Switching Elements Research Articles

Design and analysis of double-layer parasitic split-ring resonator based on O-shaped engraved microstrip based radiating structure for 5G, WiMAX, WLAN and LTE applications

A novel approach of frequency tunability to cover multiple wireless applications by using four PIN diodes as a switching element is presented. Five switching modes of PIN diodes are analyzed for frequency tunability. The parasitic metamaterial superstrate achieves performance improvement shown in the design. Numerical analysis of metamaterial rings and equivalent circuit models of the SRR and PIN diode are also presented. The structure is analyzed regarding reflection response (S11), Gain, VSWR, directivity and E-field for 2 GHz–6 GHz. Computational analysis is performed by the HFSS simulator and is compared with the fabricated structure (FR-4) for verification. Copper and liquid-based material are used for performance analysis of all the models, and comparative analysis is included. Liquid-based split ring resonator provides a maximum total gain of 5.564 dB, reflection response of −43.36 dB and tunability of 510 MHz. The proposed antenna is used in 5G, WLAN, WiMAX and LTE applications.

Metasurface-enabled polarization-independent LCoS spatial light modulator for 4K resolution and beyond

With the distinct advantages of high resolution, small pixel size, and multi-level pure phase modulation, liquid crystal on silicon (LCoS) devices afford precise and reconfigurable spatial light modulation that enables versatile applications ranging from micro-displays to optical communications. However, LCoS devices suffer from a long-standing problem of polarization-dependent response in that they only perform phase modulation on one linear polarization of light, and polarization-independent phase modulation—essential for most applications—have had to use complicated polarization-diversity optics. We propose and demonstrate, for the first time, an LCoS device that directly achieves high-performance polarization-independent phase modulation at telecommunication wavelengths with 4K resolution and beyond by embedding a polarization-rotating metasurface between the LCoS backplane and the liquid crystal phase-modulating layer. We verify the device with a number of typical polarization-independent application functions including beam steering, holographical display, and in a key optical switching element - wavelength selective switch (WSS), demonstrating the significant benefits in terms of both configuration simplification and performance improvement.

Non‐Volatile Optical Switch Element Enabled by Low‐Loss Phase Change Material

AbstractMach–Zehnder interferometers (MZIs) integrated with phase‐change materials have attracted great interest due to their low power consumption and ultra‐compact size, which are favored for reconfigurable photonic processors. However, they suffer from a low optical extinction ratio and limited switching cycles due to high material loss and poor reversible repeatability caused by material degradation. Here a non‐volatile electrically reconfigurable 2 × 2 MZI integrated with a low‐loss phase‐change material Sb2Se3 encapsulated in Al2O3 layers is demonstrated. The phase change is electrically actuated by a forward‐biased silicon p‐i‐n diode. The switch extinction ratio is more than 20 dB due to the low‐loss Sb2Se3‐based phase shifter. By dividing the Sb2Se3 patch into small sub‐cells to restrict the material reflow, more than 10 000 reversible phase‐change cycles and 6‐bit multilevel switching states are achieved by programming the electrical pulses. Its non‐volatility, high endurance, and fine‐tuning capability makes the device promising in large‐scale low‐power reconfigurable photonic processors.

Impact of Bias Temperature Instabilities on the Performance of Power Electronics Employing SiC MOSFETs

In this work a reliability study of SiC power MOSFETs working as switching elements in a DC-DC Boost converter circuit is discussed. A critical parameter for a high-performance operation is the stable characteristics of the transistors employed. However, charge trapping effects such as bias temperature instabilities can affect e.g. the threshold voltage of transistors and thus lead to a variation in circuit behavior and efficiency. Furthermore, a time-dependent drift of the threshold voltage (ΔVth) of the MOSFET over time can cause an increase of the on-resistance (RDS(ON)) too, and thus affect the static on-state power losses accordingly (PON). In this work, we use our physical reliability simulator Comphy to extract the threshold voltage drift of the transistor over time for various mission profiles for gate biases under device operation. Using the extracted ΔVth values from the simulator, we can reproduce the measured behavior of the DC-DC boost converter circuit. With the calibrated toolset, we can obtain the ΔVth values over a long operation time to predict the aged behavior of the circuit parameters employing Spice simulations, which could be beneficial for circuit design and lifetime prediction of the system.

Design and analysis of a new multi-level inverter topology with a reduced number of switches and controlled by PDPWM technique

With their many advantages, including low power dissipation in power switches, low harmonic content, and reduced electromagnetic interference (EMI) from the inverter, multilevel converter (MLI) topologies are becoming more and more in demand in high and medium power applications. This paper introduces a novel multi-level symmetric inverter topology with adopted control. The objectives of this article are to architecturally define the positions of the various switches, to choose the right switches and to propose an inverter control strategy that will eliminate harmonics while producing the ideal output voltage/current. By using fewer switching elements, fewer voltage sources, and switches with a total harmonic content (THD) which reduces losses and a drop in minimum voltage (Vstrssj), the proposed topology is more efficient than conventional inverters with the same number of levels. The new topology will be demonstrated using a seven-level single-phase inverter. For various modulation indices, MATLAB-SIMULINK is used to study and validate the topology.

A nine‐level T‐type inverter (9L‐TTI) with voltage boost capability

AbstractThis paper introduces a 9L T‐type boost inverter (9L‐TTI) based multilevel topology, which generates a nine‐level output voltage in the boost mode. This topology uses 12 switching elements alongside less voltage stress and one switched capacitor unit. This is the significant advantage of the mentioned topology. Following the discussion of the advantages of the provided design, a comparative study is conducted. This results in a reduction in device counts, cost‐effectiveness, and voltage stress on the devices. For switching scheme, fundamental switching frequency‐based modulation is incorporated by having nearest level control (NLC) technique. For proper validation of this work, it is also demonstrated through test results. Here the results are demonstrated at different load conditions, which include resistive and inductive loads. Further, it is demonstrated at different modulation indices and total harmonic distortion (THD) of converter voltage and current for RL‐load, is validated from the power quality improvement point.

Broadband 32 × 32 Strictly‐Nonblocking Optical Switch on a Multi‐Layer Si3N4‐on‐SOI Platform

AbstractLarge‐scale silicon optical switches are essential to support the ever‐increasing data traffic. Among the various switching architectures, the well‐known switch‐and‐select (S&S) architecture has the advantages of low crosstalk and strict non‐blocking. However, it suffers from high path‐dependent losses as the waveguide crossings increase dramatically with the number of ports. In this paper, a large‐scale 32 × 32 S&S optical switch on a multi‐layer Si3N4‐on‐SOI platform is reported. The optical switch chip incorporates 1984 broadband thermo‐optic Mach‐Zehnder interferometer (MZI)‐based switch elements, 246 016 three‐dimensional (3D) waveguide crossings, and 2048 interlayer couplers. Both ≈1‐mdB‐loss 3D waveguide crossings and ≈0.3‐dB‐loss interlayer couplers are realized, significantly reducing the overall insertion loss and footprint of the switch chip. The measured average fiber‐to‐fiber insertion loss is 12.88 dB at the 1580 nm wavelength. In addition, the crosstalk is less than −20.7 dB over the 110‐nm wavelength range. The power consumption of the entire switch chip is only ≈0.98 W due to the air trenches and substrate undercut. High‐fidelity optical transmission of a 50 Gb s−1 quadrature phase‐shift keying signal verifies the high‐performance routing capability of this chip. These results indicate that the large‐scale optical switch with broadband, low crosstalk, and high‐power efficiency is promising for datacenter optical network applications.

A novel e‐bike energy management for improvement of the rider metabolism

AbstractIn this study, a switch controller manages the power‐sharing between the battery and human mode to improve the rider's metabolism and manage the battery SOC. The main idea is to optimize this power source switching element for changing the status to reach a trade‐off between lack of tiredness and keeping the SOC high. Calorie burning is closely related to the rider's physical characteristics. In this paper, these parameters are investigated to calculate calorie burning. When the electric‐powered mode is activated, the SOC level comes down. When the human‐powered mode is activated, the human power source provides energy. The model converts the bicycle speed into the rider's heart rate and then changes it into burned calories based on some equations. These equations are obtained by poly fitting after experiments. This optimization causes 33.5% and 50% burning calorie reduction in Cleaveland and Portuguese driving cycles. Also, in the Portuguese driving cycle, the battery usage percentage decreases 39.56% from to 20.54% after optimization; therefore, the burning calorie decreases 265.84 Kcal to 176.83 Kcal.

Large-Area Electronics-Enabled High-Resolution Digital Microfluidics for Parallel Single-Cell Manipulation.

Large-area electronics as switching elements are an ideal option for electrode-array-based digital microfluidics. With support of highly scalable thin-film semiconductor technology, high-resolution digital droplets (diameter around 100 μm) containing single-cell samples can be manipulated freely on a two-dimensional plane with programmable addressing logic. In addition, single-cell generation and manipulation as foundations for single-cell research demand ease of operation, multifunctionality, and accurate tools. In this work, we reported an active-matrix digital microfluidic platform for single-cell generation and manipulation. The active device contained 26,368 electrodes that could be independently addressed to perform parallel and simultaneous droplet generation and achieved single-cell manipulation. We demonstrate a high-resolution digital droplet generation with a droplet volume limit of 500 pL and show the continuous and stable movement of droplet-contained cells for over 1 h. Furthermore, the success rate of single droplet formation was higher than 98%, generating tens of single cells within 10 s. In addition, a pristine single-cell generation rate of 29% was achieved without further selection procedures, and the droplets containing single cells could then be tested for on-chip cell culturing. After 20 h of culturing, about 12.5% of the single cells showed cell proliferation.

Integration of ZnO-Based Resistive-Switching Memory and Ge2Sb2Te5-Based Phase-Change Memory

Memristor devices exhibited many advantages, such as fast write/read speed, high storage density, low power consumption, and simple structure, which could be applied to 3D stacking. However, the sneak current during stacking would become a major issue in the development of 3D structures. In this study, we proposed an integrated structure, one phase-change memory one resistive random access memory (1P1R), to suppress the sneak current. The 1P1R device was always kept at [0 1] or [0 0] (logic state) with high resistance to suppress the sneak current, while it was switched to [1 1] or [1 0] (working states) to write/read its state. Phase-change memory acted as the switching element, and resistive random access memory acted as the memory. Our electrical measurement confirmed its feasibility, and the property analysis provided the information for its speculated mechanism. The results successfully demonstrated that the novel 1P1R structure could be used to suppress sneak current, demonstrating potential for 3D IC manufacturing.

Nanocellulose-Based Thermoplastic Polyurethane Biocomposites with Shape Memory Effect

In 2020, we published a review on the study of semi-crystalline thermoplastic polyurethane elastomers and composites based on the shape memory effect. The shape recovery ability of such polymers is determined by their sensitivity to temperature, moisture, and magnetic or electric fields, which in turn are dependent on the chemical properties and composition of the matrix and the nanofiller. Nanocellulose is a type of nanomaterial with high strength, high specific surface area and high surface energy. Additionally, it is nontoxic, biocompatible, environmentally friendly, and can be extracted from biomass resources. Thanks to these properties, nanocellulose can be used to enhance the mechanical properties of polymer matrices with shape memory effect and as a switching element of shape memory. This review discusses the methods for producing and properties of nanocellulose-based thermo-, moisture-, and pH-sensitive polyurethane composites. The synergistic effect of nanocellulose and carbon nanofillers and possible applications of nanocellulose-based thermoplastic polyurethane biocomposites with shape memory effect are discussed. A brief description of nanocellulose terminology is also given, along with the structure of shape memory thermoplastic polyurethanes. There is significant interest in such materials for three primary reasons: the possibility of creating a new generation of biomaterials, improving the environmental friendliness of existing materials, and exploiting the natural renewability of cellulose sources.

Ultra-low-loss multi-layer 8 × 8 microring optical switch

Microring-based optical switches are promising for wavelength-selective switching with the merits of compact size and low power consumption. However, the large insertion loss, the high fabrication, and the temperature sensitivity hinder the scalability of silicon microring optical switch fabrics. In this paper, we utilize a three-dimensional (3D) microring-based optical switch element (SE) on a multi-layer Si3N4-on-SOI platform to realize high-performance large-scale optical switch fabrics. The 3D microring-based SE consists of a Si/Si3N4 waveguide overpass crossing in the bottom and the top layers, and Si3N4 dual-coupled microring resonators (MRRs) in the middle layer. The switch is calibration-free and has low insertion loss. With the 3D microring-based SEs, we implement an 8×8 crossbar optical switch fabric. As the resonance wavelengths of all SEs are well aligned, only one SE needs to be turned on in each routing path, which greatly reduces the complexity of the switch control. The optical transmission spectra show a box-like shape, with a passband width of ∼69 GHz and an average on-state loss of ∼0.37 dB. The chip has a record-low on-chip insertion loss of 0.52–2.66 dB. We also implement a non-duplicate polarization-diversity optical switch by using the bidirectional transmission characteristics of the crossbar architecture, which is highly favorable for practical applications. 100 Gb/s dual-polarization quadrature-phase-shift-keying (DP-QPSK) signal is transmitted through the switch without significant degradation. To the best of our knowledge, this is the first time that 3D MRRs have been used to build highly scalable polarization-diversity optical switch fabrics.

DNMT3A-coordinated splicing governs the stem state switch towards differentiation in embryonic and haematopoietic stem cells.

Upon stimulation by extrinsic stimuli, stem cells initiate a programme that enables differentiation or self-renewal. Disruption of the stem state exit has catastrophic consequences for embryogenesis and can lead to cancer. While some elements of this stem state switch are known, major regulatory mechanisms remain unclear. Here we show that this switch involves a global increase in splicing efficiency coordinated by DNA methyltransferase 3α (DNMT3A), an enzyme typically involved in DNA methylation. Proper activation of murine and human embryonic and haematopoietic stem cells depends on messenger RNA processing, influenced by DNMT3A in response to stimuli. DNMT3A coordinates splicing through recruitment of the core spliceosome protein SF3B1 to RNA polymerase and mRNA. Importantly, the DNA methylation function of DNMT3A is not required and loss of DNMT3A leads to impaired splicing during stem cell turnover. Finally, we identify the spliceosome as a potential therapeutic target in DNMT3A-mutated leukaemias. Together, our results reveal a modality through which DNMT3A and the spliceosome govern exit from the stem state towards differentiation.

Design and Implementation of RF Resonant Inverter With Matching Circuit to Generate Plasma for Possible Endoscopy Sterilization

This research focuses on the design and implementation of an RF resonant inverter with a matching circuit to generate plasma for possible endoscopy sterilization. The circuit topology is a half-bridge inverter with the operating frequency of 13.56 MHz. The soft switching is achieved by the matching circuits and resonant network to reduce switching loss. Conventionally, an RF power amplifier associated with an automatching circuit is used to match the chamber to 50 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $</tex-math> </inline-formula> , which will be presented in detail as a reference. Alternatively, the half-bridge inverter is designed to identify the chamber impedance, and therefore, the CLCL matching circuits can be designed to match the chamber. The matching circuits were designed based on chamber-impedance measurement to obtain the first point, and through Smith Chart, one can reach the destination, 50 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $</tex-math> </inline-formula> , point by point to determine a set of CLCL component values. The overall system is verified with a 300-W half-bridge inverter using GaN MOSFET switching elements.

Regulated control of virus replication by 4-hydroxytamoxifen-induced splicing.

Designing a modified virus that can be controlled to replicate will facilitate the study of pathogenic mechanisms of virus and virus-host interactions. Here, we report a universal switch element that enables precise control of virus replication after exposure to a small molecule. Inteins mediate a traceless protein splicing-ligation process, and we generate a series of modified vesicular stomatitis virus (VSV) with intein insertion into the nucleocapsid, phosphoprotein, or large RNA-dependent RNA polymerase of VSV. Two recombinant VSV, LC599 and LY1744, were screened for intein insertion in the large RNA-dependent RNA polymerase of VSV, and their replication was regulated in a dose-dependent manner with the small molecule 4-hydroxytamoxifen, which induces intein splicing to restore the VSV replication. Furthermore, in the presence of 4-hydroxytamoxifen, the intein-modified VSV LC599 replicated efficiently in an animal model like a prototype of VSV. Thus, we present a simple and highly adaptable tool for regulating virus replication.

Conducting Polymer Switches Permit the Development of a Frequency-Reconfigurable Antenna

Conjugated polymers (CPs) undergo a wide range of reversible intrinsic property changes including electrical conductivity, electromagnetic absorption, volume, and charge mobility upon electrochemical oxidation/reduction, which has made them popular as ON/OFF organic-based switchable materials. Recent studies on the insulating-to-conductive transition within CPs have paved the way for a next generation of flexible switches that permit the creation of “dynamic” electric circuits. Here, we present an approach to a low-voltage, low-power electrochemically controllable, switchable, and printable CP-based conductive element that acts as a platform for the configuration of frequency-reconfigurable radiative antennas. We demonstrate that the DC conductivity of a soluble PEDOT derivative, PE2, film can be switched electrochemically by 4 orders of magnitude across large insulating gaps up to 15 mm within 20 s. Its integration in a DC switching element that is incorporated along the poles of a half-wave dipole antenna structure is able to generate an AC resonant frequency switch, and thus a radiation frequency shift, in the microwave (i.e., 1–2 GHz) range. This type of printable antenna fills an important need for the demand of bandwidth that is growing beyond the crowded frequency spectrum, by relying on the development of frequency-reconfigurable antenna systems capable of dynamically tuning their spectral properties when desired.

A Reconfigurable Frequency Selective Surface for Wi-Fi Application

This work presents the development of a reconfigurable frequency selective surface (RFSS) for application in the 2400-2483.5 MHz band, standard IEEE 802.11b/g/n (Wi-Fi). The proposed RFSS is based on the four-arms star geometry and PIN diodes were used as switching elements. In the initial design, numerical and measured results, especially for y polarization, PIN diode on-state, shown a difference of 15% for the resonant frequency. To overcome this drawback, a scaling factor was adopted and RFSS was redesigned and characterized, achieving the desired frequency response. The RFSS reconfigurability is confirmed, with a variation of at least 15 dB, when switching the states of the PIN diode. Moreover, the signal strength was measured directly on a notebook, confirming the reconfiguration of the RFSS. Finally, for the y polarization, it was found that for this polarization the frequency response remains virtually unchanged, even for angles of incidence up to 45°. In addition to the Wi-Fi signal control, the observed features make the developed RFSS especially attractive for reconfigurable antennas applications.

A rationally designed optochemogenetic switch for activating canonical Wnt signaling

Accurate spatiotemporal control of multicellular self-organization by various signaling pathways is essential for developmental stages. In particular, evolutionarily conserved Wnt signaling serves as a major morphogenetic switch to determine the anteroposterior axis of the embryo. Here, we developed a genetically encoded optochemogenetic Wnt switch, named optochemoWnt, by coupling a blue light-inducible CRY2olig and rapamycin-inducible LRP6c clustering. The rationally designed optochemoWnt successfully modulated Wnt signaling with AND-gated patterns and demonstrated an improved signal-to-noise ratio (SNR). The dual-triggered switch provides a safeguard to prevent signal leakage resulting from ambient light sources under general laboratory conditions. OptochemoWnt expands the molecular toolbox available for the fields of developmental biology and tissue engineering. In addition, the AND-gated strategy of optochemoWnt may be used for other biomedical applications that integrate user defined switch elements with Boolean logic gates.

Voltage-Controlled Fast and Low-Loss Single-Photon Cross-Bar Switch Using Integrated Photonics

A high-speed, low-loss modular cross-bar switching element suitable for single photons is demonstrated. Entanglement preserving voltage-driven switching of single photons is achieved with a unique combination of ultra-fast and low-loss characteristics (less than 50 ps 10%–90% transition time and greater than 90% transmission), and we present a roadmap towards even lower losses. The switch properties are well matched to the wavelength, bandwidth and lifetime of photons generated by spontaneous four-wave mixing sources also realized in silicon photonics. Such a switch can enable reconfigurability of each single photon and addressing of each time bin, and benefit future quantum photonic circuits.

Smith predictor–based sliding mode control with hyperbolic tangent function for unstable processes

In this work, a modified Smith predictor–based sliding mode control (SP-SMC) method is proposed for unstable plus time-delay processes. Sliding mode control has a discontinuous part in its control law which may cause chattering in the control signal if conventional switching strategy is used. A hyperbolic tangent function is employed as a switching element in the suggested SP-SMC technique to minimize the chattering effect. Optimal values of the controller’s unknown parameters are obtained using whale optimization algorithm which is a meta-heuristic technique. The process model used in the proposed Smith predictor control architecture is identified using measurements of limit cycle output which is obtained from online relay test. The proposed controller is found to be robust towards process parameter uncertainties and load disturbance. Suggested control technique results in fast set-point tracking response and significantly improved disturbance rejection performance compared to some other related methods.