- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - Atlanta, GA, USA (2018.10.31-2018.11.2)] 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - Design Considerations for a Gallium Nitride Based Phase Shifted Full Bridge DC-DC Converter for Space Applications
摘要： The main design considerations for the practical implementation of a Phase Shifted Full Bridge DC-DC converter with synchronous rectification using recently released radiation hardened Gallium Nitride (GaN) Field Effect Transistors (FETs) for space applications are presented in this paper. A brief survey comparing the benefits of GaN FETs for space power applications against current Silicon power transistor technology is conducted. Also, the main drivers for topology selection, and design considerations to implement the selected topology for space applications resulting from the limited radiation hardened components available today are described in detail. In addition, power loss breakdown from analysis and final design choices are presented. A converter was designed to validate design based on the considerations outlined. The implemented converter operates from a 100 V DC bus and delivers 400 W from a fixed 20 V output at more than 95% efficiency.
关键词： rad-hard,converter,space,radiation hardened,full bridge,phase shifted,DC-DC,GaN
更新于2025-09-04 15:30:14
-
[IEEE 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz 2018) - Nagoya (2018.9.9-2018.9.14)] 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Terahertz Quasiparticle Acceleration: From Electron-Hole Collisions To Lightwave Valleytronics
摘要： Intense lightwaves can accelerate quasiparticles inside solids. This strong-field light-matter interaction results in the emission of high-harmonic or high-order sideband radiation. While the former process relies on a complex coupling between simultaneously driven interband polarization and intraband currents, high-order sidebands originate from a ballistic acceleration of the quasiparticles within the bands. This mechanism allows for the implementation of a quasiparticle collider in order to study those entities in close analogy to conventional collision experiments. Accelerating electrons and holes in a monolayer of transition metal dichalcogenides extends this scheme to internal quantum degrees of freedom. Our experiments show a lightwave-induced switching of the valley pseudospin, paving the way to ultimately fast valleytronics.
关键词： valley pseudospin,terahertz,high-harmonic generation,lightwave valleytronics,electron-hole collisions,quasiparticle acceleration,high-order sideband radiation,transition metal dichalcogenides
更新于2025-09-04 15:30:14
-
Ultraviolet Solar Spectral Irradiance Variation on Solar Cycle Timescales
摘要： Ultraviolet (UV) Solar spectral Irradiance (SSI) has been measured from orbit on a regular basis since the beginning of the space age. These observations span four Solar Cycles, and they are crucial for our understanding of the Sun-Earth connection and space weather. SSI at these wavelengths are the main drivers for the upper atmosphere including the production and destruction of ozone in the stratosphere. The instruments that measure UV SSI not only require good pre?ight calibration, but also need a robust method to maintain that calibration on orbit. We will give an overview of the catalog of current and former UV SSI measurements along with the calibration philosophy of each instrument and an estimation of the uncertainties in the published irradiances.
关键词： Sun: activity,Sun: UV radiation,instrumentation: spectrographs
更新于2025-09-04 15:30:14