Measurement-based equivalent circuit model for ferrite beads (original) (raw)
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Measurement of electromagnetic parameters and FDTD modeling of ferrite cores
2009 IEEE International Symposium on Electromagnetic Compatibility, 2009
The paper describes a methodology for an efficient design of novel products based on magneto-dielectric (ferrite) materials with desirable frequency responses that satisfy EMC and SI requirements. The methodology starts from estimating complex permittivity and permeability of these materials. This requires measurement techniques, approximation resultant frequency characteristics for permittivity and permeability using a curve-fitting procedure, and development of a full-wave numerical simulation tool that could deal with frequencydispersive materials. An example of a ferrite material measurement, constitutive parameters extraction using a genetic algorithm, and corresponding FDTD modeling over the frequency range from 10 to 500 MHz is provided.
Inductive response of ferrites based on resonance effects
Journal of Optoelectronics and Advanced Materials
A method and a setup are presented that allow the investigation of the magneto-inductive phenomenon in the development of position, stress and field sensors, as well as in studying fundamental properties of the used ferromagnetic materials. The phenomenon of resonance in a series RLC circuit is used to study the effect of displacement of the soft ferrite core of the inductor on the peak output voltage across the resistor at resonance. More specifically, the displacement of the core affects the inductance of the circuit and therefore the resonance frequency and the peak output voltage. Several ferrite samples have been used having undergone treatments such as oxidization, annealing and corrosion. The same RLC circuit has also been used to study the effect of applied tensile stress and magnetic field at various frequencies when the core of the inductor is a 25cm long ribbon made of an iron alloy. In this case, the resonance frequency is constant and the output voltage across the resistor is recorded as a function of frequency, stress, and magnetic field. In both cases, the results are correlated to the permeability of the core and the way its permeability changes with respect to the applied stress or field, the frequency of excitation, the treatment it has undergone and its magnetic history. Thus, the presented system may also serve as a tool for determination of the electric and magnetic properties of the under test samples.
Characterization and modelling of miniature ferrite transformer for high frequency applications
Microelectronics International, 2012
PurposeSignificant achievements in ferrite material processing enable developments of many ferrite devices with a wide range of power levels and working frequencies, which make demands for new characterization and modelling methods for ferrite materials and components. The purpose of this paper is to introduce a modelling and measurement procedure, which can be used for the characterization of two‐port ferrite components in high frequency range.Design/methodology/approachThis paper presents a commercially available ferrite component (transformer) modelling and determination of its electrical parameters using in‐house developed software. The components are measured and characterized using a vector network analyzer E5071B and adaptation test fixture on PCB board. The parameters of electrical equivalent circuit of the ferrite transformer parameters are compared with values extracted out of measured scattering parameters.FindingsA good agreement between modelled and extracted electrical...
Ferrite Material Characterization Using S-Parameters Data
2017
Since many applications rely on the knowledge of the electromagnetic material properties of ferrites, such as ferrite phase shifters, this paper presents an algorithm for characterizing ferrite materials in a single frequency using a rectangular waveguide system. In this method, the extraction of ferrite parameters is implemented through minimizing the difference between the measured data and the results from modal analysis of the system. The main advantage of this method compared to the other ones is that the proposed method only needs the amplitude of the reflection and transmission coefficients to estimate the parameters of ferrite materials. This makes the implementation easy and eliminates the problems associated with phase calibrations and measurements. This validation is achieved by simulation and experimental tests. The proposed algorithm is validated by characterizing YIG and SL-470 ferrites.
High Frequency Characteristics Of Ferrite Materials And Applications To Microstrip Circuits
Dispersion behavior of the parameters of microstrip lines printed on ferrite substrate is presented. The characteristic impedance for lines on magnetized ferrite substrates are obtained for partially magnetized substrates in the direction of wave propagation and vertically magnetized substrates with variable DC magnetic field. The obtained results are applied to analyze variable phase shifters, controlled resonators, and impedance matching.
Journal of Electrical Engineering
Besides their magnetic properties, Mn-Zn ferrites are also characterized by appreciable electrical properties. This electro- magnetic nature of Mn-Zn ferrites material properties causes a dimensional resonance to occur in samples. The latter hinders measurements of the frequency dependences of intrinsic permittivity and electrical conductivity. In the paper, we present a sign in measurement results that shows the frequency range in which dimensional resonance has already occurred. Above this range, properties extracted from measurements are not intrinsic any longer. We refer to the sign to determine the last point of the measurement data set that is used as an input for an equivalent circuit modelling of the electrical properties. This “last point” criterion helps to exclude the possibility of modelling apparent properties instead of intrinsic ones. The results obtained show that the frequency dependent electrical properties may be well modeled even if the upper limit of the input f...
Nonlinear Loss Model in Absorptive-Type Ferrite Frequency-Selective Limiters
IEEE Transactions on Microwave Theory and Techniques, 2019
Absorptive-type ferrite-based frequency-selective limiters (FSLs) utilize nonlinear (NL) phenomena in magnetized ferrites to provide real-time analog signal processing of RF/microwave electromagnetic (EM) signals. There are no commercially available modeling tools that simulate these interactions, and the development and optimization of FSLs are largely done experimentally. FSL modeling and design is complicated by NL, multiscale, and multiphysics nature of operation. In this article, an NL loss model in a ferrite is proposed and implemented in an efficient numerical algorithm. The equivalent linear magnetic loss tangent is represented in a closed form. A full-wave numerical EM model with high-fidelity meshing is set up so that material properties are assigned to each mesh element and are iteratively adjusted depending on the local magnetic field. The numerical model is sliced along the EM wave propagation, and an NL eigenvalue is obtained for each slice as a function of frequency, power, and external magnetic bias field and stored in lookup tables. The slices are cascaded, and power attenuation is calculated with loss changing along the wave path according to the lookup tables. The resulting data are processed to be suitable for equivalent circuit models. Numerical results for coplanar waveguide FSL are validated by measurements. The proposed modeling approach is useful for engineering FSL devices.
Comparison of various high-frequency models of RF chip inductors
Przegląd Elektrotechniczny, 2011
RF chip inductors are the most widely used inductors. Due to the miniaturization the continuous improvement of the electrical parameters are highly requested. This demand of the improvement makes the accurate electrical model of the inductors essential. The purpose of the paper is to present an evaluation and comparison of the currently available methods for calculating the inductor behaviour in frequency domain using analytic formulas, finite element simulations, and real measurements on market available RF chip inductors Streszczenie. Induktory z czipami o czestotliwościa radiowych RF są najszerzej uzywanymi induktorami. Dzieki miniaturyzacji ciągle ulepszanie parametrow elektrycznych jest poządane. Żądanie poprawy czyni, ze dokladne elektryczne modele induktorow zyskują na znaczeniu. Celem pracy jest pokazanie ewaluacji i porownania obecnie dostepnych metod dla obliczania dzialania induktora w dziedzinie czestotliwości przy uzyciu wzorow analitycznych, symulacji metodą elementow ...
Parameters Extraction of Ferrite EMI Suppressors for PCB Applications Using Microstrip Test Fixture
IEEE Transactions on Magnetics, 2010
The goal of this work was to investigate the behavior of a ferrite electromagnetic interference (EMI) suppressor when placed in a real surrounding. Electrical parameter measurements of the same EMI suppressor can differ for different combination of instruments and test fixtures. For that reason specially designed microstrip test fixtures are developed for the vector network analyzer (VNA) measurements. This paper describes the measurement technique, parameters extraction, and characterization of ferrite EMI suppressors for printed circuit board (PCB) applications. Two commercially available components, multilayer chip SMD inductors in a ferrite body, are measured and characterized using a VNA E5071B and developed adaptation test fixture on PCB board. These measurements describe intrinsic and extrinsic parameters of the components and their behavior. If the components are mounted on the PCB, i.e., in a real environment, then the two-port EMI suppressor model with extrinsic parameters has to be used at RF frequencies. The comparison of measured and datasheet values is further presented.