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研究了影响毫米波谐波回旋管互作用效率的多个因素,通过采用三次谐波工作,94 GHz回旋管的工作磁场降低到了1.185 T,使采用永磁体取代超导磁体成为可能.利用自洽非线性计算和粒子模拟研究了回旋振荡管的注-波互作用过程,发现了腔体品质因数与互作用效率的内在联系,研究了工作电压和电子注横纵速率比对耦合强度的影响,考虑了磁场渐变及电子注速度离散对互作用效率的影响,通过选择合理的工作模式和系统参数,当工作电压为40 kV、工作电流为12 A、电子注横向速度离散为3%时获得了95 kW的输出功率及19.7%的效率.当采用单级降压收集极后,效率可以进一步提高到39.2%. 相似文献
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二次谐波回旋管所需磁场仅为基模的一半,极大地降低了对工作磁场的要求.基于回旋管线性和自洽非线性理论设计了一只0.5 THz回旋管,采用TE56模为工作模式,分析了多项关键参数对注波互作用效率的影响,当其工作电压为49 kV,工作电流为5A,工作磁场为时9.94 T,效率为22.52%,输出功率可达55 kW. 相似文献
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介绍了220 GHz同轴腔回旋管的设计,工作模式为TE04圆电模式.采用自洽非线性理论对谐振腔的工作参数进行了参数优化,选取工作电压50 k V,工作电流10 A,工作磁场8.4 Tesla.设计的同轴型双阳极磁控注入式电子枪,电子注速度横纵比1.5,速度零散5.2%.并采用粒子模拟方法进行了整管仿真.理论计算与粒子模拟结果表明,设计的220 GHz同轴腔回旋管有望获得200 k W以上的输出功率与40%以上的互作用效率. 相似文献
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太赫兹回旋管是一类基于电子回旋受激辐射机理的快波器件,同时也是目前最具发展前景的高功率太赫兹辐射源.本文根据回旋管的线性理论和自洽非线性理论对三次谐波、工作频率0.6 THz的回旋管进行了研究,重点讨论了引导中心分别为0mm的实心回旋电子注和0.315mm的空心回旋电子注的模式竞争.通过分析比较,发现工作在0.6THz 、三次谐波的众多模式中TE37模是一比较理想的工作模式,它不仅有相对较高的功率输出,而且还有相对较少的模式竞争.本文中的设计采用55kV/1.0A,电子注的速度横纵比为1.5,在工作磁场7.86T下,数值计算结果表明输出功率达4.73kW. 相似文献
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利用线性和非线性理论研究了电子注偏心对0.22 THz回旋行波管注波互作用的影响。基于色散方程研究了电子注偏心对线性增益、绝对不稳定性的起振电流和返波振荡的起振条件的影响。引入自洽非线性理论,分析了电子注偏心对输出功率和注波互作用效率的作用。同时,在考虑速度离散的情况下,研究了电子注质量对共焦波导注波互作用的影响。结果表明,电子注偏心会导致效率的降低。 相似文献
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介绍了JGFD51A型AGc放大器的主要特点及其在应答机和接收机中的应用,通过具体电路的应用和试验结果,介绍了该器件在调试中遇到的问题及解决办法,并得出应用结论。 相似文献
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基于IP的异步通信接口UART设计及其FPGA实现方法 总被引:5,自引:0,他引:5
介绍了基于IP模块的异步通信接口UART(通用异步接收发送设备)设计以及在FPGA(现场可编程门阵列)上实现的设计流程,包括UART模块的Verilog源代码设计,以及多种EDA(电子设计自动化)软件的使用:利用Debussy对源代码进行了调试,分析了设计的组织结构,利用ModelSim SE 5.8对设计进行了仿真,利用Synplify Pro 7.2进行了综合,利用Project Navigator对设计进行了布局布线,并完成了时序仿真,最后在Xilinx的SPARTANⅡE芯片上下载实现,经验证符合设计要求. 相似文献
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阐述了CEI的测量原理,提出了一种基于GPS卫星校准的CEI的测量体制,并对该体制中各测量元素的测量方法进行了讨论,对各测量元素的测量精度进行了分析,探讨了该体制应用于同步卫星定轨的可行性。 相似文献
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Terahertz (THz) communication is considered to be one of the demanding technology for the upcoming 5G standards. The incredible demand for high rate through wireless channel necessitates the use of THz frequency for communication. The development of communication systems in this frequency band possess technical challenges as the characteristic of THz band is very much different from the present wireless channel. However, the advancements in the development of transceiver and antenna systems are rapidly bringing the THz communication into reality. The high path loss in THz band limits the communication range of this channel. Even, for a distance of few meters (>5m), the absorption coefficient is very high and hence the performance of the system is poor. Performance over this frequency channel can be enhanced by considering transmission windows over this band instead of the entire band. The transmission windows are the frequencies over which the absorption is relatively low. Though there is an improvement in the performance with this adaptive modulation scheme, but not sufficient for longer distance. Apart from path loss, the frequency selective nature of this high bandwidth channel is also a major reason for the poor performance of THz channel. Orthogonal Frequency Division Multiplexing (OFDM) is a promising solution to mitigate the effects of frequency selective nature of the wireless channel. OFDM has been exploited in this paper to improve the performance of terahertz channel. The results show that the Bit Error Rate (BER) of the terahertz channel is considerably improved with OFDM. 相似文献
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湿地蒸散发量是湿地水量支出的重要组成部分。利用遥感技术可以合理有效地计算出地形复杂的湿地的蒸散发量。将遥感图像分类技术与定量遥感蒸散发模型结合起来,考虑各类地物不同的蒸散发源和水热传输机制,建立了集成模型,分析和计算了湿地主要地物的蒸散发量。通过对各地物类的样区平均蒸散发量与实测数据进行比较,证明结合地物分类的湿地蒸散发量计算集成模型能够取得很好的结果。 相似文献
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本文论述了S频段地面测控站全频带适应统一应答机的设计特点,提出了全频带相参应答机的设计思想,该机具有测距,测速,解,调遥控指令副载波和发射遥测副载波的功能,在S频段带宽大于100MHz的情况下满足地面测控站的标校和联试要求。 相似文献
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电源监控系统作为一种新型的管理模式,正越来越多地被通信企业所采用,它的建立和发展对维护机制的转变产生了深刻的影响,同时,它又是一个需不断完善和提高的维护体系,文中就其在通信生产中的应用及有待改进之处提出个人的一些观点和看法。 相似文献
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The relative stabilities of silver neodecanoate, tungsten hexacarbonyl, and a seriesof metal acetyl- and hexafluoroacetyl- acetonates, were determined using differential ther-mal analysis (DTA) and weight loss
analysis. In general, the acetylacetonates decom-pose in the solid state at relatively low temperatures (100-200° C), with
several of them exhibiting appreciable vapor pressures at temperatures below which their decomposi-tion rate is significant.
Hexaf luoro derivatives of these compounds are, in general, more volatile and decompose at higher temperatures. The thermal
decomposition behavior of palladium(II) acetylacetonate and palladium(II) hexafluoroacetylacetonate were each investigated
using DTA at atmospheric pressure and under each compound’s equilib-rium or decomposition product(s) vapor pressure in conjunction
with weight loss and residue composition analysis. At the heating rates employed, ≤2° C/min, palladium(II) acetylacetonate
tends to decompose upon heating in either an inert or oxidizing atmo-sphere before significant quantities volatilize. On the
other hand, palladium(II) hex-afluoroacetylacetonate tends to volatilize completely before any signs of decomposition are
observed under the same conditions. Heating palladium(II) acetylacetonate in ar-gon, at ≤2° C/min, shows the onset of an endotherm
at approximately 196° C, at the conclusion of which a product containing 75% palladium was found, the remainder com-prised
of carbon, hydrogen and oxygen. In an oxidizing atmosphere at the above men-tioned heating rate, Palladium(II) acetylacetonate
decomposes exothermically at 180° C yielding essentially pure palladium. Continued heating in oxygen, to 800° C results in
pure PdO. At 900° C, the PdO decomposes yielding pure palladium. Depending upon the heating rates applied, one or two endotherms
may be observed during the heating of palladium(II) hexafluoroacetylacetonate. Heating at 2° C/min in either an argon or ox-ygen
atmosphere, results in an endothermic transition due to fusion at 105° C in argon (101° C in oxygen), followed by a second
endothermic transition at 231° C in argon (223° C in oxygen), due to the normal boiling point being achieved. If heating rates
are slow enough,e.g. 0.1° C/min, complete volatilization may occur before the normal boiling point is reached. 相似文献
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为实现高精度光电编码器非匀速转动时动态细分误差的检测,提出了一种基于非均匀采样的莫尔条纹光电信号分析方法.首先,利用曲线拟合的最小二乘法将采集到的编码器非均匀信号数据重构出真实的信号波形.然后,根据离散傅里叶变换算法分析重构信号,同时推导出信号的频率、幅值和相位的计算表达式,运用软件仿真评估算法可行性.最后,采用该方法对某21位绝对式光电轴角编码器精码信号进行分析,根据信号参数与细分误差的关系获得动态细分误差,其细分极值误差为+2.41"和-3.08".实验结果表明,该方法利用信号重构和傅里叶变换算法得到信号参数,真实的反应了莫尔条纹信号质量,在编码器非匀速转动时,可有效地测量动态细分误差,为实际工作现场编码器精度误差的实时检测奠定了基础. 相似文献