The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Jin Jun Feng - One of the best experts on this subject based on the ideXlab platform.
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Traveling-Wave Tube harmonic amplifier in terahertz and experimental demonstration
IEEE Transactions on Electron Devices, 2015Co-Authors: Jun Cai, Xianping Wu, Jin Jun FengAbstract:In this paper, a novel Traveling-Wave Tube (TWT) harmonic terahertz (THz) amplifier is proposed for a high-power, wideband, and practical electromagnetic vacuum radiation source. The amplifier is based on the reuse of harmonic infor- mation in the spent beam of a normal TWT by harmonic generation, selection, amplification, and coupling. In order to verify this concept, a W-band folded Waveguide pulsed TWT with a second-harmonic extraction system in Cascade has been developed for a G-band (170–260 GHz) TWT second-harmonic amplifier. Simulation results from CST Particle Studio show that the amplifier exhibits a good performance. Then, a prototype of the amplifier was fabricated and tested. The experimental results show that over 100-mW second-harmonic output power at most frequencies of the 11.4 GHz of bandwidth at 1% duty cycle was achieved, and the maximum second-harmonic output power reached 500 mW. This paper demonstrates the feasibility that TWT harmonic amplifiers can be used as a potential THz vacuum radiation source, and further progress in development of such novel THz devices is anticipated.
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Numerical simulation of noise in Traveling Wave Tube
2015 IEEE International Vacuum Electronics Conference (IVEC), 2015Co-Authors: Tao Tang, Yu-bin Gong, Hua Rong Gong, Wentao Dai, Jin Jun FengAbstract:The electron beam noise in Traveling Wave Tube was simulated by a one dimensional Lagrange model. The analysis conformed the predication of the noise theory of the space charge Wave.
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W-Band 1-kW Staggered Double-Vane Traveling-Wave Tube
IEEE Transactions on Electron Devices, 2012Co-Authors: Jianqiang Lai, Zhao Yun Duan, Yu-bin Gong, Yanyu Wei, Wen Xiang Wang, Xiong Xu, Jin Jun FengAbstract:A design study for a W-band Traveling-Wave Tube (TWT) using a staggered double-vane slow-Wave structure com- bined with a sheet electron beam shows that an output power of over 1 kW should be possible. Numerical eigenmode calculations indicated that the structure has a strong longitudinal component of electric field for interaction with the electron beam. A novel input and output coupler was proposed that can produce good input and output matches. Finally, a TWT model with moderate dimensions was established. The particle-in-cell simulation results revealed that the Tube can be expected to produce over 1 kW of peak power in the range from 90 to 95 GHz, assuming an RF input signal with a peak power of 0.15Wand a beam power of 10.3 kW. The corresponding conversion efficiency values vary from 9.87% to 12.15%, and the maximum gain is 39.2 dB at 93 GHz.
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DESIGN OF A V-BAND HIGH-POWER SHEET-BEAM COUPLED-CAVITY Traveling-Wave Tube
Progress In Electromagnetics Research, 2012Co-Authors: Jin Xu, Minzhi Huang, Yu-bin Gong, Yanyu Wei, Wen Xiang Wang, Xiong Xu, Fei Shen, Jin Jun FengAbstract:The design and analysis of a high-power wideband sheet- beam coupled-cavity Traveling-Wave Tube operating at V-band is presented. The interaction circuit employs three-slot doubly periodic staggered-ladder coupled-cavity slow-Wave structure, and a 5 : 1 aspect- ratio sheet electron beam is used to interact with the circuit. Combined with design of the well-matched input and output couplers, a 3-D particle-in-cell model of the sheet-beam coupled-cavity Traveling-Wave Tube is constructed. The electromagnetic characteristics and the beam- Wave interaction of the Tube are investigated. From our calculations, this Tube can produce saturated output power over 630Watts ranging from 58GHz to 64GHz when the cathode voltage and beam current are set to 13.2kV and 300mA, respectively. The corresponding saturated gain and electron efficiency can reach over 32.5dB and 15.9%. Compared with the circular beam devices, the designed sheet- beam TWT has absolute advantage in power capability, and also it is more competitive in bandwidth and electron efficiency.
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Experimental study of high-power gyrotron Traveling-Wave Tube with periodic lossy material loading
IEEE Transactions on Plasma Science, 2012Co-Authors: E. Feng Wang, Jin Jun Feng, Bentian Liu, Zhiliang Li, Xu Zeng, Shiqiu ZhuAbstract:The distributed wall loss is a good approach for the suppression of spurious oscillations in gyrotron Traveling-Wave Tube (gyro-TWT). The periodic lossy dielectric loading in the interaction region of gyro-TWT can effectively suppress the spurious oscillations. We designed and employed a periodic lossy-material-loaded circuit in our experimental study of TE_01 Ka-band gyro-TWT. The output characteristics were greatly improved. A peak output power of 290 kW was measured with 56-dB maximum gain, 34.2% efficiency, and 2.1-GHz 3-dB bandwidth when the accelerating voltage was 66 kV and beam current was 13 A.
Neville C. Luhmann - One of the best experts on this subject based on the ideXlab platform.
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0.2-THz Dual Mode Sheet Beam Traveling Wave Tube
IEEE Transactions on Electron Devices, 2017Co-Authors: Yuan Zheng, Diana Gamzina, Neville C. LuhmannAbstract:Equipping the adjustable horizontal focusing electrodes (FEs), a dual mode electron gun providing different current beams, has been proposed and evaluated. Employing this tunable FE electron gun, a continuous Wave (CW)/pulsed dual mode, 0.2-THz sheet beam Traveling Wave Tube (SB-TWT) has been designed. The Tube employs a high density and high current sheet beam for pulsed mode operation, and a reduced size and lower current sheet beam for the CW mode. This scheme provides CW mode increased efficiency and higher beam transmission factor than other, more conventional, dualmode techniques such as by changing the RF drive power. Using a 1.2-T uniform focusing magnetic field, both beams are predicted to have excellent transmission factor (more than 99%) to the collector through the 65-mm beam tunnel. Driven by the pulsed, high current electron beam, the 0.2-THz SB-TWT exhibits more than 100-W power over a 20-GHz bandwidth. Driven by the low current electron beam, the Tube provides 20-dB gain and 10-W CW output power over the required bandwidth of 0.19 THz-0.21 THz.
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Investigation of terahertz sheet beam Traveling Wave Tube amplifier with nanocomposite cathode
Physics of Plasmas, 2010Co-Authors: Young-min Shin, Larry R. Barnett, Jinfeng Zhao, Neville C. LuhmannAbstract:Particle-in-cell simulations of a staggered double grating array Traveling Wave Tube intended as a wideband amplifier for terahertz communications, sensing, and imaging applications showed that, for an electron beam power of 5 kW, it produces 150–275W, corresponding to 3%–5.5% electronic efficiency, at 0.22 THz with over30% bandwidth and with greater than 12 dB/cm growth rate. The circuit has been fabricated by both UV lithography and high precision computer-numerical-control machining with 2–3 m dimensional tolerance and 50 nm surface roughness. A scandate nanocomposite Sc2O3–W cathode for the electron beam source has successfully emitted 120 A/cm2 space charge limited at 1150 °C and 50 A/cm2 at 1050 °C for 8000 h as required to produce the requisite high current density electron beam.
N S Ginzburg - One of the best experts on this subject based on the ideXlab platform.
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gain analysis of a 0 2 thz Traveling Wave Tube with sheet electron beam and staggered grating slow Wave structure
IEEE Transactions on Electron Devices, 2018Co-Authors: Tatiana A Karetnikova, N. M. Ryskin, A. G. Rozhnev, A E Fedotov, S V Mishakin, N S GinzburgAbstract:Results of numerical simulation of a miniaturized sub-THz Traveling-Wave Tube amplifier with sheet electron beam and planar grating slow Wave structure (SWS) are presented. Cold characteristics of the SWS are calculated. Small-signal and large-signal gain regimes are studied by the 1-D parametric frequency-domain code. The results are verified by simulations using 3-D particle-in-cell codes.
N. M. Ryskin - One of the best experts on this subject based on the ideXlab platform.
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Theoretical and Experimental Study of a Compact Planar Slow-Wave Structure on a Dielectric Substrate for the W-Band Traveling-Wave Tube
Technical Physics, 2020Co-Authors: R. A. Torgashov, N. M. Ryskin, A. G. Rozhnev, A. V. Starodubov, A. A. Serdobintsev, A. M. Pavlov, V. V. Galushka, I. Sh. Bakhteev, S. Yu. MolchanovAbstract:A miniature planar meander-type slow-Wave structure (SWS) for a W -band Traveling-Wave Tube is studied. Computer simulation of the SWS electrodynamic parameters is performed. A new technology for fabrication of planar microstrip SWSs with the aid of laser ablation is proposed. The S -parameters of the SWS are experimentally studied. The experimental data are in good agreement with the results of the 3D computer simulation. Output characteristics of the Traveling-Wave Tube with a sheet electron beam and planar SWS are calculated.
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gain analysis of a 0 2 thz Traveling Wave Tube with sheet electron beam and staggered grating slow Wave structure
IEEE Transactions on Electron Devices, 2018Co-Authors: Tatiana A Karetnikova, N. M. Ryskin, A. G. Rozhnev, A E Fedotov, S V Mishakin, N S GinzburgAbstract:Results of numerical simulation of a miniaturized sub-THz Traveling-Wave Tube amplifier with sheet electron beam and planar grating slow Wave structure (SWS) are presented. Cold characteristics of the SWS are calculated. Small-signal and large-signal gain regimes are studied by the 1-D parametric frequency-domain code. The results are verified by simulations using 3-D particle-in-cell codes.
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nonstationary nonlinear discrete model of a coupled cavity Traveling Wave Tube amplifier
IEEE Transactions on Electron Devices, 2009Co-Authors: N. M. Ryskin, V N Titov, Anton V YakovlevAbstract:A nonstationary nonlinear model for numerical simulation of a coupled-cavity Traveling-Wave Tube is described. The model is based on the nonstationary discrete theory of excitation of a periodic Waveguide structure, when it is supposed that the beam-Wave interaction takes place only inside the cavity gaps separated by drift spaces. Such an approach allows one to consider properly the dispersion of the slow-Wave structure (SWS) and to simulate processes at any point inside the SWS passband, including interaction near cutoff and even beyond the passband. Results of numerical simulations of amplification in small-signal and large-signal regimes are presented. Self-excitation processes near cutoff frequency are studied. In particular, drive-induced self-excitation that takes place only in the presence of a sufficiently strong driving signal is discussed.
Yu-bin Gong - One of the best experts on this subject based on the ideXlab platform.
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Numerical simulation of noise in Traveling Wave Tube
2015 IEEE International Vacuum Electronics Conference (IVEC), 2015Co-Authors: Tao Tang, Yu-bin Gong, Hua Rong Gong, Wentao Dai, Jin Jun FengAbstract:The electron beam noise in Traveling Wave Tube was simulated by a one dimensional Lagrange model. The analysis conformed the predication of the noise theory of the space charge Wave.
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u shaped microstrip meander line slow Wave structure for ka band Traveling Wave Tube
International Conference on Microwave and Millimeter Wave Technology, 2012Co-Authors: Fei Shen, Minzhi Huang, Yanyu Wei, Yang Liu, Tao Tang, Yu-bin GongAbstract:Study on U-shaped microstrip meander-line slow-Wave structure for a low voltage, wide bandwidth millimeter Traveling-Wave Tube is presented. The electromagnetic characteristics and the sheet beam-Wave interaction of this structure are carried out. The simulation results predicts that this millimeter-Wave power amplifier is capable of delivering hundreds of watts output power in the frequency range of 29–38 GHz, and the peak power is about 200 watts with the correspond-ding gain of 33 dB at 35 GHz.
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W-Band 1-kW Staggered Double-Vane Traveling-Wave Tube
IEEE Transactions on Electron Devices, 2012Co-Authors: Jianqiang Lai, Zhao Yun Duan, Yu-bin Gong, Yanyu Wei, Wen Xiang Wang, Xiong Xu, Jin Jun FengAbstract:A design study for a W-band Traveling-Wave Tube (TWT) using a staggered double-vane slow-Wave structure com- bined with a sheet electron beam shows that an output power of over 1 kW should be possible. Numerical eigenmode calculations indicated that the structure has a strong longitudinal component of electric field for interaction with the electron beam. A novel input and output coupler was proposed that can produce good input and output matches. Finally, a TWT model with moderate dimensions was established. The particle-in-cell simulation results revealed that the Tube can be expected to produce over 1 kW of peak power in the range from 90 to 95 GHz, assuming an RF input signal with a peak power of 0.15Wand a beam power of 10.3 kW. The corresponding conversion efficiency values vary from 9.87% to 12.15%, and the maximum gain is 39.2 dB at 93 GHz.
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DESIGN OF A V-BAND HIGH-POWER SHEET-BEAM COUPLED-CAVITY Traveling-Wave Tube
Progress In Electromagnetics Research, 2012Co-Authors: Jin Xu, Minzhi Huang, Yu-bin Gong, Yanyu Wei, Wen Xiang Wang, Xiong Xu, Fei Shen, Jin Jun FengAbstract:The design and analysis of a high-power wideband sheet- beam coupled-cavity Traveling-Wave Tube operating at V-band is presented. The interaction circuit employs three-slot doubly periodic staggered-ladder coupled-cavity slow-Wave structure, and a 5 : 1 aspect- ratio sheet electron beam is used to interact with the circuit. Combined with design of the well-matched input and output couplers, a 3-D particle-in-cell model of the sheet-beam coupled-cavity Traveling-Wave Tube is constructed. The electromagnetic characteristics and the beam- Wave interaction of the Tube are investigated. From our calculations, this Tube can produce saturated output power over 630Watts ranging from 58GHz to 64GHz when the cathode voltage and beam current are set to 13.2kV and 300mA, respectively. The corresponding saturated gain and electron efficiency can reach over 32.5dB and 15.9%. Compared with the circular beam devices, the designed sheet- beam TWT has absolute advantage in power capability, and also it is more competitive in bandwidth and electron efficiency.
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Progress on the V-band Traveling-Wave Tube
2012 International Conference on Microwave and Millimeter Wave Technology (ICMMT), 2012Co-Authors: Yang Liu, Jianqiang Lai, Minzhi Huang, Yanyu Wei, Fei Shen, Tao Tang, Yu-bin GongAbstract:In this paper, the recent research progress on the V-band Traveling-Wave Tube in our laboratory is presented. Several robust full-metal slow-Wave structures, including two circular beam structures and two sheet-beam structures, are investigated and employed to design the V-band Traveling-Wave Tube. The corresponding operating characteristics are predicted by using the particle-in-cell method.
