The use of multi-section slow wave circuits is an effective method to improve output power and efficiency of traveling wave tubes(TWTs). This article discusses the selection for the positions and widths of severs in sub-millimeter wave three-section TWTs by numerical simulation. Based on the existing E-band two-section TWT, a three-section interaction circuit was designed and simulated output powers and electronic efficiencies of the two were compared while maintaining the same operating voltage, operating current and total interaction length. The general methods for severs of sub-millimeter wave multi-stage TWTs are summarized.

A broadband E-band continuous wave (CW) 120W Traveling Wave Tube (TWT) is developed to meet the requirements of high resolution radar. A new type of non-concentric serpentine wave-guide circuit with variable narrow edges (NSWC) and a dual anode long-range electron gun are adopted in this E-band CW TWT. The first prototype tube has been assembled and tested. Within 5GHz operation bandwidth of 81-86 GHz, this TWT provides saturated output power of more than 120.4 W and -1dB compression point powers of more than 88.81W with saturated gain higher than 32.83dB. This work achieves high saturated output power and -1dB compression point powers comparing with other existing E-band CW TWTs.

Hybrid beamformers based on the sub-connected subarray architectures have been employed for multi-beam multiplexing with reduced implementation cost and complexity. To further lower the system requirement, the interleaved/localised and overlapped subarray architectures, where each antenna is associated with one and multiple analogue coefficients, respectively, are employed for joint optimisation of antenna selection and phase-only analogue beamforming. In the proposed design, antenna number minimisation is achieved by sparsity based optimisation and the selected antennas share an equal magnitude for their analogue beamforming coefficients. Design examples are provided to demonstrate the effectiveness of our solutions.

A broadband E-band continuous-wave (CW) 100-W traveling-wave tube (TWT) is developed to meet the requirements of radar and electronic warfare systems. The following methods are adopted in this E-band CW TWT to expand the operation bandwidth, improve the gain flatness, and increase the output power: flat dispersion curves and high coupling impedance by adopting a new type slow wave structure of nonconcentric serpentine waveguide circuit with variable narrow edges (NSWC), improved output power in the high-frequency end by using the positive and negative phase velocity jump technology, high electron beam transmission by a dual-anode long-range electron gun, and minimized reflection within the widest possible frequency band by sapphire box windows with linear double gradient transition waveguides. The first prototype tube has been assembled and tested. Within 8-GHz operation bandwidth of 80-88 GHz, this TWT provides the saturated output power of more than 112.9 W and -1-dB compression point powers of more than 81.44 W. The saturated gain and the small signal gains are higher than 32.37 dB with fluctuations less than 2.23 and 34.92 dB with fluctuations less than 4.96 dB, respectively. Compared with other existing CW TWTs in E-band, this TWT has a wider operating bandwidth, higher linear output power, and better gain flatness.

伴随着卫星通信系统对可变且高效载荷的需求,空间行波管放大器将加速由单机专用模式向功率可调多任务模式发展.为解决功率可调空间行波管在不同输出功率条件下保持高效率的设计难点,针对某Ku波段螺旋线辐冷型空间行波管开展了功率可调高效率的研究.通过设计提高行波管在不同阳极电压下的电子效率、收集极效率和电子流通率,使Ku波段行波管在500 MHz工作带宽内连续波输出功率大于150 W,总效率大于68％,输出功率回退3 dB时整管效率大于60％.

采用计算机模拟的方法对一种基于双排矩形波导慢波结构(SDRWS)的340 GHz返波管进行详细研究.首先对返波管所需的电子枪和永磁聚焦系统进行计算机模拟,结果表明,永磁聚焦系统与电子枪相结合,能够产生并维持14～17 kV,43.4 mA的电子注和18～21 kV,56.1 mA的电子注,且电子注电压在14～21 kV之间时,电子注在慢波结构区域的最大半径小于0.08 mm,半径波动最大值为0.034 mm.利用所计算的电子注,对基于SDRWS的340 GHz返波管进行互作用计算,结果表明,当电子注电压在14～21 kV之间调谐时,输出电磁波在326～352.6 GHz之间,输出功率大于2 W.同时,SDRWS的电子注通道半径为0.09 mm,相对较大,降低了返波管的制造难度.

An extended interaction oscillator(EIO) based on a single cavity composed of 12 periods of staggered double rectangular waveguide slow wave structure (SDRWSWS) is modeled and calculated on computer, those methods and steps for determining the structural parameters and the beam parameters are given. A new method called "phase re-synchronization technology" is proposed to improve electron efficiency of EIO, the method is to decrease the periods of the fifth and sixth periods of SDRWSWS counted from the entrance of the beam by 10%, so that the magnitude of the z component of electric field intensity becomes weaker in the segment which is far from the output port, but becomes stronger in the segment which is near from the output port, and such an E-z distribution is in favor of good bunching in the beam as the beam is proceeding. On the other hand, the phase of the z component of electric field intensity increases about 51. 6 degrees between the 7 to 12 periods, so that the electric field maintains synchronization with the space electric charge wave in the beam and abstracts more kinetic energy from the beam. Computer simulation results show that both power and electron efficiency become higher conspicuously , the maximum improved values are over double of unimproved ones.

作为微波功率模块的核心部件,行波管被广泛应用于通信、雷达以及电子对抗等众多军事装备系统中.为解决行波管小型化、高效率的技术难点,针对某X波段螺旋线行波管的输能耦合结构开展小型化研究.采用在螺旋线末端加载调配筒实现输能系统长度压缩的方法,不但可以使行波管的输入窗阻抗变换尺寸缩短33.0％;输出窗阻抗变换尺寸缩短21.4％,而且行波管整管效率得到提升.

An extended interaction klystron, which is composed of an input cavity and an output cavity both based on 8 periods of staggered double rectangular waveguide structure (SDRWS) and an intermediate cavity based on 6 periods of SDRWS, is calculated in details on computer. After calculating S 11 of the input cavity and an output cavity and the eigenmodes of the intermediate cavity, the structural parameters of the input cavity and an output cavity and the intermediate cavity are determined, then PIC simulation is done to predict the ElK's performance, the results show that the EIK has an 1 GHz-wide of 3 dB band which cover 219.5-220.5GHz, a 456 W of maximum power and a 40.06 dB of maximum gain. Furthermore, stagger tuning by adjusting the structural parameter a of the intermediate cavity is performed to analyse how a affects the ElK's performances, and the results show that the 3 dB band of the EIK mainly depends on the passband of the input cavity and an output cavity, but also depends on the resonant frequency of the intermediate cavity in some cases. When the resonant frequency of the intermediate cavity is located at the lower or higher ends of the passband of the input cavity and an output cavity, the 3 dB band of the EIK may be extended to certain extent. Particularly, when the resonant frequency of the intermediate cavity is located at or beyond the higher ends of the passband of the input cavity and an output cavity, it is verified that the EIK has steady output signal featuring with pure spectrum and has flat gains over the 3 dB band. The final results of the stagger tuning show that, when the structural parameter a of the intermediate cavity is 0.747 mm, the EIK reaches almost the optimum performances, with an 1 GHz-wide of 3 dB band which cover 219.5-220.7GHz, a 630 W of maximum power companied with a 11.3% of efficiency, and a 47 dB of maximum gain.

采用谐振法,基于小孔耦合设计了W波段矩形槽交错双栅色散测试方案.考虑了倒圆角带来的影响,采用精密计算机数控技术(CNC)工艺加工慢波结构进行测试,获得了辨识较高的谐振峰,得到了0～π相移范围内所有对应的本征谐振点.基于小孔耦合谐振法的仿真值与严格谐振法、准周期法的仿真值相比最大偏差0.1％,证明了色散测试方案的合理性.基于小孔耦合谐振法的实测值与仿真值相比最大偏差0.3491％,充分说明慢波结构的加工精度满足工程应用需求,这些结果为深入开展下一步试验打下良好基础.

对一种基于双排矩形波导慢波结构(SDRWS)结构的3腔EIK进行了详细计算机模拟计算,通过对基于SDRWS结构的EIK用输入输出腔的S11的模拟计算及对分布作用速调管用中间腔的本征频率的模拟计算,初步确定了EIK用输入输出腔及中间腔的结构参数,进而对EIK进行了PIC互作用模拟计算,结果表明:该EIK的3 dB工作频带为219.5～220.5 GHz,3 dB带宽为1 GHz,最大功率为456 W,最大增益为40.06 dB.在此基础上,通过调整中间腔的波导头宽度以进行参差调谐,用PIC互作用模型模拟计算研究了中间腔谐振频率对EIK整体性能的影响.结果表明,EIK的3 dB工作频带主要由输入输出腔的通频带决定,而中间腔的谐振频率也具有重要影响.当中间腔的谐振频率分别处于输入输出腔的通频带的低频端或高频端时,可以使EIK的3 dB工作频带向低频端或高频端得到一定程度展宽;当中间腔的谐振频率高于输入输出腔的通频带的高频端时,EIK的增益在其3 dB工作频带内较为平坦,EIK的输出信号在其3 dB工作频带内比较稳定,频谱的纯净程度较好.参差调谐的最终结果表明,当中间腔的波导头宽度为0.747 mm时,EIK获得了接近最优的性能,3 dB工作频带为219.5～220.0 GHz,3 dB带宽扩展到1.2 GHz,最大功率为630 W,相应的最大电子效率为11.3％,最大增益为47 dB.

Beam-wave interaction for a W band traveling wave tube(TWT)based on staggered double rectangular waveguide structure(SDRWS)is calculated by CST PIC,showing that the TWT has over 35 W output power and over 30 dB gain and about 5% electron efficiency from 92 GHz to 97 GHz on the condition of a 10 kV,70 mA beam.Even if the beam voltage of 10 kV is relatively low,the sizes of SDRWS still remain relatively large,meaning that SDRWS is in favor of evading the difficul-ties in manufacturing.A process based on wire electrical discharge machining(wire-EDM)is proposed to manufacture SDRWS for W band TWT,and an SDRWS assembly is successfully obtained.Besides,box-shaped window and electron gun are also simula-ted by computer,and correspondent parts are manufactured and then put together into assemblies.Then"cold test"is performed on an SDRWS assembly put together with two box-shaped windows,showing that voltage standing wave ratio is lower than 2.067 from 92 GHz to 100 GHz.

In order to improve the rationality of sound diffuser design algorithm to reduce the computational complexity , the scatter diagram decision and ε-MOPSO based schroder sound diffuser multi objective design method was proposed .Firstly, the Fraunhofer theory was used to establish the quantitative method for sound diffusion char-acteristics of Schroder diffusion , which could obtained the diffusion coefficient of 1/3 octave band , and used the normalization method to eliminate the edge diffraction scattering effect under the limit size .Secondly , the sound dif-fusion multi-objective optimization model was built , and by resetting the diffusion coefficient , the problem of repeat-ed and equivalent diffusion can be eliminated .Then using the ε-MOPSO algorithm to divided the target space into a fixed number of n grid, so as to maintain the population diversity of solutions , and achieve sound diffuser parame-ter optimization , the dispersion diagram of the decision mode was selected to achieve the ultimate diffuser design . Finally, three different design models by simulation were evaluated and selected .

Using CST Microwave Studio,the dispersion characteristics of a staggered double rectangular grating slow wave structure(SDRG SWS)is calculated,and the structure parameters of SDRG SWS for a 0.22 THz(D band)traveling wave tube (TWT)are determined based on the dispersion data.Then phase velocity re-synchronization techniques are applied in D band TWT based on SDRG SWS,and four D band TWTs which have different period configurations are simulated by CST PIC solver. The results demonstrate that the phase velocity re-synchronization techniques have raised output power level from 10-13 W to 1 9-28 W,as well as electron efficiency from 1.4%-2.2% to 2.6%-3.9% within 218-232 GHz in those TWTs which has a concen-trated attenuator,and have raised output power level from 8-1 6.8 W to 32-41 W,as well as electron efficiency from 1.5%-2.8%to 4.4%-5.7% within 218-232 GHz in those TWTs which has not a concentrated attenuator.Besides,whether a TWT has a con-centrated attenuator or not,phase velocity re-synchronization techniques have obviously improved its’gain flatness.

A three dimensional (3-D) nonlinear analysis of the beam-wave interaction in the single-grating rectangular waveguide (SGRW) sheet-beam Back-ward Wave Oscillator (BWO) is presented, in which space-charge effects and conductivity losses are considered. The results are compared with those obtained by CST-PS code PIC simulations.

基于ANSYS有限元分析软件的热分析功能,在匹配吸收和材料高温环境稳定工作的条件下,对0.1 THz波功率探头两种不同结构的功率敏感体进行建模,在0~50 m W输入功率条件下,仿真计算它们的温度分布,通过比较温差大小、达到温度平衡稳定的时间以及材料的温度承受能力等,确定哪种结构使探头性能更好,能更准确地定标。

A three dimensional (3-D) nonlinear model for illustrating the beam-wave interaction in a single-grating rectangular waveguide sheet-beam Cerenkov maser is presented. The dynamical equations and the equations of motion are solved self-consistently to predict the device performance. Space-charge effects and Ohmic losses are considered in the model. A 1.03 THz backward wave oscillator and a 0.65 THz traveling wave tube are discussed as two illustrative examples.

A 3-D frequency domain large signal code called sheet beam traveling-wave tube 3-D (SBTWT3-D) for illustrating the nonlinear beam-wave interaction in the SBTWT is presented in this paper. A recent published field theory model for illustrating the staggered double-grating arrays waveguide (SDGAW) slow-wave structure is adopted in the code to obtain the RF circuit fields' distribution and ohmic loss. The sheet beam is simulated by a set of discrete rays. The ac and dc space-charge fields are obtained by solving the discrete Helmholtz equations and the discrete Poisson equation, respectively. A 3-D nonlinear beam-wave interaction analysis for a W-band SDGAW SBTWT is performed and the calculation results are compared with those obtained from time-domain 3-D particle-in-cell simulations.

Based on a sheet electron beam propagating through the tunnel of a staggered double-grating arrays waveguide (SDGAW) slow-wave structure (SWS), a three dimensional linear theory for describing beam-wave interaction is presented, in which the higher order terms inside the groove were retained. With the optimized parameters, a 1THz SDGAW Cerenkov traveling wave amplifier (CTWA) may obtain a moderate net gain larger than 10dB/cm in 0.92THz to 1.145THz considering the serious Ohmic losses in THz frequency range.

实现了一种基于DSP的GIS局部放电检测仪。采用宽频带的压电薄膜声电传感器将局部放电产生的声信号或超声信号转化为电信号,通过DSP片内高速AD对来自超声传感器的信号进行采样,并对是否抓取到放电信号进行初步智能判断。确认有局部放电发生后,依次显示被抓取的放电信号的波形、幅度和频率。在用户现场测试的结果表明,通过比较多台检测仪的检测结果,可以将局部放电位置定位于GIS设备的两个绝缘环之间。