Effects of Random Positioning Errors Upon Electromagnetic Characteristics of a Wire Grid

Journal of Electromagnetic Waves and Applications

2014

A uniaxial wire medium is a medium formed by a two-dimensional array of conducting parallel thin wires. An analytical study of small imperfections in positioning of wires is considered for an equivalent surface impedance of this wire medium. It is studied that effects of these small imperfections in positioning of wires introduce an equivalent additional surface impedance. This additional impedance is taken to be an error impedance which is mainly dependent upon the positioning error standard deviations along two orthogonal directions. It is further studied that an increase in the positioning error standard deviations along two perpendicular directions increases the magnitude of this error impedance. Also, if the propagation of wave is taken to be normal inside the wire medium then the effects of imperfections in a plane along direction of propagation are more pronounced than these imperfections in a plane transverse to the direction of propagation.

“…The factor Z w is the axial impedance per unit length of a conducting wire and is given by [48,49]. For perfectly conducting wires, this factor is zero, i.e.…”

Section: A Uniaxial Periodic Wire Mediummentioning

confidence: 99%

Imperfections for an equivalent surface impedance of a uniaxial wire medium

Journal of Electromagnetic Waves and Applications

2014

“…The impedance properties of a wire grid with different background media have been of an interest to scientific community because of their important technical applications [1–21]. They have applications in impedance matching, filters, artificial dielectrics or lens, electromagnetic shields, screens, antenna reflectors, and epsilon negative metamaterials.…”

Section: Introductionmentioning

confidence: 99%

“…A two-dimensional extension of a wire grid can be taken as a wire medium or epsilon-negative metamaterial and have been studied by Belove et al [14] and by Awan [15]. The impedance characteristics of a parallel wire grid with the free space background have been studied by many authors [16–21]. A study of impedance properties of a parallel wire grid under oblique angles of incidence has been carried out by Macfarlane [16] and Marcuvitz [17].…”

Section: Introductionmentioning

confidence: 99%

“…Yatsenko et al [20] concluded that if the spacing among wires is equal to the free space wavelength then the wire grid becomes transparent to the incoming wave. The effects of positioning errors upon the impedance, reflection, and transmission properties of a parallel wire grid with the free space background have been investigated by Awan [21]. He found that by increasing the positioning errors in the wires of the grid increases the magnitude of surface impedance.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Surface impedance properties of a wire grid embedded in a chiral medium

Int. J. Microw. Wireless Technol.

2019

Self Cite

The surface impedance characteristics of a wire grid composed of infinitely long parallel conducting wires embedded in lossless and lossy frequency-dispersive chiral background media have been investigated. Using wavefield decomposition approach for a chiral background and with the application of impedance boundary conditions for a wire grid, an analytic expression for the surface impedance of a wire grid with a chiral background has been derived. It is shown that the surface impedance magnitude of a wire grid with chiral nihility background is close to zero and almost independent of incident polar angles. A strong chiral background significantly enhances the surface impedance magnitude of a wire grid for incident polar angles closer to right angle as compared to the free space background. The same electromagnetic appearance of a wire grid with frequency-dispersive chiral and free space background media at some critical frequency has also been discussed which may find applications in electromagnetic illusions. It is also shown that if the value of incident polar angles are closer to right angle then the impedance magnitude of a wire grid embedded in the realistic chiral background is smaller as compared to the same wire grid when placed in the free space background.

“…This is the study of a current paper. Random errors in positioning of a wire grid composed of infinitely long conducting wires has been discussed in [12].…”

Section: Introductionmentioning

confidence: 99%

Effects of Random Errors Upon Effective Permittivity of a Composite Containing Short Needles

Rizvi²

2011

PIER M

Abstract-A composite medium containing perfectly conducting short needles can have a range of frequency for which the real part of the effective permittivity of the composite is negative. Such a range of frequency can be taken as negative bandwidth. This negative bandwidth for a composite medium is dependent upon parameters like positioning, orientation, length and needle density of short needles. Effects of random errors in positioning and orientation of short needles upon the ensemble averaged effective permittivity are analyzed. It is studied theoretically that increasing error in positioning and orientation of short needles reduces negative bandwidth.