Comparison of Luebbers' and Maliuzhinets' Wedge Diffraction Coefficients in Urban Channel Modelling

Aïdi, M.; Lavergnat, J.

doi:10.2528/pier00112005

Cited by 16 publications

(32 citation statements)

References 16 publications

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“…Alternatively, the MZ is another option for solving the configuration with the thin material discontinuities. All of these solutions [10][11][12][13][14][15] are based on the MZ method. Unlike W-H and MZ solutions, the solution developed in this work recover the proper local plane wave Fresnel reflection and transmission coefficients (FRTCs), and surface wave constants, respectively, for the actual material, and they also allow the material to be both double positive (DPS) or double negative (DNG).…”

Section: (A)mentioning

confidence: 99%

“…It is necessary to introduce this unknown constant in this 3-D situation to suppress the nonphysical poles, which may occur in the tangential field components E z and H z for the skew incidence case. In addition, this unknown constant W will make the 3-D PWS integral in (13) to recover the 2-D PWS integral when β o → π/2 or at normal incidence. This unknown constant W will be determined later.…”

Section: Ansatz For the Obliquely Incident Plane Wave Illumination Camentioning

confidence: 99%

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An Approximate Utd Ray Solution for the Radiation and Scattering by Antennas Near a Junction Between Two Different Thin Planar Material Slab on Ground Plane

Lertwiriyaprapa¹,

Pathak²,

Volakis³

2010

PIER

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Abstract-A new, approximate, uniform geometrical theory of diffraction (UTD) based ray solutions are developed for describing the high frequency electromagnetic (EM) wave radiation/coupling mechanisms for antennas on or near a junction between two different thin planar slabs on ground plane. The present solution is obtained by extending the normal incidence solution in order to treat the more general case of skew (or oblique) incidence (three-dimensional 3-D). Plane wave (for oblique or skew incidence) and spherical wave illumination are all considered in this work. Unlike most previous works, which analyze the plane wave scattering by such structures via the Wiener-Hopf (W-H) or Maliuzhinets (MZ) methods, the present development can also treat problems of the radiation by and coupling between antennas near or on finite material coatings on large metallic platforms. In addition, the present solution does not contain the complicated split functions of the W-H solutions nor the complex MZ functions. Unlike the latter methods based on approximate boundary conditions, the present solutions, which are developed via a heuristic Corresponding author: T. Lertwiriyaprapa (ttp@kmutnb.ac.th). 228Lertwiriyaprapa, Pathak, and Volakis spectral synthesis approach, recover the proper local plane wave Fresnel reflection and transmission coefficients and surface wave constants of the material slabs. There is a very good agreement, with less than ±1 dB differences when the numerical results based on the presented UTD solution for a material junction are compared with that of the MZ solution.

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Section: (A)mentioning

confidence: 99%

Section: Ansatz For the Obliquely Incident Plane Wave Illumination Camentioning

confidence: 99%

An Approximate Utd Ray Solution for the Radiation and Scattering by Antennas Near a Junction Between Two Different Thin Planar Material Slab on Ground Plane

Lertwiriyaprapa¹,

Pathak²,

Volakis³

2010

PIER

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“…A perturbation technique is developed to determine an approximate field solution. Furthermore [3], examines the question of the choice between two kinds of diffraction coefficients used to model urban channels. Scattering by wedge structures is analyzed to explain the motivation of the choice.…”

Section: Introductionmentioning

confidence: 99%

On smoothening the singular field developed in the vicinity of metallic edges

Valagiannopoulos

2009

International Journal of Applied Electromagnetics and Mechanics

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Metallic wedges can be considered as parts of corner reflectors, open-ended waveguides, transmission lines and other devices with polygonal shape existing in an electromagnetics laboratory. The fields developed in the vicinity of these conducting edges possess substantial magnitudes which can affect negatively the conducted experiments and the measurement procedures. In this work, a cylindrical cap of lossy material is used to weaken the damaging radiation of the edge. The influence of the cylinder's radius, the material's permittivity and conductivity and the angular extent of the wedge on the interfering field is illustrated through various numerical examples.

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“…Here, Fresnel reflection coefficient, , are calculated with angle and as per angular definition of Aidi and Lavergnat [9] given as…”

Section: Available Heuristic Diffraction Coefficientmentioning

confidence: 99%

“…However, these coefficients were neither reciprocal nor symmetrical. In [7], a reciprocal heuristic coefficient was defined that used the angle definition proposed by Aidi et al [9] and showed good agreement over other available coefficients. However, this showed the reciprocity property only when the transmitter (Tx) and the receiver (Rx) were either side of the wedge.…”

Section: Introductionmentioning

confidence: 99%

A Novel Symmetrical Heuristic Coefficient for Urban Microcellular Environments

Chauhan¹

2012

IJIEE

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Abstract-A novel heuristic diffraction coefficient is presented which is perfectly reciprocal and symmetrical. The prediction obtained using proposed coefficient is compared with that obtained using rigorous Maliuzhinets' solution. It is shown that the proposed coefficient is more efficient than available diffraction coefficient. The comparison is made for both soft and hard polarization. Further, the applicability of proposed coefficient in complex urban scenario is demonstrated by applying the coefficient in the city of Ottawa. IndexTerms-Deterministic propagation model, microcellular scenario, ray tracing, uniform theory of diffraction (UTD). I. INTRODUCTIONGeometrical theory of diffraction (GTD) [1] and Uniform theory of diffraction (UTD) [2] are high frequency asymptotic solution to the problem of diffraction by a wedge. The modeling of wireless propagation channel based on deterministic approach is usually performed using Geometrical theory of diffraction (GTD) and its extension uniform theory of diffraction (UTD) [1], [2]. GTD gives fair prediction of the diffracted field at the points away from the shadow boundaries but fails to predict the field at the shadow boundaries. Uniform theory of diffraction which is an extension of GTD is based on Clemmow method of steepest descent gives continuous field at the boundaries (though not accurate). In order to make the UTD applicable for lossy dielectric wedge, this is modified by Luebbers [3] by heuristically incorporating Fresnel reflection coefficient as a multiplying factor to the components of diffraction coefficient. As a result, the coefficient becomes applicable for dielectric wedge. However, it lacks accuracy in certain region such as shadow region (e.g. See [4], Fig.13, 14). Holm [5] proposed modification of the original Luebbers coefficient by modifying the multiplying factors to be used in the coefficient. This resulted in the improvement in the accuracy of shadow region. However, Holm's coefficient lacked accuracy in the illumination region. The modification to Luebbers formulation was proposed by Kate A. Remley et al. [4] who modified the angles to be used in the calculation of Reflection coefficient. As a result, this improved the accuracy in the shadow region. coefficient was proposed by . In this, for exterior and interior wedge both, the angle definition used in Fresnel reflection coefficient in the calculation of diffraction coefficient were defined extensively. They show good agreement with the rigorous Maliuzhinets solution. However, these coefficients were neither reciprocal nor symmetrical. In [7], a reciprocal heuristic coefficient was defined that used the angle definition proposed by Aidi et al. [9] and showed good agreement over other available coefficients. However, this showed the reciprocity property only when the transmitter (Tx) and the receiver (Rx) were either side of the wedge. When the Tx and Rx were both on the same side, it was not reciprocal. Moreover, it does not show symmetry property.The present work proposes the heuris...

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Comparison of Luebbers' and Maliuzhinets' Wedge Diffraction Coefficients in Urban Channel Modelling

Cited by 16 publications

References 16 publications

An Approximate Utd Ray Solution for the Radiation and Scattering by Antennas Near a Junction Between Two Different Thin Planar Material Slab on Ground Plane

An Approximate Utd Ray Solution for the Radiation and Scattering by Antennas Near a Junction Between Two Different Thin Planar Material Slab on Ground Plane

On smoothening the singular field developed in the vicinity of metallic edges

A Novel Symmetrical Heuristic Coefficient for Urban Microcellular Environments

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