Modal attenuation in multilayered coated waveguides

Modal Method Analysis of Multilayered Coated Circular Waveguide Using a Modified Characteristic Equation

“…The key to this method is the accurate calculation of the propagation constants of modes in coated circular waveguide. To overcome numerical difficulties, such as overflow, encountered in solving characteristic equation [12,13], the characteristic equation is modified using the Hankel function of the second kind, instead of Bessel function of the first kind in the coated layers. The modified characteristic equation can be accurately solved to obtain the propagation constants even for very large circular waveguide with highly lossy coatings.…”

“…Exaggerated cross-sectional view of multilayered coated waveguide. Figure 1 shows an exaggerated view of the coating layers to illustrate the geometrical features of the circular waveguide as in [12]. In real applications, the coating layers will be very thin relative to the diameter of the guide.…”

Pseudo-Analytical Modeling for Electromagnetic Well-Logging Tools in Complex Geophysical Formations

“…By contrast, in Muller's approach, the same guess will converge to the complex-valued solution, as illustrated in the works on corrugated as well as dielectric loaded waveguides shown in [92]. The Muller's method also was successful to find a few low-order complex eigenvalues in lossy stratified cylindrical waveguides [11,12,[93][94][95][96]. By using the above described root-finding methods there is no guarantee that all zeros are found.…”

Analogy Between Circular Core-Cladding and Impedance Waveguides and Their Membrane Functions

“…It is well known [46,47] that for multi-layer waveguide the straightforward derivation yields dispersion equation in the form of zero determinant of large size matrix. To avoid problems associated with such matrices, the so-called matrix approach was proposed in [46].…”