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  • AIP Publishing  (3)
  • He, Juntao  (3)
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  • AIP Publishing  (3)
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  • 1
    In: AIP Advances, AIP Publishing, Vol. 11, No. 6 ( 2021-06-01)
    Abstract: The energy consumption of high-power microwave sources has attracted much attention in the research field of high-power microwaves. One way of decreasing the energy consumption is to reduce the guiding magnetic field. In this work, a high-efficiency transit-time oscillator is proposed with a low guiding magnetic field. In order to enhance the modulation depth of electrons and increase the conversion efficiency under a low guiding magnetic field, two bunchers are adopted to modulate the electron beam. 2.5D simulation results show that the proposed device generates microwaves with a power of 3.6 GW and a frequency of 4.31 GHz. The power conversion efficiency is 40% and the modulation depth is 125% when the guiding magnetic field is only 0.5 T. In addition, a 3D simulation verifies the results.
    Type of Medium: Online Resource
    ISSN: 2158-3226
    Language: English
    Publisher: AIP Publishing
    Publication Date: 2021
    detail.hit.zdb_id: 2583909-3
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  • 2
    In: Physics of Plasmas, AIP Publishing, Vol. 29, No. 12 ( 2022-12-01)
    Abstract: During hypersonic vehicle flight at high speed, plasma sheath on the vehicle surface will attenuate or even interrupt the communication signal, leading to the “communication blackout” problem. The vehicle probably moves a long distance during the communication blackout due to its high speed, which is a serious threat to the safety of the vehicle. This paper proposes a method to solve the communication blackout problem using high-power microwave (HPM) irradiation. The multicomponent compressible model, finite difference time domain algorithm, and multi-fluid model are used to simulate the interaction between HPM and plasma sheath. The results show that after HPM irradiation, the electromagnetic (EM) wave transmissivity of the plasma sheath will change, and the electric field (E-field) amplitude and irradiation time of HPM significantly influence the change of transmissivity. Thereafter, analyses of the changes of the collision and plasma frequencies of the plasma sheath after HPM irradiation showed the transmissivity of the plasma sheath to low-frequency EM waves is improved by optimizing E-field amplitude and irradiation time of HPM. Therefore, HPM irradiation can be performed to enhance the transmissivity of the plasma sheath to the communication signal, thus alleviating the communication blackout problem.
    Type of Medium: Online Resource
    ISSN: 1070-664X , 1089-7674
    Language: English
    Publisher: AIP Publishing
    Publication Date: 2022
    detail.hit.zdb_id: 1472746-8
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  • 3
    Online Resource
    Online Resource
    AIP Publishing ; 2022
    In:  AIP Advances Vol. 12, No. 7 ( 2022-07-01)
    In: AIP Advances, AIP Publishing, Vol. 12, No. 7 ( 2022-07-01)
    Abstract: An improved X-band coaxial transit time oscillator is proposed in this paper. First, the device uses a non-uniform three-gap modulation cavity to improve the clustering of electron beams under a low magnetic field and to increase the depth of the fundamental current modulation. The operating mode of the modulation cavity is the 2π/3 mode of TM01. Second, the dual-cavity extraction structure works in π mode, which can continuously and intensively extract the electron beam energy. The physical characteristics of the device are studied through simulation and experiment. The experimental results indicate that the high power microwave with a frequency of 8.38 GHz and a power of 1.78 GW is generated when the diode voltage is 520 kV and the guiding magnetic field is 0.65 T, yielding a pulse width of 27 ns and an efficiency of 32%.
    Type of Medium: Online Resource
    ISSN: 2158-3226
    Language: English
    Publisher: AIP Publishing
    Publication Date: 2022
    detail.hit.zdb_id: 2583909-3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
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