Article
Engineering, Electrical & Electronic
Chen Zhao, Sheel Aditya, Shaomeng Wang
Summary: A novel coplanar slow-wave structure (SWS) for millimeter-wave backward-wave oscillator (BWO) application is proposed, featuring reduced dielectric loading effect with metal layer only on the top surface of the substrate. Suitable for fabrication using PCB or microfabrication techniques, this structure can be directly fed with coplanar waveguide (CPW) and covers a -15-dB S-11 frequency range from 13.7 to 120 GHz. Simulation results show a tunable frequency range of 32.7 GHz and a maximum output power of 22.7 W at 114 GHz for a BWO based on the proposed SWS, with good potential for microfabrication techniques.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Computer Science, Information Systems
Ruichao Yang, Lingna Yue, Jin Xu, Pengcheng Yin, Jinjing Luo, Hexin Wang, Dongdong Jia, Jian Zhang, Hairong Yin, Jinchi Cai, Guo Guo, Guoqing Zhao, Wenxiang Wang, Dazhi Li, Yanyu Wei
Summary: This paper proposes a new slow-wave structure for microstrip line traveling-wave tubes, which increases the output power by widening the transverse width and achieves a wide bandwidth and low phase velocity. The designed input/output structure exhibits good transmission characteristics, and particle-in-cell simulation results show that the tube has high output power and electronic efficiency.
Article
Engineering, Electrical & Electronic
Hexin Wang, Shaomeng Wang, Zhanliang Wang, Xinyi Li, Duo Xu, Zhaoyun Duan, Zhigang Lu, Huarong Gong, Sheel Aditya, Yubin Gong
Summary: A novel dielectric-supported staggered dual-meander-line planar slow-wave structure is proposed for a traveling-wave tube operating at E-band. The staggered arrangement of meander-lines leads to stronger beam-wave interaction and higher output power. Simulation results show that the proposed structure can achieve high power output with maximum gain and electronic efficiency.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Chen Zhao, Shuo Tian, Wangqi Liu, Xiaoyi Liao, Xiaoxing Fang, Shaomeng Wang
Summary: This article investigates the operation principle and dispersion properties of the co-planar slow wave structure (SWS). The SWS is analyzed using an equivalent circuit model, and the theoretical calculation results are in good agreement with the simulations. Particle-in-cell (PIC) simulation and measurements validate the tunable frequency range and high power output characteristics of the proposed SWS, making it suitable for millimeter-wave BWO applications.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Chen Zhao, Wangqi Liu, Lei Zhu
Summary: An effective numerical method for accurate extraction of the properties of slow-wave structures (SWSs) is proposed in this article. This method allows us to determine all four per-unit-length parameters of the SWS with good accuracy by reducing the coupling effect among unit cells and calculating the properties using the ABCD matrix of the core SWS. The effectiveness of the method is verified through the study of two verification structures.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Engineering, Electrical & Electronic
Liangjie Bi, Andrey D. Andreev, Ahmed M. N. Elfrgani, Edl Schamiloglu, Lin Meng, Yong Yin
Summary: In this study, numerical calculations were performed to investigate the dispersion relation of electromagnetic modes supported by finite-length, overmoded, corrugated, cylindrical slow wave structures, and compared with analytically calculated results. The results showed that analytically calculated dispersion curves of higher order TM0n modes are combinations of dispersion curves defining those high-order modes and some parts of dispersion curves defining lower order TM0(n-k) modes.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Junwan Zhu, Zhigang Lu, Jingrui Duan, Zhanliang Wang, Huarong Gong, Yubin Gong
Summary: This paper proposes a modified staggered double grating traveling wave tube (SDG-TWT) slow wave structure (SWS) for wide-band and high-power TWTs operating in the W-band or higher terahertz band, which shows improved performance in terms of saturated power, electron efficiency, and gain.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Chen Zhao, Hang Xu
Summary: A modified double staggered grating waveguide (DSGW) slow wave structure (SWS) is proposed for millimeter-wave and sub-THz traveling wave tubes (TWTs). The proposed SWS, which uses gratings with a cross section outline of exponential curves, exhibits higher interaction impedance compared to DSGW, resulting in higher output power and gain. Particle-in-cell (PIC) simulations show that a TWT with sheet electron beam (SEB) and the proposed SWS achieves a maximum power of 116.64 W, indicating a significant improvement compared with the traditional DSGW.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Jian Zhang, Xuebing Jiang, Jin Xu, Lingna Yue, Hairong Yin, Shuangzhu Fang, Ruichao Yang, Pengcheng Yin, Jinchi Cai, Guoqing Zhao, Wenxiang Wang, Zhenhua Wu, Dazhi Li, Wenxin Liu, Minzhi Huang, Yanyu Wei
Summary: The letter proposes a modified flat-roofed sine waveguide slow-wave structure for a wide-band high-power sub-terahertz traveling-wave tube, showcasing advantages such as wide operating bandwidth, low loss, minimal reflection, and ease of fabrication. Simulation results demonstrate a transmission parameter exceeding -5.0 dB in the frequency range of 210 to 250 GHz.
IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Kedong Zhao, Wenxin Liu, Longlong Yang, Zhiqiang Zhang, Zhaochuan Zhang, Yue Ou, Zhengyuan Zhao, Ziqiang Yang, Yanyu Wei
Summary: In this study, a new structure is proposed to enhance the output power of a 0.5-Terahertz backward wave oscillator. Numerical simulations show that this structure can significantly improve the output performance and reduce the time of start oscillation. Moreover, the effect of factors such as conductivity and roughness on the output power is studied.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Sergey Samsonov, Grigoriy G. Denisov, Alexander A. Bogdashov, Igor G. Gachev
Summary: The proposed microwave system utilizes a quasi-optical transmission line for amplifier or oscillator based on cyclotron resonance maser instability. By guiding an electron beam with high perpendicular velocities through periodically spaced focusing mirrors and static B-field, the system achieves minimal sensitivity to particle velocity spread and enables frequency tunability at wavelengths of 1-2 mm with more than an octave bandwidth through zigzag CRM.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Physics, Multidisciplinary
Zi-Chao Gao, Chao-Hai Du, Fan-Hong Li, Zi-Wen Zhang, Si-Qi Li, Pu-Kun Liu
Summary: This paper investigates a scheme to alleviate the strong ohmic losses in traditional THz ECM systems, by introducing traveling-wave operation and using a lossy belt and a down-tapered magnetic field to improve output efficiency.
Article
Engineering, Electrical & Electronic
Zhigang Lu, Ruidong Wen, Zhanliang Wang, Huarong Gong, Yubin Gong
Summary: The novel sine groove waveguide slow wave structure (SGW-SWS) proposed for wideband terahertz (THz) traveling wave tube (TWT) shows high interaction impedance, wide beam tunnel, and can be fabricated using Nano-Computer Numerical Control (CNC) milling techniques. Compared to the sine waveguide slow wave structure (SW-SWS), SGW-SWS has a wider passband and higher average interaction impedance throughout the passband. The beam tunnel size of SGW-SWS is independent of dispersion characteristics, allowing for further increase in beam current.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Computer Science, Information Systems
Yijun Zhu, Yang Xie, Ningfeng Bai, Xiaohan Sun
Summary: A new machine learning deep learning synthesis algorithm is proposed for the design of a microstrip meander line slow wave structure, achieving low training error with exact numerical simulation data, obtaining feasible geometry parameters when desired performance is reached, and successfully designing a D-band MML SWS with a 20 GHz bandwidth.
Article
Physics, Fluids & Plasmas
Yang Wu
Summary: This article presents a klystron-like relativistic backward wave oscillator with a five-period slow-wave structure and a TM02 mode extractor. By introducing the five-period SWS and the TM02 mode extractor, the beam bunching process is enhanced and the beam power is efficiently converted to microwave power.
IEEE TRANSACTIONS ON PLASMA SCIENCE
(2023)
Article
Physics, Fluids & Plasmas
Gregory S. Nusinovich, Olgierd Dumbrajs
PHYSICS OF PLASMAS
(2018)
Article
Physics, Fluids & Plasmas
Gregory S. Nusinovich
PHYSICS OF PLASMAS
(2019)
Article
Physics, Fluids & Plasmas
Jayakrishnan Appanam Karakkad, Gregory S. Nusinovich, Brian L. Beaudoin, Antonio C. Ting, Amith H. Narayan, Thomas M. Antonsen
PHYSICS OF PLASMAS
(2019)
Article
Engineering, Electrical & Electronic
Mikhail Proyavin, Olgierd Dumbrajs, Gregory Nusinovich, Mikhail Glyavin
JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES
(2020)
Article
Physics, Fluids & Plasmas
Gregory S. Nusinovich, Xianfei Chen, Olgierd Dumbrajs, Houxiu Xiao, Xiaotao Han
PHYSICS OF PLASMAS
(2020)
Article
Physics, Fluids & Plasmas
A. P. Gashturi, G. S. Nusinovich, I. V. Zotova, E. S. Semenov, S. P. Sabchevski, M. Yu. Glyavin
PHYSICS OF PLASMAS
(2020)
Article
Physics, Fluids & Plasmas
Xianfei Chen, Gregory S. Nusinovich, Olgierd Dumbrajs, Houxiu Xiao, Donghui Xia, Tonghai Ding, Luwei Liu, Xiaotao Han, Tao Peng
Summary: This study investigates the shadowing phenomenon that may occur during the startup process of gyrotrons operating in high-order modes, preventing the desired mode from being excited. The research is divided into two parts: a generalized approach to studying the problem and an analysis of a Megawatt-class gyrotron with a diode-type electron gun to determine if moving to higher-order modes will lead to shadowing of the desired mode.
PHYSICS OF PLASMAS
(2021)
Article
Physics, Fluids & Plasmas
A. P. Fokin, V. L. Bakunin, M. Yu. Glyavin, G. S. Nusinovich
Summary: The study focuses on analyzing automodulation instability in harmonic gyrotrons, particularly when there are parasitic modes at the fundamental near the desired second harmonic mode. It examines the derivation of equations describing this instability in the context of cold-cavity approximation, and determines the region of instability for a second harmonic gyrotron optimal for efficient operation. Additionally, the study considers gyrotrons operating in specific modes surrounded by specific sideband modes at the fundamental.
PHYSICS OF PLASMAS
(2021)
Article
Engineering, Electrical & Electronic
Xianfei Chen, Gregory S. Nusinovich, Olgierd Dumbrajs, Houxiu Xiao, Xiaotao Han, Donghui Xia, Tao Peng
Summary: This article investigates the mode excitation problem during the startup process of gyrotrons operating in high-order modes. It proposes a generalized approach to selectively excite the desired mode by controlling the relationship between the beam and mod-anode voltages.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Review
Engineering, Electrical & Electronic
S. P. Sabchevski, M. Yu Glyavin, G. S. Nusinovich
Summary: The study of mode interaction in gyrotrons is important for understanding the physical principles and optimizing gyro-devices. With advancements in terahertz frequencies, the competition between modes has become pronounced. This overview presents the evolution and progress of these investigations, supporting the development of high-performance gyrotrons for emerging applications.
JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Andrey P. Fokin, Vladimir L. Bakunin, Mikhail Yu Glyavin, Gregory S. Nusinovich
Summary: The paper focuses on analyzing the parametric mode interaction in second harmonic gyrotrons, presenting equations describing instability and calculating the region of instability in terms of frequency mismatches. Numerical self-consistent simulations are used to complement the general theory.
2021 46TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER AND TERAHERTZ WAVES (IRMMW-THZ)
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Mikhail Proyavin, Gregory Nusinovich, Olgierd Dumbrajs, Mikhail Glyavin
2020 IEEE 21ST INTERNATIONAL CONFERENCE ON VACUUM ELECTRONICS (IVEC 2020)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
M. Yu Glyavin, A. P. Gashturi, I. Zotova, A. P. Fokin, A. G. Luchinin, A. Tsvetkov, R. M. Rozental, E. S. Semenov, A. S. Sergeev, G. S. Nusinovich
2020 45TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Olgierd Dumbrajs, Gregory S. Nusinovich
2018 43RD INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ)
(2018)
Proceedings Paper
Engineering, Electrical & Electronic
Brian L. Beaudoin, Antonio Ting, Steven Gold, Amith H. Narayan, Jayakrishnan A. Karakkad, Gregory S. Nusinovich, Thomas M. Antonsen
2018 IEEE INTERNATIONAL VACUUM ELECTRONICS CONFERENCE (IVEC)
(2018)