Basic Circuit Research Articles

Design and Fabrication of Low-Power Single-Flux-Quantum Circuits Toward Quantum Bit Control

we report low-power single-flux-quantum (SFQ) circuits fabricated with a lowered critical current density process and low-voltage design. We selected 250 A/cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{2}$</tex-math></inline-formula> to obtain 2–10 μA Josephson junctions (JJs) easily using conventional facilities. Our numerical simulation shows that the expected operating frequency is 10 GHz and that we can reduce the bias voltage to 0.1–0.5 mV; power consumption can be reduced to around 1 nW per JJ. We newly developed a fabrication process featuring four planarized Nb layers and a Pd resistor layer. We obtained the correct operation of several basic SFQ circuit elements designed with the lowered critical currents to 1/2 of the conventional circuits at 4.2 K. We also evaluated the Josephson junction critical currents, specific capacitance, resistance, and inductance at 3 K and 300 mK. We observed an increase of 7% in the critical currents at 300 mK, while the other parameters were unchanged. We demonstrated a 0.5-mV Josephson transmission line where we lowered the critical currents to 1/10. We expect such low-power SFQ circuits to operate at 20 mK, providing classical, general-purpose digital processing near quantum bits.

A class of novel discrete memristive chaotic map

Since Chua introduced the memristor as the fourth basic circuit component, memristors and memristive chaotic maps have received great attention. In this paper, we present a class of novel memristive chaotic map by coupling the discrete memristor with the internal item in an original boundary function. Several examples are presented based on classical one dimensional (1D) and high dimensional (HD) chaotic maps, and numerical simulation results display their improved dynamical performance and chaos complexity. We analyze the influences of introducing the memristor on the chaotic map and the generality for designing discrete chaotic maps of the proposed memristive model. Particularly, with the newly emerging features of no fixed points and multistability, we can robustly control the output sequence by setting their initial-states, which accommodates to many arisen applications of chaotic systems. Furthermore, based on the proposed memristive chaotic map, we construct the hardware platform to acquire its attractors, and design the Pseudorandom Number Generator (PRNG) to explore its application prospects.

Transistors for Solid-State Microwave Switches (A Review)

Introduction. The characteristics of solid-state microwave switches are subject to different requirements depending on the application area and technical problems to be solved. No versatile solution exists that could satisfy all requirements at once. The desire to improve the parameters of switches has led to the emergence of devices based on various technologies. In order to elucidate the current trends and future prospects in the field of switch technologies, semiconductor devices that form the basis of switch circuits should be considered.Aim. To review transistor types used in solid-state switches.Materials and methods. The search and selection of literature sources for review was based on the chronological principle. The search depth for considering the parameters of finished components was no more than 10 years, for considering technologies and structural solutions – more than 10 years. This choice was explained by our desire to trace the history of development and approaches to the creation of semiconductor devices that have led to the emergence of the modern component base. The final array of sources comprised scientific publications presenting factual information on the objects under consideration.Results. The types, structures, materials, characteristics and manufacturing technologies of transistors used in switches are considered. The achievable parameters of the switches based on the considered devices are presented. Conclusion. The choice of a particular transistor type for switches depends on the requirements for the parameters and performance characteristics of the final device. At present, transistor solutions for switches are dominated by field-effect transistors (FETs) of various types: GaAs and GaN transistors with a high electron mobility (HEMT) and Si CMOS FETs implemented by standard as well as silicon-on-insulator and silicon-on-sapphire technologies. The conducted literature review has revealed prospects for the development of technologies based on BiCMOS heterojunction bipolar transistors.

Core processing neuron‐enabled circuit motifs for neuromorphic computing

AbstractBased on brain‐inspired computing frameworks, neuromorphic systems implement large‐scale neural networks in hardware. Although rapid advances have been made in the development of artificial neurons and synapses in recent years, further research is beyond these individual components and focuses on neuronal circuit motifs with specialized excitatory–inhibitory (E–I) connectivity patterns. In this study, we demonstrate a core processor that can be used to construct commonly used neuronal circuits. The neuron, featuring an ultracompact physical configuration, integrates a volatile threshold switch with a gate‐modulated two‐dimensional (2D) MoS2 field‐effect channel to process complex E–I spatiotemporal spiking signals. Consequently, basic neuronal circuits are constructed for biorealistic neuromorphic computing. For practical applications, an algorithm‐hardware co‐design is implemented in a gate‐controlled spiking neural network with substantial performance improvement in human speech separation.image

Programmable In-Memory Computing Circuit for Solving Combinatorial Matrix Operation in One Step

Matrix operations are widely used in practical engineering, but the traditional processing methods rely on the loop iterations and neural network algorithm on the software, requiring a long time to calculate. To address such problem, this paper proposes full hardware in-memory computing circuits based on programmable memristor unit array that can solve combinatorial matrix operations of any order in just one step. First, two basic circuit modules are introduced, which can respectively solve matrix multiplication and matrix equation. Further, the basic modules can be linked to solve combinatorial matrix operations with different forms. It’s worth noting that every module can parallel program the value of each memristor in the memristor unit array and complete one-step computation by hardware. Then, some matrix operations are given in the paper as examples to prove the high accuracy of proposed method, where the average accuracy rate achieves <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$99\%$</tex-math> </inline-formula> . The PSPICE simulation results demonstrate that the processing speed is improved enormously according to the comparison of hardware and software. Moreover, the proposed method has broad application prospect in practical engineering, such as using designed combinational circuit to solve domain shift problem in zero-shot learning, which greatly accelerates the training process of zero-shot learning.

Design of stress monitoring system for planetary gear shaft

A remote sensing gear shaft stress monitoring system is studied to deal with the stress balance of transmission gear, which realizes the real-time dynamic monitoring of the planetary gear shaft stress. The design of the whole system structure, the installation position of the basic system and the special working environment of the gear are carried out; the circuit of each function unit is designed, which is based on the overall index requirement and installation space limitation; the software program design is carried out on the basis of the hardware circuit; The main components of the system and the principle of dynamic monitoring system are described; each functional unit and the whole of the system are tested and analyzed in detail. The operation results show that the design is reliable, the actual functions of each unit can meet the design index, and has a certain contribution in the field of gear shaft stress monitoring.

Multidirectional Associative Memory Neural Network Circuit Based on Memristor.

Multidirectional associative memory neural network(MAMNN) is a direct extension of bidirectional associative memory neural network, which can handle multiple associations. In this work, a circuit of MAMNN based on memristor is proposed, which simulates the complex associative memory behavior more in line with the brain mechanism. Firstly, the basic associative memory circuit is designed, which is mainly composed of memristive weight matrix circuit, adder module and activation circuit. It realizes the associative memory function of single-layer neurons input and single-layer neurons output, so that the information can be transmitted unidirectionally between double-layer neurons. Secondly, on this basis, an associative memory circuit with multi-layer neurons input and single-layer neurons output is realized, which makes information transfer unidirectionally between multi-layer neurons. Finally, several identical circuit architectures are extended, and they are combined into a MAMNN circuit through the feedback connection from the output to the input, which realizes the bidirectional transmission of information between multi-layer neurons. Pspice simulation shows that: 1) When single-layer neurons are selected to input data, the circuit can associate data from other multi-layer neurons, realizing one-to-many associative memory function in the brain. 2) When multi-layer neurons are selected to input data, the circuit can associate the target data and realize the many-to-one associative memory function in the brain. The MAMNN circuit is applied to the field of image processing, which can associate and restore damaged binary images, showing strong robustness.

Experimental studies of using the digital control system in power conversion equipment of high-voltage power supply systems in spacecrafts with a hydrogen energy accumulator

Solar-hydrogen energy for spacecraft, space interplanetary stations, space bases on the planets of the solar system must reliably provide energy: spacecraft during peak periods (repairs at a space facility, energy-consuming experiments, cleaning of facilities, regeneration of waste to extract oxygen and hydrogen, etc. .d.) and bases on planets, especially where the night lasts for a long time.The onboard hydrogen module of the solar-hydrogen plant includes: a container with water; distiller; deionizer; water lines with adjustable shut-off valves; electrolyzer; cryogenic side tanks with hydrogen and oxygen; fuel cell, hydrogen safety sensor systems based on leakage and concentration sensors; level gauges; cryogenic and gas pipelines of hydrogen and oxygen; onboard cryo-refrigerator; automatic control system for the hydrogen module. The article presents the results of experimental studies of static, dynamic and mass-dimensional characteristics of power conversion equipment (hereinafter - PCE) in the power supply system (hereinafter - PSS) of the spacecraft (hereinafter - spacecraft) with a digital control system. The purpose of experimental research is to verify the theoretical results obtained earlier in the design of digital PCE control systems of high-voltage PSS spacecraft, including the study of static and dynamic characteristics. We developed and manufactured an experimental PCE sample with an output power of 2500W in this research. It includes: four voltage stabilization modules and the 100V load supply output bus filter. Each voltage stabilization module includes a battery energy conversion channel, a solar battery energy conversion channel and a digital control system unit. The power conversion channel of the accumulator battery is designed and made on the basis of a bridge volt-booster inverter-transformer circuit. Voltage control in energy converter of accumulator battery is based on phase shift in control pulses of transistors in adjustable inverter rack related to unregulated one. The power conversion channel of the solar battery is designed and made on the basis of a two-phase circuit of a direct voltage converter of an increasing type with switching throttles. The digital control system of the voltage stabilization module is designed on the basis of analogues in the modern electronic component base in the Space class and consists of four identical channels. Each channel of the control system controls its own voltage stabilization module. We obtained the following results during our experimental studies: some pulsations of the output voltage of the energy conversion equipment during operation on an active load, transient processes of the output voltage of the energy conversion equipment during pulsations of the load current without changing the mode of operation, transient processes of the output voltage of the energy conversion equipment when changing the modes of its operation and weight and size characteristics for different values of the output power. The obtained results of experimental studies confirm the previously obtained theoretical results, and also showed that the use of a distributed digital control system will increase the specific energy characteristics of the newly developed PSS spacecraft while ensuring the given static and dynamic characteristics of output voltage quality. The results of the work are designed to create a new on-board power conversion equipment for power supply systems of promising spacecraft. The area of application of the project results is space instrumentation.

Effective Teaching Design Based on the Combination of BOPPPS Model and Tina Virtual Simulation Software

Good teaching effect comes from effective teaching design. In this article, we combined the advanced teaching concept BOPPPS model with Tina virtual simulation software to develop the teaching design. BOPPPS model is an effective and efficient teaching model. It includes six parts such as bridge-in, objective, preassessment, participatory learning, postassessment, and summary. In this article, bridge-in is introduced by practical examples of triode amplifier circuits. Objective includes knowledge objective, ability objective, and value objective. Preassessment is realized by simulating the triode output characteristic. Participatory learning is presented by simulating three kinds of basic amplifier circuits and analyzing simulation results. Besides that, flipping classroom is designed to stimulate students’ learning enthusiasm and innovation ability. Postassessment is completed by asking some questions. Summary is completed by students and supplemented by teachers. In this process, different simulation waveforms are obtained by using the Tina virtual software to simulate the various circuits layer by layer. Practice has shown that the proposed method not only improves students’ ability of analyzing and designing practical circuits, but also stimulates students’ learning enthusiasm. Teaching design ideas become clearer, and the teaching quality is improved.

Implementation of Digital Circuits using the Internet of Things

Digital circuits are used everywhere in day to day lives. There is a need to learn it practically by every undergraduate in laboratories. Digital trainer kits are being used in laboratories which use a basic circuit connection approach. Only this approach is not sufficient for a student to explore deep enough because digital circuits can be implemented by any number of approaches. A smart approach is required for enhancement of the trainer kit. This project incorporates the Iot approach required for implementation of digital circuits. This project works as a digital demo kit which helps students to smartly learn boolean functions with the Iot approach. Arduino microcontroller is a substitute for digital circuits and it brings smartness and digital logic in one platform to easily achieve the required digital functionality. In this project, implementation of logic gates, basic combinational and sequential circuits will be done. This project uses Arduino programming which is executed with respect to digital circuits. The inputs are given using ultrasonic sensors, input parameters are given efficiently using the bluetooth module and the outputs will be shown on a two bit seven segment display. Trainer kits can be fabricated using this mechanism and components and thus, it would definitely find a good application in laboratories helping undergraduates to learn in a better manner.

Development of Vertical Axis Wind Turbine Charger as Alternative Power Source

The study was focused on the development of Vertical Axis Wind Turbine Charger with D.C Air Compressor to address power shortage in the coastal area in the Province of Isabela. This project development research tried to achieve the following objectives; a) Design and Construct Vertical Axis Wind Turbine Charger with D.C Air Compressor; b) Test the functionality of the project by conducting various activities concerning to basic electrical and electronics circuits, blade adjustment and experiments; c) Determine the acceptability of the project in terms of functionality, workability, durability, safety and instructional applicability as evaluated by the respondents; and d) Make an activity manual to supplement the developed project. The five-point’s Likert’s scale was used to determine the descriptive meaning of the indicators of the variables used. Furthermore, the Weighted Average Mean (WAM) was used to interpret the equivalent meaning of the data gathered. The Analysis of Variance (ANOVA) was employed to determine the significant difference between the evaluations of the respondents. The completed project was evaluated by selected twenty (20) technology instructors 25 students, ten (10) Engineers from Isabela State University-Ilagan, Roxas, San Mateo, Cauayan Campus and TESDA Ilagan Evaluation result shows that the project obtained an overall mean of 4.52 which means the Vertical Axis Wind Turbine Charger is “HIGHLY ACCEPTABLE” to the evaluators based on the criteria of functionality, aesthetics, workability, durability, economy, safety and instructional applicability.

Topology Analysis of Full-Controlled Hybrid Switching Network in Fusion Device

Switching network unit (SNU) of fusion device excites the plasma and finally establishes the plasma current. The full-controlled hybrid scheme is the research trend and hotspot of SNU in a nuclear fusion device. Based on the analysis of the SNU schemes in the current fusion devices, two kinds of full-controlled hybrid circuits are compared and analyzed. Through the principle analysis, theoretical calculation, and model simulation under 50 kA, the system operation process and the influence of arc voltage and other related parameters on the operation process are studied and discussed. Finally, the main characteristics and applicable conditions of the two circuits are described. At the same time, the aspects needing attention in circuit design are explained. The research shows that the basic circuit is suitable for high-current circuits, and the multistage commutation circuit is suitable for high-voltage circuits. The above study can provide a useful reference for the design of full-controlled hybrid SNU.

Neurobeachin controls the asymmetric subcellular distribution of electrical synapse proteins

The subcellular positioning of synapses and their specialized molecular compositions form the fundamental basis of neural circuits. Like chemical synapses, electrical synapses are constructed from an assortment of adhesion, scaffolding, and regulatory molecules, yet little is known about how these molecules localize to specific neuronal compartments. Here, we investigate the relationship between the autism- and epilepsy-associated gene Neurobeachin, the neuronal gap junction channel-forming Connexins, and the electrical synapse scaffold ZO1. Using the zebrafish Mauthner circuit, we find Neurobeachin localizes to the electrical synapse independently of ZO1 and Connexins. By contrast, we show Neurobeachin is required postsynaptically for the robust localization of ZO1 and Connexins. We demonstrate that Neurobeachin binds ZO1 but not Connexins. Finally, we find Neurobeachin is required to restrict electrical postsynaptic proteins to dendrites, but not electrical presynaptic proteins to axons. Together, the results reveal an expanded understanding of electrical synapse molecular complexity and the hierarchical interactions required to build neuronal gap junctions. Further, these findings provide novel insight into the mechanisms by which neurons compartmentalize the localization of electrical synapse proteins and provide a cell biological mechanism for the subcellular specificity of electrical synapse formation and function.

Modeling and Optimal Design of Inductor-Integrated Three-Phase 3-D Wound Core Transformer Under SPWM Excitation

Compared with the laminated core transformer (LCT), the 3D wound core transformer(3D-WCT) has the characteristics of symmetrical magnetic circuit and low vibration. This article focuses on the modeling and optimal design of the 3D-WCT for isolated DC/AC application. Firstly, based on the Jiles-Aterton model, a nonlinear magnetic circuit model of the 3D-WCT is established to calculate the flux density and core loss accurately under SPWM excitation. A thermal network model is presented for the steady-state temperature-rise calculation of the forced-air cooled 3D-WCT. Secondly, the optimal design method is carried out on the basis of the magnetic circuit and thermal network models. Based on the optimized design results, a regression analysis is performed to establish the relationship between the design variables and the performance objectives. Finally, a 75kVA 3D-WCT prototype is manufactured and tested in the actual inverter power supply to verify the established magnetic circuit and thermal network models. The 3D-WCT prototype is applied to the 150kVA inverter power supply, which contributes to achieving high power density and high efficiency of the power supply.

English

The environment is deteriorating every day. In the face of this problem, there are innovative ways to counteract this phenomenon that could lead to the massive extinction of living beings. The automotive fleet is a serious polluting factor in the world, emitting many toxic gases and pollutants into the environment, within which we will focus on noxious gases and NOx. The objective of this study is to realize a detector of noxious gases emitted by the exhaust pipe promoting a reduction of these, separated by two major phases, detection and filtering (regeneration). For this purpose, we have used the guide of filter families that are being promoted by environmental standards for better quality in the environment. Following this, a prototype is designed using basic circuit design components that are controlled by a free programmable microcontroller (Arduino UNO), guided by the technology present in the ECH and DPF filters. The prototype showed values in real-time and indicated when to switch from one process to another, in addition to displaying graphically how many values, in parts per million, are being detected, activating LED indicators that show an immediate response. Taking into account the above mentioned, it is recommended to promote research and use of the family of filters that will be presented to reduce the problem of air pollution and the environment.

The Analysis of Parkinsons Disease using Phase-Amplitude Coupling Method

Parkinson's disease (PD) is now the second most prevalent chronic neurological illness worldwide. For motor symptoms of PD, PD is linked to a number of dyskinesia, including rigidity, bradykinesia, postural instability, and tremor at rest. PD dyskinesia is the most common cause of Parkinsonism. Meanwhile, PD dyskinesia may be closely linked to the neural oscillations between neural circuits. PD dyskinesia is associated, in particular, with beta oscillation, which is directly related to the incidence and development of the motor. For the purpose of analysing neural oscillations between neural circuits, phase-amplitude coupling (PAC) can be utilised as a biomarker. As a potential biomarker of beta oscillation, PAC has been widely used in the research of PD. Therefore, this article reviews the latest concepts of dyskinesia, methods of calculating PAC and applications of PAC in Parkinson's disease, aiming to provide a good theoretical basis for finding neural circuits involved in PD dyskinesia to establish better deep brain stimulation therapy.

Design of FIR Filter Using Low-Power and High-Speed Carry Select Adder for Low-Power DSP Applications

Adders are one of the basic arithmetic circuits of any processor, microcomputer, multiplication circuits, etc. Presently, the most substantial areas in the research of VLSI design are area, power, and efficient high-speed circuits. In this paper two new architectures Carry Select Adder (CSLA) using D-latch and CSLA using multiplexers are proposed to reduce the power, delay, and its efficiency is compared with conventional carry select adder (CSLA) and existing literature. Architectural level power reduction is the most important area where it plays a vital role in improving the speed and power of the overall circuit. The existing and proposed CSLAs are synthesized with the Synopsys EDA tool using 32 nm technology node is used for the design and implementation. The values obtained across technology in nm underline the dominance of the proposed adder architectures in terms of delay and energy and area efficiency. For the proposed architectures, the evaluation results show that 60%–75% improvement in delay and 22%–56%in power when compared to other architectures. Proposed architectures shows increment in area but overall are delay product reduces compares to existing designs The proposed CSLA-DLATCH-FIR obtained significant reduction for 16-bits for power (46.4 (µW)), delay (0.66), ADP (359.8 × 10–15), and PDP (30.63 × 10–15). While the proposed CSLA-MUX-FIR has attained substantial performance for power (52.44 (µW)), delay (0.82 ns), ADP (457.392 × 10–15), and PDP (42.9 × 10–15). With the use of this proposed CSLA, a FIR filter was able to significantly reduce its power and delay.

Possible Extrinsic Ferroelectric-like Signals Originated from the Oxygen Vacancy Drift in HfO2-Based Films

It is generally accepted that oxygen vacancies (VO) play a central role in the emergence of ferroelectricity for HfO2-based materials, but the underlying mechanism still remains elusive. Herein, starting from the basic characterization circuit, we propose a possible extrinsic source of the ferroelectric-like signals. A key finding is that charged VO oscillate within the sample under repeated electric pulses, yielding a nonlinear current which behaves similar to the polarization current for a normal ferroelectric. This unwanted current signal results in a ferroelectric-like hysteresis loop with both remnant polarization and coercive field in good agreement with experimental values, given a charged VO concentration in the vicinity of 1 × 1020 cm–3. Moreover, it is possible to exploit this mechanism to reproduce the scattered remnant polarization values and the effects of wake-up, split-up, and limited endurance that are of crucial relevance for the device applications.

The Hidden Behavior of a D-Latch

For clock and data transitions in close temporal proximity, synchronous memory elements potentially enter metastability, which leads to unintended output behavior. Although respective analyses in literature have already derived suitable explanations, almost all of them modeled the control (clock) signal transition with negligible rise/fall time. In modern circuits this assumption is, however, not reasonable any more. In fact, due to a finite slope, intermediate clock signal values have to be considered during a large share of the storage process, while their concrete impact is not yet sufficiently explored. In this paper we thus use static and dynamic considerations to thoroughly investigate the behavior of a latch for arbitrary analog control, data and output values, i.e., during the storage process. Basic circuit considerations allow us to derive a unified model which identifies the latch as a Schmitt Trigger with vastly varying hysteresis. We verify the correctness of our predictions by comparison to analog SPICE simulations. Finally we are able to generalize our findings and thus provide explanations for yet unexplained behavior reported in literature.

Topology Derivation of Multiport DC–DC Converters Based on Reinforcement Learning

Multiport dc–dc convertersare attracting wide attention in various applications. However, conventional topology derivation methods for multiport dc–dc converters are usually intricate and time-consuming. In this article, a reinforcement learning (RL)-based topology derivation method is proposed, which can derive topologies of complex converters quickly. To apply the RL framework, the topology derivation process is regarded as a Markov decision process. In each step, the agent selects and connects two components until a complete topology is made. To ensure that the derived topologies are feasible and match given voltage specifications, basic circuit constraints and duty cycle constraints are added as hard constraints. Soft constraints are also added to obtain optimal circuits with low voltage stresses or low current stresses. The testing on topology derivation of multiport dc–dc converters shows the great speed of the proposed method. Simulation and experimental results verify that the derived topologies cannot only satisfy given voltage specifications, but also achieve optimization targets of low voltage stresses or current stresses.