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Antennas operating at the high-frequency (HF) band (3–30 MHz) are frequently electrically small due to the large wavelength of electromagnetic waves (10–100 m). However, the bandwidth-efficiency products of passively matched electrically small antennas (ESAs) are fundamentally limited. Wideband HF waveforms using bandwidths of 24 kHz or more have recently received significant attention in military communications applications. Efficiently radiating such signals from conventional passive ESAs is very challenging due to fundamental physical limits on bandwidth-efficiency products of ESAs. However, active antennas are not subject to the same constraints. In this work, we present the design and experimental characterization of a high-power, class-E active ESA with enhanced bandwidth-efficiency product compared to that of passively matched ESAs. Specifically, the proposed class-E active ESA can radiate wideband HF signals with bandwidths of 24 kHz or more at 3 MHz (fractional bandwidths of ≈ 1 % – 4 %), with total efficiencies ranging from 40 % up to 80 % depending on the modulation type and radiated power levels approaching 100 W. Our approach uses a highly efficient, integrated class-E switching circuit specifically designed to drive an electrically small, high-Q HF antenna over a bandwidth exceeding 24 kHz at 3 MHz. Using a high-Q RLC antenna model, we have successfully demonstrated wideband binary ASK, PSK, and FSK modulations with the proposed class-E active ESA. Experimental results indicate that the bandwidth-efficiency product of this class-E active ESA is 5.4–9.8 dB higher than that of an equivalent passive design with the same data rate and bit-error-rate. [ABSTRACT FROM AUTHOR]

Many researchers have focused on molecular electronics, and this field can progress faster by applying semiconductors to molecular modeling. In this work, two middle rings of a bipyridine–biborinine molecular diode are rotated from 25∘ to 90∘ such that the current along the molecule is reduced. The current is minimum and almost zero at 90∘, while it is maximum at 25∘. Accordingly, considering these two angles, the molecule can act as a switching device when the two middle rings are rotated. The bipyridine–biborinine molecular diode is modeled considering the effect of rotation by including two resistors in the model. Two parallel diodes are used in this modeling for pyridine and borinine rings. The ideality factors of these diodes are varied based on the electronegativity of pyridine and borinine rings. This model is then applied to consider different molecular logic gates such as NAND, NOR, NOT, OR and AND gates, as well as molecular logic circuits (half adder and full adder), using the unique capabilities of the LTspice software. [ABSTRACT FROM AUTHOR]

Data encryption is an essential building block in modern electronic systems to prevent spying and hacking. Every day more and more objects produce electronic data, and this needs to be encrypted before being transmitted. Hence, designing devices, circuits, and systems for data encryption that can be integrated in all kinds of objects and that consume low amounts of energy is highly necessary. Here, this work reports the fabrication of flexible and transparent electronic circuits consisting of devices that exhibit threshold‐type resistive switching with a high degree of stochasticity. The cycle‐to‐cycle variability of switching voltages and state currents is significant but confined within a well‐defined range, which is consistent across multiple devices. This allows to design an efficient protocol for true random number generation. The circuits are fabricated with only synthetic 2D materials, can be fabricated in a scalable manner, and can be integrated in any object. [ABSTRACT FROM AUTHOR]

This paper proposes an effective method to improve the power efficiency of the flyback converter in the continuous conduction mode (CCM). The proposed converter uses a simple passive circuit to reduce the switching power losses. The current through the output diode can be shifted to a new branch where one diode, one inductor, and one auxiliary winding of the transformer are included. The output diode current can be reduced to zero for the zero-current switching of the output diode. The additional inductor is used to control the changing rate of the additional diode current to reduce the reverse-recovery current. Keeping the simplicity of the passive method, the proposed converter improves the power efficiency compared to the conventional converter. The circuit configuration and the operation principle are described. The design considerations are presented, including the simulation verification. The experimental results for a 45 W prototype are discussed to evaluate the performance of the proposed converter. The proposed converter has achieved a power efficiency of 93.5% for the rated load condition, improving the power efficiency. The applications of the proposed converter are also discussed for the future research directions. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) MOSFETs are garnering widespread attention due to their superior performance in high‐temperature, high‐frequency, and high‐voltage applications, emerging as the preferred power semiconductor devices in converters for photovoltaic power generation and new energy vehicles. However, SiC MOSFETs are prone to gate drive and drain‐source voltage oscillations during high‐speed switching events, resulting in diminished system efficiency, increased electromagnetic interference, reduced device safety, and even compromising the overall reliability of the converter. This paper introduces an oscillation suppression method based on a gate LCR parallel branch, aimed at optimizing the switching performance of SiC MOSFETs. A half‐bridge circuit model based on SiC MOSFET is established, and the mechanism of gate and drain‐source oscillation is meticulously analysed using the transfer function expression. Building upon this, the LCR parallel branch parameters are meticulously designed to introduce appropriate damping in the gate drive path, effectively mitigating oscillations. Experimental results demonstrate that the proposed design not only significantly reduces the amplitude of oscillations but also shortens the switch‐transition time. This enhancement effectively increases the switching frequency and reduces switching losses. [ABSTRACT FROM AUTHOR]

This paper presents a new capacitor charger for energy-harnessing applications such as energy transfer from a low-power battery to a load capacitor. The proposed structure uses a switching technique for step-by-step charging of the load capacitor. It comprises a control section, output stage metal-oxide-semiconductor field-effect transistors, and an external inductor. In order to improve the circuit efficiency under different power transfer scenarios, the switching capacitor charger operates at the boundary of continuous conduction mode and discontinuous conduction mode. Two blocks of peak current controller and zero current detector have been employed in a feedback loop to control the inductor current, which resulted in conduction power dissipation reduction. Also, the circuit with switching at low frequencies significantly reduces the switching loss. The performance of the proposed circuit is demonstrated using theoretical elaborations. In addition, the proposed structure is evaluated and simulated in a 0.18μm standard complementary metal-oxide semiconductor technology. Based on the obtained results, the efficiency of the presented circuit at 15.62mW input power is 96%, and the charging time is about 0.54ms, which is suitable for low-power applications. [ABSTRACT FROM AUTHOR]

Resistive memory devices feature drastic conductance change and fast switching dynamics. Particularly, nonvolatile bipolar switching events (set and reset) can be regarded as a unique nonlinear activation function characteristic of a hysteretic loop. Upon simultaneous activation of multiple rows in a crosspoint array, state change of one device may contribute to the conditional switching of others, suggesting an interactive network existing in the circuit. Here, we prove that a passive resistive switching circuit is essentially an attractor network, where the binary memory devices are artificial neurons while the pairwise voltage differences define an anti-symmetric weight matrix. An energy function is successfully constructed for this network, showing that every switching in the circuit would decrease the energy. Due to the nonvolatile hysteretic function, the energy change for bit flip in this network is thresholded, which is different from the classic Hopfield network. It allows more stable states stored in the circuit, thus representing a highly compact and efficient solution for associative memory. Network dynamics (towards stable states) and their modulations by external voltages have been demonstrated in experiment by 3-neuron and 4-neuron circuits. The switching dynamics in resistive memory hardware enables efficient computations, such as stateful logic and temporal information processing. The authors show that a passive resistive switching circuit represented as an attractor network model provides high-capacity, compact and efficient solution for associative memory. [ABSTRACT FROM AUTHOR]

The ability to switch between rules associating stimuli and responses depend on a circuit including the dorsomedial prefrontal cortex (dmPFC) and the subthalamic nucleus (STN). However, the precise neural implementations of switching remain unclear. To address this issue, we recorded local field potentials from the STN and from the dmPFC of neuropsychiatric patients during behavioral switching. Drift-diffusion modeling revealed that switching is associated with a shift in the starting point of evidence accumulation. Theta activity increases in dmPFC and STN during successful switch trials, while temporally delayed and excessive levels of theta lead to premature switch errors. This seemingly opposing impact of increased theta in successful and unsuccessful switching is explained by a negative correlation between theta activity and the starting point. Together, these results shed a new light on the neural mechanisms underlying the rapid reconfiguration of stimulus-response associations, revealing a Goldilocks' effect of theta activity on switching behavior. Direct electrophysiological recordings in the human prefronto-subthalamic circuit show that behavioral switching requires an optimal level of theta activity to be successful, which is well accounted for by a negative modulation of a drift-diffusion model starting point. [ABSTRACT FROM AUTHOR]

Oxygen vacancy engineering in metal oxides is a propitious route to modulate their resistive switching properties for memory and neuromorphic applications. This review provides an account of the research works on tailoring RS behavior in oxide thin-film-based memristor devices by oxygen vacancy engineering. We discuss the recent research progress on controlling oxygen vacancy concentration in metal oxide thin films and its impact on their resistive switching properties for application in electronic memory and neuromorphic computing devices. [ABSTRACT FROM AUTHOR]

Copyright of Zhejiang Electric Power is the property of Zhejiang Electric Power Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The widespread of renewable energy sources often requires DC‐DC power converters with higher operational flexibility and voltage gain capability. The Y‐source converter offers significant features to fill this demand, but its performance can be negatively affected by coupled‐inductor leakage inductances. This paper presents simplified models for the Y‐source DC‐DC converter (YSDC) that, although not directly including the presence of leakage inductances, offer a satisfactory description of how the converter operates in terms of its steady‐state behavior, small‐signal dynamics, and estimation of power losses. These models allow for a comprehensive analysis of how non‐ideal components in the converter affect the determination of the YSDC voltage gain and efficiency and allow one to identify the most interesting design alternatives to satisfy the current and voltage stress constraints placed on the converter power switches, thus excluding undesired converter design alternatives. Experimental results with a 280 W real converter, using coupled‐inductor with leakage inductances, present results similar to those of switched circuit simulations and the derived models, thus confirming that the simplified models present satisfactory adherence to the real converter performance over the majority extent of the maximum duty cycle. [ABSTRACT FROM AUTHOR]

Railway signaling electromechanical devices (RSEDs) play a pivotal role in the railway industry. Normal wear and tear of these devices occur during day-and-night operation and even progressively develop into failures. Hence, it is imperative to predict the remaining useful life (RUL) for reliable services. However, there are three existing challenges in addressing the issue. To overcome these challenges, we introduce M 2 BIST-SPNet for RSEDs RUL prediction. The model incorporates advanced spatiotemporal feature extraction mechanisms, including a spatial-temporal attention-based convolution networks (STACN), multiple branches with multi-scale multifrequency module (MBM), and communication module (CM). Extensive experiments conducted on three typical object datasets (i.e., railway safety relay, EMU contactor, switch circuit controller) shows that the proposed approach has demonstrated state-of-the-art performance in long-term multiparameter prediction and RUL prediction. [ABSTRACT FROM AUTHOR]

In this paper, a special spoon neural network is proposed, which is composed of four neurons with direct connection and indirect connection. On this basis, the far induction network and the near induction network (NINN) are constructed by using hyperbolic tangent memristors to explore the influence of electromagnetic induction between neurons at different positions on the dynamic behavior of attractors. NINN exhibits more complex attractor structures and wider chaotic parameters, and also displays a heterogeneous coexisting attractor of limit cycles and chaos under network parameter control. By varying the parameters, coexisting chaotic attractors can be synthesized into a double scrolls attractor, and their oscillation amplitude can be controlled without changing the chaotic characteristics. The type of attractors in human brain determines the clarity of memory. These complex dynamic behaviors demonstrate that near induction has a more pronounced effect on the forgetting and disappearance of memory compared to far induction. Finally, a circuit using switches to change the type of electromagnetic induction is constructed and the results are verified. [ABSTRACT FROM AUTHOR]

This paper concentrates on the issue of anti-disturbance bumpless transfer (ADBT) control design for switched systems. The ADBT control design problem refers to designing a continuous controller and a switching rule to ensure the switched system satisfies the ADBT property. First, the concept of the ADBT property is introduced. Then, via a switched equivalent-input-disturbance (EID) methodology, a switched EID estimator is formulated to estimate the impact of external disturbances within the switched system. Second, a bumpless transfer control is then constructed via a compensator integrating an EID estimation. Finally, the effectiveness of the presented control scheme is verified by controlling a switching resistor–inductor–capacitor circuit on the Matlab platform. Above all, a new configuration for ADBT control of switched systems is established via a switched EID methodology. [ABSTRACT FROM AUTHOR]

We study relationships between lower estimates for the energy complexity E(Σ), the switching complexity S(Σ) of a normalized Boolean network Σ, and the positive sensitivity ps(f) of the Boolean function f implemented by this circuit. The lower estimate E (Σ) ⩾ ⌊ ps (f) − 1 m ⌋ is proved for a sufficiently wide class of bases consisting of monotone Boolean functions of at most m variables, the negation gate, and the Boolean constants 0 and 1. For the switching complexity of circuits, we construct a counterexample which shows that, for the standard basis of elements of the disjunction, conjunction, and negation, there do not exist a linear (with respect to ps(f)) lower estimate for the switching complexity. [ABSTRACT FROM AUTHOR]

A novel ac/dc LED driver with power factor correction and soft-switching functions is proposed. The circuit topology mainly consists of two modified single-ended primary inductance converters (SEPIC) with interleaved operation. The first half stage of SEPIC operates like a boost converter and the second half stage operates like a buck–boost converter. Each boost converter is designed to operate in discontinuous current mode (DCM) to function as a power factor corrector (PFC). The two buck–boost converters that share a commonly coupled inductor are designed to operate at near boundary conduction mode (BCM). Without using any active clamping circuit, auxiliary switch or snubber circuit, the active switches can achieve zero-voltage switching on, and all diodes achieve zero-current switching off. First, operation modes in steady state are analyzed, and the mathematical equations for design component parameters are derived. Finally, a prototype circuit of 180 W rated power was built and tested. Experimental results show satisfactory performance of the proposed circuit. [ABSTRACT FROM AUTHOR]

We propose a method for increasing power extraction from a thermoelectric generator (TEG) by switching between series/parallel circuit configurations of thermoelectric elements, which can adjust the internal impedance of the TEG. The power characteristics of the TEG can be adjusted to the load characteristics of the connected device and the relevant ambient temperature. In this paper, we analyzed the change in the TEG characteristics with the series/parallel switching function. We evaluated the power supply to the connected devices at different ambient temperatures and different series/parallel configurations and confirmed that the extracted power could be increased. By theoretically analyzing the circuit configuration of the thermoelectric devices, the switching required to improve the power extraction, and the temperature difference at which switching occurred, we devised a design method for a TEG with circuit switching in order to increase power extraction with any device. We demonstrated the configuration of switching by using a system in which a TEG supplied power to an external wireless transmitter circuit. In this system, the optimal configuration differed at temperature differences of 3.0 K and 4.0 K. At a temperature difference of 3.0 K, the 2-series/1-parallel configuration provided 10% more power to the external circuit than the 1-series/2-parallel configuration. On the other hand, at the temperature difference of 4.0 K, the 1-series/2-parallel configuration provided 23% more power than the 2-series/1-parallel configuration. [ABSTRACT FROM AUTHOR]

Abstract Silicon carbide (SiC) MOSFETs are garnering widespread attention due to their superior performance in high‐temperature, high‐frequency, and high‐voltage applications, emerging as the preferred power semiconductor devices in converters for photovoltaic power generation and new energy vehicles. However, SiC MOSFETs are prone to gate drive and drain‐source voltage oscillations during high‐speed switching events, resulting in diminished system efficiency, increased electromagnetic interference, reduced device safety, and even compromising the overall reliability of the converter. This paper introduces an oscillation suppression method based on a gate LCR parallel branch, aimed at optimizing the switching performance of SiC MOSFETs. A half‐bridge circuit model based on SiC MOSFET is established, and the mechanism of gate and drain‐source oscillation is meticulously analysed using the transfer function expression. Building upon this, the LCR parallel branch parameters are meticulously designed to introduce appropriate damping in the gate drive path, effectively mitigating oscillations. Experimental results demonstrate that the proposed design not only significantly reduces the amplitude of oscillations but also shortens the switch‐transition time. This enhancement effectively increases the switching frequency and reduces switching losses.

NaYF 4 :30%Er-NaYF 4 -NaYF 4 :20%Ho-NaYF 4 core–shell nanocrystals, which exhibit distinct upconversion (UC) luminescence in the green, yellow, and red regions under 1530 nm, 980 nm, and 1150 nm laser excitation, respectively, have been synthesized. These nanocrystals were subsequently encapsulated within a WO 3 hydrogel matrix with photochromic properties. The nanocrystals underwent a color transition to dark blue upon exposure to 365 nm ultraviolet light, a change that is reversible and allows for dynamic modulation of the UC luminescence. The integration of this nanocrystal-hydrogel system with a silicon-based photodetector facilitates a rapid reduction in current, enabling "hard switching" without the need for continuous 365 nm irradiation. Furthermore, irradiation at 365 nm induces a gradual decrease in current, which can slowly recover, thus achieving a "soft switching" effect. [Display omitted] Optical switches are increasingly acknowledged for their potential advantages over mechanical counterparts in various domains. However, research on optical switches remains relatively nascent, primarily focusing on applications like anti-counterfeiting, switching chemical reactions, etc., while neglecting the control of photocurrent switching. Here, we have developed NaYF 4 :30 %Er-NaYF 4 -NaYF 4 :20 %Ho-NaYF 4 core–shell nanocrystals with unique upconversion (UC) multi-color emission properties under 1530 nm, 980 nm and 1150 nm laser excitations. These nanocrystals allow for optical control of circuit switching by modulating photocurrent signals in photosensitive circuits. The UC emission is due to the self-sensitization of rare earth ions in the core and shell. By adjusting the intermediate shell thickness, we have optimized the luminescence and investigated the mechanism. Combining these nanocrystals with a WO 3 quantum dots (QDs) photochromic hydrogel, dynamic variation of UC emissions could be realized. Moreover, by combining with a commercial silicon photodetector, we constructed a photosensitive circuit demonstrating the modulation of photocurrent signal output and realized the "hard switching" of rapid circuit cutoff. Furthermore, by using the photochromic effect of WO 3 QDs, the "soft switching" of slow circuit cutoff and recovery were also achieved. This work has significant implications for the development and application such as energy management system and smart home of optical switches in various fields. [ABSTRACT FROM AUTHOR]

[Display omitted] Perfluorocarbon is commonly used as a coolant, chemical reaction carrier solvent, medical anti-hypoxic agents and blood substitutes. The realization of non-contact complex manipulation of perfluorocarbon liquids is urgently needed in human life and industrial production. However, most liquid-repellent interfaces are ineffective for the transport of ultra-low surface tension perfluorocarbon liquids, and struggle to maintain good durability due to unstable air or oil cushions in the surface. Therefore, preparing surfaces for stable non-contact complex manipulation of ultra-low surface tension droplets remains a challenge. In this paper, a novel solution, a photothermal responsive droplet manipulation surface based on polydimethylsiloxane brushes, has been reported. On this surface, droplets with different surface tensions (as low as 10 mN/m) can be efficiently manipulated through induced near-infrared light. Notably, this surface maintains its effectiveness after exposure to extreme anthropogenic conditions. The interface effect between perfluorocarbon droplets and polydimethylsiloxane brushes by near-infrared light-induced was investigated in detail. In addition, ultra-low surface tension droplets demonstrate the ability to transport solid particles. The conductive droplets exhibit sophisticated manipulation realizing the controlled switching of smart circuits. This research opens up new possibilities for advancing the capabilities and adaptability of ultralow surface tension droplets in a range of applications. [ABSTRACT FROM AUTHOR]

This investigation addresses the bumpless transfer fault detection (FD) problem within switched systems that possess unstable modes. A switched piecewise FD filter is developed as a residual generator by segmenting each dwell time interval. The transition between different filters precipitates pronounced, abrupt jumps in the residual signal. Consequently, a novel definition of the residual bumpless transfer performance is introduced to constrain the magnitude of residual fluctuations during switching instances. Additionally, an alternating switching strategy—characterized by slow and fast mode‐dependent average dwell time and supported by the multiple discontinuous Lyapunov function method—is devised to assure the asymptotic stability and the weighted H∞$$ {H}_{\infty } $$ performance of the augmented system. Concurrently, sufficient conditions for the solvability of the bumpless transfer FD problem are articulated in the form of linear matrix inequalities. Lastly, a switched buck‐boost circuit and a numerical example are presented to substantiate the merits of the proposed bumpless transfer piecewise filtering method. [ABSTRACT FROM AUTHOR]

Summary: This paper addresses the problem of adaptive robust safety‐critical control (ARSCC) for switched systems, where the safety of subsystems is not necessary. A novel ARSCC framework and an executable algorithm are presented to solve the ARSCC problem by finding a switching signal and controllers of subsystems. To estimate uncertainties, a novel switched piecewise‐constant adaptive law is presented, which guarantees a pre‐computable estimation error boundary. A single barrier function (SBF) method is proposed to ensure safety of switched systems with uncertainties, where the safety of subsystems is satisfied only in some subregion of a given safe set, instead of the whole safe set. Based on the SBF method, a novel state‐dependent switching law possessing different dwell times for different subsystems, is established to orchestrate the switching among potentially unsafe subsystems. As a special case of the SBF method, a common barrier function method is presented to achieve safety of switched systems with uncertainties under switching signals with given dwell times. In addition, some sufficient conditions are derived to obtain safety and asymptotic stability for switched systems with uncertainties by combining SBF and single Lyapunov function. Finally, a switched RLC circuit system is given to illustrate the effectiveness of the theoretical results. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South-Central Minzu University (Natural Science Edition) is the property of Journal of South-Central Minzu University (Natural Science Edition) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dynamic vision sensor (DVS) imaging quality is significantly affected by pixel noise and temporal contrast (TC), which is inversely proportional to sensitivity. To reduce the noise event rate and improve sensitivity in bright‐light conditions in the DVS pixel circuit, this paper proposes improvements to the conventional DVS pixel circuit. The proposed DVS pixel circuit adopts stacked medium‐threshold transistors instead of a single high‐threshold transistor in the photoreceptor and introduces a threshold switching circuit. Compared with the conventional DVS pixel circuit, this design increases event threshold normalized by root mean square (RMS) noise voltage, reducing the dim‐light noise bandwidth. Additionally, it achieves higher sensitivity in bright‐light conditions compared with dim‐light conditions. The proposed DVS pixel circuit is implemented in a 110‐nm complementary metal‐oxide semiconductor (CMOS) process. Post‐simulation results show that, for photocurrents between 5 fA and 100 pA, the proposed DVS pixel circuit achieves a 35 Hz peak event rate at 15% TC, which is reduced to 3.1% of the conventional structure. For photocurrents exceeding 30 pA, the proposed structure can switch TC from 15% to 5%, maintaining a noise event rate below 0.1 Hz. [ABSTRACT FROM AUTHOR]

A normally-off vertical gallium nitride (GaN) junction field-effect transistor (JFET) is demonstrated in this work. The device shows an on/off current ratio of 3.6 × 1010, a threshold voltage (V TH) of 1.64 V, and a specific on-resistance (R ON,SP) of 1.87 mΩ·cm2. Drain-induced channel effects were proposed to explain the change in the gate current at different drain voltages. Drain current decline in the output characteristics and the reverse turn-on between drain and source can be explained by effects. A technological computer-aided design was used to simulate the change of the depletion region and confirm the explanation. Detailed analyses of the channel effects provide a reference for the design of novel structures. The characteristics at different temperatures demonstrated the stability of threshold voltage and specific on-resistance, thus indicating the great potential of applications in switching power circuits of vertical GaN JFETs. [ABSTRACT FROM AUTHOR]

This paper proposes a new high step‐up DC–DC converter with zero input current ripple for renewable energy sources applications, such as fuel cells. In this topology, a coupled inductor and a multiplier cell are used to achieve high voltage gains. The power switch in this proposed circuit turns on under zero voltage switching conditions. An active switch limits the maximum voltage stress across the main power switch. Moreover, all circuit diodes of the converter turn off without a reverse recovery problem. A detailed analysis of a high‐gain step‐up DC–DC converter is studied along with improved efficiency. The ripple cancellation of the input stage of the converter is done by adding an input inductor and capacitor. By including the parasitic elements, an approximate loss analysis was performed in PSIM and found the maximum efficiency of ∼96% in simulation and ∼94% in hardware for 200 W power level design for 30 V input voltage. Later on, the converter laboratory hardware prototype can be developed with selected parameters, and finally, experimental results have been used to validate the properties of the converter. [ABSTRACT FROM AUTHOR]

Two K-band switch circuits, each consisting of a single-pole double-throw (SPDT) switch, have been built using a 0.15 μm GaAs process. One circuit utilizes diode techniques while the other utilizes field effect transistor (FET) techniques. The diode single-pole double-throw switches that have been devised exhibit exceptional linearity and are capable of withstanding high power levels. The switches exhibit a return loss of 10 dB or higher, an insertion loss of 3 dB or lower, and operate within a frequency range of 19 GHz to 25 GHz. They have a compact design with a core size of only 1.05 mm2 and consume a total power of 136.8 mW. The FET SPDT switch circuits are created utilizing a parallel–parallel quarter-wavelength transmission line architecture. This design allows for a higher power output compared to using a diode. The transistorized single-pole double-throw switch circuit is designed using a parallel–parallel quarter-wavelength transmission line architecture. This design ensures a low insertion loss. By adjusting the length of the transmission line, the circuit can operate in both frequency bands; the K-band and Ka-band. [ABSTRACT FROM AUTHOR]

Newly introduced Photovoltaic (PV) devices, featuring a built-in chip with an illuminating Light Emitting Diode (LED), have emerged in the commercial market. These devices are touted for their utility as both low- and high-side power switch drivers and for data acquisition coupling. However, comprehensive knowledge and experimentation regarding the limitations of these Photovoltaic Drivers in both switching and signal processing applications remain underexplored. This paper presents a detailed characterization of a Photovoltaic Driver, focusing on its performance under resistive and capacitive loads. Additionally, it delineates the device's constraints when employed in signal processing. Through the analysis of switching losses across various power switches (Silicon and Silicon Carbide) in both series and parallel driver configurations, this study assesses the driver's efficacy in operating Junction Field-Effect Transistors (JFETs). Findings suggest that Photovoltaic Drivers offer a low-cost, compact solution for specific applications, such as high-voltage, low-bandwidth measurements, and low-speed turn-on with fast turn-off power switching scenarios, including solid-state switches and hot-swap circuits. Moreover, they present a straightforward, cost-effective method for driving JFETs, simplifying the circuit design and eliminating the need for an additional negative power source. [ABSTRACT FROM AUTHOR]

In the current communication era, 2G voice services coexist with higher generation mobile network voice services like Voice over Long Term Evolution (VoLTE) in 4G and Voice over New Radio (VoNR) in 5G. Subscribers registered in the 5G network, but their voice option is in 4G so voice calls can be handled through the Evolved Packet System (EPS) Fallback or Radio access technology (RAT) Fallback. Similarly, subscribers register in a 4G network, but their voice option is in 3G or 2G so voice calls can be handled through Circuit Switched Fallback (CSFB). To provide uninterrupted voice service in such wireless networks usually handoff calls (HCs) receive higher priority than new calls (NCs). So, some guard radio resources (i.e., channels in 2G or RBs in 4G or 5G) may be reserved in each cell to handle this type of HCs. If more channels are reserved for HCs, then the handoff call-dropping probability (HCDP) will be decreased and at that time the new call-blocking probability (NCBP) will be increased. So, by considering the target HCDP if channels are reserved for HC, then HCDP will remain below the target and NCBP will be minimum. In this paper first, we proposed an optimal channel reservation (OCR) policy that reserves guard channels according to the given target HCDP. Second, we compared our OCR policy with fractional channel (FC), limited fractional channel (LFC), and uniform fractional channel (UFC) policies. Finally, we observed the performance of all these policies considering the Global System for the Mobile Communication (GSM) network. [ABSTRACT FROM AUTHOR]

This paper introduces a novel metaheuristic algorithm named the opposition-based cooperation search algorithm with Nelder–Mead (OCSANM). This enhanced algorithm builds upon the cooperation search algorithm (CSA) by incorporating opposition-based learning (OBL) and the Nelder–Mead simplex search method. The primary application of this algorithm is the design of a fractional-order proportional–integral–derivative (FOPID) controller for a buck converter system. A comprehensive evaluation is conducted using statistical boxplot analysis, nonparametric statistical tests and convergence response comparisons to assess the algorithm's performance and confirm its superiority over CSA. Furthermore, the FOPID-controlled buck converter system based on OCSANM is compared with two top-performing algorithms: one using a hybridized approach of Lévy flight distribution with simulated annealing (LFDSA) and the other employing the improved hunger games search (IHGS) algorithm. This comparison encompasses transient and frequency responses, performance indices and robustness analysis. The results reveal the notable advantages of the proposed OCSANM-based system, including 25.8% and 8.7% faster rise times, 26% and 8.8% faster settling times compared with the best-performing approaches, namely LFDSA and IHGS, respectively. In addition, the OCSANM-based system exhibits a 34.7% and 9.6% wider bandwidth than the existing approaches-based systems. Incorporating voltage and current responses of the buck converter's switched circuit with the OCSANM-based FOPID controller further underscores the algorithm's effectiveness. To provide a comprehensive assessment, the paper also compares the proposed approach's time and frequency domain responses with those of 17 other state-of-the-art approaches attempting to control buck converter systems similarly. These findings affirm the effectiveness of the OCSANM in designing FOPID controllers for buck converter systems. [ABSTRACT FROM AUTHOR]

The Hamming code or Linear block code is used in communication to identify and repair errors. Redundancy bits are introduced to the Hamming communication network (HCN) for error detection and correction. It can detect two errors and correct one error. Quantum-dot Cellular Automata (QCA) is used for designing circuits with high switching speed and low energy dissipation. This work proposes a cost-effective QCA-based (7, 4) Hamming encoder and decoder design. Hamming encoder is designed using coplanar structure and the error detector used in Hamming decoder uses a multilayer structure. The effort is to optimize the area, cost, and energy dissipation. The work proposes a coplanar (7, 4) Hamming encoder and decoder. Hamming decoder is implemented in two parts a syndrome calculator and an error detector. Proposed (7, 4) Hamming encoder circuit reduces cell count by 49.47% compared to [1] and 9.52% compared to [12]. The proposed (7, 4) syndrome calculator has reduced cell count by 56.54%, an 11.11% reduction in total area compared to [1]. The proposed design reduces the cell area, QCA cost, and also energy dissipation. The designs are realized and QCA parameters are assessed in QCADesigner2.0.3 and energy is analyzed in QCADesigner-E. [ABSTRACT FROM AUTHOR]

In this study, a current-equalization technology utilizing a variable-capacitance technique for a multiphase inductor–inductor–capacitor (LLC) converter is studied. Accordingly, the proposed method involves adjusting the resonant capacitance of the LLC resonant converter to balance the currents between phases. This is achieved primarily by biasing ferroelectric multilayer ceramic capacitors (MLCCs) through a step-down circuit and a common-mode bias structure. These ferroelectric MLCCs serve as the resonant elements, allowing for variable capacitance by leveraging capacitance sensitivity to their trans voltages. This approach provides additional control flexibility to the resonant circuit. Furthermore, since each phase operates independently, the circuit can be scaled to accommodate any number of phases. Moreover, all switches in the circuit have zero-voltage switching (ZVS) turn-on, minimizing switching losses. This study initially analyzes and evaluates the proposed common-mode bias variable capacitance technique and the corresponding operational principles. Subsequently, a two-phase LLC experimental circuit based on a field-programmable gate array (FPGA) digital controller is utilized to assess current equalization and efficiency. That is to say, this experimentation aims to validate the effectiveness of the current-equalization variable-capacitance technique in an LLC resonant converter. [ABSTRACT FROM AUTHOR]

Power grid modernization is often associated with new projects that imply the transmission network expansion, where transient overvoltages related to energization maneuvers must be studied in advance using suitable tools that consider the transmission line characteristics. Switching transient analysis is one of the options to deal with this phenomenon, but statistical switching analysis is the preferred tool to carry out multiple simulations. As opposed to existing works, this paper proposes a comprehensive approach for the statistical switching in double-circuit transmission lines based on existing transmission infrastructure that requires the installation of double-line circuits or resizing the existing ones. The switching sequence of circuit breakers based on distribution functions are discussed in detail, which are generalized using different standard deviations. Pre-insertion resistors and shunt reactors are also considered in this methodology, enabling practical results related to the calculation of the basic insulation level. All these aspects combined permit to establish the minimal requirements for the insulation coordination in double-circuit transmission lines from a practical standpoint. To showcase the method's practicality, the switching analysis of a 300-km double-circuit transmission line is conducted using the EMTP/ATP simulation package. Energization maneuvers with pre-insertion resistors and shunt reactors are studied, considering the transmission line operation at 230 and 400 kV, concluding that the minimal requirement of protection against transient overvoltages must be around 1.35 p.u. [ABSTRACT FROM AUTHOR]

Nanoparticles interconnected by insulating organic molecules exhibit nonlinear switching behavior at low temperatures. By assembling these switches into a network and manipulating charge transport dynamics through surrounding electrodes, the network can be reconfigurably functionalized to act as any Boolean logic gate. This work introduces a kinetic Monte Carlo-based simulation tool, applying established principles of single electronics to model charge transport dynamics in nanoparticle networks. We functionalize nanoparticle networks as Boolean logic gates and assess their quality using a fitness function. Based on the definition of fitness, we derive new metrics to quantify essential nonlinear properties of the network, including negative differential resistance and nonlinear separability. These nonlinear properties are crucial not only for functionalizing the network as Boolean logic gates but also when our networks are functionalized for brain-inspired computing applications in the future. We address fundamental questions about the dependence of fitness and nonlinear properties on system size, number of surrounding electrodes, and electrode positioning. We assert the overall benefit of having more electrodes, with proximity to the network's output being pivotal for functionality and nonlinearity. Additionally, we demonstrate an optimal system size and argue for breaking symmetry in electrode positioning to favor nonlinear properties. [ABSTRACT FROM AUTHOR]

This paper reports on the testing and evaluation of a passive autoranging (AR) method designed to dynamically extend the measurement range of a photonic current transducer (PCT) to pave the way toward a realization of a combined metering- and protection-class current sensor. The PCT utilizes a current transformer (CT), a piezoelectric transducer (PZT), and a fiber Bragg grating (FBG) to enable current measurement at multiple points in an electrical power network whereby multiple sensors are deployed and interrogated serially using a single optical fiber. The autoranging technique relies on incorporating static MOSFET switches to instantaneously short individual serially connected CT burdens in response to a measured current magnitude exceeding pre-set thresholds. The AR circuit switching events produce distinctive signal features that are used by the proposed switching algorithm to apply appropriate scaling factors to reconstruct the measured current from the optical signal. It is shown through laboratory experiments that the AR circuit correctly reacts to pre-set burden current thresholds of 130% of the nominal value and 22 times the nominal value, signifying its "metering" and "protection" range boundaries. The circuit reaction time is below 4 ms, rendering it suitable for standard power system protection purposes. Moreover, the operation of the AR circuit is demonstrated for burden currents of up to 100 A for over 1 s, satisfying a test procedure for the secondary CT circuit, as required by some power system operators. It is demonstrated that the proposed switching algorithm allows for a correct reconstruction of the burden currents from the optical signal acquired by the FBG interrogator, offering the potential to realize a dual-class optical current sensor. [ABSTRACT FROM AUTHOR]

The emerging wearable skin-like electronics require the ultra-flexible organic transistor to operate at low voltage for electrical safety and energy efficiency and simultaneously enable high field-effect mobility to ensure the carrier migration ability and the switching speed of circuits. However, the currently reported low-voltage organic transistors generally present low mobility, originating from the trade-off between molecular polarity and surface polarity of the dielectrics. In this work, the orientation polarization of the dielectric is enhanced by introducing a flexible quaternary ammonium side chain, and the surface polarity is weakened by the shielding effect of the nonpolar methyl groups on the polar nitrogen atom. The resulting antisolvent QPSU dielectric enables the high-dielectric constant up to 18.8 and the low surface polarity with the polar component of surface energy only at 2.09 mJ/m2. Such a synergistic polarization engineering between orientation polarization and surface polarity makes the solution-processed ultraflexible transistors present the ultralow operational voltage down to −3 V, the ultrahigh charge-carrier mobility up to 8.28 cm2 V−1 s−1 at 1 Hz, excellent cyclic operational stability and long-term air stability. These results combined with the ultrathin thickness of transistor as low as 135 nm, the ultralight mass of 0.5 g/m2, the conformal adherence capability on human skin and 1-μm blade edge, and the strong mechanical robustness with stable electrical properties for 30,000 bending cycles, open up an available strategy to successfully realize low-voltage high-mobility solution-processed organic transistor, and presents the potential application of QPSU dielectric for the next-generation wearable imperceptible skin-like electronics. [ABSTRACT FROM AUTHOR]

Due to the influence of parasitic internal parameters and junction capacitance, the silicon carbide (SiC) power devices are frequently marred by significant overshoots in current and voltage, as well as high-frequency oscillations during the switching process. These phenomena can severely compromise the reliability of SiC-based power electronic converters during operation. This study delves into the switching transient of the SiC MOSFET with the goal of establishing a quantitative correlation between the gate driving current and the overshoot in both the drain-source voltage and the drain current. In light of these findings, the innovative active gate drive (AGD) circuit, which features an adjustable gate current, is introduced. Throughout the switching process, the AGD circuit employs a dynamic monitoring and feedback mechanism that is responsive to the gate voltage and rate of change in the drain-source voltage and drain current of the SiC MOSFET. This adjustment enables gate driving current to be actively modified, thereby effectively mitigating the occurrence of overshoots and oscillations. To empirically validate the efficacy of the proposed AGD circuit in curbing voltage and current overshoots and oscillations, a double-pulse experimental setup was meticulously constructed and tested. [ABSTRACT FROM AUTHOR]

A pulse forming network (PFN) is a significant component, contributing a lot to the overall dimension of pulse generators. In order to both reduce the size of PFN and improve the output waveform quality, this paper proposes a compact low-impedance PFN with a rotational symmetry structure. The PFN consists of four groups of Blumlein pulse forming units (PFUs) connected in parallel along the angular direction, and the spline curve structure is applied in each PFU, which achieves a higher space utilization rate. The theoretical maximum energy density of PFN is 6.6 J/L as the dimensions of PFN are φ500 × 138 mm. Field-circuit co-simulation is carried out based on the spatial model of PFN and the double switch modulation circuit to analyze the effects of switch delay time (time between main switch and steep discharge switch), as well as the output port position affecting the output pulse waveform. The results show that the PFN is appropriate to achieve quasi-square wave pulse modulation as the switch delay time is 290 ns with the output port positioned at the periphery. The verification experiments are also carried out. The results show that the PFN can generate a quasi-square wave pulse with an output voltage of 49.6 kV, a pulse width of 83 ns, and a peak power of 1 GW on a matched load. The output pulse exhibits a distinct flat top, with the fluctuation of the plateau being less than 3%. [ABSTRACT FROM AUTHOR]

This study investigates the asymptotic synchronization in fractional memristive neural networks of the Riemann–Liouville type, considering mixed time delays and jump mismatches. Addressing the challenges associated with discrepancies in the circuit switching speed and the accuracy of the memristor, this paper introduces an enhanced model that effectively navigates these complexities. We propose two novel event-based hybrid impulsive controllers, each characterized by unique triggering conditions. Utilizing advanced techniques in inequality and hybrid impulsive control, we establish the conditions necessary for achieving synchronization through innovative Lyapunov functions. Importantly, the developed controllers are theoretically optimized to minimize control costs, an essential consideration for their practical deployment. Finally, the effectiveness of our proposed approach is demonstrated through two illustrative simulation examples. [ABSTRACT FROM AUTHOR]

The conventional topological approach to eliminate the multiple-input DC voltage requirement in multilevel inverter configurations for synthesizing high-output voltage levels is to deploy split capacitor banks at the input terminal. This method stipulates a less expensive, light weight, and reduced size inverter system. However, the excessive demand for several capacitor banks and the complex voltage balancing strategy associated with this conceptual approach poses numerous limitations in their deployment. In view of these drawbacks, this study proposes a self-balanced, single-phase, nine-level switched-capacitor-based inverter topology consisting of a single-input DC voltage, an auxiliary circuit, and an H-bridge circuit unit. A commensurate single carrier-based sinusoidal pulse-width modulation scheme is developed for the proposed power circuit control, enabling the synthesis of a nine-level output voltage waveform whose amplitude is four times the input voltage value. Detailed power circuit operations and switching functions are adequately provided in the proposed topology. A comparison between the proposed inverter and its recent counterparts in terms of component count, cost involvement, and output voltage-boosting ability is duly carried out using Python data visualization. Results reveal that the proposed inverter competes well in these three criteria. For varying R–L load values, the inverter has the capability of high active and reactive power delivery. Its dynamic response for step changes in the modulation index under these power-mode operations is presented in this paper. For high active power-mode operation, efficiencies of 98.27% and 98.92% under light- and heavy-load conditions, respectively, are obtained on a 3-kW-rated inverter prototype. [ABSTRACT FROM AUTHOR]

Sleep is quantitatively described by subdividing polysomnographic records into intervals each of which is allocated to one of the just 5 all-or-nothing variables called "sleep–wake stages". What are the mechanisms governing the establishment of such 5 relatively stable stages and rapid transitions between them? We modeled these stages as resulting from the competing interactions between the mutually inhibiting drives for wake, NREM sleep, and REM sleep that are proposed to work in a similar way as two-, two-, and one-way switch, respectively. The electromechanical counterparts of the stages were visualized as 5 variants of an electrical circuit connecting these switches with three lamps. During W and transient state N1, two sleep switches are switched off, and three lamps are turned off. During other transitions, one of these lamps is turning on after changing in on–off state of one or two of three switches. During transitions to N2, one (N2) lamp is turning on. During the following transitions to N3, one more (N3) lamp is turning on. During transitions from N2 to R, the N2 lamp is turning off, while the R lamp is turning on. Estimates of stage-specific scores on the 1st and 2nd principal components of the electroencephalographic spectra provided empirical evidence for such on–off states of these switches. [ABSTRACT FROM AUTHOR]

Voice-Coil Actuators (VCAs) serve as indispensable components in precision motion applications, valued for their linear force performance, smooth operation, and compact size. The optimal design of VCAs not only contributes to cost reduction in manufacturing and assembly but also results in a more compact size and increased bandwidth, enhancing VCA's overall performance. On the other hand, developing a model that captures the nonlinear features of actuator dynamics is essential for advancing high-performance controllers. In addition, such a model can be very useful in simulating the performance of controllers before implementation, as well as studying the behavior of different parts of the actuator during its operation. This paper introduces a novel approach to VCA design through a multi-objective optimization problem solved using the Non-Dominated Sorting Genetic Algorithm-II (NSGA-II). Once the optimal design is determined, it undergoes validation via finite-element analysis. After validating the optimal design, the actuator is fabricated and assembled through a detailed electromechanical design. To mitigate potential noise issues arising from switching circuits, the study proposes a high-bandwidth analog servo amplifier. This amplifier is designed to effectively mitigate noise problems, ensuring the seamless operation of the VCA in practical applications. Before modeling, the characterization process is undertaken through a combination of simulation and experimental tests. Finally, the effectiveness of the multi-physics-based modeling approach, enhanced by experimentally-driven characteristics, is evaluated against empirical results. [ABSTRACT FROM AUTHOR]

Abstract This paper proposes a new transformerless buck‐boost converter with an extended voltage conversion ratio. This converter has semi‐quadratic voltage gain, which provides more gain with lower duty cycles. This converter has a simple structure and easy implementation, which reduces the cost and increases efficiency. The proposed converter operates in continuous conduction mode and provides two operation modes by turning on and off the switches. The suggested converter has continuous input current and low input current ripple, which is important when utilizing renewable energy sources. The calculation of the proposed converter includes ideal and practical voltage gain, current calculations, voltage stresses of the switches and diodes, current stress of the switches, parameter design, efficiency, and a brief analysis of discontinuous conduction mode and boundary conditions. The proposed converter provides efficiency of about 93.1% in boost mode and 92.14% in buck mode at 50 W output power. The suggested converter varies the input voltage from 20 to 48 V in boost mode and changes the input voltage from 20 to 10.4 V in buck mode. Finally, a laboratory prototype has been built to prove and evaluate the simulation results and theoretical analysis of the proposed converter.

Eukaryotic cells learn and adapt via unknown network architectures. Recent work demonstrated a circuit of two GTPases used by cells to overcome growth factor scarcity, encouraging our view that artificial and biological intelligence share strikingly similar design principles and that cells function as deep reinforcement learning (RL) agents in uncertain environments. [ABSTRACT FROM AUTHOR]

Methods for reducing power consumption in circuits of finite state machines (FSMs) are discussed in this review. The review outlines the main approaches to solving this problem that have been developed over the last 40 years. The main sources of power dissipation in CMOS circuits are shown; the static and dynamic components of this phenomenon are analyzed. The power consumption saving can be achieved by using coarse-grained methods common to all digital systems. These methods are based on voltage or/and clock frequency scaling. The review shows the main structural diagrams generated by the use of these methods when optimizing the power characteristics of FSM circuits. Also, there are various known fine-grained methods taking into account the specifics of both FSMs and logic elements used. Three groups of the fine-grained methods targeting FPGA-based FSM circuits are analyzed. These groups include clock gating, state assignment, and replacing look-up table (LUT) elements by embedded memory blocks (EMBs). The clock gating involves a separate or joint use of such approaches as the (1) decomposition of FSM inputs and (2) disabling FSM inputs. The aim of the power-saving state assignment is to reduce the switching activity of a resulting FSM circuit. The replacement of LUTs by EMBs allows a reduction in the power consumption due to a decrease in the number of FSM circuit elements and their interconnections. We hope that the review will help experts to use known methods and develop new ones for reducing power consumption. We think that a good knowledge and understanding of existing methods of reducing power consumption is a prerequisite for the development of new, more effective methods to solve this very important problem. Although the methods considered are mainly aimed at FPGA-based FSMs, they can be modified, if necessary, and used for the power consumption optimization of FSM circuits implemented with other logic elements. [ABSTRACT FROM AUTHOR]

Three distinct synchronized switching circuits based on a magnetostrictive actuator are compared in this paper to examine their control mechanisms and circuit characteristics. These circuits include a semi-active shunt circuit, a semi-active current inversion and amplification circuit, and a semi-active automatic current inversion and amplification circuit. Each circuit type employs an additional electronic switch. The synchronized switching method enables the rational control of the circuit current generated by the magnetostrictive actuator to fulfill any desired control strategy. Simulation and experimental results on a 10-bay truss structure reveal that the three circuits can effectively adjust the polarity of the induced current as needed. The three circuits are then compared to thoroughly analyze their unique characteristics and explain their respective advantages and dis-advantages. Using the comparison results, various options available for control circuit design are demonstrated. [ABSTRACT FROM AUTHOR]

Inconsistency in the battery pack parameters results in an uneven state of charge (SoC). The active battery balancing method is an approach to equalize the SoC of the battery cells in a battery pack. In active balancing method, the battery having the highest SoC is made to equalize with the battery having the lowest SoC through the electronic circuits. However, it needs more cost and complex control circuits. To overcome this shortcoming, simple switching circuit‐based dynamic battery balancing techniques and row interconnected techniques are proposed. The proposed techniques are compared and analyzed with various conventional techniques. The experiments are conducted with 4.4 V, 6 Ah, 0.5 C lithium ferro‐phosphate battery cell and the battery pack consists of four cells. In the proposed techniques, the interconnections among the battery cells are altered using a switching matrix circuit. From the results, it is observed that the balanced row interconnected series–parallel dynamics and balanced row interconnected series–parallel have delivered superior performance under all the balancing conditions. Overall, the proposed technique enhances the battery storage capacity by 23.3% during the unbalanced SoC condition. The row interconnected series–parallel dynamics have achieved the average SoC of 96.14% under different balancing conditions. [ABSTRACT FROM AUTHOR]