A UTD Based Asymptotic Solution for the Surface Magnetic Field on a Source Excited Circular Cylinder With an Impedance Boundary Condition

Tokgöz, Çağatay; Marhefka, R.J.

doi:10.1109/tap.2006.875490

Cited by 27 publications

(20 citation statements)

References 21 publications

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“…6. The value of surface impedance Z S of the thinly coated cylinder derived from the approximation of the problems was presented in [28]. The axis of cylinder is located along z-axis.…”

Section: Utd Canonical Problem and Equationsmentioning

confidence: 99%

Path-Loss Prediction of Radio Wave Propagation in an Orchard by Using Modified Utd Method

Phaebua¹,

Phongcharoenpanich²,

Krairiksh³

et al. 2012

PIER

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Abstract-In this paper, the proposed theoretical path-loss prediction procedure and measured results of radio wave propagation in an orchard environment are presented. The path-loss prediction of wireless sensor network (WSN) in a durian (Durio zibethinus Murray) orchard is chosen to be an example of this study. The threedimensional (3-D) modified uniform geometrical theory of diffraction (UTD) for curved impedance surface and the complex source point (CSP) technique for source modeling are employed for theoretical path-loss prediction in this paper. The orchard scenario is modeled using canonical geometries of UTD, such as a dielectric flat surface and cylindrical structures with an impedance surface to respectively represent ground and trees. Moreover, since the wireless sensor node is attached to the outside peel of a hanging durian fruit, the fruit partially acts as a wireless sensor node. Therefore, to obtain greater accuracy in the source radiation pattern, the Gaussian beam (GB) expansion via the CSP technique is used for source modeling. The path loss prediction from the proposed numerical procedure and the measured results are in good agreement. The proposed numerical procedure to calculate the path loss from actual scenario of the orchard is useful for network planning such as the pre-harvesting WSN system and other orchard scenarios.

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“…6. The value of surface impedance Z S of the thinly coated cylinder derived from the approximation of the problems was presented in [28]. The axis of cylinder is located along z-axis.…”

Section: Utd Canonical Problem and Equationsmentioning

confidence: 99%

Path-Loss Prediction of Radio Wave Propagation in an Orchard by Using Modified Utd Method

Phaebua¹,

Phongcharoenpanich²,

Krairiksh³

et al. 2012

PIER

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“…2(b), where Green's functions are extracted from the IBC and asymptotically treated. Asymptotic Green's functions for the electric field due to an electric source are the dual from those appearing in [4] but including a τ dependence on the surface impedance. Essentially, the Watson transformation is applied to the vector potentials calculated from IBC.…”

Section: A Hybrid Sd-utd With Ibcmentioning

confidence: 99%

“…Recently, a new UTD based asymptotic solution with impedance boundary conditions (IBC) has been introduced for surface field determination on a circular cylinder [4]. Current solution derives Green's functions transforming the original problem, a dielectric-coated PEC circular cylinder, into a equivalent problem, a circular cylindrical surface impedance, by setting an IBC.…”

Section: Introductionmentioning

confidence: 99%

Surface impedance characterization for UTD based solution with IBC for surface fields on a dielectric-coated PEC circular cylinder

Garcia-Aguilar

Šipuš

Sierra‐Pérez

2012

2012 6th European Conference on Antennas and Propagation (EUCAP)

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Abstract-A novel formulation for the surface impedance characterization is introduced for the canonical problem of surface fields on a perfect electric conductor (PEC) circular cylinder with a dielectric coating due to a electric current source using the Uniform Theory of Diffraction (UTD) with an Impedance Boundary Condition (IBC). The approach is based on a TE/TM assumption of the surface fields from the original problem. Where this surface impedance fails, an optimization is performed to minimize the error in the SD Green's function between the original problem and the equivalent one with the IBC. This new approach requires small changes in the available UTD based solution with IBC to include the geodesic ray angle and length dependence in the surface impedance formulas. This asymptotic method, accurate for large separations between source and observer points, in combination with spectral domain (SD) Green's functions for multidielectric coatings leads to a new hybrid SD-UTD with IBC to calculate mutual coupling among microstrip patches on a multilayer dielectric-coated PEC circular cylinder. Results are compared with the eigenfunction solution in SD, where a very good agreement is met.

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“…Another UTD solution for the scattering by a circular cylinder with an IBC, again in 2-D, was presented in [8]; this solution has a different form than the ones in [5], [6]. Other asymptotic solutions, valid also for three dimensional (3-D) cases, which deal with problems of surface fields excited by sources only when they are placed directly on an IBC circular cylinder are available in [9], [10]. In contrast, the present work is valid for the case of a source not near the cylinder, and is in a form which can be generalized to treat a fully 3-D convex surface with an IBC when it is illuminated by an arbitrary ray optical field incident from an arbitrary direction.…”

Section: Introductionmentioning

confidence: 99%

A Canonical UTD Solution for Electromagnetic Scattering by an Electrically Large Impedance Circular Cylinder Illuminated by an Obliquely Incident Plane Wave

Aguilar

Pathak

Sierra‐Pérez

2013

IEEE Trans. Antennas Propagat.

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Abstract-A uniform geometrical theory of diffraction (UTD) solution is developed for the canonical problem of the electromagnetic (EM) scattering by an electrically large circular cylinder with a uniform impedance boundary condition (IBC), when it is illuminated by an obliquely incident high frequency plane wave. A solution to this canonical problem is first constructed in terms of an exact formulation involving a radially propagating eigenfunction expansion. The latter is converted into a circumferentially propagating eigenfunction expansion suited for large cylinders, via the Watson transform, which is expressed as an integral that is subsequently evaluated asymptotically, for high frequencies, in a uniform manner. The resulting solution is then expressed in the desired UTD ray form. This solution is uniform in the sense that it has the important property that it remains continuous across the transition region on either side of the surface shadow boundary. Outside the shadow boundary transition region it recovers the purely ray optical incident and reflected ray fields on the deep lit side of the shadow boundary and to the modal surface diffracted ray fields on the deep shadow side. The scattered field is seen to have a cross-polarized component due to the coupling between the TE¡. and TM¡. waves (where z is the cylinder axis) resulting from the IBC. Such cross-polarization vanishes for normal incidence on the cylinder, and also in the deep lit region for oblique incidence where it properly reduces to the geometrical optics (GO) or ray optical solution. This UTD solution is shown to be very accurate by a numerical comparison with an exact reference solution.

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A UTD Based Asymptotic Solution for the Surface Magnetic Field on a Source Excited Circular Cylinder With an Impedance Boundary Condition

Cited by 27 publications

References 21 publications

Path-Loss Prediction of Radio Wave Propagation in an Orchard by Using Modified Utd Method

Path-Loss Prediction of Radio Wave Propagation in an Orchard by Using Modified Utd Method

Surface impedance characterization for UTD based solution with IBC for surface fields on a dielectric-coated PEC circular cylinder

A Canonical UTD Solution for Electromagnetic Scattering by an Electrically Large Impedance Circular Cylinder Illuminated by an Obliquely Incident Plane Wave

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