Circuit Devices Research Articles

Development of a method of surface water content research using ultraviolet rays

It is known that the process of water treatment in surface water bodies requires the development of advanced and effective technologies for the destruction of harmful microorganisms and viruses. The aim of the present study is to develop a method for the investigation of surface water content. As a result of the study, the electronic circuit of the purification device using ultraviolet rays was developed. The energy and spectral characteristics were experimentally investigated and the economic efficiency of the ultraviolet ray device was determined, taking into account the basic sanitary and hygienic requirements for the organisation of ultraviolet water disinfection. It is substantiated, that the developed scheme provides safety of conditions of work of the personnel with the equipment.

Network analysis of memristive device circuits: dynamics, stability andcorrelations

Network analysis of memristive device circuits: dynamics, stability andcorrelations

Design of On-Site Calibration Device for Electricity Meter Based on Pulse Detection

At present, the error calibration of electricity meters in operation generally adopts an off-site method; that is, the electricity meter is taken out of operation and then calibrated in the laboratory. Off-site calibration, while beneficial, may not fully capture the operational error of the electricity meter due to potential differences in environmental conditions. An on-site calibration device for electricity meters based on pulse detection is designed, which obtains the error of the electricity meter under calibration by comparing the energy pulses of the standard electricity meter with those of the electricity meter under calibration. High-precision voltage and current sampling channels are designed, with a voltage measurement error of less than 0.02% and a current measurement error of less than 0.03%. In response to the non-synchronous sampling problem caused by frequency fluctuations in the on-site verification environment, a fast optimal frequency estimation algorithm is applied to accurately calculate the signal frequency within two cycles. The sampling time interval is adjusted to achieve lock-frequency synchronous sampling, and ensure the accurate calculation of electrical parameters. In order to reduce the complexity of the device circuit structure and equipment cost, a standard electric energy pulses generation method based on digital integration-to-frequency is proposed, which uses software to generate electric energy pulses, with a maximum output frequency of up to 10 kHz. Tests conducted in the laboratory on the developed on-site calibration device for electricity meters show that its accuracy is better than the 0.05 accuracy class, meeting the application requirements for on-site verification of electricity energy meters.

Accelerated Modeling of Transients in Electromagnetic Devices Based on Magnetoelectric Substitution Circuits

During switching in electrical systems, transient electromagnetic processes occur. The resulting dangerous current surges are best studied by computer simulation. However, the time required for computer simulation of such processes is significant for complex electromagnetic devices, which is undesirable. The use of spectral methods can significantly speed up the calculation of transient processes and ensure high accuracy. At present, we are not aware of publications showing the use of spectral methods for calculating transient processes in electromagnetic devices containing ferromagnetic cores. The purpose of the work: The objective of this work is to develop a highly effective method for calculating electromagnetic transient processes in a coil with a ferromagnetic magnetic core connected to a voltage source. The method involves the use of nonlinear magnetoelectric substitution circuits for electromagnetic devices and a spectral method for representing solution functions using orthogonal polynomials. Additionally, a schematic model for applying the spectral method is developed. Obtained Results: A method for calculating transients in magnetoelectric circuits based on approximating solution functions with algebraic orthogonal polynomial series is proposed and studied. This helps to transform integro-differential state equations into linear algebraic equations for the representations of the solution functions. The developed schematic model simplifies the use of the calculation method. Representations of true electric and magnetic current functions are interpreted as direct currents in the proposed substitution circuit. Based on these methods, a computer program is created to simulate transient processes in a magnetoelectric circuit. Comparing the application of various polynomials enables the selection of the optimal polynomial type. The proposed method has advantages over other known methods. These advantages include reducing the simulation time for electromagnetic transient processes (in the examples considered, by more than 12 times than calculations using the implicit Euler method) while ensuring the same level of accuracy. The simulation of processes over a long time interval demonstrate error reduction and stabilization. This indicates the potential of the proposed method for simulating processes in more complex electromagnetic devices, (for example, transformers).

Enhanced buck-boost converter performance using a snubber circuit and advanced semiconductor devices

Conventional buck-boost converter designs often suffer from efficiency losses and performance degradation due to switching transients and voltage spikes. To address these challenges, we propose the incorporation of a snubber circuit, which is designed to absorb and mitigate these detrimental effects. The study involves the design, implementation, and experimental evaluation of the proposed enhanced buck-boost converter. The analysis focuses on the impact of the snubber circuit on key performance metrics, including efficiency, thermal behavior, and electromagnetic interference (EMI) reduction. The experimental results indicate that the snubber circuit significantly reduces voltage spikes and switching losses, leading to improved converter efficiency and reliability. These findings provide valuable insights for optimizing converter designs in a variety of applications, from renewable energy systems to portable electronic devices, ultimately contributing to the advancement of power electronics technology. Finally, the performance of the proposed converter is analyzed using advanced semiconductor devices.

Enhancing computational accuracy with parallel parameter optimization in variational quantum eigensolver

Variational quantum algorithms have promising applications in noisy intermediate-scale quantum (NISQ) devices. These algorithms rely on a classical optimization outer loop that minimizes a parameterized quantum circuit function. The optimization in variational quantum eigensolver (VQE) is NP-hard, meaning that finding the optimal solution is infeasible in the worst-case scenario. One way to address this challenge is through parallel optimization of parameters using multiple-parameterized quantum circuits. However, this approach is unsuitable for cloud-based quantum processing unit utilization due to the increased number of quantum circuit executions. Although NISQ devices have limitations in terms of gate depth, their size has been growing in recent years. Therefore, implementing multiple-parameterized quantum circuits in NISQ devices can suppress the increase in the number of executions. In this study, we propose a parallel-VQE, which leverages the parallel execution of parameterized quantum circuits to perform parallel parameter optimization in VQE, achieving convergence to solutions closer to the ground state. We validate the effectiveness of parallel-VQE in solving the random weighted max-cut problem using numerical simulations and a real quantum device. We present the results of running up to six circuits in parallel (120 qubits) and demonstrate the advantages of using multiple units to improve computational accuracy. This study provides a potential method for solving eigenvalue problems and combinatorial optimization problems for future quantum devices.

A Negative Capacitance Field-Effect Transistor with High Rectification Efficiency for Weak-Energy 2.45 GHz Microwave Wireless Transmission.

This paper proposes and designs a silicon-based negative capacitance field effect transistor (NCFET) to replace conventional MOSFETs as the rectifying device in RF-DC circuits, aiming to enhance the rectification efficiency under low-power density conditions. By combining theoretical analysis with device simulations, the impacts of the ferroelectric material anisotropy, ferroelectric layer thickness, and active region doping concentration on the device performance were systematically optimized. The proposed NCFET structure is tailored for microwave wireless power transmission applications. Based on the optimized NCFET, a half-wave rectifier circuit employing a novel diode connection configuration was constructed and verified through transient simulations. The results show that at a microwave frequency of 2.45 GHz, the designed NCFET rectifier achieves rectification efficiencies of 16.1% and 29.75% at input power densities of -10 dBm and -6 dBm, respectively, which are 7.15 and 2.3 times higher than those of conventional silicon-based MOS devices. Furthermore, it significantly outperforms CMOS rectifiers reported in the literature. This study demonstrates the superior rectification performance of the proposed NCFET under low-power density conditions, offering an efficient device solution for microwave wireless power transmission systems.

Plasma-aided direct printing of silver nanoparticle conductive structures on polydimethylsiloxane (PDMS) surfaces

We report a controlled deposition process using atmospheric plasma to fabricate silver nanoparticle (AgNP) structures on polydimethylsiloxane (PDMS) substrates, essential for stretchable electronic circuits in wearable devices. This technique ensures precise printing of conductive structures using nanoparticles as precursors, while the relationship between crystallinity and plasma treatment is established through X-ray diffraction (XRD) analysis. The XRD studies provide insights into the effects of plasma parameters on the structural integrity and adhesion of AgNP patterns, enhancing our understanding of substrate stretchability and bendability. Our findings indicate that atmospheric plasma-aided printing not only avoids the need for high-temperature sintering but also significantly enhances the electrical and mechanical properties of the conductive structures, advancing the production of robust and adaptable electronic devices for wearable technology.

Analysis and Design of Low-Power Piezoelectric Energy Harvesting Circuit for Wearable Battery-Free Power Supply Devices

Improving microelectronic technologies has created various micro-power electronic devices with different practical applications, including wearable electronic modules and systems. Furthermore, the power sources for wearable electronic devices most often work with electrical energy obtained from the environment without using standard batteries. This paper presents the structure and electrical parameters of a circuit configuration realized as a prototype of a low-power AC-DC conversion circuit intended for use as a power supply device for signal processing systems that test various biomedical parameters of the human body. The proposed prototype has to work as a wearable self-powered system that transfers electrical energy obtained through mechanical vibrations in the piezoelectric generator. The obtained electrical energy is used to charge a single low-voltage supercapacitor, which is used as an energy storage element. The proposed circuit configuration is realized with discrete components consisting of a low-voltage bridge rectifier, a low-pass filter, a DC-DC step-down (buck) synchronous converter, a power-controlling system with an error amplifier, and a window detector that produces a “power-good” signal. The power-controlling system allows tuning the output voltage level to around 1.8 V, and the power dissipation for it is less than 0.03 mW. The coefficient of energy efficiency achieved up to 78% for output power levels up to 3.6 mW. Experimental testing was conducted to verify the proposed AC-DC conversion circuit’s effectiveness, as the results confirmed the preliminary theoretical analyses and the derived analytical expressions for the primary electrical parameters.

Unraveling the Interplay Between Memristive and Magnetoresistive Behaviors in LaCoO3/SrTiO3 Superlattice‐Based Neural Synaptic Devices

AbstractMemristors and magnetic tunnel junctions are showing great potential in data storage and computing applications. A magnetoelectrically coupled memristor utilizing electron spin and electric field‐induced ion migration can facilitate their operation, uncover new phenomena, and expand applications. In this study, devices consisting of Pt/(LaCoO3/SrTiO3)n/LaCoO3/Nb:SrTiO3 (Pt/(LCO/STO)n/LCO/NSTO) are engineered using pulsed laser deposition to form the LCO/STO superlattice layer, with Pt and NSTO serving as the top and bottom electrodes, respectively. The results show that both memristive and magnetoresistive properties can coexist without any compromise in performance, and the values of ROFF/RON and tunnel magnetoresistance (TMR) ratio are both improved by ≈1000% compared to a single‐period heterostructure. Notably, the Pt/(LCO/STO)5/LCO/NSTO device demonstrates superior multilevel storage performance, characterized by extended endurance, reliable retention, high ROFF/RON ratio, significant TMR ratio, and fundamental synaptic behaviors. Furthermore, density functional theory (DFT) is employed to calculate the changes in oxygen vacancies, affecting the overall energy bands and magnetic moments in the monolayer and multi‐periodic structures. Simulations using the handwritten digit recognition classification achieve the highest accuracy of 94.38%. These attributes suggest that the devices hold considerable promise for application in data storage and neuromorphic computing, offering a platform for high‐density neural circuits in intelligent electronic devices.

Design and Implementation of Device Circuit of Microcontroller-Based Smart Traffic Light Control System

In this paper, the design and implementation of a microcontroller-based smart traffic light control system is presented. The proposed smart traffic light is meant to mitigate or entirely eliminate hassles encountered by road users, mostly at road intersections. The system is sensitive to road density and therefore operates in smart and normal modes, with normal mode as the default; however, it switches to smart whenever the need arises. The approach adopted includes; typical intersection design, circuit diagram design, circuit analysis and overall system development and implementation. The microcontroller, which serves as the overall system brain is programmed using proteus electronic software; and then interfaced with already calibrated ultrasound modules and other components. Afterwards, it is initiated to confirm that research objectives have been met. The design employs a crossbar to prevent drivers from using a lane when not supposed. The traffic light control system, if implemented would significantly minimize traffic frustrations and ugly experiences road users encounter daily on Nigeria roads. However, this work is centred more on circuit operation and design, circuit analysis and overall system development and implementation.

Machine Learning-Assisted Device Circuit Co-Optimization: A Case Study on Inverter

Machine Learning-Assisted Device Circuit Co-Optimization: A Case Study on Inverter

Ultra-sensitive and precisely decoupled pressure and temperature detection with a “soft-hard” asymmetrically structured sensor based on carbon-nanocoils

Multi-function sensors are important in smart devices and integratable systems. However, achieving both high sensing performance and decoupling between signals with a simple device structure and circuit layout remains a great challenge. Herein, we developed an asymmetric “soft-hard” structured device composing of an elastic porous carbon-nanocoil (CNC)/polydimethylsiloxane (PDMS) pressure-sensitive layer and a relatively hard nonporous CNC/PDMS temperature-sensitive layer. The CNCs showed entanglement with one another and strong interaction with the PDMS matrix, and thus the thermal expansion of polymer induced considerable change of contact points and displacement of CNCs. This, along with the tunneling resistance effect, resulted in an ultra-high temperature sensitivity of 3045.95 % °C−1 and a high resolution of 0.05 °C. Meanwhile, the porous CNC/PDMS layer delivered a high capacitive pressure-sensing performance with a low detection limit of 1.5 Pa. Importantly, the layered soft-hard device structure with a shared-electrode layout enabled precise decoupling of temperature and pressure. Our sensor was further demonstrated in object sensing and picking tests, and successfully employed as a false-touch switch, showing its great potential in smart sensing and safety guarding systems.

Integration of a-InWZnO Thin Film Transistor with Copper Conductive Bridge Random Access Memory for Low Power Consumption Displays

In the era of big data and AI, the demand for information transmission has soared, leading to a surge in portable and wearable devices while traditional signage is gradually giving way to display devices. While these display devices offer rapid information transmission, they also pose energy consumption challenges. To address this, the Memory-in-Pixel (MIP) circuit concept is introduced to reduce display power consumption. However, traditional MIP circuits using static random-access memory (SRAM) components require a minimum of 6 Thin Film Transistors (TFT) devices for memory functions [1]. This complexity in device count complicates the manufacturing process of display circuits and limits display resolution due to the large circuit area they occupy.Conductive Bridge Random Access Memory (CBRAM) has emerged as a notable non-volatile memory due to its simple Metal-Insulator-Metal (MIM) structure, low power consumption, ease of fabrication, and compatibility with other processes [2]. Meanwhile, thin film transistors (TFTs) are widely employed as driving and switching devices in display circuits. Among these, Transparent Amorphous Metal Oxide Semiconductor (TAOS) TFTs stand out as highly promising for the next generation, offering advantages such as a high energy gap in channel materials, visibility to visible light, simplified large-area manufacturing, and superior carrier mobility.Notably, in addition to their efficacy as channel materials for TFTs, TAOS materials exhibit exceptional performance as a switching layer for CBRAM [3]. This led us to integrate a CBRAM with a TFT, forming a 1T1R structure capable of both memory storage and driving functionalities. For the active layers of this 1T1R device, we utilized the emerging TAOS material amorphous indium tungsten zinc oxide (InWZnO, IWZO) as the switching and channel layer.To enhance CBRAM performance, we introduced an ultrathin TiO2 dielectric into the switching layer. Furthermore, we explored the impact of the thickness of the IWZO switching layer on CBRAM characteristics. Regarding TFT components, we fine-tuned the sputtering conditions of the IWZO layer to optimize electrical characteristics and driving capabilities. Ultimately, the CBRAM and TFT devices exhibiting the best performance were integrated into the 1T1R structure.Based on experimental results, we significantly improved the DC endurance cycles of our CBRAM with the TiO2 insertion layer while reducing operating voltage and limiting current. This optimized CBRAM and TFT combination resulted in low operating power consumption (~20 μW) and holds promise for low-power MIP display circuits. Reference: [1] S. H. Lee, B. C. Yu, H. J. Chung, and S. W. Lee, “Memory-in-pixel circuit for low-power liquid crystal displays comprising oxide thin-filmtransistors,” IEEE Electron Device Lett., vol. 11 (11), pp. 1551–1554, 2017.[2] K. J. Gan, P. T. Liu, D. B. Ruan, Y. C. Chiu, Simon M. Sze, “Annealing effects on resistive switching of IGZO-based CBRAM devices,” Vacuum, vol. 180, 109630, 2020.[3] C. C. Hsu, P. T. Liu, K. J. Gan, D. B. Ruan, Simon M. Sze, “Investigation of deposition technique and thickness effect of HfO2 film in bilayer InWZnO-based conductive bridge random access memory”, Vacuum, vol. 201, 111123, 2022.

Effect of Thermal Runaway Trigger Methods for Battery Safety Characterization

Lithium-ion batteries are prone to risks with fire hazard due to the possibility of thermal runaway propagation. During battery product development and subsequent safety tests for design validation and safety certification, the thermal runaway onset is triggered by various test methods such as nail penetration, thermal ramp, or external short circuit. This failure initiation method affects the amount of heat contributions and the composition of gas generations. This study1 compares two such trigger methods, by external heating and by using a thermally activated internal short circuit device (ISCD). The effects of the trigger method on total heat generation are experimentally investigated within 18650 cylindrical cells at single cell level as well as at multiple cell configuration level.During thermal abuse conditions, it is known that internal short circuits occur before thermal runaway, but this joule heating does not contribute much to heat generation2. But during internal short circuits initiating at lower temperatures, joule heating plays a major role in thermal runaway process. Previous modeling studies have enhanced our understanding of the role of multiple physical processes during thermal runaway3-4. In this study we use a combination of models and experiments to characterize battery safety in terms of abuse tolerance, severity of thermal runaway and propagation. The severity of failure was observed to be worse for cells with ISC devices at single cell level whereas quite opposite results were observed at multiple cell configuration level. A preliminary numerical analysis was performed to better understand the battery safety performance with respect to thermal runaway trigger methods and heat transfer conditions. Mallarapu, A., Sunderlin, N., Boovaragavan, V., Tamashiro, M., Peabody, C., Pelloux-gervais, T., Li, X., Sizikov, 2024, Effects of Trigger Method on Fire Propagation during the Thermal Runaway Process in Li-ion Batteries, Journal of The Electrochemical Society, 171 040514Ren, D., Feng, X., Liu, L., Hsu, H., Lu, L., Wang, L., He, X., Ouyang, M., 2021, Investigating the relationship between internal short circuit and thermal runaway of lithium-ion batteries under thermal abuse condition, Energy Storage Materials 34, 563–573Feng, X., He, X., Ouyang, M., Wang, L., Lu, L., Ren, D., Santhanagopalan, S., 2018, An electrochemical-thermal coupled overcharge-to-thermal-runaway model for lithium ion battery, Journal of The Electrochemical Society, 165 A3748Coman, P. T., Darcy, E. C., Veje, C. T., White, R. E., 2017. “Modelling Li-Ion cell thermal runaway triggered by an internal short circuit device using an efficiency factor and arrhenius formulations.” Journal of The Electrochemical Society, 164 A587

Microfabrication Technologies for Interaction Circuits of THz Vacuum Electronic Devices.

Advances in manufacturing technology are allowing for the realization of interaction circuit with microstructures. The capability to produce small circuit structures is allowing new opportunities for vacuum electronic devices producing terahertz (THz) frequency radiation, which is impractical with traditional machining technology. This publication reviews recent progress on advanced microfabrication technologies applicable to interaction circuits of THz vacuum electronic devices, including LIGA/UV-LIGA (Ultraviolet Lithographic, Galvonoformung and Abformung), deep reactive ion etching (DRIE), micro/nano computer numerical control (CNC) milling, three-dimension (3D) printing, etc., and describes the current State-of-the-Art of their applications.

Design of a pHEMT RF mixer based on compact microstrip diplexer

Abstract This paper presents a new topology for a microwave active mixer using compact microstrip diplexer constituted from two dual-mode open loop resonators. The resonators are tuned to the radio frequency (RF) and local-oscillator (LO) frequencies, respectively, to effectively isolate the two input signals, while the diplexer output port is connected to the gate circuit of a commercial low cost GaAs pHEMT transistor. The drain circuit of the active device is connected to the load via an intermediate-frequency (IF)-modified Chebyshev low-pass filter to remove the unwanted RF and LO signals and reduce other spurious frequencies at the output of the mixer circuit. The circuit has been designed and constructed for an RF of 850 MHz, LO frequency of 1050 MHz, and an IF of 200 MHz. Experimental measurements show that the circuit provides a conversion gain of 18 dB at LO drive power of +2 dBm. It also operates satisfactorily over the RF range from 800 to 900 MHz with good image frequency rejection and stable operation.

Double-pentagon silicon chains in a quasi-1D Si/Ag(001) surface alloy

Silicon surface alloys and silicide nanolayers are highly important as contact materials in integrated circuit devices. Here we demonstrate that the submonolayer Si/Ag(001) surface reconstruction, reported to exhibit interesting topological properties, comprises a quasi-one-dimensional Si-Ag surface alloy based on chains of planar double-pentagon Si moieties. This geometry is determined using a combination of density functional theory calculations, scanning tunnelling microscopy, and grazing incidence x-ray diffraction simulations, and yields an electronic structure in excellent agreement with photoemission measurements. This work provides further evidence of pentagonal geometries in 2D materials and heterostructures and elucidates the importance of surface alloying in stabilizing their formation.

High-Data-Rate Modulators Based on Graphene Transistors: Device Circuit Co-Design Proposals

The multifunctionality feature of graphene field-effect transistors (GFETs) is exploited here to design circuit building blocks of high-data-rate modulators by using a physics-based compact model. Educated device performance projections are obtained with the experimentally calibrated model and used to choose an appropriate improved feasible GFET for these applications. Phase-shift and frequency-shift keying (PSK and FSK) modulation schemes are obtained with 0.6 GHz GFET-based multifunctional circuits used alternatively in different operation modes: inverting and in-phase amplification and frequency multiplication. An adequate baseband signal applied to the transistors’ input also serves to enhance the device and circuit performance reproducibility since the impact of traps is diminished. Quadrature PSK is also achieved by combining two GFET-based multifunctional circuits. This device circuit co-design proposal intends to boost the heterogeneous implementation of graphene devices with incumbent technologies into a single chip: the baseband pulses can be generated with CMOS technology as a front end of line and the multifunctional GFET-based circuits as a back end of line.

A Wireless Multimodal Physiological Monitoring ASIC for Animal Health Monitoring Injectable Devices.

Utilizing injectable devices for monitoring animal health offers several advantages over traditional wearable devices, including improved signal-to-noise ratio (SNR) and enhanced immunity to motion artifacts. We present a wireless application-specific integrated circuit (ASIC) for injectable devices. The ASIC has multiple physiological sensing modalities including body temperature monitoring, electrocardiography (ECG), and photoplethysmography (PPG). The ASIC fabricated using the CMOS 180 nm process is sized to fit into an injectable microchip implant. The ASIC features a low-power design, drawing an average DC power of 155.3 µW, enabling the ASIC to be wirelessly powered through an inductive link. To capture the ECG signal, we designed the ECG analog frontend (AFE) with 0.3 Hz low cut-off frequency and 45-79 dB adjustable midband gain. To measure PPG, we employ an energy-efficient and safe switched-capacitor-based (SC) light emitting diode (LED) driver to illuminate an LED with milliampere-level current pulses. A SC integrator-based AFE converts the current of photodiode with a programmable transimpedance gain. A resistor-based Wheatstone Bridge (WhB) temperature sensor followed by an instrumentation amplifier (IA) provides 27-47 °C sensing range with 0.02 °C inaccuracy. Recorded physiological signals are sequentially sampled and quantized by a 10-bit analog-to-digital converter (ADC) with the successive approximation register (SAR) architecture. The SAR ADC features an energy-efficient switching scheme and achieves a 57.5 dB signal-to-noise-and-distortion ratio (SNDR) within 1 kHz bandwidth. Then, a back data telemetry transmits the baseband data via a backscatter scheme with intermediate-frequency assistance. The ASIC's overall functionality and performance has been evaluated through an invivo experiment.