In this paper, we propose to use the junction temperature difference estimated by two temperature-sensitive electric parameters (TSEPs), threshold voltage, and p-n junction forward voltage of the IGBT module to monitor the aging of the bond wires. When the bond wires are lifted off, the chip surface temperature and the overall temperature gradient will increase, making the temperature difference measured by these two TSEPs larger. A new method is proposed in this paper to monitor the aging of the bonding wires of IGBT modules by the difference between them, and the correctness of the proposed method is verified by experiments on IGBT modules with different degrees of bonding wire aging.

Three-phase pulse width modulation (PWM) converter has been widely used in motor drive field, data center system and grid-connected power generation system for the advantages of operating at unit power factor and bidirectional power transmission. However, under the input voltages unbalance condition, the dc output of PWM rectifier will have a large second-order voltage ripple with conventional control strategy, which can deteriorate the performance of dc side, leading to odd input currents harmonics and reduce efficiency. To solve the above problems, especially the second order voltage ripple, a digital control strategy for three-phase PWM rectifier is proposed in this letter. Compared with the existed control strategies, the proposed control strategy does not need to extract positive and negative sequence components of input voltages, so that there is no phase locked loop and complex calculation. The correctness and effectiveness of the proposed control strategy are verified by simulation results and experimental results.

This letter proposes a simpler and more efficient circuit scheme than the conventional current fed full bridge converter. In the proposed circuit, an auxiliary resonant capacitor is added to the conventional circuit to eliminate the adverse effects of leakage inductance of the transformer on the circuit operation, and at the same time, soft switching is achieved. As a result, switching losses were reduced and the efficiency was improved by approximately 4.7% compared to the conventional method, which was confirmed on LTspice. First, the basic structure of the proposed circuit is shown, followed by the principle of operation. Next, the advantages and disadvantages of the proposed method are presented. Finally, we compare the proposed method with the conventional method.

The health status estimation of lithium-ion battery is a challenging through measurement. To establish a connection between battery health status and data features, a battery State of Health (SOH) estimation method based on data feature mining is proposed. Four features are extracted from the battery charging curve, and the grey correlation analysis is used to determine the high correlation between features and health status. The method combines a Backpropagation (BP) neural network with Genetic Algorithm (GA) for feature training and learning, enabling the estimation of battery SOH. The feasibility of the proposed method is validated using the NASA battery dataset. The results show that the battery SOH estimation method proposed in this paper outperforms the traditional BP neural network method achieving accurate estimation.

In this paper, a broadband reconfigurable frequency-selective surface (FSS) in terahertz band based on different metal-insulator transition (MIT) temperature of vanadium dioxide (VO₂) is proposed. By using different MIT temperature of VO₂, the broadband reconfigurable design of the FSS is realized. The results show that the center frequency of the FSS is 2.15THz and when the temperature is lower than 60°C, the relative bandwidth is 74.19%. When the temperature is between 60°C and 72°C, the relative bandwidth is 55.59%. Above 72°C, the relative bandwidth is 33.78%. The FSS has broad application prospects in other emerging terahertz fields such as terahertz regulation and communication.

By using the XOR method to obfuscate response of Arbiter PUFs (APUFs), the ability to resist machine learning (ML) modeling attacks can be improved, but this method will reduce the stable of PUF to a certain extent, making PUF lose usability. In view of this, a highly stable XOR APUF (HS-XOR APUF) circuit is proposed by studying the generation mechanism of unstable response bits and the screening characteristics of the logic gates delay signals. First, the maximum and minimum delay signals are screened with AND/OR gate to generate highly stable response bits; Then, by inserting a inverter in the APUF switch unit, the delay time of the signal is increased, and the influence of environmental factors on the comparison signal with small delay deviation is weakened; Finally, the FPGA experimental results show that the response stability of HS-XOR APUF is rarely affected by the count of XOR units, and the AND/OR gate delay signal screening structure is simple and consumes a small amount of hardware resources, which can be widely used in the fields of information security.

Event-based deep neural networks (DNNs) have shown great promise in computer vision under difficult lighting conditions. However, existing hardware solutions cannot provide efficient event-based DNN accelerations owing to the characteristic of event streams, which are typically in low datarate and high-dynamic range. In this letter, we present a novel hardware design that can handle event-based DNNs according to the data characteristic of event streams. Furthermore, we provide a dataflow that enables flexible DNN data encodings (including both bitmask and compressed sparse row (CSR)) based on the event data characteristic for energy saving. Comprehensive evaluations based on four famous event-based benchmarks show that the proposed design can achieve higher performance and better energy efficiency compared with representative accelerator baselines.

This paper presents an experimental characterization of grounded coplanar waveguides (GCPWs) with uncertainty analysis. GCPW lines to be analyzed were fabricated using different subtractive printed circuit board (PCB) manufacturing processes: panel plating method and pattern plating method. Using a modified multiline method, we have extracted the propagation constants with uncertainty propagation analysis. This considered instrumentation noise, length uncertainty, and impedance mismatch caused by variations in cross-section due to the fabrication capabilities of each manufacturing process. By reformulating the propagation constant, we obtained the attenuation per unit length and the effective relative permittivity as a function of frequencies up to 43.5GHz with 95% confidence interval. These results showed good agreement with full-wave simulations and highlighted the differences between the PCB manufacturing processes.

We developed a terahertz-wave balanced mixer fabricated on a SiC substrate using epi-layer-transferred InP/InGaAs Fermi-level managed barrier (FMB) diodes. The FMB diodes were monolithically integrated with waveguide couplers, a 90-degree hybrid circuit, and low-pass filters. The fabricated mixer was then assembled in a two-input-port module with a broadband transimpedance amplifier and exhibited an intermediate frequency bandwidth of about 26GHz with good inter-port isolations of more than 13dB. The obtained minimum noise equivalent power was as low as 2×10^-19W/Hz in the fundamental mixing mode at around 300GHz for a local-oscillator power of about 400µW.

This paper presents an effective medium modeling method for frequency selective surface (FSS). The proposed method only retrieves the electromagnetic parameters of the effective medium once, then the reflection/transmission coefficients under arbitrary incidence can be calculated. Compared with previous works, the proposed method reduces the modeling and calculation time by equating the complex FSS to single-layer or multi-layer dielectric slabs. For verification, we built an effective medium model for gridded square loop FSS and obtained a modeling empirical formula. The calculated results are in good agreement with CST and better than the equivalent circuit method.