MEMS 3-DoF gyroscope design, modeling and simulation through equivalent circuit lumped parameter model

Equivalent lumped circuit model and S-parameter of indirect-heating thermoelectric power sensor

A Tonpilz type piezoelectric ceramic ultrasonic transducer is investigated through the methods of equivalent circuit and finite element analysis(FEA). The emphasis of this paper lies in the difference between the two methods. Essentially, the piezoelectric constitutive equation is the common law of them. Derived from this equation, the Mason’s equivalent circuit and the frequency equation of the piezoelectric transducer is obtained, and then the finite element control equation is obtained. A mason’s equivalent circuit model and a 1/4 symmetry finite element model of the Tonpilz type piezoelectric ceramic ultrasonic transducer are both constructed. A comparison about the frequency performance and the admittance performance which are respectively obtained from the two methods and the corresponding test shows that, the method of FEA is more quickly and accurately, and its analysis error is controlled within 5%. What is worth to mention is that some performance and the vibration of the transducer have been predicted distinctly through FEA. So FEA is suitable to the piezoelectric transducer. A transducer prototype which is made according to the analysis result has a good performance and satisfying applied requirements.

Analysis of pore structure of circulating fluidized bed fly ash-based foam lightweight filler based on electrochemical impedance spectroscopy

This study analyzes an underwater inductive wireless power transfer (UIWPT) to be used in offshore vehicles. Fixating on inadvertent eddy current losses (ECLs), this study offers an approach to tackle this concern based on the optimal selection of main design parameters of Archimedean magnetic coils. An accurate analytical electromagnetic field model is derived for directly calculating ECLs, and based on the ECL model, the main design parameters of coils are selected. The electrical fundamental components of coils are calculated as a function of the selected design parameters. A numerical metaheuristic optimization method along with the formulation of a multi-objective function and inequality constraints is utilized to estimate the selected parameters of coils. This function addresses various design objectives simultaneously, considering the water medium and inequality constraints. For optimization purposes, an electrical equivalent circuit model is derived, considering the ECLs impact by reflecting these losses in the equivalent circuit model. The ECL model is verified through Finite Element Analysis (FEA). Finally, a laboratory scale setup is developed and UIWPT experiments are conducted to validate the equivalent circuit and analytical modeling, the calculation of components, and the simulation study.

This paper presents modeling and simulation results of a modified copper-column-based flip-chip interconnect with ultrafine pitch for wafer-level packaging, and the process and prototyping procedure are described as well. This interconnect consists of multiple copper columns which are electrically in parallel and supporting a solder bump. A simple analytical model has been developed for correlation between the interconnect geometry and the thermal fatigue life. In comparison to the conventional single-copper-column (SCC) interconnects, numerical analysis reveals that the multi-copper-column (MCC) interconnect features enhanced compliances and, hence, higher thermomechanical reliability, while the associated electrical parasitics (R, L, and C) at dc and moderate frequencies are still kept low. Parametric studies reveal the effects of geometric parameters of MCC interconnects on both compliances and electrical parasitics, which in turn facilitate design optimization for best performance. By using coplanar waveguides (CPWs) as feed lines on both chip and package substrate, a high-frequency (up to 40 GHz) S-parameter analysis is conducted to investigate the transmission characteristics of the MCC interconnects within various scenarios which combines various interconnect pitches and common chip and package substrates. An equivalent lumped circuit model is proposed and the circuit parameters (R, L, C, and G) are obtained throughout a broad frequency range. Good agreement is achieved for the transmission characteristics between the equivalent lumped circuit model and direct simulation results.

A full lumped element-based equivalent circuit model for connected slot antenna arrays (CSAA) is proposed with three configurations of the CSAA being considered: infinite, semi-infinite, and finite slots. First, an equivalent circuit model was developed from the available Green’s Function (GF) based analytical expression of the active impedance of CSAA. It was demonstrated that by combining PI or T networks with parallel RLC resonant circuits and modeling the higher order modes via the series inductor, the active impedance and the reflection characteristics of the CSAA can be represented in an efficient and accurate manner. Secondly, utilizing the proposed equivalent circuit model, a generalized design procedure was developed to assist the design and analysis of arbitrary configurations of CSAA at both microwave and millimeter wave (mm-wave) bands. Finally, the effectiveness and accuracy of the proposed approach are validated by several numerical and measured results. A 2x2 CSAA prototype was fabricated at 3 GHz to validate the proposed equivalent circuit model. For the finite slot case, the proposed RLC+T network outperforms both the available transmission line-based equivalent circuit model and the proposed RLC+PI network, in describing the resonance frequencies and the values of the impedances of the finite slot. It was demonstrated that the proposed equivalent circuit model had a maximum of 4.55% and 5.27% average errors for the real and imaginary parts of the impedances, as compared with the full-wave simulator, while the computational time was reduced by more than two orders of magnitude.

Characterization of high-power lithium-ion batteries by electrochemical impedance spectroscopy. II: Modelling

This paper presents design and analysis results of a 2.6-kW interior permanent-magnet synchronous motor developed for an electrohydraulic power steering system. The motor was designed by using the proposed equivalent magnetic circuit model in consideration with a core loss. To analyze motor characteristics by using the equivalent magnetic circuit model, inductance and iron-loss resistance, which are affected critically by magnetic saturation, are obtained by using finite-element analysis. Finally, motor characteristics such as armature current, torque, and efficiency are calculated by the equivalent magnetic circuit model and verified by experimental results.

In this letter, a periodic end-coupled leaky-wave antenna is designed based on an asymmetrically loading unit. A simple balancing condition in the equivalent distributed circuit model is developed for the open stopband suppression by introducing a complex effective resonant frequency. The proposed balancing condition naturally satisfies both the frequency-balancing condition and Q-balancing condition in the lumped circuit model. Based on the derived formula, the physical parameters could be quantitatively determined. Subsequently, two typical periodic end-coupled leaky-wave antennas are designed, implemented, and verified experimentally. The measured reflection coefficient and the radiation results show that the open stopband at the broadside frequency is successfully suppressed.

By virtue of the negative electric parameter concept, i.e. negative lumped resistance, inductance, conductance and capacitance (N-RLGC), the lumped equivalent models of transmission line systems, including the circuit model, two-port π-network and T-network, are given. We start from the N-segment-ladder-like equivalent networks composed distributed parameters, and achieve the input impedance in the form of a continued fraction. Utilizing the continued fraction theory, the expressions of input impedance are obtained under three kinds of extreme cases, i.e. the load impedances are equal to zero, infinity and characteristic impedance, respectively. When the number of segment N is limited to infinity, they are transformed to lumped elements. Comparison between the distributed model and lumped model of transmission lines, the expression of tanh γd, which is the key term in the transmission line equations, are obtained by RLGC, furthermore, according to input admittance, admittance matrix and ABCD matrix of transmission lines, the lumped equivalent circuit models, π-networks and T-networks have been given. The models are verified in the frequency and time domain, respectively, showing that the models are accurate and efficient.

The authors present equivalent circuit models of skeletal muscle tissue for the directions parallel and transverse to the fiber. The parallel model is based on a distributed parameter equivalent circuit approach where the tissue between the electrodes is divided into small segments, each of which is represented by an equivalent circuit. Parameters for the equivalent circuits me calculated from the electrical characteristics of the tissue components and their physical arrangement. The authors compare the conductivity frequency response of the equivalent circuit modelling approach to other models presented in the literature. The advantage to the authors' equivalent circuit approach is that the tissue models can be readily integrated in circuit simulators such as SPICE. An equivalent circuit model of the tissue load that incorporates both spatial and frequency dependence can be simulated in combination with instrumentation circuits and can aid in the design and optimization of these systems. The possibility of using the equivalent circuit models to simulate nonlinear tissue characteristics is currently being investigated.

Magnitude-phase equivalent circuit and steady-state power-angle characteristic analysis of DFIG

This paper reports the design and evaluation of a multi-electrode design that improves upon the statistical significance and spatial resolution of cellular impedance data measured using commercial electric cell-substrate impedance sensing (ECIS) systems. By evaluating cellular impedance using eight independent sensing electrodes, position-dependent impedance measurements can be recorded across the device and compare commonly used equivalent circuit and mathematical models for extraction of cell parameters. Data from the 8-electrode device was compared to data taken from commercial electric cell-substrate impedance sensing (ECIS) system by deriving a relationship between equivalent circuit and mathematically modelled parameters. The impedance systems were evaluated and compared by investigating the effects of arsenic trioxide (As2O3), a well-established chemotherapeutic agent, on ovarian cancer cells. Impedance spectroscopy, a non-destructive, label-free technique, was used to continuously measure the frequency-dependent cellular properties, without adversely affecting the cells. The importance of multiple measurements within a cell culture was demonstrated; and the data illustrated that the non-uniform response of cells within a culture required redundant measurements in order to obtain statistically significant data, especially for drug discovery applications. Also, a correlation between equivalent circuit modelling and mathematically modelled parameters was derived, allowing data to be compared across different modelling techniques.

A simple analysis technique for a concept in frequency selective surfaces (FSSs) basis from Babinet's principle, of two closely coupled conducting elements is presented. A layer of conducting patch elements and a layer of slot elements are designed on either side of a substrate, named as complementary FSS (CFSS). An equivalent circuit (EC) model in conjunction with transmission line (TL) model is employed to analyze the response of the structure. This method can predict the scattering parameters with high accuracy at a normal and oblique angle of incidence for both parallel and perpendicular polarizations. A parametric study of CFSS array aimed at their EC model optimization is presented. The CFSS exhibits a highly stable passband for normal and oblique incidences. The validity of the proposed method is verified with commercial simulation software package. It is observed that the results obtained by both methods are very good in agreement.

The need for flexible energy storage devices for advanced technologies has encouraged researchers to focus on environmental‐friendly biopolymers. In this work, chitosan (CS) and potato starch (PS) biopolymers are blended to prepare proton conducting solid electrolytes. Based on the X‐ray diffraction (XRD) inspection, the most amorphous blended film with the lowest crystallinity degree was selected to prepare polymer electrolytes. The variation in Fourier‐transform infrared spectroscopy (FTIR) bands were used to investigate the occurrence of interactions among the ammonium thiocyanate (NH4SCN) salt and CS:PS polymer blends. The experimental results of electrochemical impedance spectroscopy (EIS) were simulated with electrical equivalent circuit (EEC) modeling to determine the circuit elements. The highest value of S cm−1 was recorded for the sample included 40 wt.% of dopant salt. The dielectric analyses were helpful in separating the regions ascribed to electrode and molecular polarizations. The combination of circuit elements achieved from the EEC modeling and Koops phenomenological interpretation is used to understand the behavior of the loss tangent (tanδ) pattern. The AC conductivity pattern followed Jonscher's power law. The relaxation dynamics interrelated with ions is explained using electric modulus approaches. The peaks hidden in the dielectric loss () spectra, were manifested in the imaginary part of electric modulus () pattern. The ‐ patterns were used to shed light on the coupling between ionic motion and polymer chain dynamics.