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Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes/issues, but are citable by Digital Object Identifier (DOI).
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, Available online , doi: 10.11884/HPLPB202537.250017
Abstract:
Background Purpose Methods Results Conclusions
Magnetically driven flyer plate technology can be used for the study of high-pressure equation of state and material properties. Generally, when the same force pushes objects of different masses, the lighter object always gains greater velocity. However, in a magnetically driven symmetrical flyer plate launch experiment, the same current drove two flyer plate couple of thicknesses 0.37 mm and 0.48 mm. The final measurement velocity of the 0.37 mm flyer plate couple was 18 km/s, and the final measurement velocity of 0.48 mm flyer plate couple was 19 km/s; that is, the measured velocity of the thick flyer plate couple was even greater.
This paper studies the physical mechanism of this anomalous phenomenon in the magnetically driven symmetrical flyer plate launch experiment.
A two-dimensional magnetically driven simulation code (MDSC2), in which the boundary magnetic field is affected by ablation, was used to simulate and analyze this experiment.
The numerical simulation shows that, the MDSC2 code with the boundary magnetic field affected by ablation can correctly simulate the dynamic process of 0.37 mm and 0.48 mm flyer plate couple, and the simulated velocities of 0.37 mm and 0.48 mm flyer plate couple are consistent with the measured velocities. The reason the final recorded velocity of the thicker flyer plate couple is larger than that of thinner one is that the time to complete melting for the thicker flyer plate is longer than that of thinner one in the magnetically driven symmetrical flyer plate experiment.
This work advances the physical understanding of magnetically driven flyer plate launch process, and further confirms the correctness of the boundary magnetic field formula with the ablation effect.
, Available online , doi: 10.11884/HPLPB202537.250043
Abstract:
Background Purpose Methods Results Conclusions
With the development of active phased array radar systems, the demand for transmit-receive (TR) power supplies has increased significantly. Modern TR modules require power supplies with wide input voltage ranges, high-frequency operation, and high efficiency. dual-active bridge (DAB) converters are widely recognized for their ability to achieve these characteristics, offering diverse control strategies and broad application potential. However, key system parameters such as inductance and switching frequency in DAB converters significantly impact power transmission capabilities and the on-state current of power MOSFETs, posing challenges for optimal design.
This study aims to address these challenges by proposing a parameter optimization design method for DAB converters based on extended phase-shift (EPS) modulation. The goal is to ensure reliable operation under overload conditions while meeting critical design constraints, including maximum power transfer, MOSFET current derating, and output voltage ripple reduction.
The power transfer characteristics and inductor current expressions of the EPS-modulated DAB converter were derived theoretically. A reliability-oriented operating region (ROA) was defined by integrating constraints such as maximum power transfer under overload, MOSFET on-state current derating, and minimum output voltage ripple frequency. The optimization process involved systematic parameter planning to determine optimal inductance values and switching frequencies.
MATLAB simulations of a dual-output DAB converter demonstrated that the proposed method effectively reduced output voltage ripple, minimized MOSFET on-state current, and achieved the desired power output. The simulation results aligned with theoretical predictions, validating the accuracy of the derived equations and the feasibility of the optimization approach.
The EPS-based parameter optimization method provides a systematic framework for designing DAB converters tailored to TR power supply requirements. By addressing key design constraints and leveraging ROA analysis, this approach enhances power transmission efficiency and device reliability. The results highlight the potential of EPS-modulated DAB converters in advanced TR modules, offering a practical solution for high-performance phased array radar systems.
, Available online , doi: 10.11884/HPLPB202537.250073
Abstract:
Background Purpose Method Result Conclusion
Radio frequency (RF) front-end components are among the most vulnerable elements in integrated circuit systems when exposed to intense electromagnetic environments. Investigating their degradation mechanisms and failure thresholds is therefore critical for identifying system weak points and devising effective protection and reinforcement strategies. However, existing high power microwave (HPM) injection tests rely on manual operation, lack standardized procedures and deliver limited repeatability.
In order to achieve precise and efficient evaluation of device degradation and failure thresholds and to establish standardized test methods and assessment procedures.
This work developed a high power microwave (HPM) automatic measurement platform grounded in the interaction mechanism between HPM and devices, and designed two testing protocols—single pulse excitation for electrical stress characterization and continuous pulse excitation for thermal failure evaluation.
A commercial low noise amplifier (LNA) served as the test device; synchronous measurements of time domain response, frequency domain characteristics and operating current, combined with pre/post test parameter comparison, pinpointed damage thresholds. Furthermore, we conducted a comprehensive evaluation of first, second, and third damage events, correlating cumulative damage effects with key device parameters through microphysical analysis to elucidate the dominant failure mechanisms.
The proposed measurement system and evaluation methodology offer a robust framework for reliability assessment of semiconductor devices in high power electromagnetic environments and provide essential experimental support for damage resilience analysis and optimized device design.
, Available online , doi: 10.11884/HPLPB202537.250041
Abstract:
Background Purpose Methods Results Conclusions
The confocal waveguide structure can effectively suppress mode competition due to its characteristic of reducing mode density through diffraction loss, thereby facilitating stable operation of gyro-traveling-wave tube amplifiers (gyro-TWTs) in the terahertz (>100 GHz) frequency range.
This study aims to conduct a comprehensive analysis of the diffraction loss rate (DLR) in a 220 GHz confocal waveguide gyro-TWT, employing a combination of theoretical analysis and three-dimensional particle-in-cell (3D-PIC) simulations.
The research integrates field distribution theory with 3D-PIC simulations to investigate the DLR of the confocal waveguide. A non-ideal waveguide model incorporating the mirror width angle was utilized, and simulations were performed to evaluate beam-wave interaction dynamics under varying DLR conditions.
The study reveals that a low DLR induces gyro-backward wave oscillation (GBWO) in low-order competing modes, while a high DLR significantly reduces beam-wave interaction efficiency, gain, and bandwidth, and lowers tolerance to electron beam velocity spread.
For stable single-mode operation of the HE07 mode in the designed gyro-TWT, the DLR should not be less than 0.38 dB/cm, with the corresponding mirror-surface width angle not exceeding 47°. These findings provide crucial design guidelines for terahertz gyro-TWTs.
