Maximum Current Research Articles

Design of a Low Power and Wide Frequency Range Ring VCO

This paper proposes a low-power, wide frequency range ring VCO circuit structure based on the application of switch power supply modulation technology. Circuit simulation is completed based on CMSC 180nm BCD process. Simulation results show that the VCO circuit can work at a power supply voltage of 3-5 V, and it has a relatively wide frequency range. Under a 5V power supply voltage and a control voltage range of 4.2V~2.2V, the output frequency range is 0.4-11.96MHz. Under a 3V power supply voltage and a control voltage of 2.2V~0.2V, the output frequency range is 0.56~12.3MHz. For the VCO circuit, the maximum average working current of the power supply is less than 80uA, and the average current of the power supply is only 35uA under a 5V power supply voltage and a 10MHz working frequency. The VCO circuit meets the requirements of low power consumption. It can be applied to switch power supply chips.

71‐2: Distinguished Paper: 4,670‐PPI OLEDoS Pixel Circuit Design for Wide Data Voltage Range in a 5V 0.13μm CMOS Process

OLEDoS displays hold great promise for AR/VR applications, but the ultra‐high pixel density required for microdisplays, exceeding several thousand PPI, presents significant challenges for pixel circuit design. Above all, the maximum OLED current of each OLEDoS sub‐pixel is extremely low, on the order of several nanoamperes or less, resulting in a data voltage range narrower than a few hundred millivolts. Consequently, for example, when expressing 10‐bit grayscale, designing data driver circuits to divide the data voltage range into 1,024 levels becomes exceedingly challenging. Furthermore, circuit techniques that compensate for variations in transistor characteristics are nearly inapplicable due to the ultra‐small pixel area. This paper proposes a pixel circuit design method to expand the data voltage range for a 4,670‐PPI OLEDoS display while considering luminance uniformity. The effectiveness of the proposed pixel circuit was verified through measurements on 40×120 pixel arrays fabricated in a 5V 0.13μm CMOS process.

Short-circuit current analysis of DC distribution system in a ship with non-electric propulsion

Converting conventional AC radial shipboard distribution system to DC system has been recognized as a potential high impact solution to reduce ship’s fuel consumption. As big ships in Indonesia commonly use low voltage AC (LVAC) distribution system an effort to apply low voltage direct current (LVDC) distribution system without replace the propulsion system is a plausible choice. However, technical and economical investigations are required before recommendation to convert the shipboard distribution system to LVDC is officially launched. In this study, technical aspect in the term of short-circuit current is discussed. The goal of this study is to analyze how much the impact on the short-circuit current when LVDC system replaces LVAC system. The impact may affect the feasibility of LVDC system as the short-circuit current in a system dictate the scheme and capacity of the protection devices. Numerical simulations on a sample vessel are performed to obtain the profile of maximum short-circuit currents on all panels. The results show that the utilization of LVDC system decreases the short-circuit current by 10 times. Further investigations on the economic aspect needs to be performed to give clearer view of the feasibility of the LVDC system.

Enhanced OER performance by varying Al-WO3 electrocatalyst thickness: Process optimization

Oxygen evolution reactions (OER) are highly significant and play a critical role in the advancement of fuel cells, electrolyzers, chemicals, and solar energy conversion devices. The challenge in the quest is attributed to the absence of an efficient electrocatalyst assembly that functions optimally. A simple method of electrodeposition of Al:WO3 on a fluorinated tin oxide (FTO) electrode was used to investigate the OER in this study. The electrodepositions were achieved by employing a three-electrode cell at various scan rates ranging from 10 to 100 mV/s. During this investigation, the influence of the scan rate on electrocatalyst loadings and the impact of electrocatalyst layer thickness on the OER were examined. The electrodepositions of Al:WO3@FTO were analyzed using a range of optical, chemical, and physical techniques such as SEM, XRD, FT-IR, Raman spectroscopy, EDX, EDS mapping, and electrochemical tests. The FTIR and Raman analysis confirmed the synthesis of AL:WO3 while the peaks detected at angles 38.7° and 43° by XRD with planes (111) and (200), served as a distinctive characteristic for identifying aluminum (Al). The peaks observed at angles of 27.8°, 30.7°, 33°, 50.45°, and 58° correspond to WO3 material. The characterization techniques also confirmed that the synthesized material is highly crystalline in nature. The OER potential using Al:WO3@FTO electrodes with different electrocatalyst thicknesses, ranging from 8 nm to 31 nm was investigated by studying various electrochemical techniques such as CV, LSV, CPE, Tafel slope, HP2P splitting, EIS, TOF, short and long-term electrode stability, and double layer capacitance. The linear regression coefficient (R2) was also calculated to measure the relationship between the electrocatalyst's thickness and each electrochemical test. The findings indicated that increasing the scan rates resulted in thinner and denser electrodepositions on the FTO substrate as the thinnest film was formed at 100 mV/s. An inverse relationship between electrocatalyst layer thickness and OER activity was observed. The electrode with the thinnest and most compact electrocatalyst layer, specifically ED Al:WO3@FTO08, exhibited the lowest onset potential of 1.48 V and a maximum current of 84 mA/cm2 at 1.76 V. It also demonstrated superior reaction kinetics, as evidenced by its lower Tafel slope value of 49 mV/dec, which is the lowest among all the electrodes that were prepared. In particular, the electrode with a thin and compact electrocatalyst layer worked better in OER operations than the other five electrodes that had higher amounts of Al:WO3.

Electric Field-Modulated Electrospray Ionization Mass Spectrometry for Quantity Calibration and Mass Tracking.

Analyses conducted by electrospray ionization (ESI) mass spectrometry (MS) typically entail performing a number of preparatory steps, which include quantity calibration and mass calibration. Quantity calibration can be affected by signal noise, while mass calibration can be affected by instrumental drift if analyses are performed over an extended period of time. Here, we present two methods for achieving these calibrations using modulation of electrospray plume by alternating electric fields and demodulating the resulting MS ion currents. For this purpose, we use an ESI source fitted with three ring electrodes between the electrospray emitter and the mass spectrometer's inlet. One of these electrodes is supplied with a sine electric signal. Optionally, a nanoESI emitter is also placed between the ring electrodes and the mass spectrometer's orifice to supply calibrant ions. The ion currents, recorded with this setup, present wave-like features. In the first variant, using a triple quadrupole mass analyzer, the ion currents are subjected to data treatment by fast Fourier transform (FFT), and the resulting FFT magnitudes are correlated with analyte concentrations to produce a calibration plot. In the second variant, using a quadrupole time-of-flight mass analyzer, the mass spectra recorded at the analyte ion current maxima are mass-checked using the m/z value of the internal standard (injected via nanoESI emitter), which appears predominantly in the time intervals corresponding to the analyte ion current minima. The setup has been characterized using simulation software and optimized. Overall, the method enables the preparation of quantity calibration plots and monitoring (minor) m/z drifts during prolonged analyses.

Green energy generation via water splitting by non-photocatalytic process based on Gd doped magnesium ferrite hydroelectric cells

This study presents compelling empirical evidence that highlights the notable effect of increased defect concentration on the splitting of water molecules in MgGdxFe2-xO4 hydroelectric cells (HECs), which serve as a promising avenue for environmentally friendly electricity generation. The MgGdxFe2-xO4 (x = 0.00, 0.02, 0.06 and 0.10) series for eco-friendly electricity generation has been successfully synthesized using a facile sol-gel technique. These materials exhibit the characteristic spinel cubic structure with the Fd-3 m space group confirmed using Rietveld analysis of X-ray diffraction plots. A maximum strain of 7.49×10-3 was observed in the MgGd0.10Fe1.90O4, indicating the formation of a probable defective structure. Moreover, the X-ray density values decrease with increase in Gd concentration, suggesting an increase in porosity of the samples. Langmuir hysteresis curve follows a typical type IV pattern further consolidating the mesoscopic nature of the materials. Furthermore, the conclusive identification of defects, particularly oxygen vacancies, through Photoluminescence and X-ray Photoelectron Spectroscopic (XPS) studies, holds an utmost importance in facilitating the water dissociation process at room temperature by ferrites. Impedance spectroscopy has been employed to scrutinize the contribution of small polaron hopping-assisted ionic conduction to the observed improved current density. The maximum short circuit output current of 6.8, 10.1, and 13.4 mA was achieved for MgGd0.02Fe1.98O4 (GMF-1), MgGd0.06Fe1.94O4 (GMF-2) and MgGd0.10Fe1.90O4 (GMF-3) HECs, respectively. The corresponding open cell voltage values were found to be 0.85 V, 0.92 V and 0.98 V. Off-load peak power output was 5.78 mW, 9.29 mW, and 13.13 mW, respectively. The estimated Gibbs free energy values were -164.02, -177.53, and −189.11 kJ/mol. MgGdxFe2-xO4-based hydroelectric cells possess the advantages of being cost-effective and yielding eco-friendly by-products without reliance on photocatalytic activity, acid/alkali solutions, or electrolytes. The incorporation of Gadolinium (Gd) dopant not only enhances the hydroelectric current but also contributes to sustained current generation over extended periods. The extended operational lifespan of the cell positions it as an excellent candidate for practical applications

Characterizing the internal wave wakes and synthetic aperture radar image features of underwater moving objects

In this study, a refined and improved theoretical model was proposed for calculating the synthetic aperture radar (SAR) images of internal wave wakes. This model was based on an equivalent source model of internal wave wakes and the velocity-bunching principle. Wake field, scattering field, and SAR image characteristics were systematically calculated for multiple scenarios. The model described the transfer and solution processes by inputting the background flow field temperature and salinity profiles to map the radar image intensity distribution. The physical mechanisms of the internal wave wake generation and its capture by SAR were comprehensively explained. The effects of various parameters on the internal wave wake SAR images were analyzed comprehensively. The SAR image features containing internal wave wakes were determined based on the gray-level co-occurrence matrix and image power spectrum, which revealed that the maximum surface current induced by the internal wave modes of the same amplitude was considerably larger than that induced by surface-wave mode. When traveling far from the water surface, the rate of change in the total scattering coefficient because of the Bragg effect was approximately 20 times that of the slope effect. In SAR images, the recognizability of wakes depends primarily on the maximum intensity rather than the average disturbance on the sea surface. Therefore, SAR images exhibit considerable differences during downwind radar observations, with the most prominent contrast differences occurring at the maximum spreading angle of wake scattering and 1500 m behind underwater objects. In the image power spectrum, the frequency range of the first modal internal waves was approximately 10–30 Hz, whereas the higher-order modal internal waves had frequencies lower than 10 Hz. Furthermore, the frequency range of the surface-wave mode was larger than that of internal-wave modes, approximately 50–60 Hz.

Experimental Approach for Reliability Analysis of Medium-Power Zener Diodes under DC Switching Surge Degradation

This study investigated the reliability of Zener diodes subjected to a gradually increasing DC switching surge amplitude with delay internals between surges to avoid thermal degradation from different manufacturers with similar specifications. The analysis involved applying occasional 3 ms direct current (DC) switching surges with a gradual increasing surge voltage, followed by a constant current test to verify device functionality for three different selected manufacturer 5.1 V Zener diodes. This experimental approach was used to identify the maximum surge current that each Zener diode could handle before failing to clamp the surge voltage at the specified Zener reference voltage. Statistical analysis revealed significant differences in the maximum average surge current between different manufacturers. The maximum average surge current findings just before failure were 1.98 A, 3.18 A, and 3.33 A, respectively, and associated 95% confidence interval ranges can be used as a reliable metric to compare Zener diode population reliability against occasional DC switching surges. The findings revealed variations in the DC switching surge current handling capabilities between Zener diodes from different manufacturers with similar electrical specifications. The statistically measured maximum average surge current just before device failure can be considered an effective metric to compare the reliability of Zener diodes against DC switching surge degradation.

Sodium alginate/carbon nanotube energy harvesting fibers: Axial functional group gradient and moist-electric performance

Moist-electric generation, a green and environmentally friendly energy harvesting technology, is undoubtedly one of the effective methods to alleviate energy shortages and environmental damage. However, the lack of fiber-like moist-electric generators (MEGs) that combine continuous power generation and high electrical output performance has constrained the development of moist-electric in the fields of flexible wearable and self-power supplies. In this work, sodium alginate (SA)/multi-walled carbon nanotubes (MWCNT) fibers with axial heterogeneous (axi-he) of oxygen-containing functional groups (Ocfgs) are prepared through a mold forming method in assistance with the coagulation process. The interaction between axi-he MEG and moisture is investigated by analyzing the electrical signal changes of dried MEG under moisture stimulation. The maximum output voltage and current of axi-he MEG can reach 0.35 V and 1.92 μA under the stimulation of moisture. Based on the regulation of Ocfgs, axi-he MEG has a continuous high moist-electric performance and environmental adaptability. The maximum output power density (Pmo) of axi-he MEG with a length of only 2 cm can reach 27.37 μW cm–2 at RH = 90 %, which exceeds most of the MEGs reported in literature. Meanwhile, a continuous output voltage of 0.33–0.37 V for more than 15 h can be obtained from this axi-he MEG. Thus, the axi-he MEG from Ocfg distribution design and mold forming method provides a new way of clean energy generation using moisture from the ambient environment, exhibiting enormous potential in energy supply for Internet of Things (IoT) devices.

Critical thermal maxima and oxygen uptake in Elysia viridis, a sea slug that steals chloroplasts to photosynthesize.

Photosynthetic animals produce oxygen, providing an ideal lens for studying how oxygen dynamics influence thermal sensitivity. The algivorous sea slug Elysia viridis can steal and retain chloroplasts from the marine alga Bryopsis sp. for months when starved, but chloroplast retention is mere weeks when they are fed another green alga, Chaetomorpha sp. To examine plasticity in thermal tolerance and changes in net oxygen exchange when fed and starving, slugs fed each alga were acclimated to 17°C (the current maximum temperature to which they are exposed in nature) and 22°C (the increase predicted for 2100) and measured at different points during starvation. We also examined increased illumination to evaluate a potential tradeoff between increased oxygen production but faster chloroplast degradation. Following acclimation, we subjected slugs to acute thermal stress to determine their thermal tolerance. We also measured net oxygen exchange before and after acute thermal stress. Thermal tolerance improved in slugs acclimated to 22°C, indicating they can acclimate to temperatures higher than they naturally experience. All slugs exhibited net oxygen uptake, and rates were highest in recently fed slugs before exposure to acute thermal stress. Oxygen uptake was suppressed following acute thermal stress. Under brighter light, slugs exhibited improved thermal tolerance, possibly because photosynthetic oxygen production alleviated oxygen limitation. Accordingly, this advantage disappeared later in starvation when photosynthesis ceased. Thus, E. viridis can cope with heatwaves by suppressing metabolism and plastically adjusting heat tolerance; however, starvation influences a slug's thermal tolerance and oxygen uptake such that continuous access to algal food for its potential nutritive and oxygenic benefits is critical when facing thermal stress.

Optimal parameters identification for PEMFC using autonomous groups particle swarm optimization algorithm

The precise model for Polymer Electrolyte Membrane Fuel Cells (PEMFCs) is vital for simulation, control, and performance analysis of PEMFCs. It is crucial to accurately estimate the model parameters. Over the past decade, the extraction of unknown parameters of PEMFCs model is formulated as optimization problem and several meta-heuristic techniques have emerged to solve this problem. Despite the development of these techniques to tackle the problem, the slow convergence rate and susceptibility to being trapped in local minima are regarded as weaknesses of these methods. Additionally, because the PEMFC model is a nonlinear and complex model, not all optimization algorithms are suitable for solving it. This article introduces a novel approach that utilizes the Autonomous Groups Particle Swarm Optimization (AGPSO) algorithm for extracting precise values for uncertain parameters inherent in PEMFC model of 250Wstack and BCS-500W stack utilized significantly in the literature. The optimization problem's fitness function is formulated as the total squared errors (TSEs) between the voltage datasets measured and estimated. Three different versions of AGPSO algorithm are presented. Statistical analysis is performed on these three versions to assess their robustness, and the most robust version is identified. Furthermore, the performance of the most robust version is extensively tested and analyzed through a complete comparison with recent optimization algorithms findings from the updated state-of-the-art literature such as BO, QOBO, TGA, HHO and ASO. Further, a statistical analysis was carried out that ensured the reliability and robustness of the introduced AGPSO. The results highlight the efficacy and feasibility of AGPSO-based approach across all compared algorithms, demonstrating an enhancement in the accuracy of the PEMFC model. A two-phase sensitivity analysis, conducted through Monte Carlo Simulation (MCS), was employed to assess how variations in optimized parameters affect the objective function (TSEs). Furthermore, the uncertainty in the maximum power reference current is identified.

Quantum revivals in HgTe/CdTe quantum wells and topological phase transitions

The time evolution of a wave packet is a tool to detect topological phase transitions in two-dimensional Dirac materials, such as graphene and silicene. Here we extend the analysis to HgTe/CdTe quantum wells and study the evolution of their electron current wave packet, using 2D effective Dirac Hamiltonians and different layer thicknesses. We show that the two different periodicities that appear in this temporal evolution reach a minimum near the critical thickness, where the system goes from normal to inverted regime. Moreover, the maximum of the electron current amplitude changes with the layer thickness, identifying that current maxima reach their higher value at the critical thickness. Thus, we can characterize the topological phase transitions in terms of the periodicity and amplitude of the electron currents.

All-in-one 2LabsToGo system for analysis of ergot alkaloids in whole rye

Ergot alkaloids, naturally occurring mycotoxins of Claviceps fungi, pose health risks. This necessitates accurate analysis methods to ensure food safety. This study explored the open-source miniaturized all-in-one 2LabsToGo system to analyze ergot alkaloids in whole rye samples. It is suited for sustainable atline analysis as it combines all planar chromatography tasks, allowing low-cost quality control in milling plants. The LOD and LOQ of ergocristine were determined to be 0.4 and 1.2 ng/zone, respectively. Detectability of ergot alkaloids was proven to be below the current maximum limit of 500 µg/kg for rye milling products. The repeatability (%RSD) was 4.1 % and the coefficient of determination of the analytical response (R2) was 0.9918 for ergocristine. The mean recovery rate of ergot alkaloids in spiked whole rye grain was close to 100 %. Results of screening whole rye for ergot alkaloids were successfully verified by comparison with those obtained by conventional status quo HPTLC instrumentation.

Development of a superconducting undulator cryostat based on the thermosiphon effect

As a specific device for light production, undulators have been researched and developed since the third generation of synchrotron photon sources. Nowadays, superconducting undulators become a research hotspot. However, the cryostat, which is used to create a liquid helium temperature environment, often causes the failure of the superconducting undulator. In this paper, a cryostat for a superconducting undulator is designed and investigated. First, a new refrigeration distribution is proposed that can provide more excess cooling capacity at 4.2 K temperature. For the cooling of the superconducting magnet, a liquid helium circulation loop based on the thermosiphon effect is designed, which has no pump or any other moving parts. Next, based on high-temperature superconducting technology, six binary current leads are used to decrease the heat load. The beam chamber is cooled below 20 K to reduce possible effect on the magnet. In addition, for the tubes that connect the 4.2 K helium tank to the room temperature component, the thermoacoustic oscillation is studied. In the experiment, the superconducting magnet could be cooled and maintained at 4.2 K depending on the thermosiphon loop. No helium was discharged when the magnet went through a quench which generated large heat in a short time. There was no liquid helium consumption and the excess cooling capacity reached 2.2 W. The maximum magnet current is as high as 470 A. This study can provide a valuable reference for the development of superconducting undulator cryostats.

Flexible hybrid nanogenerator coupling of triboelectric and photovoltaic effects based on fluoride dielectric regulation for energy harvesting

Recently, constructing hybrid nanogenerators (NGs) that can simultaneously harvest frictional and solar energies has attracted a growing interest, among which halide perovskite is considered as one of the most suitable active materials. However, current perovskite-based hybrid NGs are low in performance and limited to rigid substrates. Strategies to minimize performance loss caused by deep defects in perovskite functional layer are still lacking. In this work, we proposed a fluoride additive passivation strategy to fabricate a new kind of flexible, efficient perovskite-based hybrid NGs. The fluoride with high electronegativity can effectively passivate defect density of perovskite film and further enhance its dielectric constant to minimize the ability of defects to capture charges. Hence, more efficient charge transport and suppressed recombination loss are achieved, which maximizes the triboelectric-photovoltaic coupling effect. The maximum current of the hybrid NG is up to 9.7 μA under illumination, which is about 25 times higher than that of the control device. The hybrid NG could light 50 LEDs and charge capacitors. Moreover, it exhibited excellent flexibility to act as a self-powered wearable sensor to detect human motions. Our work proposed a new strategy for flexible triboelectric-photovoltaic hybrid NGs with high-output performance for smart wearable applications.

Effect of Crystallinity on the Field Emission Characteristics of Carbon Nanotube Grown on W-Co Bimetallic Catalyst.

Carbon nanotube (CNT) is an excellent field emission material. However, uniformity and stability are the key issues hampering its device application. In this work, a bimetallic W-Co alloy was adopted as the catalyst of CNT in chemical vapor deposition process. The high melting point and stable crystal structure of W-Co helps to increase the grown CNT diameter uniformity and homogeneous crystal structure. High-crystallinity CNTs were grown on the W-Co bimetallic catalyst. Its field emission characteristics demonstrated a low turn-on field, high current density, stable current stability, and uniform emission distribution. The Fowler-Nordheim (FN) and Seppen-Katamuki (SK) analyses revealed that the CNT grown on the W-Co catalyst has a relatively low work function and high field enhancement factor. The high crystallinity and homogeneous crystal structure of CNT also reduce the body resistance and increase the emission current stability and maximum current. The result provides a way to synthesis a high-quality CNT field emitter, which will accelerate the development of cold cathode vacuum electronic device application.

Control strategy for current limitation and maximum capacity utilization of grid connected PV inverter under unbalanced grid conditions

Under grid voltage sags, over current protection and exploiting the maximum capacity of the inverter are the two main goals of grid-connected PV inverters. To facilitate low-voltage ride-through (LVRT), it is imperative to ensure that inverter currents are sinusoidal and remain within permissible limits throughout the inverter operation. An improved LVRT control strategy for a two-stage three-phase grid-connected PV system is presented here to address these challenges. To provide over current limitation as well as to ensure maximum exploitation of the inverter capacity, a control strategy is proposed, and performance the strategy is evaluated based on the three generation scenarios on a 2-kW grid connected PV system. An active power curtailment (APC) loop is activated only in high power generation scenario to limit the current’s amplitude below the inverter’s rated current. The superior performance of the proposed strategy is established by comparison with two recent LVRT control strategies. The proposed method not only injects necessary active and reactive power but also minimizes overcurrent with increased exploitation of the inverter’s capacity under unbalanced grid voltage sag.

Development of bipolar high-current correction magnet power supply for TPS facility

Taiwan Photon Source (TPS) is a globally renowned 3 GeV synchrotron accelerator light source. With a successful decade of operation, various subsystems have continuously improved and maintained an optimal research facility environment. Presently, there is a concerted effort towards energy conservation. This technical report focuses on the future development of the TPS-II Permanent Magnet Trim Coil Power Supply for the correction magnet, emphasizing a Bipole high-current correction magnet power source. According to the prototype specifications, the maximum output current is 20 A with an operating voltage of 48 V. This augmentation increases the amplitude of the magnetic field correction in the permanent magnet-associated Trim core, providing greater flexibility in manufacturing the permanent magnet correction coils. To design a power supply with high current and stability, the system adopts the Danisense DP50-IP-B DC Current Transducers (DCCT) as the current feedback component and Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) as power switches in a full-bridge (H-bridge) configuration. The driving frequency is set at 40 kHz. Analog modulation control circuitry and protective circuits ensure precise control loop modulation. In the power laboratory, a hardware prototype circuit was constructed, featuring a 48 V input voltage, 20 A output current, a maximum power of 960W, and a current ripple component maintained within 100 μA. This experiment validates the control loop design of the prototype, showcasing the ability to achieve rapid and stable output current performance. Using a 1 V input reference signal for small-signal testing, the bandwidth displayed a -3 dB bandwidth of 8.51 kHz. Long-term current stability is within ± 10 ppm, and interface compatibility with the existing TPS correction magnet power source interface allows direct operation within the current system.

4670‐PPI OLEDoS pixel circuit design for wide data voltage range in a 5 V 0.13 μm CMOS process

AbstractOLEDoS displays hold great promise for AR/VR applications, but the ultra‐high pixel density required for microdisplays, exceeding several thousand PPI, presents significant challenges for pixel circuit design. Above all, the maximum OLED current of each OLEDoS sub‐pixel is extremely low, on the order of several nanoamperes or less, resulting in a data voltage range narrower than a few hundred millivolts. Consequently, for example, when expressing 10‐bit grayscale, designing data driver circuits to divide the data voltage range into 1024 levels becomes exceedingly challenging. Furthermore, circuit techniques that compensate for variations in transistor characteristics are nearly inapplicable due to the ultra‐small pixel area. This paper proposes a pixel circuit design method to expand the data voltage range for a 4670‐PPI OLEDoS display while considering current uniformity. The effectiveness of the proposed pixel circuit was verified through measurements on 40 × 120 pixel arrays fabricated in a 5 V 0.13 μm CMOS process.

Omnidirectional circularly polarized base station antenna with high gain and wide band

Omnidirectional circularly polarized base station antenna with high gain and wide band