共查询到20条相似文献,搜索用时 27 毫秒
1.
M. Sumathy K. J. Vinoy S. K. Datta 《Journal of Infrared, Millimeter and Terahertz Waves》2009,30(2):151-158
A simple equivalent circuit model for the analysis of dispersion and interaction impedance characteristics of serpentine folded-waveguide
slow-wave structure was developed by considering the straight and curved portions of structure supporting the dominant TE
10-mode of the rectangular waveguide. Expressions for the lumped capacitance and inductance per period of the slow-wave structure
were derived in terms of the physical dimensions of the structure, incorporating the effects of the beam-hole in the lumped
parameters. The lumped parameters were subsequently interpreted for obtaining the dispersion and interaction impedance characteristics
of the structure. The analysis was simple yet accurate in predicting the dispersion and interaction impedance behaviour at
millimeter-wave frequencies. The analysis was benchmarked against measurement as well as with 3D electromagnetic modeling
using MAFIA for two typical slow-wave structures (one at the Ka-band and the other at the W-band) and close agreement observed. 相似文献
2.
M. Sumathy K.J. Vinoy Subrata Kumar Datta 《AEUE-International Journal of Electronics and Communications》2010,64(12):1192-1195
A simple yet accurate equivalent circuit model was developed for the analysis of slow-wave properties (dispersion and interaction impedance characteristics) of a rectangular folded-waveguide slow-wave structure. Present formulation includes the effects of the presence of beam-hole in the circuit, which were ignored in existing approaches. The analysis was benchmarked against measurement as well as with 3D electromagnetic modeling using MAFIA for two typical slow-wave structures operating in Ka- and Q-bands, and close agreements were observed. The analysis was extended for demonstrating the effect of the variation of beam-hole radius on the RF interaction efficiency of the device. 相似文献
3.
Murugan Sumathy Subrata Kumar Datta 《Journal of Infrared, Millimeter and Terahertz Waves》2017,38(5):538-547
A single-section slow-wave structure for a W-band folded-waveguide traveling-wave tube with operating bandwidth of around 4% was designed for delivering the output power of 50 W at the operating voltage of 13.5 kV and operating beam current of 80 mA. The design was carried out using analytical formulations and 3D electromagnetic simulations. The beam-wave interaction analysis was carried out using large signal Lagrangian analysis and particle-in-cell simulation. The folded-waveguide slow-wave structure along with input-output couplers and RF windows were fabricated. Cold test measurements were carried out for dispersion characteristics of the slow-wave structure and voltage standing-wave ratio and insertion loss characteristics of the RF window. The measured cold circuit parameters show close agreement with the analysis. 相似文献
4.
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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《Electron Devices, IEEE Transactions on》1957,4(1):70-78
Periodic traveling-wave tube gain fluctuations with frequency are described in terms of fundamental tube parameters and readily measurable quantities using the simplified one-wave theory of Pierce. An analysis of the feedback existing in a traveling-wave amplifier due to mismatches in the discontinuity regions is presented. Thus, the form, periodicity, and magnitude of these fluctuations and their dependence upon the beam voltage are quantitatively determined. The microwave structure is analyzed from a network point of view and the circuit parameters are defined with mismatches in the lumped center attenuator and at the ends of the slow-wave transmission line. The gain fluctuations are related to the cold circuit parameters and standing wave measurements. Pertinent experimental data, indicating the correlation of gain fluctuations to vswr variations, are included, in addition to an elementary discussion of the distortion effects possible due to such periodic gain variations in a traveling-wave tube. 相似文献
7.
平面人工传输线是一款性能良好的新型慢波结构,主要由弯曲线电感、交指电容等微带准集总元件构成。系统研究了弯曲线电感和交指电容的等效集总参数随结构参数变化的规律并给出反映这些规律的经验公式,考虑微带介质基板厚度和介电常数的影响,将所得经验公式进行修正使之适用于不同介质基板厚度和介电常数的情况,将修正的经验公式应用于基于平面人工传输线的威尔金森功分器的设计中。所得经验公式可用来快速、准确地设计平面人工传输线,对其他微带不连续或慢波结构的设计也具有参考意义。 相似文献
8.
A Simple and Accurate Analysis of Conductivity Loss in Millimeter-Wave Helical Slow-Wave Structures 总被引:1,自引:0,他引:1
S. K. Datta Lalit Kumar B. N. Basu 《Journal of Infrared, Millimeter and Terahertz Waves》2009,30(4):381-392
Electromagnetic field analysis of a helix slow-wave structure was carried out and a closed form expression was derived for
the inductance per unit length of the transmission-line equivalent circuit of the structure, taking into account the actual
helix tape dimensions and surface current on the helix over the actual metallic area of the tape. The expression of the inductance
per unit length, thus obtained, was used for estimating the increment in the inductance per unit length caused due to penetration
of the magnetic flux into the conducting surfaces following Wheeler’s incremental inductance rule, which was subsequently
interpreted for the attenuation constant of the propagating structure. The analysis was computationally simple and accurate,
and accrues the accuracy of 3D electromagnetic analysis by allowing the use of dispersion characteristics obtainable from
any standard electromagnetic modeling. The approach was benchmarked against measurement for two practical structures, and
excellent agreement was observed. The analysis was subsequently applied to demonstrate the effects of conductivity on the
attenuation constant of a typical broadband millimeter-wave helical slow-wave structure with respect to helix materials and
copper plating on the helix, surface finish of the helix, dielectric loading effect and effect of high temperature operation
– a comparative study of various such aspects are covered. 相似文献
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10.
本文选用矩形耦合腔作为太赫兹扩展互作用振荡器(EIO)的慢波结构,鉴于其结构的复杂性,采用等效电路方法计算其色散.详细研究了腔体和耦合槽的电路参数,计算了不同结构尺寸、圆形和矩形电子通道的0.12THz和0.225THz慢波结构的色散特性.并采用专业电磁软件,研究了不同结构参数下的色散特性、耦合阻抗和特征阻抗.通过对色... 相似文献
11.
《Electron Devices, IEEE Transactions on》1970,17(4):383-384
A slow-wave structure intended for use in solid-state traveling-wave amplifiers is described. The structure is a meander line with adjacent conducting elements electrically connected by lumped capacitors. The dispersion curve is derived and shown to agree with experiment. The structure is found to have a passband which is dependent on the coupling capacitors. The interaction impedance is estimated. 相似文献
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13.
《Solid-State Circuits, IEEE Journal of》1973,8(4):269-275
Describes an approach to the design of Schottky-clamped integrated circuit transistor layouts. Three-dimensional distributed resistances are modeled using a grid of lumped resistors. A computer circuit analysis program is used to obtain a simple lumped equivalent circuit for the clamped transistor. The equivalent circuit enables accurate prediction of the useful range of d.c. operating conditions for a given structure. An improved small-area clamped transistor layout has been developed using this approach. 相似文献
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文中提出了一种能在两个工作频段对高功率微波进行自适应防护的双频能量选择表面,它由两个分
别加载了二极管和集总电容的开口谐振环构成,在C 波段(5. 4~6. 0 GHz)和S 波段(2. 6~2. 8 GHz)各产生一个信号
通带。当入射波的场强超过设定阈值时,二极管被谐振环上的感应电压导通,使得谐振环的谐振状态发生变化,两
个信号通带自动关闭,从而屏蔽高功率微波。通过表面电流和电场分布阐述了设计思路和工作原理。采用PCB 工
艺制作了样件并分别在弱场和高功率辐照下进行了传输系数的测量实验。仿真和实验结果具有良好的一致性,表
明双频能量选择表面在两个信号通带的插入损耗均小于1 dB,防护效果大于15 dB(其中C 波段的信号通带内防护
效果大于25 dB),能对高功率微波进行有效防护。 相似文献
17.
S. V. Mukhin 《Journal of Communications Technology and Electronics》2012,57(12):1276-1286
A model of the slow-wave cavity structures that can be used for the analysis of electrodynamic parameters and excitation by the fixed current is electrodynamically substantiated. A possibility of the calculation of electrodynamic parameters using the 3D simulation is demonstrated for the slow-wave cavity structures. The calculated electrodynamic parameters of the two- and four-port slow-wave structures are presented. 相似文献
18.
Daniel Mitrani Jordi Salazar Antoni Turó Miguel J. García Juan A. Chávez 《Microelectronics Journal》2009,40(9):1398-1405
Based on simplified one-dimensional steady-state analysis of thermoelectric phenomena and on analogies between thermal and electrical domains, we propose both lumped and distributed parameter electrical models for thermoelectric devices. A couple of important advantages of the presented models are that the temperature dependence of material properties is considered and that they can be easily simulated using an electronic simulation tool such as SPICE. For a single free-standing pellet, comparisons are made between SPICE simulations using the proposed models and with numerical simulations carried out with Mathematica software. Results illustrate accuracy of the distributed parameter models and show how inappropriate it is to assume, in some cases, constant material parameters for an entire thermoelectric element. 相似文献
19.
基于GaN功率器件工艺自主研发的大栅宽GaN高电子迁移率晶体管(HEMT)管芯,采用内匹配技术和宽带功率合成技术相结合的方法,研制出了一款C波段160 W连续波GaN HEMT内匹配功率器件。通过优化管芯的结构,设计出了满足连续波使用要求的大功率GaN管芯,然后进行了内匹配器件的设计,在设计中首先采用负载牵引法进行了器件参数提取,并以此为基础设计了阻抗变换网络进行阻抗变换和功率合成。研制出了工作频率为4.4~5.0 GHz、工作电压32 V、连续波输出功率大于160 W、功率附加效率大于50%、功率增益大于12 dB的GaN HEMT内匹配功率管,具有广阔的工程应用前景。 相似文献
20.
Interwinding planar micro-transformers are developed using micro-machining technique. The transformers with a vertically stack coil structure on silicon monolithic substrate are designed to achieve high coupling and high inductance value in a relatively small coil area. In this work, various types of stack interwinding transformer are fabricated, measured and compared. The results show that the metal-to-metal effect of a multi-layer structure contributes to the significant increase of parasitic capacitances and hence limits the operating frequency. Moreover, the lumped element parameters are analyzed by extracting the measured S-parameter. This investigation can give important information for the future development of three-dimensional RF devices. 相似文献