Transfer Functions Of Circuits Research Articles

A novel robustness matching method based on amplitude-frequency characteristic for high power ultrasonic system under variable load

In order to solve the insufficiency of the driving capacity when the load of the ultrasonic driver changes, a high robustness LC matching design method is proposed based on the equivalent circuit modeling and the amplitude-frequency characteristic analysis of circuit transfer function. The transfer function of the input current including the matching capacitance and inductance is established by using the amplitude-frequency characteristics of the circuit transfer function. In order to simplify the transfer function, two new parameters as: impedance coefficient kz and frequency coefficient kf is introduced and a robust matching method based on uncertainty solving is proposed. The superiority of the proposed method compared with the existing matching method is proved by simulation and experiment. The experimental results show that the current fluctuation is less than 10% from light load to full load, which proves the reliability and robustness of our proposed method is higher than the existing matching method. It can ensure the amplitude stability of the ultrasonic transducer, and its performance is optimal than the existing general matching method.

From qualitative to quantitative: the state of the art and challenges for plant synthetic biology

The flourishing plant science promotes the exploding number of data and the expansion of toolkits. Plant synthetic biology is still in its early stages and requires more quantitative and predictable study. Despite the challenges, some pioneering examples have been successfully demonstrated in model plants.BackgroundsAs an increasing number of synthetic switches and circuits have been created for plant systems and of synthetic products produced in plant chassis, plant synthetic biology is taking a strong foothold in agriculture and medicine. The ever‐exploding data has also promoted the expansion of toolkits in this field. Genetic parts libraries and quantitative characterization approaches have been developed. However, plant synthetic biology is still in its infancy. The considerations for selecting biological parts to design and construct genetic circuits with predictable functions remain desired.ResultsIn this article, we review the current biotechnological progresses in field of plant synthetic biology. Assembly standardization and quantitative approaches of genetic parts and genetic circuits are discussed. We also highlight the main challenges in the iterative cycles of design‐build‐test‐learn for introducing novel traits into plants.ConclusionPlant synthetic biology promises to provide important solutions to many issues in agricultural production, human health care, and environmental sustainability. However, tremendous challenges exist in this field. For example, the quantitative characterization of genetic parts is limited; the orthogonality and the transfer functions of circuits are unpredictable; and also, the mathematical modeling‐assisted circuits design still needs to improve predictability and reliability. These challenges are expected to be resolved in the near future as interests in this field are intensifying.

Design and Simulation Analysis of High Power Density Superboost Circuit

A battery discharge regulator system based on the Superboost converter is presented, and the working principle of the Superboost converter is analyzed. In order to meet the developing requirements of high efficiency and high power density converters, GaN devices are applied to the Superboost circuit to increase the switching frequency of the circuit. Thanks to this, the weight and volume of the passive devices can be reduced, and the power density of the circuit can be increased. In high-frequency conditions, the device parameters of the circuit are designed, and the theoretical derivation of the circuit transfer function is carried out. Finally, simulation software is used to verify the rationality and feasibility of the design.

Modeling, Analysis, and Reduction of Radiated EMI Due to the Voltage Across Input and Output Cables in an Automotive Non-Isolated Power Converter

This article investigates the radiated electromagnetic interference (EMI) due to the voltage between input and output cables in a non-isolated power converter. The radiated EMI model of a non-isolated power converter is first developed and quantified based on the circuit topologies, printed circuit board (PCB) parasitics, switching waveforms, and transfer functions. Second, an antenna model is developed for converter cables based on the antenna impedance and the antenna transfer function. Third, a complete radiated EMI model is developed based on the converter's EMI model and the cable's antenna model. Fourth, the radiated EMI is analyzed based on the developed model. Finally, two radiated EMI noise reduction techniques, optimizing PCB layout and adding a cross capacitor, are proposed. The developed radiated EMI model and the proposed radiated EMI reduction techniques are verified with both simulations and experiments. The techniques are also extended to other two non-isolated power converter topologies when the radiated EMI is caused by the voltage between the input and output cables.

Quick Access to Circuit Transfer Functions via NAM Determinant/Cofactors Using UaL Technique

Quick Access to Circuit Transfer Functions via NAM Determinant/Cofactors Using UaL Technique

МЕТОД ОДНОВРЕМЕННОЙ ОПТИМИЗАЦИИ ХАРАКТЕРИСТИК ЭЛЕКТРИЧЕСКИХ ФИЛЬТРОВ В ЧАСТОТНОЙ И ВРЕМЕННОЙ ОБЛАСТЯХ

A new method of searching for optimal transfer functions of radio circuits and devices was developed. This method allows optimizing performance in the frequency and time domain simultaneously. These tasks cannot be solved by analytical methods. The searching was performed in the coordinatespace of transfer function poles and zeros. The heuristic algorithm of multistart local search type was applied. Computation of transfer function, gain and transient response and goal function was implemented at each step of local search. In order to compute transient response the state space method was employed. This method provides robustness to rounding errors. The proposed method has the advantages of universality and flexibility due to the fact that it allows varying the set of quality parameters and their weighted coefficients in the goal function. Another advantage of this method is its capability of searching a set of Paretooptimal solutions, from which we can select the most suitable one. Some examples of the transient function optimization under conditions of gain-frequency response in the stop-band are considered. The found approximations have performance exceeding that of the Bessel and Butterworth filters.

Formally Verifying Transfer Functions of Linear Analog Circuits

Editor’s note: This article presents an approach to extend mathematical formal analysis towards verification of linear analog circuits. — Jayanta Bhadra, NXP

Switching-Converter Dynamic Analysis with Fast Analytical Techniques: Overview and Applications

If mesh-node analysis lends itself well to solving transfer functions of electrical circuits, obtaining a meaningful symbolic formula at once is often impossible and requires extra efforts to get it. Applying classical analysis techniques to obtain a so-called low-entropy expression-implying the factored form in which you distinguish gains, poles, and zeros-can often lead to algebraic paralysis, as R.D. Middlebrook commented in his foundational papers [1], [2]. This is where the fast analytic circuits techniques (FACTs) can help you build on what you learned during your years at university and extend the reach to drastically simplify analyses. By using FACTs, you not only gain in execution speed, but the final result appears in a wellordered polynomial form, often without the need of further factoring efforts [3], [4].

Identifying and 3D Displaying Poles and Zeros in Analog Circuit Transfer Functions: Bode Surfaces

A new technique is developed that extends the normal Bode plots from two-dimensional to three-dimensional, including the$$\sigma $$źaxis into the plots. By utilizing MATLAB, it is shown how the Bode plots of a transfer function in an analog circuit can turn into a 3D Bode surface. In general, a tool is developed that integrates WinSpice and MATLAB so that in a comprehensive AC analysis Bode surfaces are directly generated for any given circuit transfer function. The technique is shown to be ideal to identify, and hence subsequently to extract, the poles and zeros of a transfer function. The applications can be extended into exploring feedback theory, analog filter design and stability analysis of control systems in high-performance circuits. Examples particularly for analog CMOS circuits are worked out that demonstrate some of the capabilities of the tool.

Linear Circuit Transfer Functions: An Introduction to Fast Analytical Techniques [Member News

Linear Circuit Transfer Functions: An Introduction to Fast Analytical Techniques [Member News

Two-stage fuzzy inference system for symbolic simplification of analog circuits

This paper presents a knowledge-based fuzzy approach to symbolic circuit simplification in an effort to imitate human reasoning and knowledge of circuit designer experts. The fuzzy approach differs from the conventional simplification techniques in that it can efficiently combine different input variables to obtain optimal simplified expressions. Additionally, this method was chosen due to its adjustability and interpretability, as well as its ability to manage very complex symbolic expressions. The proposed algorithm uses fuzzy logic to simplify the symbolic circuit transfer functions in two stages. In the first stage, a fuzzy system is applied to directly eliminate nonessential circuit components, resulting simplified circuit topology which also yields simpler transfer function. In the second stage, another fuzzy system is used to further simplify the symbolic transfer function from the already simplified circuit, such that deeper insight into the circuit behavior can be obtained. Symbolic and numerical results show that the fuzzy approach outperforms the conventional techniques in terms of accuracy, expression complexity, and CPU running time.

A sum-over-paths algorithm for third-order impulse-response moment extraction within RC IC-interconnect networks

We have created the first stochastic SoP (Sum-over-Paths) algorithm to extract third-order impulse-response (IR) moment within RC IC interconnects. It employs a newly discovered Feynman SoP Postulate. Importantly, our algorithm maintains computational efficiency and full parallelism. Our approach begins with generation of s-domain nodal-voltage equations. We then perform a Taylor-series expansion of the circuit transfer function. These expansions yield transition diagrams involving mathematical coupling constants, or weight factors, in integral powers of complex frequency s. Our SoP Postulate enables stochastic evaluation of path sums within the circuit transition diagram to order s3—corresponding to the order of IR moment (m3) we seek here. We furnish, for the first time, an informal algebraic proof independently validating our SoP Postulate and algorithm. We list, as well, detailed procedural steps, suitable for coding, that define an efficient stochastic algorithm for m3 IR extraction. Origins of the algorithm’s statistical “capacitor-number cubed” correction and “double-counting” weight factors are explained, for completeness. Our algorithm was coded and successfully tested against exact analytical solutions for 3-, 5-, and 10-stage RC lines. We achieved better than 0.65% 1-σ error convergence, after only 10K statistical samples, in less than 1s of 2-GHz Pentium® execution time. These results continue to suggest that stochastic SoP algorithms may find useful application in circuit analysis of massively coupled networks, such as those encountered in high-end digital IC-interconnect CAD.

Multivariate analysis and optimization of linear periodically time-variable circuits at the enviroment of MAOPCs

Introduction. The architecture of MAOPCs functions system and examples of its application for solving the tasks of multivariate analysis of linear periodically time-variable (LPTV) circuits based on the frequency symbolic method are considered in this paper. The method is based on approximation of transfer functions of LPTV circuits in the form of trigonometric polynomials of the Fourier. The MAOPCs functions system is implemented in the environment of MATLAB. Architecture and functions of the system MAOPCs. The system consists of 17 functions that are implemented in the environment of MATLAB. Each function has arguments and global variables and carries out over them identified transformation. Functions and global variables form the input data program for research LPTV circuit and should be defined (set) at the time of calling the function. Conclusions. The MAOPCs functions system enables to investigate LPTV circuits, setting in program input data the algorithms for their research and to use a strong symbolic apparatus and other standard functions of the package MATLAB in full, without understanding the deep of mathematical apparatus of implemented methods.

Design and stability analysis of CFOA-based amplifier circuits using Bode criterion

In this paper the frequency stability of small-signal high-speed amplifier circuits using Bode criterion is analysed theoretically. In particular, the inverting and non-inverting amplifiers employing current-feedback operational amplifiers are under review. Based on the analysis of the operational principle, the equations for complex transfer functions of both circuits and formulas for the related electrical parameters are obtained. Moreover, using these formulas recommendations for a stable operation are given. As well, design procedure of the amplifiers with resistive and capacitive load is suggested. The efficiency of the proposed procedure and recommendations are verified by simulation modelling and experimental testing of sample electronic circuits.

Model Reduction and Controller Design of a DC-DC Converter

The reduced-order small-signal model and controller design of a two-transistor forward converter（TTFC）are presented in this paper. First, the small-signal circuit model and transfer function of control to output are found for the TTFC. Then by finding dominant energy poles of the transfer function, the model reductions are performed and the controller design of the converter is simplified. The effective of the proposed model reduction and controller design are demonstrated by bode plots and experimental results.

Analysis and design of voltage‐controlled current sources for a grounded load

SummaryThe paper presents the structure and the principle of operation of the ‘improved’ Howland current pumps (or voltage‐controlled current sources (VCCSs) for a grounded load). In particular, under review is the VCCS employing power operational amplifier (op amp) and the VCCS using low power op amp and an additional power transistor, extending working dynamic range. On the basis of analysis of the operational principle, the equations for transfer functions of both circuits and formulas for the related dynamic electrical parameters are obtained. Moreover, using these formulas, a design procedure is developed, and recommendations for simulation modelling are given. The efficiency of the proposed procedure is verified by simulation modelling and experimental testing of sample electronic circuits of VCCSs. Copyright © 2013 John Wiley & Sons, Ltd.

Evaluation of Equivalent Circuit Diagrams and Transfer Functions for Modeling of Lithium-Ion Batteries

AbstractThe rapid developments in the field of electrochemistry, enabled lithium-ion batteries to achieve a very good position among all the other types of energy storage devices. Therefore they became an essential component in most of the modern portable and stationary energy storage applications, where the specific energy and the life time play an important role. In order to analyze and optimize lithium-ion batteries an accurate battery model for the dynamic behavior is required. At the beginning of this paper four different categories of electrical models for li-ion cells are presented. In the next step a comparison between equivalent circuit diagrams and fractional rational functions with the complex variable s is shown for lithium-ion battery modeling. It is described how to identify the parameters of the models in the time domain and also in frequency domain. The validation of the different models is made for high and low dynamic current profiles. In the first step the dependency of all model parameters on the temperature and on the battery age is neglected. These effects will be taken into account in the continuation of this work

Analysis on Equivalence between Transfer Function and Equivalent Circuit Simulation in General Hamiltonian Modeling

Take generator system included AVR (automatic voltage regulator) and PSS (power system stabilizer) as an example, Using the time simulation method, Study the equivalence between the transfer function model and the equivalent circuit simulation, and establish the corresponding relations between the circuit structures, internal parameters and transfer function parameters, based on the energy of equivalent circuit, the Hamiltonian function of transfer function is derived indirectly, and the Hamiltonian model is established. The study in this paper provides a new way to establish generalized Hamiltonian model for linear system based on transfer function.

Novel Feedback Theory of Electric Circuits—Part I: Cut-Based Decomposition

In this paper and in its companion, a novel cut-based decomposition for transfer functions of linear time-invariant circuits is introduced and an invariance property, with respect to the cut, is proven for the set of quantities introduced by this cut-based decomposition. These results naturally lead to a novel feedback theory of electric circuits which, unlike Bode's feedback theory, is based on the unambiguous decomposition of transfer functions. Such feedback theory provides a natural extension to the elementary model of feedback amplifiers based on block diagrams, from system theory to circuit theory, and a natural extension to Blackman's formula.

Novel Feedback Theory of Electric Circuits—Part II: Loop Invariants

In this paper and in its companion, a novel cut-based decomposition for transfer functions of linear time-invariant circuits is introduced and an invariance property, with respect to the cut, is proven for the set of quantities introduced by this cut-based decomposition. These results naturally lead to a novel feedback theory of electric circuits which, unlike Bode's feedback theory, is based on the unambiguous decomposition of transfer functions. Such feedback theory provides a natural extension to the elementary model of feedback amplifiers based on block diagrams, from system theory to circuit theory, and a natural extension to Blackman's formula.