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宽带大功率限幅器小型化研究 总被引:1,自引:0,他引:1
采用微波混合集成电路设计方法,用并联二极管和检波二极管,在很小的腔体内制作了无源微波限幅器。其电参数为:频率范围2~18GHz;承受功率4W(连续波);限幅电平≤30mW(Pin为4W,连续波);插入损耗为2.5dB以下;驻波系数为2.0以下。外形尺寸为13.5mm×6mm×3mm;输入输出端为50?绝缘子。 相似文献
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Zinc oxide (ZnO) nanospheres with excellent sensing ability towards formaldehyde were successfully synthesized using a single-capillary electrospinning method. Structural and electrical characteristics of the as-synthesized ZnO nanospheres were systematically investigated. The scanning electron microscope (SEM) images clearly display a novel structure of ZnO with pores distributed on the surface of the nanospheres. The results demonstrate that the ZnO nanospheres possess excellent formaldehyde gas-sensing properties. At room temperature, the response of ZnO nanospheres to formaldehyde with concentration of 100 ppm is determined to be 126.3. In addition, the ZnO nanosphere sensors exhibit short response time of 30 s and short recovery time of 2 s. These excellent gas-sensing properties make the ZnO nanospheres a promising material for the application in environmental monitoring devices. 相似文献
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以前在单片机教学过程中,由于仿真器的价格比较高,编程器要不停地对单片机进行拔插,给调试带来不便,使一些实验无法让学生亲自动手,给单片机教学带来诸多不便,现在由于ISP技术的发展,克服了以上诸多不便,也给单片机教学和实验教学带来机遇。 相似文献
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本文分析了电容式加速度传感器的工作原理,在此基础上设计了一种大量程加速度计,通过MATLAB进行系统仿真和ANSYS仿真验证,结果显示本设计可以很好的实现要求:量程70g,线性度小于2%,并有较好的稳定性。 相似文献
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We present a novel electrochemical technique for the fabrication of nano-photonic crystal structures. Based on a specially designed electrolyte, porous silicon(PSi) layers with different porosities are possible to be produced on highly-doped n-type silicon substrate by varying the applied current density which determines the size and the morphology of pores. By applying an alternative current density modulation during anodization, porous silicon photonic crystals are obtained using HF-containing electrolyte without oxidizing components. The current burst model(CBM) is employed to interpret the mechanism of the formation of the macropore porous silicon. 相似文献
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Optical and electrical properties of composites formed by mixing porous silicon (PS) and poly (9, 9-diocty-2, 7-fluoreneco-4, 4’-butoxydiphenyl) (PFP) have been studied by Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and photoluminescence (PL) spectroscopy. The optical spectra show that porous silicon is incorporated into the polymer without significant change in the polymer properties. The FT-IR spectroscopy has detected the existence of specific interactions, which may be attributed to non-conjugated alkoxy segment. By fitting the current-voltage (I-V) curve of PFP/PS structure with the modified standard equation, the n factor and I0 are determined. 相似文献