material is studied in this paper. Both of the transverse electric and the transverse magnetic polarizations of the incident waves have been analyzed and formulated. The presented analysis and formulations are general for any perfect conductor cylinder (PEC, PMC, or PEMC) with general isotropic/anisotropic material coatings that include plasma and metamaterials. The co-polarized and the cross-polarized components of the scattered fields are computed for different cases of the anisotropic plasma coated PEMC cylinders and for an anisotropic plasma column. Bistatic echo widths for the cases of PEMC, PEC (perfect electric conductor) and PMC (perfect magnetic conductor) cores have been computed and compared. The behavior of the monostatic echo width with the variation of the admittance parameter for the co-polarized and the cross polarized fields is also investigated. The comparisons of the computed results of the presented formulations with the published results of some special cases confirm the accuracy of the presented analysis.

Diffraction of a plane wave by a perfectly electromagnetic conducting (PEMC) slot

Using the duality transformations introduced by Lindell and Sihvola, an analytic theory for the electromagnetic diffraction from a perfect electromagnetic conductor (PEMC) slot is developed. Transformations have been applied to the diffracted field of a plane wave from a perfect electric conductor (PEC) slot. The problem was solved by using the Sommerfeld Green’s function and Fresnel integral.

Scattering from a buried perfect electromagnetic conductor of circular cylindrical shape and coated by a chiral material

The scattering effects of different types of chiral materials used as coating on a perfect electromagnetic conductor (PEMC) circular cylinder buried in a dielectric half space have been investigated in this paper. The coating layers of double positive (DPS) chiral, double negative (DNG) chiral, and chiral nihility have been considered in the analysis. The spectral plane wave solution is used to handle the multiple interactions between the buried cylinder and the dielectric interface separating the two half spaces. Numerical results obtained for scattering of a perpendicularly polarized electromagnetic plane wave from this configuration have been presented.

Modeling of the perfect electromagnetic conducting boundary in the finite difference time domain method

AbstractThe perfect electromagnetic conducting (PEMC) boundary, a nonreciprocal generalization of both perfect electric conducting (PEC) and perfect magnetic conducting (PMC) boundaries, is modeled in the finite difference time domain (FDTD) method. Since the PEMC boundary condition requires collocation of same components of both electric and magnetic fields at the boundary grids, which is not compatible with the original FDTD algorithm, its implementation in FDTD is challenging and requires modification in the algorithm. To do this task, first, the original FDTD cell is modified by inserting the required field components not present in the original cell. Then, a novel formulation is developed for updating fields' components at the boundary. Modeling of a PEMC planar interface, a corner point, and a wedge point are presented. Finally, numerical examples are presented to show stability, accuracy, and applicability of the proposed approach. Validation is achieved by comparisons with existing analytic methods and/or conventional FDTD for special cases of PEC and PMC boundaries.

Scattering of electromagnetic wave by perfect electromagnetic conductor (PEMC) sphere placed in chiral media

A theoretical investigation has been carried out for electromagnetic waves scattering from a perfect electromagnetic conductor (PEMC) sphere which is placed in chiral media. The formulation of the problem is realized by expanding the incident as well as the scattered electromagnetic fields in terms of left circularly polarized (LCP) and right circularly polarized (RCP) waves. By applying the boundary conditions at the chiral-PEMC interface, eight simultaneous equations are generated, which yield the scattering coefficients associated with the Left and Right electromagnetic waves. The relative contribution of Co-polarized and Cross-polarized components of fields to the calculations of scattering cross-section is presented. The effect of admittance parameter and the effect of chirality parameter in cases of lossless, lossy permittivity and lossy permeability on Co and Cross components of scattering cross sections are observed. The results are also compared with available published literatures which are in good agreement.

Diffraction by a perfectly electromagnetic conducting (PEMC) step

An analytic theory for the electromagnetic diffraction from a perfect electromagnetic conductor (PEMC) step is developed. By using the duality transformations introduced by Lindell and Sihvola, the diffracted field from a PEMC step has been evaluated. Transformations have been applied to a known problem, the diffracted field by a plane wave from a perfect electric conductor (PEC) step.

Electromagnetic fields in a circular waveguide with D'B'-boundary conditions internally coated with chiral-nihility medium

The present study deals with the propagation of electromagnetic fields and power in a circular waveguide, with D'B'- boundary conditions, internally coated with chiral-nihility medium. The electromagnetic fields inside the two layer circular waveguide defined by D'B'-boundary conditions, with one layer containing free space while other layer containing chiral- nihility medium, is investigated. D'B'-boundary conditions require vanishing of derivatives of the normal field components of D and B vectors, hence named as D'B'-boundary conditions. It has been investigated that unlike to the chiral-nihility coated perfect electromagnetic conductor (PEC) waveguide, there is a non-zero power transfer in chiral-nihility region in waveguide with D'B' boundary conditions.

Reflection From Stratified Media Backed by a Perfect Electromagnetic Conductor (PEMC)

Perfect electromagnetic conducting (PEMC) boundary is a generalization of both PEC and PMC boundaries, creating nonreciprocal reflection which could be cross-polarized with respect to the incident wave. In this communication, reflection from a stratified medium, backed by a PEMC boundary due to an oblique incident plane wave is calculated analytically. In general, the medium is considered as N layers of frequency dispersive bianisotropic media. Applying the PEMC boundary condition, the reflection dyadic is computed using the notion of propagators and wave-splitting technique. The method is validated through deriving the reflection dyadics of a plane wave from 1) PEC-backed stratified medium and 2) a PEMC-free space interface whose analytical expressions exist. Furthermore, few numerical examples illustrating the method as well as its applications are provided.

Plane wave scattering by a circular PEMC cylinder coated with anisotropic media

Analytical solution of plane wave scattering by a circular PEMC (Perfect Electromagnetic Conductor) cylinder coated with anisotropic media was presented in this article. When referred to principal axes (ρ, ϕ,z) in the anisotropic region, both permittivity and permeability tensors were biaxial and diagonal; so, the radial Eigen-functions were complex ordered Bessel's functions. The monostatic and bistatic scattering cross-sections of a PEMC cylinder coated with both of anisotropic DPS (double-positive) medium with positive values of relative permittivity and elements of permeability tensors and anisotropic DNG (double-negative) metamaterial with negative values of relative permittivity and permeability elements of tensors were calculated. The validity of the presented relations was achieved by comparing the results of specific cases of isotropic coated cylinder and anisotropic coated perfect electric conductor cylinder with those of previously published methods. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.

Minkowskian Isotropic Media and the Perfect Electromagnetic Conductor

The perfect electromagnetic conductor (PEMC) was introduced as an observer-independent “axion medium” that generalizes the concepts of perfect electric conductor (PEC) and perfect magnetic conductor (PMC). Following the original boundary definition, its 3-D medium definition corresponds to a 4-D representation that is, actually, observer-dependent (i.e., it is not isotropic for the whole class of inertial observers), leading to a nonunique characterization of the electromagnetic field inside. This characterization of the PEMC, then, violates the boundary conditions-unless some extraneous waves, called “metafields,” are surgically extracted from the final solution. In this paper, using spacetime algebra, we define the PEMC as the unique limit of the most general class of isotropic media in Minkowskian spacetime, which we call Minkowskian isotropic media (MIM). An MIM is actually a “dilaton-axion medium.” Its isotropy is a Lorentz invariant characterization: It is an observer-independent property, contrary to isotropy in 3-D Gibbsian characterization. Hence, a more natural definition of a PEMC is herein presented: It leads to a unique electromagnetic field in its interior; it corresponds, though, to the same original boundary definition. This new approach is applied to the analysis of an air-MIM interface that, as a particular case, reduces to an air-PEMC interface.