Comprehensive Design Guidelines Research Articles

Iterative printing of bulk metal and polymer for additive manufacturing of multi-layer electronic circuits

In pursuing advancing additive manufacturing (AM) techniques for 3D objects, this study combines AM techniques for bulk metal and polymer on a single platform for one-stop printing of multilayer 3D electronic circuits with two novel aspects. The first innovation involves the embedded integration of electronic circuits by printing low-resistance electrical traces from bulk metal into polymer channels. Cross-section grinding results reveal (92 ± 5)% occupancy of electrically conductive traces in polymer channels despite the different thermal properties of the two materials. The second aspect encompasses the possibility of printing vertical bulk metal vias up to 10 mm in height with the potential for expansion, interconnecting electrically conductive traces embedded in different layers of the 3D object. The work provides comprehensive 3D printing design guidelines for successfully integrating fully embedded electrically conductive traces and the interconnecting vertical bulk metal vias. A smooth and continuous workflow is also introduced, enabling a single-run print of functional multilayer embedded 3D electronics. The design rules and the workflow facilitate the iterative printing of two distinct materials, each defined by unique printing temperatures and techniques. Observations indicate that conductive traces using molten metal microdroplets show a 12-fold reduction in resistance compared to nanoparticle ink-based methods, meaning this technique greatly complements multi-material additive manufacturing (MM-AM). The work presents insights into the behavior of molten metal microdroplets on a polymer substrate when printed through the MM-AM process. It explores their characteristics in two scenarios: When they are deposited side-by-side to form conductive traces and when they are deposited out-of-plane to create vertical bulk metal vias. The innovative application of MM-AM to produce multilayer embedded 3D electronics with bulk metal and polymer demonstrates significant potential for realizing the fabrication of free-form 3D electronics.

Physical Modelling Of The Wave Field Around An Array Of Centrally Controlled Wave Energy Converters

Stepped revetments have shown to be effective in limiting wave overtopping and wave run-up compared to sloped revetments. However, literature on wave impact pressures and comprehensive design guidelines for these structures is scarce. Laboratory experiments support establishing design recommendations. So far, studies for wave impacts at stepped revetments were mainly performed at small scales. Results from these tests are likely to be subjected to scale effects and therefore inaccurately replicate the wave-structure interaction at full scale. This study quantifies scale effects of wave impact characteristics for design cases based on a comparison to small-scale tests (Kerpen et al., 2018). Full-scale flume experiments were studied with a slope of 1:3 and uniform step heights of 0.17 m and 0.50 m in the Large Wave Flume (GWK) in Hannover, Germany. Horizontal and vertical wave impacts were measured at 15 locations in the plunging region of the revetment for a range of wave steepnesses (). The results show that previous small-scale tests underestimate design wave impact pressures by a factor of up to 7.7. Impact loadings occur considerably faster than at small scale with relative peak rising times decreasing by a factor of up to 5.6. Prediction formulae are derived for the vertical distribution of horizontal impact pressures (Figure 1b) as well as for temporal characteristics of these pressures at stepped revetments.

Utilizing Ragone framework for optimized phase change material-based heat sink design in electronic cooling applications

This study explores the latent thermal energy storage potential of an organic phase change material with porous copper foam and its applicability in electronic cooling under varying heat load conditions. The organic phase change material, n-eicosane, is known for its inherently low thermal conductivity of 0.15 W/mK, rendering it vulnerable during power spikes despite its abundant latent heat energy for phase transition from solid to liquid. Porous copper foams are often integrated into n-eicosane to enhance the composite's thermal conductivity. However, the volume fraction of the phase change material in the porous foam that optimally improves the thermal performance can be dependent on the boundary condition, the cut-off temperature, and the thickness. A finite difference numerical model was developed and utilized to ascertain the energy consumption for the composite of n-eicosane with two kinds of porous copper foam with varying porosity under different heat rates, cut-off temperatures, and thickness. In addition, the results are compared with a metallic phase change material (gallium), a material chosen with a similar melting point but significantly high thermal conductivity and volumetric latent heat. For validation of the numerical model and to experimentally verify the effect of boundary condition (heat rate), experimental investigation was performed for n-eicosane and high porosity copper foam composite at varying heat rates to observe its melting and solidification behaviors during continuous operation until a cut-off temperature of 70 °C is reached. Experiments reveal that heat rate influences the amount of latent energy storage capability until a cutoff temperature is reached. For broad comparison, the numerical model was used to obtain the accessed energy and power density and generate thermal Ragone plots to compare and characterize pure gallium and n-eicosane - porous foam composite with varying volume fractions, cutoff temperature, and thickness under volumetric and gravimetric constraints. Overall, the proposed framework in the form of thermal Ragone plots effectively delineates the optimal points for various combinations of heat rate, cut-off point, and aspect ratio, affirming its utility for comprehensive design guidelines for PCM-based composites for electronic cooling applications

Impacts of distributed thermal and electric contact resistance on performance and geometric optimization of thermoelectric generators

Thermal and electric contact resistance (TCR/ECR) critically impact performance and geometric optimization of thermoelectric generators (TEGs). However, conventional treatments usually ignored or simplified them as lumped variables, neglecting their actual distributions across the TEG system. In this study, we proposed a multi-physical model to characterize TEG performance with explicitly specifying TCRs/ECRs at different TEG interfaces (locations). The numerical results show that the lumped-variabletreatment led to maximal overestimations of 16.9 % and 24.5 % in the TEG output power and efficiency, respectively, compared to the results with distributed TCR in this article. Importantly, it also reveals that the TEG performance was susceptible to the TCR location—the interfaces on the cold side exerted more negative impacts than those on the hot side. Furthermore, reducing both TCR and ECR could improve TEG performance and reducing TCR is more effective. It is shown that an 80 % reduction in TCR increased the maximum TEG output power by 35.6 %, while the same reduction percentage in ECR only improved it by 8.8 %. As to geometric optimization, an optimal TE leg height equal to 0.6 mm was obtained for the maximum output power. This contrasts with previous studies without considering TCR and ECR, which always favoured shorter heights. As for copper electrodes, their optimal heights were in the range of 0.2–0.4 mm corresponding to the maximum efficiency, far smaller than those (0.7–1.2 mm) obtained when TCR/ECR were neglected. The latter even further resulted in a reduction in the maximum efficiency by more than 1 % compared to its true peak. In this study, all these numerical results clearly elucidate the important impacts of distributed TCR and ECR on TEG performance, and provide a comprehensive and balanced guideline for TEG design.

Aeroelastic metastructure for simultaneously suppressing wind-induced vibration and energy harvesting under wind flows and base excitations

This paper proposes an innovative dual-functional aeroelastic metastructure that effectively suppresses wind-induced structural vibrations under either pure aerodynamic galloping or concurrent galloping and base excitations, while simultaneously harnessing the vibratory energy to potentially allow for self-powered onboard low-power sensing applications. Two configurations are theoretically and experimentally analysed and compared, one consisting of simply regular locally resonating masses subjected to no external forces, while the other comprising locally resonating bluff bodies which experience additional aerodynamic galloping forces. Numerical investigation is conducted based on an established aero-electro-mechanically coupled model. Wind tunnel wind tunnel and base vibration experiments are carried out using a fabricated aeroelastic metastructure prototype to characterize the energy transfer mechanisms and validate the numerical results. The mutual effects of key system parameters, including the frequency ratio, mass ratio, load resistance and electromechanical coupling strength, on the dual-functional capabilities are examined, providing a comprehensive design guideline for efficiently enhancing the energy transfer and conversion. Experimentally, the galloping displacement of the primary structure is attenuated by 78% with a measured power output of 2.63 mW from a single auxiliary oscillator at a wind speed of 8 m s−1. This research opens new possibilities for designing novel metastructures in practical scenarios where both wind-induced vibration suppression and energy harvesting are crucial.

Advancements in Fiber-Reinforced Polymer Composites: A Comprehensive Analysis.

Composites made from fiber-reinforced polymers (FRPs) are a crucial and highly adaptable category of materials widely utilized in numerous fields. Their flexibility and the range of criteria for classification enable the creation of tailored solutions to address distinct requirements in sectors such as civil engineering, aerospace, automotive, and marine, among others. The distinguishing characteristics of FRP composites include the type of reinforcing fiber used, the composition of the matrix material, the employed manufacturing process, the orientation of the fibers, and the specific end-use application. These classification variables offer engineers a versatile structure to determine and select the most appropriate materials and production techniques for their specific needs. Furthermore, the present study aims to reunite the criteria of classification for FRPs and specific manufacturing technologies of FRPs, such as conventional ones (matched die molding, contact molding), automated ones (filament winding, tape lay-up, and fiber placement), and advanced ones (electrospinning and additive manufacturing),with the chronological development of FRPs, insights on material characteristics, and comprehensive design guidelines based on their behavior in different environments of use.

Design guidelines for sustainable utilization of agricultural appropriate technology: Enhancing human factors and user experience

Abstract The utilization of appropriate technology (AT) has become the Indonesian government strategy to increase productivity of agricultural commodities due to its simplicity and cost-effectiveness. However, the current utilization of AT remains suboptimal mostly due to design deficiencies that insufficiently account for human factors and user experience. In response, the aim of this study is to establish comprehensive AT design guidelines for sustainable AT utilization, focused on agricultural processing machines. An intensive observation was initially conducted in a rural community in Indonesia, to summarize difficulties faced by AT users. Supported by an exhaustive review of literature, a total of 44 human factors related design criteria were defined. Subsequently, these criteria underwent rigorous validation through a questionnaire administered to 197 respondents, consisting of AT designers, experts, and users. Employing the framework of principal component analysis (PCA), novel dimensions of AT design criteria were suggested, encompassing safety and error prevention, functionality and economics, user-friendly, low physical effort, physical workspace compatibility, and perceptible information. To augment the insights gleaned from the PCA, a matrix of importance-performance analysis was created, affording a map of the relative significance and concurrent performance of the defined criteria. The implications of this study are further discussed.

Criteria for the Dyslexic Games: A Systematic Literature Review

The advancement of technology has witnessed the increasing use of game-based intervention and it is proven beneficial for people with specific learning disorder such as Dyslexia. Initially developed for entertainment, a game is generally considered a tool with the key features of challenge, motivation, and rewards which add more fun and excitement to Dyslexia teaching and learning. Many game applications have been developed in the area; each incorporates several criteria to meet the specific needs of the dyslexics. To date, these criteria are still dispersed in numerous publications, leading to the duplication of basic games that have previously been developed by others. This study aimed to identify the dispersed criteria by adopting PRISMA approach in the systematic literature review, and analyze them to formulate a comprehensive guideline for future design and development of the dyslexic games. Five main databases were chosen which are Scopus, ACM Digital Library, EBSCO-host, Wiley and Web of Science (WOS). Out of 551 articles that have been screened, only 50 articles were eligible to be analyzed based on the relevancy to the criteria, and only 23 articles were included in the study after further screening. A total of 135 criteria were identified with some redundancies, and were further classified into four categories: device and platform; features; interface and gameplay. These criteria can be utilized by the educational game developers as reference when designing the dyslexic games. A better dyslexic-friendly games could be produced when the developers design it with their special learning needs in mind.

Nonisolated Dual-Output Single-Phase Boost Inverter With Reduced Active and Passive Components

This article proposes a nonisolated dual- output single-phase boost inverter with reduced active and passive components. The suggested inverter can serve two single-phase ac loads independently like two full-bridge inverters, but owing to the use of a pair of three-switch legs in the inverter bridge, it has a 25% reduction in active switches. The proposed inverter is capable of obtaining a boost output voltage while employing fewer passive components compared to the traditional impedance source inverter. And the high-frequency current commutation problem of diodes in the traditional split-source inverter is solved by replacing the diodes with two complimentary switches. A hybrid sinusoidal and constant pulsewidth modulation control strategy is elaborated, which enables the proposed inverter to operate in equal frequency mode and different frequency mode. Comprehensive working principles, modulation strategy, steady-state analysis, and parameter design guideline are introduced, both simulation and experimental results are presented to confirm the characteristics of the proposed topology.

Signal-to-Noise Ratio Optimization for Planar Multijunction Thermal Converters

We investigate a comprehensive design guideline for optimizing the signal-to-noise ratio (SNR) of planar multijunction thermal converters (MJTCs). Optimizing the leg-length of the thermocouple using a shunted copper patch facilitates an increase in the sensitivity to more than twice that of a conventional thermocouple when the device fulfills the thermal impedance matching condition. The SNR does not depend on the thermocouple number or the leg cross-section at a fixed total cross-sectional area. Finally, during thermocouple material selection, different combinations of three thermophysical parameters, the Seebeck coefficient, electrical resistivity, and thermal conductivity, that provide the same figure of merit would lead to different values of the SNR. For improving the SNR, increasing the Seebeck coefficient is the most desirable approach. The reduction of thermal conductivity is desirable for short leg-lengths, whereas increasing the electrical resistivity is better for long leg-lengths. The findings provide a useful guide to design optimal planar MJTCs by maximizing the SNR.

The Art of Substrate-Integrated-Waveguide Power Dividers

Substrate-integrated-waveguide (SIW) technology can eliminate the limitations associated with conventional rectangular waveguides, i.e., bulky structures and production complexity at higher frequencies. Moreover, SIW technology replaces microstrip structures eliminating the drawback of excessive radiation leakage at higher frequencies. SIW power dividers are key elements in SIW antenna array synthesis. A SIW power divider’s design procedures are more complicated than conventional microstrip power dividers. However, no comprehensive review with design guidelines of substrate-integrated-waveguide (SIW) power dividers has been reported. In this paper, different types of SIW power dividers based on their configurations, functionality, and operating principles are analyzed and some recommendations are made for selection purposes. A comprehensive design guideline for SIW power dividers is given in this paper through a comparative study of T- and Y-type SIW junctions. These guidelines are based on key parameters, including insertion loss, isolation, co-phase bandwidth, return loss bandwidth, and phase balancing. This study provides valuable information for selecting and designing the best possible configuration of SIW power dividers for specific applications in microwave and millimeter-wave frequency ranges. A case study of a Ku-band SIW power divider is performed for a Ku-band soil moisture radiometer SIW antenna array.

A Comprehensive Design Guideline of Hairpin Windings for High Power Density Electric Vehicle Traction Motors

The rapidly increasing demand on power density levels of electric vehicle (EV) drive systems is pushing the boundaries of traction motor performance. Hairpin windings are becoming a popular option for EV motors due to their reduced dc losses and improved heat dissipation capability when compared to traditional random windings. In this article, a comprehensive design approach of hairpin winding layouts is first presented. The flexibility and limitation of end-winding patterns are thoroughly investigated in terms of basic pin connections, special jumpers, transposition, parallel branches, terminal positions, phase shift, winding pitches, as well as slot–pole combinations. To address the challenge of much reduced practical layout options with increased slot number per pole per phase, two novel hairpin winding designs are proposed. A 160-kW, 18 000-r/min permanent magnet (PM) traction motor featuring the new winding layout with 54-slot, 6-pole is developed using a multidomain design platform, which puts special focus on the conductor size optimization. The advantages of the designed motor are clearly revealed by comparison with the more traditional 48-slot, 8-pole counterpart. Finally, a corresponding stator prototype with the proposed hairpin winding is built to validate its manufacturability.

Design of a Highly Efficient 20-kW Inductive Power Transfer System With Improved Misalignment Performance

Due to the urgent desire for a fast, convenient, and efficient battery charging technology for electric vehicle (EV) users, extensive research has been conducted into the design of high-power inductive power transfer (IPT) systems. However, there are few studies that formulate the design as a multiobjective optimization (MOO) research question considering both the aligned and misaligned performances and validate the optimal results in a full-scale prototype. This article presents a comprehensive MOO design guideline for highly efficient IPT systems and demonstrates it by a highly efficient 20-kW IPT system with the dc–dc efficiency of 97.2% at the aligned condition and 94.1% at 150-mm lateral misalignment. This achievement is a leading power conversion efficiency metric compared to IPT EV charging systems disseminated in today’s literature. Herein, a general analytical method is proposed to compare the performances of different compensation circuits in terms of the maximum efficiency, voltage/current stresses, and misalignment tolerance. An MOO method is proposed to find the optimal design of the charging pads, taking the aligned/misaligned efficiency and area/gravimetric power density as the objectives. Finally, a prototype is built according to the MOO results. The charging pad dimension and total weight, including the housing material, are 516*552*60 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> /25 kg for the transmitter and 514*562*60 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> /21 kg for the receiver. Correspondingly, the gravimetric, volumetric, and area power density are 0.435 kW/kg, 581 kW/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , and 69.1 kW/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , respectively. The measured efficiency agrees with the anticipated value derived from the given analytical models.

Fracture and dynamic mechanical analysis of seawater aged aluminum-BFRP hybrid adhesive joints

Adhesively bonded hybrid FRP-aluminium structures have recently become an efficient solution for marine engineering applications. However, polymer adhesives' bond performance is sensitive to the marine environment due to polymer and interfacial degradation. This study aims to develop mode I, mode II delamination toughness, and Tg data as a comprehensive design guideline for hybrid BFRP-aluminum modified-adhesively bonded joints subjected to seawater aging. The hybrid joints were exposed to long-term seawater aging (for 6 months) to reveal their fracture and thermomechanical performances. Besides, the adhesive was reinforced with HNTs to increase fracture resistance with additional nano-scale toughening mechanisms and to delay the water absorption. After the long-term aging, reinforced adhesively bonded joints exhibited ∼36% higher fracture toughness than neat adhesively bonded joints. Moreover, DMA was conducted on miniaturized SLJ samples, which revealed that HNT modified adhesive joints showed ∼11.5 °C higher Tg. The calculated aging rates also proved the effectiveness of HNTs modification on the epoxy adhesive’s aging performance since the HNT reinforced adhesive represented 43% lower aging rates in terms of storage modulus. It is considered that experimental results will help comprehend long-term aging influences on the composite-aluminum hybrid designs’ fracture and thermomechanical performances. These exciting findings will pave the way for the safe use of high stiffness and cost-effective aluminum-BFRP hybrid structures for the marine industry.

Development of novel design strength model for sustainable concrete columns: A new machine learning-based approach

Billions of tons of construction and demolition (C&D) waste generation is causing global environmental crises. The application of C&D waste in concrete columns is a sustainable avenue but hindered due to a lack of comprehensive design guidelines. Currently, no work is available in the open literature regarding the machine-learning-based comprehensive design strength models of spiral steel confined natural aggregate concrete (SSCNAC) and recycled aggregate concrete (SSCRAC) columns. This study comprehensively evaluates ten machine-learning techniques, including random forest, gradient boost, Ada boost, k-nearest neighbor, bagging regressor, support vector, XG boost, decision tree, artificial neural network, and gene expression programming for design strength modeling of SSCNAC and SSCRAC columns. A test database comprising 290 experiment results is developed and used for modeling. The accuracy of models is improved using hyper-parameter tuning and cross-validation functions. The performance of machine-learning techniques is evaluated through various statistical parameters. Results indicate that the spiral steel strength and the unconfined concrete compressive strength are the most critical inputs to predict the design strength of SSCNAC and SSCRAC columns. All the machine-learning models can accurately predict the design strength of SSCNAC and SSCRAC better than the existing models and can be practical tools for the accurate design strength modeling of the SSCNAC and SSCRAC. A one of its kind of a comprehensive machine learning-based design equation is proposed in this study, which can be used to predict the design strength of SSCNAC and SSCRAC accurately, leading towards the sustainable design of eco-friendly concrete columns.

Inorganic additive-incorporated composites with infrared radiation performance for thermal management

PurposePersonal thermal management in functional textiles is in increasing demand for health care, outdoor activity and energy saving. Thus, developing new strategies is highly desired for radiative cooling and/or heating by manipulation of the transmissivity, reflectivity and absorptivity of the textiles within solar energy and human body heat radiation ranges.Design/methodology/approachInorganic additives including TiO2, Fe2O3, carbon black (CB), graphene and mica were incorporated into polymer films. The inorganic additives' full spectrum properties and thermal responses were comprehensively investigated.FindingsThe CB composite film showed the highest absorptivity over the full solar to human body radiation spectrum. The mica-white (mica-w) (mica coated with TiO2) and mica-red (mica-r) (mica coated with Fe2O3) composites showed the lowest solar energy absorptivity and a strong body heat radiation reflectivity. Furthermore, according to composites' thermal responses to the simulated solar and human body radiations, CB and mica are promising for both cooling and heating when applied in dual-functional thermal management textiles.Research limitations/implicationsResearch has limitation related the amount of additives which can be added to textile. When powder is added to polyester yarn, the amount is limited by 2–3%. When powder is added to the composite which is used for printing, the amount of powder is limited by 5%.Practical implicationsA lot of apparel, especially sport apparel, contains prints. Decoration is one part of print application. Now, a lot of companies work under development of different additives, which provide additional properties to apparel. The closest targets for powder added to prints are cooling and heat retention. Quite often, inorganic additives possess dual properties: the inorganic additives may be heat reflective which his needed for heat retention, but may have high-thermal conductivity, which works well for cooling. Human body has complicated mechanism of heat exchange: convection, radiation and moisture evaporations play main role. The same additive may be cooling if there is a contact with skin but may be heating (IR reflective) if placed in the second or third layer. Thus, effect is needed to be studied first before real application.Originality/valueThis work could provide a comprehensive guideline for the rational design and application of thermal management composite textile materials by revealing the full solar to human body radiation performance of a series of inorganic materials.

Modeling of water-PCM solar thermal storage system for domestic hot water application using Artificial neural networks

• Artificial Neural Network model of solar thermal storage for hot water application. • Framework to develop and optimize the artificial neural network model parameters. • Validated numerical model used to train and test the artificial neural network model. • Artificial neural network model outperforms traditional regression modeling. • Neural network model yields five orders improvement in the computational time. • Optimized model-generated design map for the solar thermal storage system. Numerical modeling of solar thermal storage systems is often challenged with limitations on the computational effort due to their transient non-linear behavior that dictates accurate modeling of the physics over long-term operations (i.e., annual). Such challenges result into scarcity of literature on comprehensive design guidelines for solar thermal storage systems. This study presents a framework through which the potential of artificial neural network (ANN) modeling of a hybrid solar thermal storage system involving phase change materials is extensively investigated. An experimentally validated numerical model for the system is used to generate the training and testing datasets for the ANN model. The effect of changing the sampling method and the number of training samples is studied on the ANN model prediction. The results show that Sobol sequence sampling is superior to other sampling methods especially for low number of samples. The best sampling method is utilized to generate the training dataset with which the hyperparameters of the learning algorithm are optimized. The optimized ANN model is ultimately used to predict the system solar fraction under various design conditions to develop design maps that offer better visualization and sizing guidelines for the hybrid solar thermal storage systems. ANN is shown to offer a potential candidate for accurate and computationally efficient modeling of complex thermal systems. Upon proper configuration and training, the ANN model can accurately (i.e., a coefficient of determination of 0.9999) predict the performance of the hybrid thermal storage system with approximately five orders of magnitude reduction in computational time compared to conventional numerical models.

Development of a Comprehensive Design Guideline to Evaluate the User Experiences of Meal-Assistance Robots considering Human-Machine Social Interactions

ABSTRACT Meal-assistance robots (MARs) help feed meals to users with disabilities or who need help consuming their meals. Although such MARs have been introduced in various fields, guidelines for evaluating MARs are limited. This study aims to develop comprehensive guidelines to assess the user experience (UX) of MAR designs considering its social interaction characteristics between humans and robots. Participants from three groups (patients, doctors, and caregivers) with different perspectives on MARs were recruited and a focus group interview was conducted to collect their UXs with MARs. The three groups showed different UXs with MARs in user interface design, robot arm motion, and safety and mobility. In addition, based on the literature review, eight UX features (usability, emotion, value, naturalness, assistance, acceptance, personality, and culture) are proposed to evaluate MAR interfaces. The proposed comprehensive design guideline will be particularly useful in evaluating and designing the UX of MARs.

Comprehensive Analysis and Improvement Methods of Noise Immunity of Desat Protection for High Voltage SiC MOSFETs With High DV/DT

This paper comprehensively analyzes desaturation (desat) protection for high voltage (>3.3 kV) silicon carbide (SiC) MOSFETs and especially how to build in noise immunity under high <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dv/dt</i> . This study establishes a solid foundation for understanding the trade-offs between noise immunity and response speed of desat protection. Two implementations of the desat protection for high voltage SiC MOSFETs are examined, including desat protection based on discrete components and desat protection realized with a gate driver integrated circuit (IC). Both positive <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dv/dt</i> and negative <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dv/dt</i> are investigated. Analysis results show that the high <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dv/dt</i> with long duration caused by high voltage SiC MOSFETs’ switching results in strong noise interference in the desat protection circuitry. The impact of numerous influencing factors is investigated analytically, such as parasitic capacitances, parasitic inductance, damping resistance, and clamping impedance. Under high positive <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dv/dt</i> , extremely small parasitic capacitances (<0.01 pF) between the drain terminal and protection circuitry could still compromise noise immunity of the desat protection circuitry that has a high-impedance voltage divider. Comprehensive design guidelines are summarized to boost the noise immunity, including circuit design, component selection, and PCB layout. The noise immunity margin under the positive <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dv/dt</i> is also derived quantitatively to guide the noise immunity improvement. The noise immunity analysis results and noise immunity improvement methods are validated with simulation and experimental results obtained from a phase leg based on 10 kV/20 A SiC MOSFETs.

Built-in Ring Transmission Line Structure for Signal Integrity Optimization of PAM4 Signaling in PCBs

In this article, we propose a built-in ring differential transmission line for four-level pulse amplitude modulation (PAM4) signal integrity optimization. An optimized ring structure, which comes from the simplistic idea to leverage the voltage produced by near-end crosstalk inside the ring, is attached at the end of the transmission line to improve the eye diagram. Additionally, we introduce the comprehensive design guideline with analytically derived formulas that is beneficial to designers to obtain an accurate design without significant effort. The proposed structure is implemented on a 100 mm transmission line, six-layer printed circuit board. The proposed structure can achieve an improvement of up to 32.9% eye height with a 4 Gsps PAM4 signal.