Input Admittances Arising From Explicit Solutions to Integral Equations for Infinite-Length Dipole Antennas

Abstract

Abstract-When one uses integral equations to determine the input admittance of dipole antennas, one must choose between two kernels, the exact and the approximate kernel, and also between (at least) two types of feed, the delta-function generator and the frill generator. For dipole antennas of infinite length, we investigate-analytically and numerically-the similarities and differences between the various admittance values. Particular emphasis is placed on the fact, discussed in detail in recent publications, that certain combinations lead to nonsolvable integral equations.

On the Equivalent Radius of a Radiating Slot in Impedance Calculations

“…The values obtained are in perfect agreement with those obtained for a dipole antenna using induced emf method [12]. Further, for 2L = λ/2, one of the factors, assumes 0/0 form when φ is odd multiple of π/2, for θ = π/2 in (18) and θ = 0 in (20). In the process of the evaluation of the integrals, the limiting value of 0/0 form is evaluated using L Hospital's theorem.…”

“…However if 2L ∼ λ/2 i.e., in the immediate vicinity of the λ/2 it is possible to derive closed form expressions for these integrals with the help of some approximations [6][7][8]. With these simplifications the expressions in (18), (20) reduces to,…”

“…The results for the radiation resistance and input reactance of a planar dipole antenna of width 2w and length 2L computed from the numerical evaluation of integration in (18) and (20) where standard X-band waveguide parameters have been taken is shown in Fig. 2.…”

“…Hallen [10] has found the radius of the equivalent cylindrical dipole using static field considerations. Warne et al [13] evaluated the equivalent radius for narrow slots in terms of the solution to the Hallen's integral equations [10,19,20] using Galerkin method with piecewise sinusoidal function. Rhodes [8] has established the equivalence between a planar and cylindrical dipole using spectral domain approach.…”

Hybrid Tdie-Tdpo Method for Studying on Transient Responses of Some Wire and Surface Structures Illuminated by an Electromagnetic Pulse

“…In the study of EMC and EMI problems of various communication systems, we often require wideband transient responses of many perfectly conducting objects with arbitrary geometries in the presence of one or more electromagnetic interference signals [1][2][3][4][5][6][7][8][9][10]. We know that time-domain electric field integral equation (TD-EFIE) technique [11][12][13][14][15][16][17][18][19] has been used for studying many scattering, radiation and signal transmission problems in the time domain.…”