Mathematical modeling of composites made a dielectric base and randomly oriented metal inclusions is considered.Different sources frequency-dependent conductivity at optical frequencies are taken into account.These include the skin-effect, dimensional (length-size) resonance particles, Drude model.Also, mean free path electrons in metals can be smaller than characteristic sizes nanoparticles, this leads to decrease inclusions.These effects incorporated Maxwell Garnett mixing formulation,...

Composites containing conducting inclusions are required in many engineering applications, especially, for the design of microwave shielding enclosures to ensure electromagnetic compatibility and immunity. Herein, multilayer structures studied, with both absorbing re∞ecting composite layers. In this paper, flber-fllled composites considered. For modeling low concentration cylindrical (below percolation threshold), Maxwell Garnett theory is used. layers, when close or above threshold,...

The microwave permittivity and permeability of Co2Z barium ferrite composite samples are measured as functions frequency volume fraction the ferrite. Magnetostatic properties bulk determined. This allows Snoek’s law [J. L. Snoek, Physica 14, 204 (1948)] to be verified by comparing magnetostatic constants. modification for hexagonal ferrites suggested recently Acher et al. [Phys. Rev. B 62, 11324 (2000)] is also verified. Acher’s constant found from measurements agree with value calculated...

Frequency-dependent causal RLGC(f) models are proposed for single-ended and coupled transmission lines. Dielectric loss, dielectric dispersion, skin-effect loss taken into account. The substrate is described by the two-term Debye frequency dependence, line conductors of finite conductivity. In this paper, three frequency-dependent RLGC studied. One known analytical model (RLGC-I), second RLGC( f) (RLGC-II) in third (RLGC-III) same as -II, but with causality enforced Hilbert transform domain....

Novel coaxial cable sensors that feature high sensitivity and spatial resolution are developed for health monitoring of concrete structures using a time-domain reflectometry (TDR). The new sensor was designed based on the topology change its outer conductor, which fabricated with tightly wrapped commercial tin-plated steel spiral covered solder. cracks within will lead to out-of-contact local spirals. This results in large impedance discontinuity can be measured TDR. A simplified equivalent...

Copper foil in printed circuit board (PCB) transmission lines/interconnects is roughened to promote adhesion dielectric substrates. It important characterize PCB substrate dielectrics and correctly separate conductor losses, especially as data rates high-speed digital designs increase. Herein, a differential method proposed for separating losses PCBs with rough conductors. This approach requires at least three lines identical, or close technologically possible, basic geometry parameters of...

Generalized Snoek's law proposed in an integral form by Acher and coauthors is a useful tool for investigation of high-frequency properties magnetic materials. This referred to as Acher's allows evaluating the ultimate performance RF microwave devices which employ It may also be helpful obtaining information on structure morphology The key factor practical application opportunity either measured or calculated data available over finite frequency range. paper uses simple calculations check...

An analytical model based on an equivalent capacitance circuit for expressing a static effective permittivity of composite dielectric with complex-shaped inclusions is presented. The constant 0–3 composites investigated using this model. geometry the capacitor containing discretized into partial parallel-plate elements, and obtained from structure. First, individual cell diphasic (a high-permittivity spherical inclusion enclosed in lower parallelepiped) considered. modeled as function...

DC power-bus modeling in high-speed digital design using the finite-difference time-domain (FDTD) method is demonstrated herein. The dispersive character of dielectric layers used printed circuit board substrates taken into account this study. In particular, FR-4 considered. complex permittivity approximated by a Debye model. A wide-band frequency response (100 MHz-5 GHz) obtained through single FDTD simulation. Good agreement achieved between modeled and measured results for typical dc...

An effective method for extracting parameters of a Debye or Lorentzian dispersive medium over wideband frequency range using genetic algorithm (GA) and transmission-line model is presented. Scattering (S-parameters) the sections, including parallel plate, microstrip, stripline, are measured. Wave equations TEM/quasi-TEM mode with complex propagation constant frequency-dependent wave impedance used to evaluate corresponding S-parameters in an analytical model. The discrepancy between modeled...

Conductors with a roughened surface have significant effects on high-speed signal propagation backplane traces designed for 10+ Gb/s network. An accurate approach to evaluate these effects, including the attenuation and phase delay, is proposed in this paper. A differential extrapolation roughness measurement technique first used extract dielectric properties of substrate lamination, then periodic model calculate an equivalent conductor impedance, which modify transmission line...

Analytical and numerical modeling of composites with an isotropic dielectric base multiphase conducting inclusions for the development wideband microwave shields is considered. The model uses Maxwell Garnett formalism mixtures. Such are required in many engineering applications, including electromagnetic compatibility.

The paper is devoted to a methodology and an improved technique of characterization low-loss dielectrics on printed circuit boards. based measuring S-parameters recalculating them into complex propagation constant. Phase correction proposed assure that the phase constant passes through zero at frequency. An effect dielectric loss upon considered in analytical model for parameter extraction. Dielectric conductor losses are separated using model, which includes surface roughness conductors....

An analytical model of an efiective permittivity a composite taking into account statistically distributed orientations inclusions in the form prolate spheroids will be presented. In particular, this paper considers normal Gaussian distribution for either zenith angle, or azimuth both angles describing orientation inclusions. The is extension Maxwell Garnett (MG) mixing rule multiphase mixtures. resulting complex tensor general case. formulation presented shows that parameters law afiect...

A methodology to efficiently design products based on magneto-dielectric (ferrite) materials with desirable frequency responses that satisfy electromagnetic compatibility and signal integrity requirements over RF microwave bands is presented here. This an analytical model of a composite material both frequency-dispersive permittivity permeability. procedure for extracting complex permeability from experimental data transmission line measurements. The genetic algorithm applied approximating...

A mixing rule in the theory of composites is intended to describe an inhomogeneous composite medium containing inclusions one or several types a host matrix as equivalent homogeneous medium. The Maxwell Garnett widely used effective electromagnetic properties (permittivity and permeability) composites, particular, biphasic materials, canonical shapes (spherical, cylindrical, ellipsoidal). This paper presents procedure for deriving Debye model that approximates geometry-based randomly...

A procedure to synthesize a suitable biphasic composite material from the given Shielding effectiveness (SE) specifications is proposed herein. In particular, this paper presents an analytic approach for calculating parameters of Debye-like equivalent homogeneous material, which meets SE requirements in frequency range. Establishing relationship with intrinsic and morphological properties will make it possible effectively find lossy model, starting characteristic. The Maxwell Garnett mixing...

A simple method of approximating frequency characteristics composites in a form convenient for time-domain numerical modeling is proposed. The can be obtained from experiment or calculations based on the Maxwell Garnett mixing formalism. resultant characteristic might complex shape corresponding to combination number absorption peaks. approximation made by series Debye-like terms using genetic algorithm (GA). This leads necessity taking series. Every term corresponds its pole, i.e., where...

A methodology to efficiently design novel products based on magneto-dielectric materials containing ferrite or magnetic alloy inclusions is presented. The engineered should provide desirable frequency responses satisfy requirements of electromagnetic compatibility/immunity over RF and microwave bands. uses an analytical model a composite material with both frequency-dependent permittivity permeability. Bruggeman asymmetric rule for effective permeability modified take into account...

A model to substitute conductor surface roughness in printed circuit boards by a layer with an effective material (lossy dielectric) is proposed and tested using the 2D finite-element method (FEM) electromagnetics numerical simulations. The results of modeling multilayered structure corresponding stripline transmission line substituted are compared experimental obtained on TRL-calibrated test vehicle significant conductors made standard (STD)-roughness copper foil.

Recently, an experiment-based traveling-wave technique to separate conductor loss from dielectric on printed circuit board (PCB) striplines, called the differential extrapolation roughness measurement (DERM), has been proposed. The further development of this procedure is presented in paper. new applied both constant and phase constant, as opposed previous procedure, which only constant. A parameter QR quantify surface proposed, it used improved procedure. This allows for more accurate...

A hybrid approach, based on the two-dimensional finite-element method (2-D-FEM) and a genetic algorithm (GA) optimization, is used to extract relative permittivity permeability of ferrites flexible magnetodielectric composite materials over wide frequency bands. S-parameters material under test (MUT) placed into coaxial fixture are measured by vector network analyzer simulated using 2-D-FEM code. The GA optimization procedure then minimize discrepancies between iteratively searching possible...