scholarly journals The Evaluation of an Asymptotic Solution to the Sommerfeld Radiation Problem Using an Efficient Method for the Calculation of Sommerfeld Integrals in the Spectral Domain

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1339
Author(s):  
Sotiris Bourgiotis ◽  
Panayiotis Frangos ◽  
Seil Sautbekov ◽  
Mustakhim Pshikov

A recently developed high-frequency asymptotic solution for the famous “Sommerfeld radiation problem” is revisited. The solution is based on an analysis performed in the spectral domain, through which a compact asymptotic formula describes the behavior of the EM field, which emanates from a vertical Hertzian radiating dipole, located above flat, lossy ground. The paper is divided into two parts. We first demonstrate an efficient technique for the accurate numerical calculation of the well-known Sommerfeld integrals. The results are compared against alternative calculation approaches and validated with the corresponding Norton figures for the surface wave. In the second part, we introduce the asymptotic solution and investigate its performance; we compare the solution with the accurate numerical evaluation for the received EM field and with a more basic asymptotic solution to the given problem, obtained via the application of the Stationary Phase Method. Simulations for various frequencies, distances, altitudes, and ground characteristics are illustrated and inferences for the applicability of the solution are made. Finally, special cases leading to analytical field expressions close as well as far from the interface are examined.

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
K. Ioannidi ◽  
Ch. Christakis ◽  
S. Sautbekov ◽  
P. Frangos ◽  
S. K. Atanov

We consider the problem of radiation from a vertical short (Hertzian) dipole above flat lossy ground, which represents the well-known “Sommerfeld radiation problem” in the literature. The problem is formulated in a novel spectral domain approach, and by inverse three-dimensional Fourier transformation the expressions for the received electric and magnetic (EM) field in the physical space are derived as one-dimensional integrals over the radial component of wavevector, in cylindrical coordinates. This formulation appears to have inherent advantages over the classical formulation by Sommerfeld, performed in the spatial domain, since it avoids the use of the so-called Hertz potential and its subsequent differentiation for the calculation of the received EM field. Subsequent use of the stationary phase method in the high frequency regime yields closed-form analytical solutions for the received EM field vectors, which coincide with the corresponding reflected EM field originating from the image point. In this way, we conclude that the so-called “space wave” in the literature represents the total solution of the Sommerfeld problem in the high frequency regime, in which case the surface wave can be ignored. Finally, numerical results are presented, in comparison with corresponding numerical results based on Norton’s solution of the problem.


2013 ◽  
Vol 21 (04) ◽  
pp. 1350016 ◽  
Author(s):  
KRZYSZTOF SZEMELA

The high frequency asymptotic formulas for the acoustic impedance modal coefficients of a clamped circular plate located at the boundary of the three-wall corner region have been obtained. The method of contour integral analysis, the series for the Bessel and Neumann functions and the stationary phase method have been used. Some sample modal coefficients of the acoustic resistance and reactance together with the absolute approximation error have been illustrated as the functions of a parameter proportional to the vibration frequency. The computational efficiency of the presented asymptotic formulas has been compared with the computational efficiency of the integral formulas. The cases, in which the asymptotic formulas allow to reduce the calculation time in comparison with the integral formulas, have been determined. The presented formulas can be used to decrease the computation time of the acoustics power radiated by a clamped circular plate located at the boundary of the three-wall corner region. Moreover, the sound pressure calculations can be performed much faster by using these formulas when the acoustic attenuation is included.


Author(s):  
Dafang Zhao ◽  
Muhammad Aamir Ali ◽  
Artion Kashuri ◽  
Hüseyin Budak ◽  
Mehmet Zeki Sarikaya

Abstract In this paper, we present a new definition of interval-valued convex functions depending on the given function which is called “interval-valued approximately h-convex functions”. We establish some inequalities of Hermite–Hadamard type for a newly defined class of functions by using generalized fractional integrals. Our new inequalities are the extensions of previously obtained results like (D.F. Zhao et al. in J. Inequal. Appl. 2018(1):302, 2018 and H. Budak et al. in Proc. Am. Math. Soc., 2019). We also discussed some special cases from our main results.


2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Didier Pilod ◽  
Jean-Claude Saut ◽  
Sigmund Selberg ◽  
Achenef Tesfahun

AbstractWe prove several dispersive estimates for the linear part of the Full Dispersion Kadomtsev–Petviashvili introduced by David Lannes to overcome some shortcomings of the classical Kadomtsev–Petviashvili equations. The proof of these estimates combines the stationary phase method with sharp asymptotics on asymmetric Bessel functions, which may be of independent interest. As a consequence, we prove that the initial value problem associated to the Full Dispersion Kadomtsev–Petviashvili is locally well-posed in $$H^s(\mathbb R^2)$$ H s ( R 2 ) , for $$s>\frac{7}{4}$$ s > 7 4 , in the capillary-gravity setting.


2019 ◽  
Vol 33 (30) ◽  
pp. 1950370
Author(s):  
Kunwei Pang ◽  
Haihong Li ◽  
Gang Song ◽  
Pengfei Zhang

Molecular J-aggregates are widely used as emitters to achieve the quantum effects, such as the strong coupling phenomenon. We investigate the lateral shift splitting/Goos–Hänchen (GH) shift splitting induced by strong coupling in Kretschmann configuration involving molecular J-aggregates by using classical methods. The optical response of molecular J-aggregates is modeled by a single Lorentzian oscillator, and Fresnel equations and the stationary phase method are employed to solve our proposed structure. Our results show that the lateral shift versus the incident wavelength shows Rabi splitting-like line shape and the reflection spectrum exhibits the strong coupling phenomenon. Based on the results of the previous experiment work, we well explain the relation between Rabi splitting and the thickness of the metal film and provide a new method to choose the parameters of the structure for experiment.


2008 ◽  
Author(s):  
Johann Cussey ◽  
Frederic Patois ◽  
Nicolas Pelloquin ◽  
Jean-Marc Merolla

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