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12 pages, 6717 KB

Open AccessArticle

Design and Non-Uniform Current Analysis of a 0.35-THz Extended Interaction Oscillator Based on Pseudospark-Sourced Multiple Sheet Electron Beams

by Ruibin Peng, Hailong Li, Yong Yin, Bin Wang, Xiaotao Xu, Liangjie Bi, Yu Qin and Lin Meng

Electronics 2023, 12(7), 1519; https://doi.org/10.3390/electronics12071519 - 23 Mar 2023

Viewed by 1769

Abstract

A novel method, which combines a multiple-beam extended interaction oscillator (EIO) with pseudospark-sourced (PS) sheet electron beams, is applied to generate high-power terahertz sources. For a multiple-beam EIO, the beam cross-section is significantly improved by replacing the commonly used pencil electron beams with sheet electron beams. The PS electron beams have the advantage of high current density and operate without a focus magnetic field. The volume of the cavity is larger when the EIO operates in the TM₃₁-3π mode than in the conventional TM₀₁-2π mode at the same operating frequency. The EIO operating at the terahertz frequency has a larger cavity volume, which means greater power capacity and lower manufacturing difficulty. For a PS multiple-beam EIO, the non-uniformity of electron beam currents is a common problem. In order to study this problem, an original high-order mode EIO driven by PS multiple sheet electron beams is presented with enhanced output power at 0.35 THz. The authors analyze electron beams with different currents through particle-in-cell (PIC) simulations. Simulation results show that the EIO can operate stably even in the case of non-uniform PS electron beam currents. When each current is 1.4 A, simulation results show the EIO’s output power of 4.9 kW at 0.35 THz. Considering the low conductivity of 1.1 × 10⁷ S/m, the efficiency is still 1.42%. Full article

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8 pages, 2992 KB

Open AccessCommunication

Preliminary Study of a G-Band Extended Interaction Oscillator Operating in the TM₃₁-3π Mode Driven by Pseudospark-Sourced Multiple Electron Beams

by Ruibin Peng, Bin Wang, Yong Yin, Hailong Li, Xuesong Yuan, Xiaotao Xu, Liangjie Bi, Yu Qin and Lin Meng

Electronics 2022, 11(23), 3961; https://doi.org/10.3390/electronics11233961 - 29 Nov 2022

Cited by 2 | Viewed by 2002

Abstract

This paper presents the first design that combines pseudospark-sourced (PS) electron beams with a multiple-beam extended interaction oscillator (EIO). The PS electron beam is an excellent choice for driving EIOs because it has high current density and does not require a focusing magnetic field. The EIO with coaxial structure adopts the method of multiple electron beams, which plays a crucial role in improving the average output power. At the same frequency, the EIO operating in the high-order TM₃₁-3π mode has a larger cavity size than the EIO operating in the traditional TM₀₁-2π mode. The high-order TM₃₁-3π mode solves the problem of the EIO’s manufacture at high frequency. In order to verify the above points, a G-band PS multiple-beam EIO operating in TM₃₁-3π mode has been designed. The beam–wave interaction particle-in-cell simulation results show that the EIO’s peak output power is 39.2 kW at 217 GHz, and that its efficiency is around 6.1%. The EIO with six pencil beams operates at a voltage of 43 kV. The total current of the six electron beams is 15 A (equally distributed among the six beams), and the corresponding current density is about 5000 A/cm². Considering the ohmic loss and the effect of skin depth, the conductivity used in these simulations is 2 × 10⁷ S/m. The design is an excellent way to improve the output power of EIO operating at high frequency. Full article

(This article belongs to the Section Electronic Materials, Devices and Applications)

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10 pages, 2821 KB

Open AccessArticle

Research of the Oscillation Start-Up Time in an Extended Interaction Oscillator Driven by a Pseudospark-Sourced Sheet Electron Beam

by Ruibin Peng, Hailong Li, Yong Yin, Xiaotao Xu, Qingyun Chen, Liangjie Bi, Che Xu, Bin Wang, Xuesong Yuan, Ping Zhang and Lin Meng

Electronics 2022, 11(4), 664; https://doi.org/10.3390/electronics11040664 - 21 Feb 2022

Cited by 2 | Viewed by 2197

Abstract

High current density and high brightness are critical factors for high-power and compact extended interaction oscillators (EIOs) which are operated in the terahertz (THz) waveband. The pseudospark-sourced (PS) sheet electron beam, which combines merits including high current density, a relatively big beam cross-section and no requirement for the external focusing magnetic field, is a good choice for application to high-frequency EIO. The pulse generated by the PS electron beam can last around tens of nanoseconds or even less, thus the EIO’s oscillation start-up time (OST) should be short enough. This paper researched how to reduce OST in an EIO driven by the PS sheet electron beam. The authors realized that the OST of EIO was very sensitive to the gap length under the equal period. The distribution of the electric field is optimized by adjusting the length of the gap. The strong electric field strength is conducive to the beam-wave interaction, and the OST is affected by the beam-wave interaction. When the gap length reaches a suitable value, the OST becomes the shortest. The simulation results showed the EIO’s shortest OST was 8 ns and the corresponding peak output power was 2 kW at 0.19 THz, while the current density was 500 A/cm². When current density reached 10,000 A/cm², the shortest OST could even be 1.9 ns. Full article

(This article belongs to the Section Microwave and Wireless Communications)

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