A novel slotted helix slow-wave structure （SWS） is proposed to develop a high power, wide-bandwidth, and high reliability millimeter-wave traveling-wave tube （TWT）. This novel structure, which has higher heat capa...A novel slotted helix slow-wave structure （SWS） is proposed to develop a high power, wide-bandwidth, and high reliability millimeter-wave traveling-wave tube （TWT）. This novel structure, which has higher heat capacity than a conven- tional helix SWS, evolves from conventional helix SWS with three parallel rows of rectangular slots made in the outside of the helix tape. In this paper, the electromagnetic characteristics and the beam-wave interaction of this novel structure operating in the Ka-band are investigated. From our calculations, when the designed beam voltage and beam current are set to be 18.45 kV and 0.2 A, respectively, this novel circuit can produce over 700-W average output power in a frequency range from 27.5 GHz to 32.5 GHz, and the corresponding conversion efficiency values vary from 19% to 21.3%, and the maximum output power is 787 W at 30 GHz.展开更多
The study on a miniaturized, low-voltage, wide-bandwidth, high-efficiency modified V-shaped microstrip meander-line slow-wave structure is presented. This structure is evolved from the original U-shaped microstrip mea...The study on a miniaturized, low-voltage, wide-bandwidth, high-efficiency modified V-shaped microstrip meander-line slow-wave structure is presented. This structure is evolved from the original U-shaped microstrip meander-line slow-wave structure, combining the advantages of a traditional microstrip and a rectangular helix. In this paper, simulations of the electromagnetic characteristics and the beam-wave interaction of this structure are carried out. Our study shows that when the design voltage and the current of a sheet electron beam are set to be 4700 V and 100 mA, respectively, this miniature millimeter-wave power amplifier is capable of delivering 160-W output power with a corresponding gain of 37.3 dB and a maximum interaction efficiency of 34% at 97 GHz.展开更多
A three-dimensional model of the double-slot coupled cavity slow-wave structure （CCSWS） with a solid round elec- tron beam for the beam-wave interaction is presented. Based on the ＂cold＂ dispersion, the ＂hot＂ di...A three-dimensional model of the double-slot coupled cavity slow-wave structure （CCSWS） with a solid round elec- tron beam for the beam-wave interaction is presented. Based on the ＂cold＂ dispersion, the ＂hot＂ dispersion equation is derived with the Maxwell equations by using the variable separation method and the field-matching method. Through numerical calculations, the effects of the electron beam parameters and the staggered angle between adjacent walls on the linear gain are analyzed.展开更多
On the basis of a rigorous field theory, two different physical models of attenuator and sever have been proposed. One is named High attenuation （HATT） model in which both attenuator and sever are considered as a un...On the basis of a rigorous field theory, two different physical models of attenuator and sever have been proposed. One is named High attenuation （HATT） model in which both attenuator and sever are considered as a unified attenuator, but the sever is regarded as an area of very high loss; the other is called Sever and attenuator （SATT） model in which the sever is modelled as a drift area in which the electric and magnetic fields both vanish. A complex function is derived and potential sinking effect is also considered. Thus, a set of more practical self-consistent equations of nonlinear beam-wave interaction is formulated. Simulations are carried out under the conditions of the two different physical models, and the simulation results are compared with the experimental data. The results show that in the case of single signal drive, the unknown second harmonic should be included for predicting the saturated output power. It is also evident that the SATT model and the HATT model predict the same physical nature, whereas the results predicted by the HATT model are much closer to the experimental data than those obtained from the SATT model. Therefore, these results provide a strong theoretical basis for designing broadband and high gain helix travelling wave tubes.展开更多
The paper mainly presents the design of beam-wave interaction of a C-band high-peakpower high-efficiency broadband klystron.The beam-wave interaction section is designed based on considerations of efficiency and bandw...The paper mainly presents the design of beam-wave interaction of a C-band high-peakpower high-efficiency broadband klystron.The beam-wave interaction section is designed based on considerations of efficiency and bandwidth synthetically.As a part of beam-wave interaction section,buncher section is simulated by Particle-In-Cell(PIC) code to observe the bunching process of electron beam to achieve high conversion efficiency of electron beam and RF field.When it comes to the other part,output circuit is designed as a three-section filter by an output cavity loaded with Chebyshev filter,and the cold test results are given.The beam-wave interaction is simulated by EGUN code and Arsenal-MSU code respectively.The simulated results indicated that,the existence of power dips in the operating bandwidth is verified by Arsenal-MSU code,comparing proper results by EGUN code.Then,the method that design parameters are not adjusted except parameters of buncher cavities to remove potential power dips is described.What is more,the simulated results of electron optics system are given by EGUN code and Arsenal-MSU code respectively.The further hot test results of klystron prove that the whole design of beam-wave interaction is effective.展开更多
A linear theory of a rectangular Cerenkov maser （RCM） with a sheet electron beam is developed by using the field- match method. Based on the three-dimensional beam-wave interaction model proposed in this paper, a hy...A linear theory of a rectangular Cerenkov maser （RCM） with a sheet electron beam is developed by using the field- match method. Based on the three-dimensional beam-wave interaction model proposed in this paper, a hybrid-mode dispersion equation and its analytical solution are derived for the RCM. Through numerical calculations, the effects of the beam-grating gap, beam thickness, current density, beam voltage and waveguide width on the linear growth rate axe analysed. Moreover, the performance difference between the RCM with the closed transverse boundary and that with the upper open boundary is compared. The results show that the closed RCM model can avoid the effect of RF radiation on beam-wave interaction, which is more rational for practical applications.展开更多
A linear and nonlinear analysis of crossed-field gyrotron operating on whispering-gallery mode TE<sub>m11</sub> is presented. The detailed discussions are given for the starting oscillationcondition, the e...A linear and nonlinear analysis of crossed-field gyrotron operating on whispering-gallery mode TE<sub>m11</sub> is presented. The detailed discussions are given for the starting oscillationcondition, the effect of the internal conductor in coaxial cavity on the cut-off frequency of modeand the spacing between adjacent modes as well as the effect of the applied voltage on thecyclotron frequency of electron, the starting oscillation beam power and the electron efficiency.It is shown that the efficiency of 41% can be attained for m=2. A comparison of these resultswith those in cylindrical cavity is made. The analyses are helpful for the engineering design.展开更多
A three-dimensional model of a dielectric-loaded rectangular Cerenkov maser with a sheet electron beam for the beam-wave interaction is proposed.Based on this model,the hybrid-mode dispersion equation is derived with ...A three-dimensional model of a dielectric-loaded rectangular Cerenkov maser with a sheet electron beam for the beam-wave interaction is proposed.Based on this model,the hybrid-mode dispersion equation is derived with the Borgnis potential function by using the field-matching method.Its approximate solution is obtained under the assumption of a dilute electron beam.By using the Ansoft high frequency structural simulator（HFSS） code,the electromagnetic field distribution in the interaction structure is given.Through numerical calculations,the effects of beam thickness,beam and dielectric-layer gap distance,beam voltage,and current density on the resonant growth rate are analysed in detail.展开更多
带状注相对论扩展互作用速调管放大器是一种高功率、高频率的微波毫米波放大型器件,具有广阔的应用前景.本文分析了扩展互作用结构多间隙谐振腔的渡越时间效应,推导了2π模场情况下谐振腔的能量交换系数和电子负载电导,且通过计算表明...带状注相对论扩展互作用速调管放大器是一种高功率、高频率的微波毫米波放大型器件,具有广阔的应用前景.本文分析了扩展互作用结构多间隙谐振腔的渡越时间效应,推导了2π模场情况下谐振腔的能量交换系数和电子负载电导,且通过计算表明工作在2π模式三间隙腔的电子负载电导是单间隙腔的9倍左右,多间隙结构有利于提高器件效率.利用三维粒子仿真软件,对工作在Ka波段的带状注相对论扩展互作用速调管放大器进行了模拟研究,采用宽高比为30:1的带状电子束以降低空间电荷效应,在电子束电压为500 kV,束流为1 k A,轴向引导磁感应强度为0.8 T的情况下,器件输出微波功率为190 MW,频率为40 GHz,器件效率为38%,器件增益为69 d B.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61271029)the Natural Science Key Laboratory Foundationthe Natural Science Fund for Distinguished Young Scholars of China(Grant No.61125103)
文摘A novel slotted helix slow-wave structure （SWS） is proposed to develop a high power, wide-bandwidth, and high reliability millimeter-wave traveling-wave tube （TWT）. This novel structure, which has higher heat capacity than a conven- tional helix SWS, evolves from conventional helix SWS with three parallel rows of rectangular slots made in the outside of the helix tape. In this paper, the electromagnetic characteristics and the beam-wave interaction of this novel structure operating in the Ka-band are investigated. From our calculations, when the designed beam voltage and beam current are set to be 18.45 kV and 0.2 A, respectively, this novel circuit can produce over 700-W average output power in a frequency range from 27.5 GHz to 32.5 GHz, and the corresponding conversion efficiency values vary from 19% to 21.3%, and the maximum output power is 787 W at 30 GHz.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60971038)the Fundamental Research Funds for the Central Universities (Grant No. ZYGX2009Z003)
文摘The study on a miniaturized, low-voltage, wide-bandwidth, high-efficiency modified V-shaped microstrip meander-line slow-wave structure is presented. This structure is evolved from the original U-shaped microstrip meander-line slow-wave structure, combining the advantages of a traditional microstrip and a rectangular helix. In this paper, simulations of the electromagnetic characteristics and the beam-wave interaction of this structure are carried out. Our study shows that when the design voltage and the current of a sheet electron beam are set to be 4700 V and 100 mA, respectively, this miniature millimeter-wave power amplifier is capable of delivering 160-W output power with a corresponding gain of 37.3 dB and a maximum interaction efficiency of 34% at 97 GHz.
基金Project supported by the National Natural Science Foundation of China(Grant No.11205162)
文摘A three-dimensional model of the double-slot coupled cavity slow-wave structure （CCSWS） with a solid round elec- tron beam for the beam-wave interaction is presented. Based on the ＂cold＂ dispersion, the ＂hot＂ dispersion equation is derived with the Maxwell equations by using the variable separation method and the field-matching method. Through numerical calculations, the effects of the electron beam parameters and the staggered angle between adjacent walls on the linear gain are analyzed.
基金supported by the National Natural Science Foundation of China (Grant Nos 60601007 and 60532010)the Youth Science and Technology Foundation of University of Electronic Science and Technology of China (Grant No JX05018)
文摘On the basis of a rigorous field theory, two different physical models of attenuator and sever have been proposed. One is named High attenuation （HATT） model in which both attenuator and sever are considered as a unified attenuator, but the sever is regarded as an area of very high loss; the other is called Sever and attenuator （SATT） model in which the sever is modelled as a drift area in which the electric and magnetic fields both vanish. A complex function is derived and potential sinking effect is also considered. Thus, a set of more practical self-consistent equations of nonlinear beam-wave interaction is formulated. Simulations are carried out under the conditions of the two different physical models, and the simulation results are compared with the experimental data. The results show that in the case of single signal drive, the unknown second harmonic should be included for predicting the saturated output power. It is also evident that the SATT model and the HATT model predict the same physical nature, whereas the results predicted by the HATT model are much closer to the experimental data than those obtained from the SATT model. Therefore, these results provide a strong theoretical basis for designing broadband and high gain helix travelling wave tubes.
文摘The paper mainly presents the design of beam-wave interaction of a C-band high-peakpower high-efficiency broadband klystron.The beam-wave interaction section is designed based on considerations of efficiency and bandwidth synthetically.As a part of beam-wave interaction section,buncher section is simulated by Particle-In-Cell(PIC) code to observe the bunching process of electron beam to achieve high conversion efficiency of electron beam and RF field.When it comes to the other part,output circuit is designed as a three-section filter by an output cavity loaded with Chebyshev filter,and the cold test results are given.The beam-wave interaction is simulated by EGUN code and Arsenal-MSU code respectively.The simulated results indicated that,the existence of power dips in the operating bandwidth is verified by Arsenal-MSU code,comparing proper results by EGUN code.Then,the method that design parameters are not adjusted except parameters of buncher cavities to remove potential power dips is described.What is more,the simulated results of electron optics system are given by EGUN code and Arsenal-MSU code respectively.The further hot test results of klystron prove that the whole design of beam-wave interaction is effective.
基金supported by the National Natural Science Foundation of China (Grant No. 60801031)
文摘A linear theory of a rectangular Cerenkov maser （RCM） with a sheet electron beam is developed by using the field- match method. Based on the three-dimensional beam-wave interaction model proposed in this paper, a hybrid-mode dispersion equation and its analytical solution are derived for the RCM. Through numerical calculations, the effects of the beam-grating gap, beam thickness, current density, beam voltage and waveguide width on the linear growth rate axe analysed. Moreover, the performance difference between the RCM with the closed transverse boundary and that with the upper open boundary is compared. The results show that the closed RCM model can avoid the effect of RF radiation on beam-wave interaction, which is more rational for practical applications.
文摘A linear and nonlinear analysis of crossed-field gyrotron operating on whispering-gallery mode TE<sub>m11</sub> is presented. The detailed discussions are given for the starting oscillationcondition, the effect of the internal conductor in coaxial cavity on the cut-off frequency of modeand the spacing between adjacent modes as well as the effect of the applied voltage on thecyclotron frequency of electron, the starting oscillation beam power and the electron efficiency.It is shown that the efficiency of 41% can be attained for m=2. A comparison of these resultswith those in cylindrical cavity is made. The analyses are helpful for the engineering design.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60801031 and 10905032)the Knowledge Innovation Project of the Chinese Academy of Sciences (Grant No. YYYJ-1123-5)
文摘A three-dimensional model of a dielectric-loaded rectangular Cerenkov maser with a sheet electron beam for the beam-wave interaction is proposed.Based on this model,the hybrid-mode dispersion equation is derived with the Borgnis potential function by using the field-matching method.Its approximate solution is obtained under the assumption of a dilute electron beam.By using the Ansoft high frequency structural simulator（HFSS） code,the electromagnetic field distribution in the interaction structure is given.Through numerical calculations,the effects of beam thickness,beam and dielectric-layer gap distance,beam voltage,and current density on the resonant growth rate are analysed in detail.
文摘带状注相对论扩展互作用速调管放大器是一种高功率、高频率的微波毫米波放大型器件,具有广阔的应用前景.本文分析了扩展互作用结构多间隙谐振腔的渡越时间效应,推导了2π模场情况下谐振腔的能量交换系数和电子负载电导,且通过计算表明工作在2π模式三间隙腔的电子负载电导是单间隙腔的9倍左右,多间隙结构有利于提高器件效率.利用三维粒子仿真软件,对工作在Ka波段的带状注相对论扩展互作用速调管放大器进行了模拟研究,采用宽高比为30:1的带状电子束以降低空间电荷效应,在电子束电压为500 kV,束流为1 k A,轴向引导磁感应强度为0.8 T的情况下,器件输出微波功率为190 MW,频率为40 GHz,器件效率为38%,器件增益为69 d B.
