Passive Filter Research Articles

Laser Ablation of Silicon Nanoparticles and Their Use in Charge-Coupled Devices for UV Light Sensing via Wavelength-Shifting Properties.

This study explores the controlled laser ablation and corresponding properties of silicon nanoparticles (Si NP) with potential applications in ultraviolet (UV) light sensing. The size distribution of Si NPs was manipulated by adjusting the laser scanning speed during laser ablation of a silicon target in a styrene solution. Characterization techniques, including transmission electron microscopy, Raman spectroscopy, and photoluminescence analysis, were employed to investigate the Si NP structural and photophysical properties. Si NP produced at a laser scanning speed of 3000 mm/s exhibited an average diameter of ~4 nm, polydispersity index of 0.811, and a hypsochromic shift in the Raman spectrum peak position. Under photoexcitation at 365 nm, these Si NPs emitted apparent white light, demonstrating their potential for optoelectronic applications. Photoluminescence analysis revealed biexponential decay behavior, suggesting multiple radiative recombination pathways within the nanoscale structure. Furthermore, a thin film containing Si NP was utilized as a passive filter for a 2nd generation CCD detector, expanding the functionality of the non-UV-sensitive detectors in optics, spectrometry, and sensor technologies.

Two inverting CFOA-Based lossless floating immittance simulator

Inverting current feedback operational amplifier (ICFOA)-based lossless floating immittance simulator (FIS) is introduced in this manuscript. In the proposed FIS, floating capacitance multiplier (FCM), simulated floating inductor (SFI), and floating frequency-dependent negative resistor (FFDNR) can be obtained with selections of the passive elements. The proposed FIS is realized with a minimum number of passive elements. The proposed FIS is not suffered from any resistor and/or capacitor matching conditions; nevertheless, all the passive elements are chosen as floating. All the simulations of the FCM, SFI, and FFDNR are made by using the SPICE program in which 0.18 µm CMOS technology parameters are utilized. As an application example, the second-order passive band-pass filter is given for the FCM and SFI. Simulation results confirm the ideal results between about 5 Hz and 2 MHz for the FCM, between approximately 200 Hz and 5 MHz for the SFI, and between about 50 kHz and 13 MHz for the FFDNR. The proposed circuit has 1.49 mW power dissipation. In addition, the experiments of the proposed circuit and application are achieved by using AD844s instead of the ICFOAs.

Interval Type - 2 Fuzzy Logic Controller Based Shunt Active Power Filter for Power Quality Enhencement

Frequent wide spread of power electronics equipment to consumers have led to power quality problem in power system network, as a result to their nonlinear in nature. Due to this problem, current and voltage wave forms are no longer sinusoidal, which resulted in harmonics on them. Various methods have been deployed in order to mitigate the harmonic issues, like passive power filters and shunt active power filters. Presently, passive power filters are limited in used, because of its demerits as it produced parallel resonances, heavy in size and mitigate few harmonics. With the advancement in technology, shunt active power filters have become superior to passive power filters due to its limitations. Shunt active power filters was tested for suppressing harmonics produced by nonlinear loads. This article, used synchronous reference frame (SRF) in generating harmonic produced by nonlinear loads. However, T2FLC is utilized in controlling the DC bus voltage of the filter constant. Hysteresis current controller was introduced for firing the gating signal of the IGBT inverter circuit. MATLAB software was deployed in the simulation work. Results obtained have satisfied the tolerable 2014 revised harmonics limit.

Performance investigations of five-level reduced switches count Η-bridge multilevel inverter

Introduction. This research paper describes a simple five-level single-phase pulse-width modulated inverter topology for photovoltaic grid applications. Multilevel inverters, as opposed to conventional two-level inverters, include more than two levels of voltage while using multiple power switches and lower-level DC voltage levels as input to produce high power, easier, and less modified oscillating voltage. The H-bridge multilevel inverter seems to have a relatively simple circuit design, needs minimal power switching elements, and provides higher efficiency among various types of topologies for multi-level inverters that are presently accessible. Nevertheless, using more than one DC source for more than three voltage levels and switching and conduction losses, which primarily arise in major power switches, continue to be a barrier. The novelty of the proposed work consists of compact modular inverter configuration to connect a photovoltaic system to the grid with fewer switches. Purpose. The proposed system aims to decrease the number of switches, overall harmonic distortions, and power loss. By producing distortion-free sinusoidal output voltage as the level count rises while lowering power losses, the constituted optimizes power quality without the need for passive filters. Methods. The proposed topology is implemented in MATLAB/Simulink with gating pulses and various pulse width modulation technique. Results. With conventional topology, total harmonic distortion, power switches, output voltage, current, power losses, and the number of DC sources are investigated. Practical value. The proposed topology has proven to be extremely useful for deploying photovoltaic-based stand-alone multilevel inverters in grid applications.

Power quality improvement using rabbit optimization FOPID controlled photovoltaic- battery powered hybrid power filter

This paper presents the tuning of a fractional proportional controller (FOPI) using artificial rabbit optimization for the control of photovoltaic (PV) and battery power series active power filters along with a shunt passive filter which is known as a hybrid power filter. The PV power generation is combined into a series active filter to alleviate the problem of voltage sag and swell in the power system and also supply real power to the grid. Generally, the proportional controller is used to control the series active filter, but this is a linear controller and is not able to control the non-linear power system effectively. This problem is effectively controlled by non-linear control, i.e., a fractional-order proportional integral controller. Another problem in FOPI is finding the optimal value for proportional gain, integral gain, and fractional order. There are no standard rules for finding these values. This will make system design more complex. In this paper, artificial rabbit optimization is used to simplify the system design by finding optimal values of the FOPI controller for the series active filter and enhance the overall performance of the system. The MATLAB 2020b/Simulink environment is utilized to assess the recommended controller’s performance. According to the experimental findings, the suggested system has a total harmonic distortion (THD) value for load voltage of 0.10 % and a total harmonic distortion value for grid current of 1.87 %. The proposed artificial-rabbit optimized FOIPI controller effectively controls the system against voltage sag, swell, and non-linear loads and also obeys IEEE power quality standards.

RETRACTED ARTICLE: Improvement of power quality in grid connected renewable energy systems using passive filters

RETRACTED ARTICLE: Improvement of power quality in grid connected renewable energy systems using passive filters

Long-term effects on water chemistry and macroinvertebrates of selective thinning along small boreal forest streams

The maintenance of narrow strips of trees (forest buffers) along the shorelines of surface water bodies during logging is a common measure to protect freshwater habitats. The functionality of forest buffers may be improved by actively managing the streamside forest early in the rotation for their eventual function as buffers, including by increasing the proportion of broadleaf trees in spruce-dominated stands. In this study, long-term effects of different selective thinning regimes along two small forest streams were investigated in south-central Sweden. In a young coniferous forest, a c. 10 m-wide band along the streams was selectively thinned in 1998 to create a band with purely broadleaf trees along one of the streams and purely conifers along the other. Forest stand characteristics, water chemistry and benthic macroinvertebrates data were collected during 1996–2003 (before and after selective thinning). The streams were re-investigated 20–22 years after thinning, together with three streams representing operational forest management. The forest adjacent to all five streams was inventoried and litterfall, stream water chemistry, and benthic macroinvertebrates composition were monitored between spring and late autumn during 2018–2020. Twenty years after thinning, the thinned bands beside the streams were still dominated by either broadleaf trees or conifers, depending on the stream. Over the longer term, the differences in water chemistry between the streams with selective thinning were mainly related to lower pH, ANC, Tot-P and Tot-N concentrations in the stream bordered by mainly broadleaf trees. Analysis of benthic macroinvertebrates was based on environmental quality indices (ASPT and EPT), diversity and abundance metrics, and relative abundances of functional feeding groups. Streams with higher broadleaf litter inputs tended to score better on the ASPT and EPT indices than those with lower broadleaf inputs, as well as supporting higher relative abundances of one or more groups of invertebrate detritivores (leaf shredders, collector-gatherers and/or passive filter feeders). This suggests that management of the density of broadleaf trees beside these streams might support higher ecological status and will support a greater proportion of detritivores in benthic food webs.

Harmonic Mitigation using Hybrid Power Filter to Improve Power Quality

This paper represents a power quality improvement using harmonic mitigation method in distribution and transmission system. This include the hybrid power filter for mitigating the harmonic in the power system, the hybrid power filter is the combination active power filter ,passive power filter and voltage source inverter with the passive component like a capacitor and the inductor. The drawback of the active and the passive power filter is overcome by designing the hybrid power filter, the capability of harmonic mitigation can be increased with dc link voltage of the voltage source inverter. in this two method of implementation is adopted for harmonic mitigation in power system like hybrid mode and the passive mode , in passive mode the passive component is used in series such as capacitor and inductor and in hybrid mode the voltage source inverter is used along with the LC-filter . The power quality improvement and the reactive power control is also represented in this paper The analysis and MATLAB simulation give the proper solution to mitigate the harmonic in the distribution and the transmission system to improve the power quality and system stability . Index Terms— ,FFT Analysis hybrid power filters, passive power filters, power system harmonics, reactive power control., Total Harmonic Distortion, power quality, transmission and distribution network..

A Portable and a Scalable Multi-Channel Wireless Recording System for Wearable Electromyometrial Imaging.

Electromyometrial imaging (EMMI) technology has emerged as one of the promising technology that can be used for non-invasive pregnancy risk stratification and for preventing complications due to pre-term birth. Current EMMI systems are bulky and require a tethered connection to desktop instrumentation, as a result, the system cannot be used in non-clinical and ambulatory settings. In this article, we propose an approach for designing a scalable, portable wireless EMMI recording system that can be used for in-home and remote monitoring. The wearable system uses a non-equilibrium differential electrode multiplexing approach to enhance signal acquisition bandwidth and to reduce the artifacts due to electrode drifts, amplifier 1/f noise, and bio-potential amplifier saturation. A combination of active shielding, a passive filter network, and a high-end instrumentation amplifier ensures sufficient input dynamic range ([Formula: see text]) such that the system can simultaneously acquire different bio-potential signals like maternal electrocardiogram (ECG) in addition to the EMMI electromyogram (EMG) signals. We show that the switching artifacts and the channel cross-talk introduced due to non-equilibrium sampling can be reduced using a compensation technique. This enables the system to be potentially scaled to a large number of channels without significantly increasing the system power dissipation. We demonstrate the feasibility of the proposed approach in a clinical setting using an 8-channel battery-powered prototype which dissipates less than 8 μW per channel for a signal bandwidth of 1 KHz.

Adaptive neural dynamic surface control of load/grid connected voltage source inverters with LC/LCL filters

Utilizing passive filters such as L, LC and LCL is preferred to cancel out high-frequency harmonics caused by pulse width modulation of voltage source inverters. However, the LC and LCL filters have shown better harmonic attenuation than the conventional L filter. Nevertheless, the control process of LC and LCL filters is more complicated due to their higher-order dynamics. The problem gets more challenging in the presence of uncertainties such as load and grid impedance variations. To overcome these challenges, two novel adaptive neural dynamic surface controllers are proposed for LC and LCL filters in the load and grid-connected modes, respectively. Meanwhile, the issue of computational complexity inherent in the conventional backstepping method is avoided here by utilizing the dynamic surface control technique. Furthermore, the matched and unmatched uncertainties of LC/LCL filters are approximated via multi-input multi-output radial basis function neural networks. Stability of the closed-loop systems is guaranteed by converging the tracking errors to a small neighborhood of the origin. Simulations are given to illustrate the effectiveness and potential of the proposed adaptive neural dynamic surface control methods under the load and grid impedance changes.

Self-switching circuit of TENG for energy storage and power management in harvesting wind energy

As an important green energy in our life, natural wind energy is widely used in power generation. Triboelectric nanogenerator (TENG) can convert wind energy in the environment into electrical signal. In this study, two independent TENGs in parallel (FHS-TENG) and the power management circuit composed of passive self-switching circuit and LC filter circuit constitute a self-supplying system, which is committed to harvesting wind energy in the environment and outputting stable voltage and improving energy storage performance. The self-switching circuit mainly includes rectifier module, energy storage module, the self-switching module, and filter module. And the on/off state of the passive self-switching is mainly controlled by two transistors, which implements the effect of switch. The results demonstrate that the energy stored by the power management circuit is more than 100 times higher than that of the universal circuit at 100 μF capacitor, and the calculator is in stable working order in simulated wind conditions. This work provides a new strategy for the passive electronic switch of TENG and the improvement of circuit energy storage performance, which is meaningful for the further application and industrialization of TENG.

A Ku-Band CMOS Balanced Driver Amplifier With Transformer-Based Notch Filter for SATCOM Phased Arrays

This brief presents a Ku-band balanced driver amplifier (BDA) for SATCOM phased arrays. To facilitate a flexible and low-loss coupler design, the non-correlation between the coupling coefficient and the output power of BDA is illustrated. The passive transformer-based notch filter is co-optimized with the inter-stage matching network. The sideband rejection is improved while maintaining high gain and linearity. The second harmonic trap technique is also applied to alleviate the amplitude-to-phase (AM-PM) distortion. Fabricated in 65-nm CMOS technology, the proposed BDA provides the maximal gain of 26 dB at 14 GHz with the highest sideband rejection of 26 dB. The input and output return losses are both better than -15 dB. It achieves a measured 1-dB compressed power (P1dB) of 19.5 dBm with the maximal power-added efficiency (PAEmax) of 27.8%. The small-signal gain and P1dB vary only 2 dB and 0.8 dBm from -55∘C to 85∘C, respectively.

A Compact and Ultra-Low-Power Low-Pass Filter Based on Band-to-Band Tunneling Effect

Continuous-time filters with low-frequency cutoff are crucial building blocks in analog signal processing circuits for speech processing and biomedical applications. The design of an integrated continuous-time filter with a cutoff frequency spanning from sub-Hz to a few kHz is constrained by the ultra-low power and area minimization requirement. In this article, we have experimentally demonstrated a low pass filter response using only a single partially depleted (PD) silicon on insulator (SOI) transistor. The proposed novel filter is based on band to band tunnelling (BTBT). This low pass filter is on-chip tunable to provide a wide cutoff frequency ranging from 2 Hz to 20 kHz, with a silicon footprint of 9 μm2 and the maximum power consumption of 0.6 nW in Global Foundries’ (GF) 45 nm RFSOI technology. The proposed tunneling-based filter is less prone to process variations and mismatches as compared to traditional integrated analog filters. The proposed BTBT-based passive RC filter with spurious free dynamic range (SFDR) of 29 dbc, outperforms previously reported filters in the literature in terms of power consumption and area. The ultra-low power consumption and area efficiency make this proposed low pass filter suitable for the multichannel analog front-end low-frequency filters for noise-tolerant neural network-based applications such as speech recognition and electrophysiological signal recognition.

Bi-Level damped double-tuned harmonic passive filters design: Multi-criteria decision-making analysis

Bi-Level damped double-tuned harmonic passive filters design: Multi-criteria decision-making analysis

Cloud Server-Assisted Remote Monitoring and Core Device Fault Identification for Dynamically Tuned Passive Power Filters

Reliability and safety are crucial for the operation of a dynamically tuned passive power filter (DTPPF). Safe performance of DTTPFs implies complete normal filtering without failure within a specified period. To prevent potential disaster or economic loss, it is desirable to achieve early warning of any core device faults in a DTPPF based on its running state and to optimize its harmonic mitigation performance. In this paper, we explore effective methods for identifying core device faults in DTPPFs. First, we summarize the characteristic parameters of faults, running state parameters, parameters required for fault monitoring, and fault type parameters. Then, a cloud server-assisted remote monitoring and fault identification system for DTPPF is proposed, which consists of monitoring system’s architecture and cloud servers’ software architecture as well as software design of the back-end service layer and functional design of the front-end application layer. Our experiments demonstrate that the proposed system can monitor the real-time operational status of the DTPPF, enabling remote diagnosis and identification of core device faults. Moreover, it is user-friendly, as it is capable of optimizing equipment maintenance schedules and utilizing manufacturers’ service capacities. Therefore, this research provides a theoretical foundation for harmonic mitigation in low-voltage distribution networks and is valuable for practical engineering applications in industrial power grids.

Profitability of filtering harmonics by passive filters for tertiary buildings: Application to a university of higher education

Profitability of filtering harmonics by passive filters for tertiary buildings: Application to a university of higher education

An Amended Crow Search Algorithm for Hybrid Active Power Filter Design

Hybrid Active Power Filter (HAPF) imbibes the advantages of both passive and active power filters. These filters are considered one of the important technologies for mitigating harmonic pollution in electrical systems. Accurate estimation of filter parameters is a key component to reduce harmonic pollution effectively. In recent years, several optimization approaches have been reported to solve this estimation problem; still, this area is worthy of further investigation. This paper is a proposal for an estimator that can estimate the parameter of HAPF configuration accurately. For evolving this estimator, first, an objective function that mathematically embeds filter parameters and harmonic pollution is presented. For handling the optimization process, an Amended Crow Search Algorithm (ACSA) is proposed. ACSA employs a local search algorithm (in the form of a pattern search) for obtaining optimal results. The analysis of the estimation process is carried out on two HAPF configurations. Various analyses that include harmonic pollution statistical analysis along with fitness function value analysis reveal that the proposed algorithm acquires optimal results as compared with other recently published and reported algorithms. Further, the proposed filter configurations are tested with the existing filter. The results prove that the proposed filter shows promising results.

Suppression of over voltage in SiC-based inverter fed induction motor

ABSTRACT Silicon carbide (SiC) based inverters are widely used due to their fast switching and ability to withstand high temperatures and Voltage. This helps to increase efficiency and reduces switching losses compared to the silicon-based inverter. However, this fast-switching device causes an increase in the Voltage at the junction of the cable and motor due to the reflected wave. The main causes of overvoltage are cable/motor impedance mismatch, fast-switching inverter devices (IGBT), and inverter-motor separation. To extend the induction motor lifespan, overvoltage reduction is necessary. Passive and active filters solve the problem, but passive filters are bulky and have high power loss. This paper presents a shunt active filter approach for an inverter-fed induction motor to reduce overvoltage. To show the effectiveness of the proposed approach, the findings were compared to the topology of the clamp-type active filter already in use. The shunt active filter used Proportional Integral (PI) and fuzzy controllers to generate reference current according to the Synchronous Reference Frame (SRF) theory. Harmonics in the power system were removed using the SRF theory. The unique aspect of this work is how the reference current is produced in the shunt active filter using the SRF theory. The proposed shunt active filter with a fuzzy controller was added to the hardware implementation to achieve better results than previous active filters.

Design and optimization of GaAs-based thin film integrated passive device bandpass filters for 5G communications

This paper outlines the development of a bandpass filter (BPF) suited for 5G communications in the n77 and n78 bands. We apply a thin-film integrated passive device (TFIPD), ideal for use in Radio Frequency (RF) front-end systems due to its streamlined design, ease of integration, and decreased losses. We utilize a Chebyshev filter formation for the BPF design, implementing a pole-zero to generate a notch pattern. The pole-zero is formed by integrating capacitance and inductance into the resonant circuit blueprint, thus enhancing the sharp-drop capability of the BPF and adjusting the passband width. The inductor component in our suggested BPF arrangements employs a spiral inductor based on an air-bridge structure to minimize unwanted effects, while a metal-insulator-metal (MIM) capacitor is incorporated into the capacitor component to streamline the construction. The BPF in the n78 band exhibits transmission zeros at 3.017 and 4.448 GHz at the center frequency, with a minimum insertion loss (ILmin) of 0.824 dB, a maximum insertion loss (ILmax) of 1.215 dB, a return loss of 27.439 dB. Similarly, the n77 band-resonant BPF is characterized by an ILmin of 0.755 dB, an ILmax of 1.237 dB, a return loss of 30.716 dB, and transmission zeros at 2.867 and 5.083 GHz. These BPFs demonstrate compatibility with other microwave devices at the System in Package (SiP) level, boasting compact physical dimensions of 1.51 × 1.33 mm2.

Assessing the accuracy of eye-tracking through passive filter and active shutter-glasses.

Assessing the accuracy of eye-tracking through passive filter and active shutter-glasses.