Experimental investigations on miniaturized high-frequency vacuum electron devices

Sch. of Phys., Seoul Nat. Univ., South Korea
IEEE Transactions on Plasma Science (Impact Factor: 0.95). 05/2005; 33(2):679 - 684. DOI: 10.1109/TPS.2005.844529
Source: IEEE Xplore

ABSTRACT We investigated the foundations for high-frequency vacuum electron devices experimentally, with emphasis on deep etch X-ray lithography: lithographie, galvanoformung, abformung (LIGA) to fabricate a miniaturized interaction circuit and a photonic crystal (PC) resonator to excite a stable high-order mode. The successful operation of a LIGA-fabricated folded-waveguide traveling-wave tube was reported. From such physical considerations as Debye length and photonic band gap, we proposed a reflex klystron adopting a cold cathode and a PC resonator.


Available from: Jin-Kyu So, Jun 23, 2014
  • [Show abstract] [Hide abstract]
    ABSTRACT: The folded waveguide Traveling Wave Tube (TWT) is a promising terahertz wave device. A 220GHz folded waveguide slow-wave structure is designed and analyzed, including dispersion relation and interaction impedance. And the simulation results show good agreement with their theory formula analysis. The folded waveguide slow-wave structure has flat dispersion relation, fairly high interaction impedance about 3.5 ohms at the central frequency of 220 GHz. The large signal performance of 27 mm (50 periods) folded waveguide circuit is predicted. Simulations show that the nonlinear gain is 13.5 dB at 220 GHz where beam voltage and current are 20.6 kV and 15 mA, respectively. A saturated 3-dB bandwidth is 11 GHz (213 GHz - 224 GHz). Microfabrication process to produce the folded waveguide circuits is discussed. The first example of folded waveguide circuit is fabricated by UV-LIGA process.
    Smart Sensors, Actuators, and MEMS V; 01/2011
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Представлены результаты электродинамического моделирования фотонно-кристаллического резонатора для диодного генератора с автоэмиссионным катодом при помощи современных программных пакетов расчета СВЧ-структур. Резонатор образован удалением центрального элемента в периодической двумерной фотонно-кристаллической решетке из диэлектрических стерженьков. Снаружи фотонно-кристаллическая структура окружена металлическим экраном, на торцевых стенках которого в центре дефекта расположены катод и анод. Результаты моделирования показали, что добротность резонатора, в первую очередь, определяется омическими потерями в анодной и катодной пластинах металлического экрана. Путем вариации конструкции вывода ВЧ-энергии можно менять нагруженную добротность резонатора в широких пределах, что позволяет оптимизировать выходную мощность и КПД генератора.
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents the design of an electron gun for terahertz vacuum tubes realized with a nanowire or nanotube cold cathode. This technology is particularly interesting in this field since it allows the reduction of gun dimensions and of power consumption with respect to the thermionic guns. We found that focusing is a rather critical aspect since cold cathodes show a relevant transverse velocity, which increases the divergence of the beam and typically induces high current losses on the anode. An analysis of the parameters that influence the transverse velocity has been performed together with the identification of a proper design procedure that reduces the transverse velocity effects. Dif- ferent electron guns have been designed that deliver a circular beam in the range of 1-4 mA with a radius in the range of 30 µm.
    IEEE Transactions on Electron Devices 09/2011; 58(9):3200-3204. DOI:10.1109/TED.2011.2158437 · 2.36 Impact Factor