Closed-form Green's functions for cylindrically stratified media

A numerically efficient technique is developed to obtain the spatial-domain closed-form Green's functions of the electric and magnetic fields due to z- and phi-oriented electric and magnetic sources embedded in an arbitrary layer of a cylindrical stratified medium. First, the electric- and magnetic-field components representing the coupled TM and TE modes are derived in the spectral domain for an arbitrary observation layer The spectral-domain Green's functions are then obtained and approximated in terms of complex exponentials in two consecutive steps by using the generalized pencil of function method. For the Green's functions approximated in the first step, the large argument behavior of the zeroth-order Hankel functions is used for the transformation into the spatial domain with the use of the Sommerfeld identity. In the second step, the remaining part of the Green's functions are approximated on two complementary parts of a proposed deformed path and transformed into the spatial domain, analytically, The results obtained in the two consecutive steps are combined to yield the spatial-domain Green's functions in closed forms.


Acar, R. Cueneyt; Dural Ünver, Mevlüde Gülbin (2008-07-11)
A hybrid method to calculate mutual coupling of electric or magnetic current elements on a cylindrically layered structure using MoM is presented. For the calculation of the MoM matrix entries, when rho = rho', if phi is not close to phi', the closed-form Greenpsilas functions are employed. When phi is close to phi', since the spectral-domain Greenpsilas functions do not converge, MoM matrix elements are calculated in the spectral domain. The technique is applied to both microstriplines and slots placed on ...
Asymptotic solution of the radial wave equation for optical fiber wavequides
Cildlr, Sema; Çakır, Serhat (2006-08-26)
In this study, analytic solutions were studied for propagation of electromagnetic waves in cylindrical fiber optic cable. An asymptotic approach was used to solve radial wave equation The solution was derived for zero order eigenvalue equation. It was found that this solution is more general than other methods. By using a computer program was obtained some diagrams for core and cladding region for different eigenvalue equations and modes.
Mutual coupling of printed elements on a cylindrically layered structure using closed-form Green's functions
Acar, R. C.; Dural, G. (EMW Publishing, 2008-01-01)
A hybrid method to calculate mutual coupling of electric or magnetic current elements on a cylindrically layered structure using closed-form Green's functions is presented. When rho = rho' and phi is not very close to phi', closed-form Green's functions are employed in the calculation of MoM matrix entries. When both rho = rho' and phi = phi', series representation of the spectral domain Green's functions do not converge, therefore closed-form Green's functions can not be employed. In that case MoM matrix e...
Nonlinear free vibration of double walled carbon nanotubes by using describing function method with multiple trial functions
Ciğeroğlu, Ender (2012-09-01)
In this paper, nonlinear free vibration of double walled carbon nanotubes (DWCNTs) embedded in an elastic medium with geometric nonlinearity and interlayer van der Waals force nonlinearity are studied. The motion of the DWCNT is represented by multiple eigenfunctions of the linear system which are referred as trial functions. Describing function method (DFM) is employed in order to represent the nonlinear forces as a multiplication of a nonlinear stiffness matrix and a displacement vector, which made it pos...
Closed-form Green's functions for finite grounded dielectric substrate
Öğücü, Gölge; ALATAN, LALE; Aydın Çivi, Hatice Özlem (Informa UK Limited, 2005-02-01)
The approximate closed-form Green's functions of the vector and scalar potentials in the spatial domain are derived for a horizontal electric dipole placed over a finite grounded dielectric medium. The effects of the discontinuity at the edges are considered by including the surface wave reflections from the edges, which are obtained as a function of the incident angle by using the edge admittance concept. The closed-form expressions of the reflection coefficients are then derived by means of the generalize...
Citation Formats
C. Tokgoz and M. G. Dural Ünver, “Closed-form Green’s functions for cylindrically stratified media,” IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, pp. 40–49, 2000, Accessed: 00, 2020. [Online]. Available: