共查询到20条相似文献,搜索用时 140 毫秒
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慢波系统的高频参量决定了行波管的功率和增益特性,谐波与基波频率下的高频参量的关系决定了行波管输出的谐波与基波的比例。本文在较宽的参数变化范围内对比分析相速、耦合阻抗在频带内的不同分布状态对低端的二次谐波比的影响。计算结果表明,相速之比为0.96 附近对应为二次谐波比最大的状态,此变化规律与频率的相关度较小;而谐波与基波的耦合阻抗之比越大,二次谐波比越大。对于宽带行波管,在翼片加载的高频结构中调整翼片内径就可以使输出的二次谐波比产生较大变化。 相似文献
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基于MAFIA软件的螺旋线慢波结构冷特性仿真 总被引:1,自引:0,他引:1
利用MAFIA软件所提供的准周期边界条件,对两种不同夹持结构的螺旋线行波管一个周期结构的色散和耦合阻抗特性进行了仿真,并与国内开发的螺旋线行波管计算软件包的计算结果进行了比较,为今后进一步优化螺旋线行波管的慢波结构打下基础. 相似文献
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当采用相位聚焦技术提高行波管的互作用效率时,应求解考虑阻抗和耦合函数变化的非线性方程组。本文从自由螺旋导面的耦合阻抗公式出发,考虑了变节距段的螺旋带、介质及金属屏蔽筒的影响,得出了实际螺旋线慢波结构变节距段的阻抗和耦合函数的变化规律,并用实验验证了此规律,取得了较好的一致性。本文还列出了Rowe和Cutler提出的结果,并进行了比较。 相似文献
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Jianhong Yang Yong Zhang Xueyuan Cai Lin Li 《Journal of Infrared, Millimeter and Terahertz Waves》2009,30(6):611-621
The effects of different metallic vane-loaded helix slow-wave structures of a traveling-wave tube are proposed based on the
analysis of the Fourier expansions of the exterior region with metallic vanes. The influences of the metallic vanes dimensions
on the phase velocity and interaction impedance are considered in detail. The computed data is compared with the reference
data in the 0−16 GHz frequency range with a good consistency. The analytical results reveal that the method of using Fourier
expansions can contribute effectively to the reducing of the error between the theoretical and experimented data (around 1.2%).
By analyzing the computed results, the performances of the helix slow-wave structure, with T-shaped metallic vanes are superior
to the sector-shaped with the same designed parameters. Adjustments can be made to the outer radius of T-shaped metallic vanes
which then control the dispersion relation showing either negative or positive, and it is similar to sector-shaped vanes by
adjusting its inner radius. And with increasing the distance between the helix and metallic vanes, the dispersion characteristics
and interaction impedance of the helix slow-wave structure with T-shaped/sector-shaped metallic vane are all improved. 相似文献
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Jianxiang Xie Yanyu Wei Yubing Gong Jin Xu Wenxiang Wang 《Journal of Infrared, Millimeter and Terahertz Waves》2005,26(10):1473-1489
This paper gives the investigations of the fundamental wave of a free elliptical helix slow-wave structure (SWS) with arbitrary eccentricity. The wave properties including the phase velocity characteristics, interaction impedance and the longitudinal electric field distribution of this mode has been fully studied. It is found that, when the eccentricity increases, the interaction impedance and the operating frequency of such SWS will be improved, which allows to have a higher gain and operating in a higher frequency band. Furthermore, the field configuration is different from that of a round helix; the azimuthal distribution of the E-field follows with the angular Mathieu function of the first kind, even with mode of zero. In radial, E-field is elliptical surface wave. When the eccentricity tends to zero, all the characteristics will be smoothly degenerates to the case of round helix correspondingly. 相似文献
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为了满足土壤表面上方雷达目标检测、识别和分类等的需要,采用空间域合成法生成高度起伏遵守Alpha-stable分布的土壤表面,选用Topp模型模拟土壤的介电常数,运用矩量法研究了锥形波入射条件下土壤与其上方运动的三角形截面柱的复合电磁散射问题,通过数值计算得到了复合散射系数随散射角的变化曲线,分析了等边三角形和不规则三角形截面柱在土壤表面上方横向平移、纵向平移、转动以及电磁波入射角对复合散射系数的影响。数值计算结果表明:复合散射系数随散射角振荡地变化,等边三角形截面柱的纵向平移和转动对复合散射系数有较大的影响,而横向平移对复合散射系数的影响很小;不规则三角形截面柱的横向平移和纵向平移对复合散射系数产生的影响很小,转动对复合散射系数的影响较大。有关结果可为民用、军用领域工程问题提供理论依据和实践方法。 相似文献
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Mukesh Kumar Alaria A. Bera A. K. Sinha V. Srivastava 《Journal of Infrared, Millimeter and Terahertz Waves》2009,30(3):211-216
This paper describes the analysis of helix slow-wave structure (SWS) for a high efficiency space traveling wave tube that
is carried out using Ansoft HFSS and CST microwave studio, which is a 3D electromagnetic field simulators. Two approaches
of simulating the dispersion and impedance characteristics of the helix slow wave structure have been discussed and compared
with measured results. The dispersion characteristic gives the information about axial propagation constant (Beta). Which
in turn yields the phase velocity at a particular frequency. The dispersion and impedance characteristics can be used in finding
the pertinent design parameters of the helix slow-wave structure. Therefore a new trend has been initiated at CEERI to use
Ansoft HFSS code to analysis of the helix slow wave structure in its real environment. The analysis of the helix SWS for Ku-band
140W space TWT has been carried out and compared with experimental results, and found is close agreement. 相似文献
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王福谦 《光纤与电缆及其应用技术》2011,(5):1-3,11
利用复数坐标系z上的儒可夫斯基变换,给出椭圆柱传输线内的TEM波的电磁场分布规律,利用数学软件Matlab绘制出TEM波在椭圆柱传输线横向截面上的场结构图,并计算出其特性阻抗。 相似文献
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26.5-40GHz 高效率宽带毫米波行波管高频系统仿真设计 总被引:1,自引:1,他引:0
优化高频系统慢波结构参数,分析了慢波结构的材料及T 型夹持杆对高频损耗的影响,设计了一种未加载翼片结构的双渐变螺线26.5-40GHz 40W 宽带行波管,试验测试宽频带内电子效率超过12%,采用4 级降压收集极后总效率大于37%。 相似文献
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该文探讨了CVD金刚石材料在宽带毫米波螺旋线行波管中的应用,研究了两类非杆状新型CVD金刚石夹持的螺旋线高频结构,利用MAFIA分析了它们的色散特性、耦合阻抗和衰减常数,与传统的矩形BeO夹持杆和矩形CVD夹持杆高频结构进行了对比,最后将这两类新型高频结构替代国内某毫米波行波管(26-40GHz)中的矩形BeO夹持杆螺旋线高频结构,利用宽带大功率行波管CAD集成环境中的注波互作用模块分析了其大信号工作特性。结果表明,分立CVD金刚石夹持高频系统兼顾了超宽带和大功率,同时由于金刚石直接和螺旋线及金属翼片大面积接触,该结构还具有极好的散热能力,是一种有重要应用前景的高频结构。 相似文献
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本文研究了一种具有新型分立介质支撑的翼片加载螺旋带慢波系统,该种慢波系统具有较高的功率容量和较宽的带宽.通过用切比雪夫多项式来展开螺旋带上的面电流,用真空层来模拟螺旋带的厚度,用均匀分层介质来等效新型分立介质支撑,考虑到过渡连接金属块的影响,用场论的方法得到了非常实用的色散方程和耦合阻抗的表达式,同时进行了HFSS模拟,发现用场论的方法所得出的结果与用HFSS模拟的结果吻合良好.本文的结果对这种新型慢波结构的设计具有指导意义. 相似文献
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Design formulas for helix dispersion shaping 总被引:9,自引:0,他引:9
《Electron Devices, IEEE Transactions on》1969,16(12):1010-1014
A simple method of calculating effects of various boundaries around the helix on the dispersion relation and the interaction impedance is presented. The analytical technique is based on the use of equivalent circuit parameters derived from rigorous field analyses. The main advantage of this method is that effects of various perturbing objects (dielectrics, shields, etc.) can be calculated independently, regardless of the model of the unperturbed system. Equivalent circuit parameters are obtained for helices with several different forms of perturbing boundaries, including wedge-shaped dielectric rods, conducting boundaries, longitudinally conducting wires and fins, and combinations of these. The method of analysis is versatile so that the dispersion relation for any one particular form of the helix may be calculated from known characteristics of another using only three sets of universal curves. 相似文献