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随着商用无线通信的迅猛发展,微波电路越来越得到重视和发展。而微波带通滤波器作为微波器件的一种也得到了大力的发展,尤其是在接收机前端,带通滤波器性能的优劣直接影响到整个接收机性能的好坏,本文就滤波器的工作原理及一些相关理论做了简要概述,并提出微带线带通滤波器的设计细则。 相似文献
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Zhefeng ZHANG 《等离子体科学和技术》2022,24(4):44002
As the main source of the vacuum arc plasma, cathode spots (CSs) play an important role on the
behaviors of the vacuum arc. Their characteristics are affected by many factors, especially by the
magnetic field. In this paper, the characteristics of the plasma jet from a single CS in vacuum arc
under external axial magnetic field (AMF) are studied. A multi-species magneto-hydro-dynamic
(MHD) model is established to describe the vacuum arc. The anode temperature is calculated by
the anode activity model based on the energy flux obtained from the MHD model. The
simulation results indicate that the external AMF has a significant effect on the characteristic of
the plasma jet. When the external AMF is high enough, a bright spot appears on the anode
surface. This is because with a higher AMF, the contraction of the diffused arc becomes more
obvious, leading to a higher energy flux to the anode and thus a higher anode temperature. Then
more secondary plasma can be generated near the anode, and the brightness of the ‘anode spot’
increases. During this process, the arc appearance gradually changes from a cone to a dumbbell
shape. In this condition, the arc is in the diffuse mode. The appearance of the plasma jet
calculated in the model is consistent with the experimental results. 相似文献
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提出了一种基于无源均流的单开关降压式四路输出LED驱动器,并分析了其工作原理及特性。该驱动器利用多电容电路结构实现了每个LED支路的均流,因此仅需控制其中一条输出支路的电流,即可实现对其他支路的电流控制。此外,所提出的LED驱动器只使用了一个有源开关,进一步减小了电路的体积,简化了驱动控制。与传统多输出LED驱动器相比,该电路可实现非隔离单开关降压转换,使其应用范围更广。最后,搭建了一台100 W四路输出实验样机,验证了所提LED驱动器理论分析的正确性与可行性。 相似文献
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