Current Issue : April-June Volume : 2026 Issue Number : 2 Articles : 5 Articles
A Si/SiC heterojunction double-trench MOSFET with improved conduction characteristics is proposed. By replacing the N+ source and P-ch regions with silicon, the device forms a Si/SiC heterojunction that exhibits Schottky-like characteristics, effectively deactivating the parasitic PiN body diode and improving third-quadrant performance. A high-k gate dielectric is incorporated to induce a strong electron accumulation layer at the heterointerface, thinning the energy barrier and enabling tunneling-dominated current transport, thereby significantly enhancing the first-quadrant performance. TCAD simulation results demonstrate that the proposed device achieves a specific on-resistance (Ron,sp) of 1.78 mΩ·cm2, representing a 20.5% reduction compared to the conventional SiC DTMOS, while maintaining a comparable breakdown voltage (BV) of approximately 1380 V. A significant reduction in the third-quadrant turn-on voltage (Von) is achieved with the proposed structure, from 2.74 V to 1.53 V. Meanwhile, the unipolar conduction mechanism similar to that of Schottky effectively suppresses bipolar degradation. To enhance device reliability, the design incorporates a trenched source and heavily doped P-well, which collectively mitigate high electric field concentrations at the trench corners. The proposed device offers an integration strategy enhancing both forward conduction and reverse conduction in high-voltage power electronics....
Power devices have a history of about 70 years. Like other semiconductor devices, they have evolved along with advancements in materials, processes, and design techniques. Today, the importance of power devices is increasing for achieving carbon neutrality, and the market continues to grow steadily. To meet market demands, major developments are underway, including the transition of silicon power devices to 300 mm wafers and the expansion of the wide-bandgap semiconductor market. In addition, the required performance of power devices varies greatly depending on the application areas in power electronics. For this reason, it is difficult to predict the future development of power devices with a simple scenario. This paper reviews the evolution of power devices and related technologies from the perspective of application requirements in power electronics. It also discusses the technologies expected to be necessary for future power devices, along with their outlook....
In this article, two wideband high-eciency Class-J power ampliers operating in X and Ku bands, respectively, are designed based on continuous mode. The optimal impedance regions of the transistors are determined using harmonic load-pull techniques. An onchip output matching network with second harmonic control functionality is designed to achieve Class-J operation. To verify the feasibility of designed circuits, both power ampli- ers are designed and fabricated using a 0.25 mm GaAs pseudomorphic high electron mobility transistor (pHEMT) process. The power ampliers are both biased at 6 V/1 V. The measured results show the X-band and Ku-band power ampliers achieve peak saturated output powers of 31.2 dBm and 30.8 dBm, respectively. The power-added eciencies (PAEs) of the two ampliers within their operating bands reach up to 48% and 45.3%, respectively. Compact size and high eciency make them suitable for integration into phased array transmit/receiver (T/R) modules....
Tuning power consumption of a tunable laser (TL) increasingly becomes an issue as the application range of wavelength division multiplexing grows in optical communications. On-chip Joule heat of a micro-heater commonly employed for a recent coherent TL needs to be exhausted out of the laser chip. It results in an increase in power consumption of laser control electronics with a thermal electric cooler (TEC) driver. An electro-optically TL whose laser wavelength is tuned by the electro-optic (EO) effect is advantageous for power-efficient tuning caused by little Joule heat during tuning unlike a micro-heater-based TL. We developed an electro-optically TL using a reflection-type transversal filter (RTF) whose reflection spectrum is tuned by the quantum-confined Stark effect (QCSE) known as a kind of the EO effect. In this paper, we describe an RTF laser with power-efficient control electronics thanks to little Joule heat fromanRTF laser, which suppressesTEC driver power consumption. While an issue of control electronics of an RTF laser is a larger negative voltage (−15 V) for the QCSE than the industrial standard +3.3 V voltage supply, we found low-noise laser operation of an RTF laser to which reverse voltages are supplied from control electronics with an inverting switching converter based on the C´ uk topology. As a result, we successfully achieve wavelength-channel-dependent power consumption of less than 150 mW of an RTF laser with control electronics. Practical light source performance for a 400G digital coherent modulation format is also demonstrated....
Accurately estimating the state of health (SOH) of power batteries is beneficial for their maintenance, delaying aging, ensuring safety, and providing a basis for their secondary use to enhance resource utilization efficiency. However, existing data‐driven methods rely heavily on laboratory data and lack adequate adaptability to real‐world vehicle conditions. Moreover, traditional gradient boosting algorithms such as gradient boosting decision trees (GBDT) and LogitBoost encounter precision and generalization issues when faced with the complex operating conditions of real vehicles, thereby limiting their practical applications. To address these challenges, this paper proposes a method for estimating the SOH of power batteries in pure electric vehicles using an extreme gradient boosting (XGBoost) model optimized by the grid search cross‐validation (GSCV) method, based on data from a vehicle manufacturer's monitoring platform. First, data are divided according to a “discharge + charge” pattern, and 16 capacity degradation feature factors from six categories are extracted from the discharge‐charge segments as input variables for the XGBoost model, while partial charged capacity is extracted from the charge segments as the output label for the model. Subsequently, to overcome the XGBoost model's sensitivity to hyperparameters and its susceptibility to overfitting, the GSCV method is employed for parameter optimization of the XGBoost model, and the GSCV‐XGBoost model is used to estimate partial charged capacity. Finally, an SOH correction method is applied to the output of the GSCV‐XGBoost model to obtain the corrected SOH. Experimental results demonstrate that the SOH estimated by the GSCV‐XGBoost model combined with the SOH correction method exhibits smaller errors and remains consistently below 2% compared to SOH corrected based on the Ampere‐hour integral method. In estimating partial charged capacity, the GSCV‐XGBoost model significantly outperforms the XGBoost model. Compared to the CBDT and linear regression (LR) models, the GSCV‐XGBoost model achieves the highest goodness of fit (R²), with the smallest mean absolute error (MAE) and root mean squared error (RMSE). The research findings presented in this paper are expected to provide effective solutions for real‐world vehicle power battery SOH monitoring....
Loading....