Unified Spectral Technique Application for Study of Radiator Behavior Near Planar Layered Composites

Abstract

Abstract-The Unified Spectral Technique (UST) is a rigorous analytical approach for calculating power fluxes of any type of source and losses in multilayered dielectric structures of canonical geometries. This method is a reasonable addition to the eigenfunctions technique. An important advantage of the method is that the power fluxes are represented in an explicit form via their spectra, avoiding cumbersome calculations via field components. In this paper, this approach is specified for a case of planar multilayered structures, including those made of composite materials. Results of computations for the simplest types of radiators (electric and magnetic dipoles) in proximity of parallel-plane composite layers, comprised of a dielectric base and conducting inclusions with concentrations below and above percolation threshold, are analyzed.

Double Statistical Distribution of Conductivity and Aspect Ratio of Inclusions in Dielectric Mixtures at Microwave Frequencies

“…In contrast, the increase of conductivity leads to the absorption peak shift to the higher frequencies [1][2][3]. To widen the bandwidth of absorptive properties of composites at both microwave and optical frequencies, it may be favorable to have mixtures of inclusions with different conductivities, including statistically distributed conductivities.…”

“…Engineering of microwave composite materials for different applications, such as electromagnetic shields, gaskets, printed circuit boards, microwave filtering devices, antenna radomes, etc., is an important practical problem [3][4][5]. The typical main requirements to shielding materials are their high shielding effectiveness, broadband performance, and omnidirectional behavior with respect to the angles of incidence of electromagnetic waves.…”

“…The typical main requirements to shielding materials are their high shielding effectiveness, broadband performance, and omnidirectional behavior with respect to the angles of incidence of electromagnetic waves. Carbon inclusions are used as fillers in absorbing materials for microwave applications [3,[6][7][8][9], though properties of such materials have not been investigated extensively in the open literature. A peculiarity of carbon-filled composites is that the conductivity of carbon inclusions typically varies over a wide range, even if all carbon particles are obtained during the same technological process (e.g., exposed to burning during the same time).…”

Modeling of Shielding Composite Materials and Structures for Microwave Frequencies

“…If a shielding structure is comprised of two or more layers of composite and/or conventional materials, the overall transmission and reflection responses of the stack of layers can be calculated from the ABCD matrices, corresponding to each of the layers, and these matrices must be combined to obtain the ABCD matrix of the entire system. Then the reflection and transmission coefficients, as well as the corresponding shielding effectiveness of the structure can be evaluated using the overall ABCD matrix of the system [28,29].…”

Attenuation in Extended Structures Coated With Thin Magneto-Dielectric Absorber Layer

“…and/or R.L. is not sufficient [16]. Engineers encountering EMC/EMI problems in their designs may need information on what attenuation for electric and magnetic fields, or electromagnetic power is produced due to the certain amount of an absorbing material -per-unit-length (in cable applications), per-unitarea, or even per-unit-volume (in cavity/enclosure patch applications).…”