Two-terminal Circuit Research Articles

Основы проектирования высокотемпературных карбид-кремниевых операционных усилителей в свободно распространяемых средах MicroCap и LTSpice

To simulate analog circuits in the freely available MicroCap and LTspice environments at temperatures up to 452 °C, template models of SiC transistors have been developed using the template modeling technique, in which the constant parameters of the model are replaced by fractional-rational functions, allowing a more accurate description of the physical processes in the JFET without violating the character their changes. Instructions have been developed for testing SiC JFet transistor models in LTspice and MicroCap environments. The purpose of the work is to study circuit solutions for high-temperature basic analog functional units, implemented on the basis of silicon carbide field-effect transistors using developed template models. The parameters of SiC two-terminal reference current circuits and dynamic loads of amplification stages of operational amplifiers with different numbers of series-connected SiC JFets, which can be used in high-temperature analog circuitry, are presented. The main characteristics of SiC differential stages and the simplest SiC operational amplifiers with paraphase output based on them were studied at temperatures of 25 °C and 452 °C. The results obtained are recommended for use in the design of high-temperature operational and instrumental amplifiers used in space instrumentation, deep well drilling equipment, automotive industry, nuclear reactors, etc. for processing signals from sensors of physical quantities and converting radio signals.

Are There an Infinite Number of Passive Circuit Elements in the World?

We found that a second-order ideal memristor [whose state is the charge, i.e., in ] degenerates into a negative nonlinear resistor with an internal power source. After extending analytically and geographically the above local activity (experimentally verified by the two active higher-integral-order memristors extracted from the famous Hodgkin–Huxley circuit) to other higher-order circuit elements, we concluded that all higher-order passive memory circuit elements do not exist in nature and that the periodic table of the two-terminal passive ideal circuit elements can be dramatically reduced to a reduced table comprising only six passive elements: a resistor, inductor, capacitor, memristor, mem-inductor, and mem-capacitor. Such a bounded table answered an open question asked by Chua 40 years ago: Are there an infinite number of passive circuit elements in the world?

Reliable and secure memristor-based chaotic communication against eavesdroppers and untrusted foundries

Chaos is a deterministic phenomenon that occurs in a non-linear dynamic system under specific condition when the trajectories of the state vector become periodic and extremely sensitive to the initial conditions. While traditional resistor-based chaotic communications are primarily concerned with the safe transfer of information across networks, the transceivers themselves can be compromised due to outsource manufacturing. With the growth of wireless sensors in resource-constrained implantable and wearable devices, chaotic communication may be a good fit if the information transmitted is reliable and the transmitter devices are secure. We believe that memristor, as the fourth fundamental two-terminal circuit element, can close the gap between reliable communication and secure manufacturing since its resistance can be programmed and saved by the designer and not the foundry. Thus, in this paper, we propose a memristor-based Chua’s chaotic transceiver that is both reliable in the presence of eavesdroppers and secure against untrusted foundries. Specifically, we consider the pair of transmitter and receiver under the same memristor value to show the possibility of uninterrupted communication as well as cases where different values of memristors are used to find out the possible range in which the message can still be meaningfully decoded. Experimental results confirm that both reliable communication and secure design can be achieved via our proposed memristor-based chaos transceivers.

Physical evidence of meminductance in a passive, two-terminal circuit element

The first intentional memristor was physically realized in 2008 and the memcapacitor in 2019, but the realization of a meminductor has not yet been conclusively reported. In this paper, the first physical evidence of meminductance is shown in a two-terminal passive system comprised primarily of an electromagnet interacting with a pair of permanent magnets. The role of series resistance as a parasitic component which obscures the identification of potential meminductive behavior in physical systems is discussed in detail. Understanding and removing parasitic resistance as a “resistive flux” is explored thoroughly, providing a methodology for extracting meminductance from such a system. The rationale behind the origin of meminductance is explained from a generalized perspective, providing the groundwork that indicates this particular element is a realization of a fundamental circuit element. The element realized herein is shown to bear the three required and necessary fingerprints of a meminductor, and its place on the periodic table of circuit elements is discussed by extending the genealogy of memristors to meminductors.

An Improved Parameter-Free Fault Locator for Untransposed Line With Unsynchronized Terminals

This letter presents a novel parameter-free fault location algorithm for a two-terminal single circuit untransposed line with flat and delta conductor configurations while considering unsynchronized measurements. It improves the existing works by introducing unequal angles of synchronism mismatch in pre-fault and fault conditions. EMTP-RV based simulation results corroborate the validity and accuracy of the developed fault location algorithm. Simulation results are also compared with existing methods to demonstrate improved features of the proposed algorithm. Field test results are also presented to further validate the performance of the proposed algorithm.

Synthesis of memristive one-ports with piecewise-smooth characteristics

ABSTRACT A generalised approach for the implementation of memristive two-terminal circuits with piecewise-smooth characteristics is proposed on an example of a multifunctional circuit based on a transistor switch. Two versions of the circuit are taken into consideration: an experimental model of the piecewise-smooth memristor (Chua’s memristor) and a piecewise-smooth memristive capacitor. Physical experiments are combined with numerical modelling of the discussed circuit models. Thus, it is demonstrated that the considered circuit is a flexible solution for synthesis of a wide range of memristive systems with tunable characteristics.

Electromagnetic Interference Effects of Continuous Waves on Memristors: A Simulation Study.

As two-terminal passive fundamental circuit elements with memory characteristics, memristors are promising devices for applications such as neuromorphic systems, in-memory computing, and tunable RF/microwave circuits. The increasingly complex electromagnetic interference (EMI) environment threatens the reliability of memristor systems. However, various EMI signals’ effects on memristors are still unclear. This paper selects continuous waves (CWs) as EMI signals. It provides a deeper insight into the interference effect of CWs on the memristor driven by a sinusoidal excitation voltage, as well as a method for investigating the EMI effect of memristors. The optimal memristor model is obtained by the exhaustive traversing of the possible model parameters, and the interference effect of CWs on memristors is quantified based on this model and the proposed evaluation metrics. Simulation results indicate that CW interference may affect the switching time, dynamic range, nonlinearity, symmetry, time to the boundary, and variation of memristance. The specific interference effect depends on the operating mode of the memristor, the amplitude, and the frequency of the CW. This research provides a foundation for evaluating EMI effects and designing electromagnetic protection for memristive neuromorphic systems.

Parametrical synthesis of the complex two-port networks for variants of their inclusion between a source of a signal and a nonlinear part by criterion of maintenance of the set characteristics amplifiers with the general feedback

Introduction: the analysis of known literature shows that the use of various types of matching quadripoles (reactive, resistive, complex, mixed) and a feedback circuit covering a non-linear element makes it possible to increase the area of physical feasibility of given forms of frequency characteristics. The purpose of the work is to increase the area of physical feasibility of given forms of frequency characteristics by optimizing the parameters of matching complex quadripoles and using an additional feedback circuit covering a nonlinear element and a mixed quadripole. Each two-terminal network of such four-terminal networks consists of both resistive and reactive elements. Materials and methods: theory of four-terminal networks, matrix algebra, decomposition method, method of synthesis of microwave control devices, circuit engineering method for analyzing the characteristics of radio devices. Results: Mathematical models of matching complex quadripole networks are obtained in the form of relationships between the elements of their transmission matrix and the dependences of the resistances of their two-terminal circuits on frequency, which are optimal in terms of the criterion for providing specified forms of frequency characteristics. Conclusion: a comparative analysis of the theoretical results (frequency response and phase response of amplifiers) obtained by mathematical modeling in the MathCad system and experimental results obtained by circuit simulation in the OrCad and MicroCap systems shows their satisfactory agreement.

An Actively Controlled Two-Terminal Network Implementing a Given Linear Nonconvolution-Type Immittance Operator

This paper is a study on the synthesis of digital filters used to control active or self-excited systems. The active two-terminal branch implements a nonconvolution-type immittance operator, which generates a current waveform depending on the given impedance or admittance operator. In this article, for the first time, the method of how to construct immittance operators for linear time-variant (nonconvolution-type) two-terminal circuits, over discrete time, is presented. These operators are useful when calculating periodic steady-state signals of a parametric circuit. The formula for the duty cycle is derived based on the current generated by this branch, assuming a known branch voltage or vice versa. This formula allows us to make a direct calculation of the duty-cycle in an analytical manner and does not refer to any auxiliary signals, e.g., sawtooth signals, or to any control systems, e.g., PI controller. The determined duty-cycles allow us to select the appropriate switching frequency and voltage value for the switched voltage source. With this method, it is also possible to assess the parameters of the current signal that would be generated in the actual active filter branch due to the calculated PWM voltage. The presented method can be an alternative to commonly used PI controllers in feedback for controlling active power filters/inverters.

Memristors in Advanced Computing [The Editors’ Desk

The memristor was first reported in the 1970s as the fourth fundamental two-terminal circuit element (the other three are the resistor, capacitor, and inductor) and has since attracted scientists working on advanced computing. The memristor is expected to become a key technology enabler for several applications, including neural networks and artificial intelligence as well as the Internet of Things. It is our pleasure to introduce Prof. Shahar Kvatinsky and Prof. Marco Ottavi as the guest editors of this special issue of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">IEEE Nanotechnology Magazine</i> .

Two-Terminal Electronic Circuits with Controllable Linear NDR Region and Their Applications

Negative differential resistance (NDR) is inherent in many electronic devices, in which, over a specific voltage range, the current decreases with increasing voltage. Semiconductor structures with NDR have several unique properties that stimulate the search for technological and circuitry solutions in developing new semiconductor devices and circuits experiencing NDR features. This study considers two-terminal NDR electronic circuits based on multiple-output current mirrors, such as cascode, Wilson, and improved Wilson, combined with a field-effect transistor. The undoubted advantages of the proposed electronic circuits are the linearity of the current-voltage characteristics in the NDR region and the ability to regulate the value of negative resistance by changing the number of mirrored current sources. We derive equations for each proposed circuit to calculate the NDR region’s total current and differential resistance. We consider applications of NDR circuits for designing microwave single frequency oscillators and voltage-controlled oscillators. The problem of choosing the optimal oscillator topology is examined. We show that the designed oscillators based on NDR circuits with Wilson and improved Wilson multiple-output current mirrors have high efficiency and extremely low phase noise. For a single frequency oscillator consuming 33.9 mW, the phase noise is −154.6 dBc/Hz at a 100 kHz offset from a 1.310 GHz carrier. The resulting figure of merit is −221.6 dBc/Hz. The implemented oscillator prototype confirms the theoretical achievements.

Linear-response magnetoresistance effects in chiral systems

The chirality-induced spin selectivity (CISS) effect enables the detection of chirality as electrical charge signals. It is often studied using a two-terminal circuit geometry where a ferromagnet is connected to a chiral component, and a change of electrical resistance is reported upon magnetization reversal. This is however not expected in the linear response regime because of compensating reciprocal processes, limiting the interpretation of experimental results. Here we show that magnetoresistance effects can indeed appear even in the linear response regime, either by changing the magnitude or the direction of the magnetization or an applied magnetic field. We illustrate this in a spin-valve device and in a chiral thin film as the CISS-induced Hanle magnetoresistance (CHMR) effect. This effect helps to distinguish spin-transport-related effects from other effects, and can thereby provide further insight into the origin of CISS.

Mechanical Manipulation of Silicon-based Schottky Diodes via Flexoelectricity

Silicon-based Schottky barrier diodes (SBDs), as a two-terminal circuit element, are widely used in modern industries due to its low cost and better compatibility with the complementary metal oxide semiconductor (CMOS) technology. Flexoelectricity resulting from strain gradient is a distinctive electromechanical coupling phenomenon compared to piezoelectricity resulting from strain. Flexoelectricity can exist in any dielectric due to the non-uniform strain breaking symmetry of materials. In this paper, we utilize the induced flexoelectric polarization to tune the behavior of a SBD made of metal and p-type Silicon. Making use of conductive atomic force microscopy (C-AFM), we measured current-voltage of the fabricated Si-based SBD under different tip forces. In order to conduct a quantitative study on the tuning effect of flexoelectricity on the performance of the fabricated Si-based SBD, we introduce an effective barrier height and provide a modified current equation according to the classical thermionic emission theory. The results show that flexoelectricity plays a significant role in dictating the Schottky barrier height, maximum rectified current (density), reverse saturation current (density), rectification ratio, and open voltage of the fabricated SBD. In addition, based on the Hertzian contact model and the measured data, the nonzero flexoelectric coefficients of the used p-type silicon are obtained.

Manufacturer-data-only-based modeling and optimized design of thermoelectric harvesters operating at low temperature gradients

The paper presents a methodology of assessing performance of thermoelectric harvesters (TEH) operating at low temperature gradients using manufacturer datasheet only. Simplified and full TEH models with temperature-independent parameters are established with the former developed in the form of a two-terminal equivalent circuit, typical for renewable energy generators. Normalized expression is derived to assess maximum extractable TEH power for certain environmental conditions, heat sink thermal resistance and thermoelectric module figure of merit. Key role of the heat sink in TEH performance is revealed and corresponding design guidelines are provided. Experimental results are provided, demonstrating close match with analytical predictions, obtained by the proposed methodology.

Physics-Based Modeling of Parasitic Capacitance in Medium-Voltage Filter Inductors

This article proposes a general physics-based model for identifying the parasitic capacitance in medium-voltage (MV) filter inductors, which can provide analytical calculations without using empirical equations and is not restricted by the geometrical structures of inductors. The elementary capacitances of the MV inductor are identified, then the equivalent capacitances between the two terminals of the inductor are derived under different voltage potential on the core. Further, a three-terminal equivalent circuit, instead of the conventional two-terminal equivalent circuit, is proposed by using the derived capacitances. Thus, the parasitic equivalent capacitance between the terminals and the core are explicitly quantified. Experimental measurements for parasitic capacitances show a good agreement with the theoretical calculations.

APPLICATION OF THE IMPEDANCE METHOD FOR DETERMINATION OF MONOSODIUM GLUTAMATE IN FOOD PRODUCTS

The article presents the results of studying how impedance analysis can be used for determination of monosodium glutamate in order to identify food fraud. We have suggested that the parameters of complex conductivity (admittance) of a two-terminal circuit could allow detecting monosodium glutamate (E 621), an additive used in the food industry to enrich the taste. The method involves passing current of different frequencies through solid foodstuffs and a cell with liquid foodstuffs, measuring the electrical conductivity, and determining and analysing the frequency dependence of admittance. The active G component and the reactive B component of the admittance have been measured at different frequencies, from 100 Hz to 100 kHz. For the experiment, food samples were prepared in accordance with the Codex Alimentarius recommendations for the dosage of the food additive E 621: orange juice with monosodium glutamate added in the amount of 0.3%, and mashed potatoes with glutamate added in the amount of 1%, of the total weight of the products. The temperature of the tested products was 22 ± 0.2°С. The results of the studies have shown the dependences of the admittance components on the frequency for the control samples of juice and mashed potatoes and for the samples with monosodium glutamate added. The dependence of the active component and the reactive component of the foodstuff admittance have been established, with monosodium glutamate (added in the above-specified proportion) and without it. The difference is in how the dependences change in their nature. The monosodium glutamate curves both in juice and in mashed potatoes are similar. The samples containing monosodium glutamate have far higher values of the active and reactive admittance component than the control samples do, with a distinct peak of the reactive component characteristic. Therefore, impedance analysis is a possible method to detect quickly the flavour enhancer monosodium glutamate in foods of different consistency and thus identify food fraud.

Fractional-Order Chaotic Memory with Wideband Constant Phase Elements.

This paper provides readers with three partial results that are mutually connected. Firstly, the gallery of the so-called constant phase elements (CPE) dedicated for the wideband applications is presented. CPEs are calculated for 9° (decimal orders) and 10° phase steps including ¼, ½, and ¾ orders, which are the most used mathematical orders between zero and one in practice. For each phase shift, all necessary numerical values to design fully passive RC ladder two-terminal circuits are provided. Individual CPEs are easily distinguishable because of a very high accuracy; maximal phase error is less than 1.5° in wide frequency range beginning with 3 Hz and ending with 1 MHz. Secondly, dynamics of ternary memory composed by a series connection of two resonant tunneling diodes is investigated and, consequently, a robust chaotic behavior is discovered and reported. Finally, CPEs are directly used for realization of fractional-order (FO) ternary memory as lumped chaotic oscillator. Existence of structurally stable strange attractors for different orders is proved, both by numerical analyzed and experimental measurement.

Algorithm for Indirect Measurement of the Parameters of the Passive Complex Conductivity of a Two-Terminal Circuit in a Multipole Electrical Circuit

An algorithm is proposed for indirect measurement of the parameters of the passive complex conductivity as a separate two-terminal circuit and also as a two-terminal device located in one of the branches of a multipole passive triangle-type electrical circuit without needing to separate it into separate two-terminal circuits. A structural diagram is presented for a microprocessor device to measure the parameters of the passive complex conductivity of a two-terminal device located in one of the branches of a multipole passive triangle-type electrical circuit. The algorithm for the indirect method of measuring the parameters of the passive complex conductivity of the two-terminal circuit is based on the theory of matrices and nondirectional graphs. Equations are obtained for calculating the modulus and components of the passive complex conductivity of a two-terminal circuit located in a multipole triangle-type electrical circuit. The proposed algorithm avoids the methodological error owing to the influence of parasitic parameters. Results are presented from an experimental test of the algorithm for indirect measurement of the conductivity of a two-terminal circuit.

An efficient memristor crossbar architecture for mapping Boolean functions using Binary Decision Diagrams (BDD)

The memristor is considered as the fourth fundamental circuit element along with resistor, capacitor and inductor. It is a two-terminal passive circuit element whose resistance value changes based on the amount of charge flowing through it. Another property of the memristor is that its resistance change is non-volatile in nature, and hence can be used for non-volatile memory applications. Researchers have been exploring memristors from various perspectives such as logic design and storage applications. In this paper, a slicing crossbar architecture for the efficient mapping of Boolean functions is proposed which exploits gate level parallelism using the memristor aided logic (MAGIC) design style. A Boolean function is first represented as a Binary Decision Diagram (BDD). The BDD nodes are expressed as netlists of NOR and NOT gates, and are mapped to the proposed slicing crossbar architecture with parallel node evaluation where possible. This is the first approach that combines BDD-based synthesis with MAGIC gate evaluation on memristor crossbar, while at the same time avoiding crossbar-related problems using a slicing architecture. Experimental evaluations on standard benchmark functions show considerable improvement in the solutions.

Algorithm for indirect measurement method of parameters of passive complex conductance of a two-pole in a multi-pole electrical circuit

An algorithm is proposed for indirectly measuring the parameters of the passive complex conductivity of a two-terminal circuit, both separate and located in one of the branches of a multi-pole passive electric circuit of the triangle-type. A block diagram of a microprocessor measurement unit is presented. The algorithm of the indirect method for measuring the parameters of the passive complex conductivity of a two-terminal circuit, the rationale of which is given on the basis of the theory of matrices and undirected graphs, is considered. Equations for calculating the modulus and components of the studied passive complex conductivity of a two-terminal device located in a multi-pole electric circuit of the triangle-type are obtained. The revealed features of the proposed algorithm exclude a methodological error due to the influence of spurious parameters. Parasitic parameters include: input complex conductivities and transmission coefficients of voltage converters; complex conductivity of a harmonic signal source; passive complex conductivity of two-terminal circuits located in other branches of the studied passive multipolar electric circuit. The results of an experimental verification of the developed algorithm of the indirect method for measuring the module of the complex conductivity of a two-terminal device are presented. The developed algorithm can be used to measure the parameters of passive complex conductivity of both an individual two-terminal circuit and a two-terminal circuit located in one of the branches of a multi-pole passive electric circuit of the triangle-type, without the need for its separation into separate two-terminal devices.