Mathematical Modeling of EMI Spectrum Envelope Based on Switching Transient Behavior

The high frequency capability and low on-state losses of Gallium Nitride (GaN) transistors offer the potential to increase converter efficiency and/or reduce heatsink and passive component size. This paper investigates the use of GaN technology to enhance the performance of power factor correction (PFC) and LLC converters for battery charging applications. First the efficiency performance of non-isolated PFC converters using GaN transistors is compared by simulation, the asymmetric bridgeless PFC converter is shown to achieve the best efficiency, with a predicted figure of 99% in a 1MHz, 200W design. The predictions are validated by an experimental prototype using a GS66502B, GaN Systems E-mode GaN transistor. Then the efficiency comparison of the PFC and LLC converter using GaN devices for battery charging applications is included in the paper. The experimental results of the PFC converter with GaN devices are also included. Additionally, this paper includes the analysis and design of a common mode input filter for the GaN-based high frequency converters for battery charging application. The size of both the converters using GaN devices is reduced by 40% than the converters based on Si devices. The switching loss comparison of GaN and Si devices are also included in the paper.

The development of wide bandgap (WBG) devices in recent years, such as silicon carbide (SiC) and gallium nitride (GaN) power devices, has resulted in power converters with power densities and efficiencies that are not possible with traditional silicon (Si) devices. While the fast switching speed of WBG devices enables higher converter efficiency and power density, a number of issues are created such as increased sensitivity to parasitics, EMI noise, high voltage and current overshoot and ringing, and heat centralization in semiconductor devices. Resonant and soft-switching techniques can be effective in resolving these issues and allow even higher power densities and efficiencies to be achieved.

Wide bandgap (WBG) devices offer the advantages of high frequency, high efficiency, and high power density to power converters due to their excellent performance. However, their low parasitic capacitance and fast switching speed also make them more susceptible to switching oscillations. The switching oscillations can cause voltage and current overshoots, shoot-through, electromagnetic interference, additional power loss, and even device damage, which can seriously affect the performance of power converters and systems. However, a comprehensive and in-depth overview is lacking on this topic. This article reviews the types, the causes and negative effects, the effects of parasitic parameters and suppression methods of these switching oscillations, which is helpful for practical engineering. First, the switching oscillations are divided into different types, and their causes and negative effects are reviewed. Then, the effects of different parasitic parameters on the switching oscillations are overviewed. It is found that due to the different physical structures of silicon carbide metal-oxide-semiconductor field-effect transistors, enhancement-mode gallium nitride high-electron mobility transistors (eGaN HEMTs), and cascode GaN HEMTs, the effects are also different. Finally, the main methods of suppressing the switching oscillations are summarized, and the advantages and disadvantages of these methods are presented. Furthermore, future research works on this topic and the conclusion of this paper are drawn, which will help readers deepen their understanding of the switching oscillations of WBG devices, and inspire readers to better use WBG devices for high-frequency and high-efficient power conversion.

Gallium Nitride (GaN) and Silicon Carbide (SiC) power devices are segmented in the Wide Bandgap (WBG) device market: GaN devices are suitable for high-frequency but low-voltage applications; SiC devices are suitable for low-frequency but high-voltage applications. Cascoding a GaN HEMT and a SiC JFET best utilizes the advantages of both of these WBG power devices. Like GaN devices, the cascode GaN/SiC device is easy to drive at high frequencies and has low gate loss; like SiC devices, it also has relatively high voltage rating and low C oss energy loss at high frequencies. In previous studies, power circuits using the cascode device achieved higher power density than circuits using only a SiC device but efficiency similar to that of a SiC device [1]. In this paper, we present our investigation of the gate loss mechanism of the SiC JFET in the cascode structure and our finding that the loss can be greatly reduced by minimizing the gate resistance of the SiC JFET (R g,Jfet ). Simulation results showed that reducing R g,Jfet from 6 Ω to 1 Ω at 13.56 MHz leads to a 5× loss reduction, and experimental data verified the simulation trend. Here we provide a simple guideline to optimize the cascode GaN/SiC device and achieve better performance in high-frequency and high-voltage applications.

It is only recently that the electric vehicle (EV) has evolved into a contemporary invention. There has been a rapid acceleration in the development of EVs in a number of nations in order to lessen their reliance on oil and their contribution to environmental pollution. In the tangible world, fully EVs do not release any carbon dioxide (CO2) emissions from their tailpipes, unlike any other conventional vehicles. This results in a 50%–70% CO2 reduction in air pollution per year. The achievement of electrification in transportation has led to a reduction in the weight and size of the vehicles as the need for internal combustion engines can be eliminated. Wide bandgap materials such as silicon carbide (SiC) and gallium nitride (GaN) offer advantages in the manufacturing of EVs. Beginning the late 2000s, the EV industry has begun to adopt GaN devices in their manufacturing processes. The semiconductor material GaN stands out as a material for power electronic systems in EVs owing to its high switching frequency, higher temperature limit, and high voltage breakdown. This review aims to provide a comprehensive overview of semiconductor GaN materials for EV applications, which could be useful to provide insights for researchers and scientists to accelerate their innovation for the improvement of EVs. This review begins with an introduction to EVs, followed by the anticipated demand for EVs. The application of GaN devices in EVs, compared to the traditional Si and SiC devices, which are the primary power devices in current EVs, is discussed. The recent advancement in GaN devices that are capable of being used in various components of a fully automated EV, such as the battery, energy storage system, auxiliary power unit, and motor drive, in addition to their use in different non-automotive vehicles such as electric aircraft, electric ships, electric railways, electric submarines, and heavy duty vehicles, is also discussed. Finally, the challenges posed by GaN devices and potential solutions to overcome these shortcomings have been addressed.

Wide-bandgap (WBG) power devices such as SiC devices can operate at higher switching speed, higher voltage and higher temperature. While the opportunities in performance improvement with WBG devices are clear, there are significant design challenges. For example, the fast switching speed and high dv/dt can cause increased level of electro-magnetic interference (EMI), current overshoot and cross-talk effect through parasitic elements of the circuit. This paper will review the opportunities and challenges in the application of SiC devices and present several potential solutions aiming to fully exploit the supervisor characteristics of these devices while attenuating their side-effects.

Nowadays, Uses for transportation are evolving in the direction of getting more electrified due to rising fuel costs and environmentally hazardous pollutants due to which The grid’s need for power is increasing dramatically. As the only solution for this is to diminish the power consumption of Electric Vehicles (EV). Enhanced component efficiency can lead to improved electric vehicle performance. Wide band gap (WBG) semiconductors, in particular silicon carbide (SiC) and Gallium Nitride (GaN), are ideal candidates of choice to address the recent growing demand in both high efficiency and great power density converters about electric vehicles. Due to their the capacity to switch at a high frequency, high temperature, high voltage, reduced size and reduced conduction losses makes them superior than Si semi-conductors. WBG devices have some properties which include rapid electron mobility, high breakdown field, and big band gap low on-state resistance and capacitance, lower co-efficient of thermal expansion (CTE) and high stability. This paper includes a study on WBG devices, their properties, and the increased efficiency of power converters i.e DC-DC boost converter and single-phase full bridge inverter using LTSpice simulation tool.

Wide band-gap (WBG) semiconductors technology represents a potential candidate to displace conventional silicon (Si) technology used in power electronics. Between Silicon Carbide (SiC) and Gallium Nitride (GaN) power semiconductors, the latter is the least mature of both technologies, with many open research problems, especially in the aerospace industry. In this paper, we address the design and implementation of a DC/DC converter for a hybrid small unmanned aerial vehicle (UAV) based on GaN technology. Both theoretical and simulation comparisons of Si, SiC and GaN transistors for the converter are presented. The conclusion is that GaN devices are the most appropriate to fulfill converter requirements for the size and weight limitations of the selected UAV. The paper presents a buck converter which handles an input voltage range of 32 V to 40 V and provides a 12 V regulated output and output power up to 60 W. The experimental results carried out on the prototype converter show how promising the GaN technology is for aerospace systems, not only regarding its volume and size, but also its efficiency. Besides, practical implementation details are reported to contribute to the design of small, light and reliable GaN power converters for aeronautics.

Wide-bandgap (WBG) semiconductors, typified by silicon carbide (SiC) and gallium nitride (GaN), have revolutionized power electronics due to their exceptional switching speed, thermal conductivity, and voltageblocking capabilities. These advantages enable the development of high-efficiency, miniaturized power converters critical for renewable energy integration, electric vehicles, and aerospace applications. Current short-circuit detection approaches for SiC/GaN wide bandgap (WBG) devices face three critical drawbacks. Single-sensor detection methods are limited by application scenarios and prone to interference. Multi-sensor fusion methods require complex implementation despite balancing speed and robustness. Additionally, the existing detection system lacks compatibility with soft-switching topologies in WBG power converters. This study focuses on short-circuit detection in wide bandgap (WBG) semiconductor devices. A hierarchical classification system for short-circuit detection methods is established, and the transient characteristics of WBG device shortcircuit faults are thoroughly analyzed. The optimization effect of electromagnetic modeling on detection circuits is quantitatively evaluated. A multi-sensor fusion detection strategy balancing speed and robustness is proposed, and application-oriented selection principles for detection methods are clarified. This paper systematically reviews state-of-the-art short-circuit detection methodologies tailored for SiC MOSFETs and GaN HEMTs, categorizing them into single-sensor approaches and multi-sensor fusion strategies (e.g., di/dt + Vgs hybrid method). Core performance metrics—detection speed (ranging from sub-100 ns to over 400 ns), sensitivity to fault signatures, and robustness against electromagnetic interference —are comprehensively analyzed. Critical challenges, including parasitic inductance/capacitance interference, false triggering caused by switching transients, and compatibility with fast-switching dynamics, are discussed in detail. Additionally, the integration of electromagnetic modeling tools (e.g., HFSS, Q3D) for optimizing detection circuit layouts is evaluated, with studies confirming that precise modeling of >100 MHz parasitics is essential for ensuring reliable detection. Finally, current research gaps and future directions are outlined, providing a valuable academic reference for advancing WBG power system protection technologies.

The adoption of wide-bandgap (WBG) switching devices such as gallium nitride (GaN) transistors in power converters enables to achieve higher switching frequencies and higher power density with reduced cooling requirements and smaller passive components. However, the potential for increased electromagnetic interference (EMI) resulting from the faster switching transients possible with WBG devices is a concern in many applications. Hence techniques for reducing EMI are of increasing interest. In this paper we present a simple implementation of a spread-spectrum pulse-modulation technique to reduce the peak EMI generated by switch-mode power converters. The method is based on an aperiodic gate drive signal generated from two periodic signals, e.g. a sawtooth and a sinewave, which are anharmonically related. Simulations and experimental measurements of conducted EMI from a prototype of a SEPIC converter incorporating a hybrid GaN HEMT demonstrated a 10 dB reduction in peak EMI.

Fast and high-frequency switching operation of wide-bandgap power semiconductor devices such as Silicon carbide (SiC) and Gallium nitride (GaN) could cause severe electromagnetic interference (EMI) noise problem in high and wide frequency range. This report experimentally investigates the dependency of gate drive circuit configuration on EMI noise characteristics of SiC-based half-bridge converter.

Wide band gap (WBG) semiconductors, such as gallium nitride (GaN), have become popular among switching power modules. In pursuing power conversion efficiency, power module's high-speed and high-power operation leads to electromagnetic (EM) noise in a very wide frequency range, potentially interfering with nearby wireless communications [e.g., long-term evolution (LTE)]. This letter analyzes the source of EM noise from the power modules using GaN transistors in half-bridge circuits. EM noise was clearly observed in the proximity of power modules and attributed to two primary sources in the frequency range of interest up to 6 GHz: 1) the periodical switching operation of GaN transistors in the output stage and 2) the logic operation of complementary metal–oxide–semiconductor digital circuits to control gate drivers, in the lower and upper side of frequencies, respectively. Measurements analyzed the EM noise characteristics at different probing locations over the assembly of two GaN power modules as well as in different operating conditions by strategically supplying source signals. The influence of EM noise on LTE receiver performance is evaluated with wireless system-level simulation and related to the degradation of its minimum receivable input power.

Advancements in power semiconductor devices are enabling the design of better electrical power conversion systems. Wide Bandgap (WBG) switching devices using materials like Silicon Carbide and Gallium Nitride can operate at higher temperatures, voltages, and frequencies with faster turn-on/off periods, improving converter performance over silicon devices. However, WBG technologies are still new, and the rapid switching transitions of these devices lead to issues such as voltage overshoots, ringing, and electromagnetic interference, which need to be addressed for widespread adoption. This work introduces a new control method for reshaping the switching voltages, which overcomes the disadvantages of fast transition time without increasing system losses. In fact, the proposed method reduces overall switching losses. Experimental results on a small-scale prototype have shown that silicon-based devices improved the efficiency of a 380W DC-DC converter from 78% to 87% and reduced noise by 20dB+. A maximum of 9% efficiency improvement was observed in a 220W 100Vin DC to 100Vrms three-phase AC converter. Using Silicon Carbide (SiC) devices for 750W DC-DC and DC-AC converters resulted in about 15dB to 20dB+ reduction in electrical noise and about 1% efficiency improvement in the proposed case compared to the conventional switching method. The system Electromagnetic Interference (EMI) performance under proposed and classical switching methods is tested and compared, and results show about 5dB to 10dB reduction in conducted EMI for frequencies above 1MHz to 30MHz range. The proposed control technique allows breaking the relationship between converter efficiency and electromagnetic noise in state-of-the-art solutions, thereby speeding up the adoption of new WBG-based power-switching devices by addressing challenges related to electromagnetic noise, leading to higher power density and efficiency.

The drive inverter represents a central component of an electric vehicle (EV) drive train, being responsible for the DC/AC power conversion between the battery and the electrical machine. In this context, novel converter topologies adopting modern 600/650V wide bandgap (WBG) semiconductor devices will play a crucial role in improving the performance of next-generation drive inverters. In fact, WBG devices theoretically allow to achieve both higher inverter power density and higher conversion efficiency with respect to conventional silicon (Si) IGBT based solutions. Even though silicon carbide (SiC) devices are already well established in the automotive industry, high-voltage gallium nitride (GaN) devices are rapidly entering the market, promising higher theoretical performance but featuring a lower degree of maturity. As a consequence, it is currently not clear which semiconductor technology is most suited for future EV drive inverters. Therefore, this paper aims to address this gap providing a comparative performance evaluation of state-of-the-art SiC and GaN 600/650V active switches. In particular, a novel figure-of-merit (FOM) representing the minimum theoretical semiconductor losses under hard-switching operation is introduced. Remarkably, this FOM enables a fair and accurate performance comparison among semiconductor devices, allowing to clearly determine the best performing technology for a given set of application-specific conditions. The results of the comparative assessment show that currently available SiC and GaN active switch technologies can outperform each other depending on the semiconductor operating temperature and the converter switching frequency.

We present a comprehensive review and outlook of silicon carbide (SiC) and gallium nitride (GaN) transistors available on the market for current and next-generation power electronics. Material properties and structural differences among GaN and SiC devices are first discussed. Based on the analysis of different commercially available GaN and SiC power transistors, we describe the state-of-the-art of these technologies, highlighting the preferential power conversion topologies and the key characteristics of each technological platform. Current and future fields of application for GaN and SiC devices are also reviewed. The article also reports on the main reliability aspects related to both technologies. For GaN HEMTs, threshold voltage stability, dynamic ON-resistance, and breakdown limitation are described, whereas for SiC MOSFETs the analysis also focuses on gate oxide failure and short-circuit (SC) robustness. Finally, we give an overview on the perspective of such materials in different fields of interest. An indication of possible future improvements and developments for both technologies is drawn. The requirements for hybrid converters, along with a careful optimization of performance and the use of innovative optimization tools, are underlined.