Perfectly conducting tape-helix model for guided electromagnetic wave propagation

Kalyanasundaram, N.; Babu, G. Naveen

doi:10.1049/iet-map.2011.0446

Cited by 12 publications

(7 citation statements)

References 9 publications

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“…By enforcing the boundary conditions E z = 0 and E j = 0 at ρ = b, the arbitrary constants C n ′ and D n ′ , n ∈ ℤ in (5) and (6) have been evaluated in terms of C n and D n to be C n ′ = − C n σ bn and…”

Section: Problem Formulationmentioning

confidence: 99%

“…where J (f, z) and J ⊥ (f, z) are the parallel and the perpendicular components of the surface current density, which is confined only to the tape surface, characterised by the axial and the angular components as J J ⊥ = sin cos cos −sin J z J f and the function g(f, z), defined in terms of the indicator functions of the disjoint (for the same value of f) intervals [3][4][5][6][7],…”

Section: Boundary Conditionsmentioning

confidence: 99%

“…behaves asymptotically due to the order being (1/|n|) for nth term of the infinite series as n approaches large values, resulting in a divergent solution. The physical explanation in [6] relates to infinite accumulation of surface charge at the tape edges due to the perpendicular surface current density component,Ĵ ⊥ . From (14) and (15), since the sinc 2 k − n ( )ŵ function is a resultant of the Fourier transform of the indicator function 1 −ŵ/2 ,ŵ/2 [ ] computed at 2π(k − n), to resolve the divergence problem, the corners of the indicator function is smoothened out by convolving it with a smooth, non-negative, compactly supported mollifier function [6] given below.…”

Section: Boundary Conditionsmentioning

confidence: 99%

“…The method of solving the boundary value problem in an open tape helix for the anisotropically conducting model was presented for the first time in [4] without making any a priori assumption about the tape-current distribution. The work was extended for perfectly conducting model of open tape helix SWSs by Kalyanasundaram and Babu [5,6] in which the perpendicular component of the surface tape current density is considered for the analysis. In [7], the method of determining the dispersion equation for the practically important case of an anisotropically conducting dielectric-loaded tape-helix enclosed in a coaxial perfectly conducting cylindrical shell was proposed.…”

Section: Introductionmentioning

confidence: 99%

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Propagation of electromagnetic waves guided by perfectly conducting model of a tape helix supported by dielectric rods

Babu

Stanislaus

2016

IET Microwaves, Antennas & Propagation

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The homogeneous boundary value problem existing in the electromagnetic wave propagation in a dielectric‐loaded perfectly conducting tape helix with infinitesimal tape thickness is investigated in this study. The ill‐posed boundary value problem is regularised using the mollification method. The homogeneous boundary value problem is solved for the dielectric loaded perfectly conducting tape helix taking into account the exact boundary conditions for the perfectly conducting dielectric loaded tape helix. The solved approximate dispersion equation takes the form of the solvability condition for an infinite system of linear homogeneous equations namely, the determinant of the infinite order coefficient matrix is zero. For the numerical computation of the dispersion equation, all the entries of the symmetrically truncated version of the coefficient matrix are estimated by summing an adequate number of the rapidly converging series for them. The tape‐current distribution is estimated from the null‐space vector of the truncated coefficient matrix corresponding to a specified root of the dispersion equation. The numerical results suggest that the propagation characteristic computed by the anisotropically conducting model (that neglects the component of the tape‐current density perpendicular to the winding direction) is only an abstinent approximation to consider for moderately wide tapes.

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Section: Problem Formulationmentioning

confidence: 99%

Section: Boundary Conditionsmentioning

confidence: 99%

Section: Boundary Conditionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Propagation of electromagnetic waves guided by perfectly conducting model of a tape helix supported by dielectric rods

Babu

Stanislaus

2016

IET Microwaves, Antennas & Propagation

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“…This method has subsequently been extended to solving the problem of guided electromagnetic wave propagation through an open tape helix for the perfectly conducting model in [3]. Beginning with the fundamental work of Sensiper [4] until the publication of [1], all the published derivations [5][6][7][8] of the propagation characteristics of electromagnetic waves guided by an open helical slow-wave structure, modeled invariably to be an anisotropically conducting tape helix, were based on some ad hoc assumption about the tape-current distribution.…”

Section: Introductionmentioning

confidence: 99%

Propagation of Electromagnetic Waves Guided by the Anisotropically Conducting Model of a Tape Helix Supported by Dielectric Rods

Kalyanasundaram¹,

Babu²

2013

PIER B

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Abstract-The practically important case of a dielectric-loaded tape helix enclosed in a coaxial perfectly conducting cylindrical shell is analysed in this paper. The dielectric-loaded tape helix for guided electromagnetic wave propagation considered here has infinitesimal tape thickness and infinite tape-material conductivity. The homogeneous boundary value problem is solved taking into account the exact boundary conditions similar to the case of anisotropically conducting open tape helix model [1,2]. The boundary value problem is solved to yield the dispersion equation which takes the form of the solvability condition for an infinite system of linear homogeneous algebraic equations viz., the determinant of the infiniteorder coefficient matrix is zero. For the numerical computation of the approximate dispersion characteristic, all the entries of the symmetrically truncated version of the coefficient matrix are estimated by summing an adequate number of the rapidly converging series for them. The tape-current distribution is estimated from the null-space vector of the truncated coefficient matrix corresponding to a specified root of the dispersion equation.

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Numerical and computational analysis of radiation characteristics of dielectric loaded helical antenna

Pandey

Pathak

2021

Int J RF Microw Comput Aided Eng

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In this paper, a full-wave analytical theory has been proposed based on the field theory approach and numerically solved for computing radiation properties of the dielectric-loaded helical antenna (DLHA). First, the dispersion equation is analytically derived from the source-free Maxwell equation subject to necessary boundary conditions. Then radiation characteristics of DLHA are derived using the field theory approach. The effect of polarization current arising due to dielectric on radiation properties is addressed for the first time in the case of DLHA. All the numerical analysis is carried out in MATLAB. To further validate the results, computation analysis is carried out using CST Microwave Studio Software. From the result, it was observed that when the circumference of the antenna (C) is comparable to the wavelength (λ) corresponding to operating frequency then the wave propagates axially through the helical wire in the axial direction and is radiated in the end-fire direction whereas when the circumference is not equal to the wavelength then the wave gets radiated in the normal direction and attenuated in the axial direction. Also, the impedance bandwidth of the antenna is increased from 2.5% to 52.9% and the gain is increased from 8.35 dB to 11.5 dB due to teflon loading. Finally, the antenna prototype is fabricated, measured, and compared with the numerical and computational results. A close agreement between the analytical, computational, and measurement results are found.

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Perfectly conducting tape-helix model for guided electromagnetic wave propagation

Cited by 12 publications

References 9 publications

Propagation of electromagnetic waves guided by perfectly conducting model of a tape helix supported by dielectric rods

Propagation of electromagnetic waves guided by perfectly conducting model of a tape helix supported by dielectric rods

Propagation of Electromagnetic Waves Guided by the Anisotropically Conducting Model of a Tape Helix Supported by Dielectric Rods

Numerical and computational analysis of radiation characteristics of dielectric loaded helical antenna

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