Metamaterial-Inspired 0.22 THz Traveling-Wave Tubes With Double Sheet Beams

Jiang, Shengkun; Tang, Xianfeng; Huang, Silong; Lyu, Zhifang; Wang, Zhanliang; Tang, Tao; Gong, Huarong; Gong, Yubin; Duan, Zhaoyun

doi:10.1109/ted.2022.3233814

Cited by 6 publications

(3 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The research, applications, and development of THz technology greatly rely on the development of stable THz radiation devices [7,8]. One such THz radiation device, namely, the THz TWT plays a significant role in high-speed communication, high-resolution radar, high-precision imaging, and biomedicines [9,10]. However, with the increase of frequency, the device size and, correspondingly the cross-sectional area of the electron beam in the device decrease.…”

Section: Introductionmentioning

confidence: 99%

Design and development of a sheet-beam electron gun with large current for a THz traveling-wave tube

Chen,

Xu,

Sun

et al. 2023

AJP

View full text Add to dashboard Cite

In this paper, the design, development and experimental investigation on a sheet-beam electron gun with large current for a THz traveling-wave tube (TWT), which can operate typically at 0.22 THz frequency, is reported. The cylindrical cathode is made of scandate, and the pencil electron beam is compressed into a sheet beam by an elliptical focusing electrode. The maximum beam current of 123.4 mA was predicted with the emission current density of 24.56 A/cm 2 in simulation with 22 kV beam voltage. In the sheet-beam electron gun, the distance between the emission surface of the cathode and the beam-waist was found as 11 mm, and the wide edge and narrow edge of the beam waist crosssection are 0.38 mm and 0.1 mm, respectively. The components of the sheet-beam electron gun were fabricated and subsequently assembled. Its assembly errors were detected. The simulation predicts that the beam transportation in the sheet-beam electron gun under the condition of assembly errors exceeds 96%. The study also includes the experimental characterization of the cathode emission of the gun. The preliminary experimental results of the sheet-beam electron gun indicate that the beam current of 80 mA with the beam voltage of 22 kV was obtained from the proposed design. The experiment remained useful towards development of a 0.22 THz futuristic TWT.

show abstract

Section: Introductionmentioning

confidence: 99%

Design and development of a sheet-beam electron gun with large current for a THz traveling-wave tube

Chen,

Xu,

Sun

et al. 2023

AJP

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

“…At present, the MTMs have been successfully used to realize the backward wave oscillators (BWOs), the extended interaction klystrons, and the THz TWTs [15][16][17][18][19][20]. In the MTM-inspired THz TWTs, the waveguide couplers are used to input and output the signals [20]. However, when the MTMs are used to design S band TWTs, the waveguide couplers would enlarge the total sizes, which is not beneficial for miniaturization.…”

Section: Introductionmentioning

confidence: 99%

Miniaturized Metamaterial-Inspired Travelling Wave Tube for S Band

Xiong

Tang

et al. 2023

Electronics

Self Cite

View full text Add to dashboard Cite

A miniaturized traveling wave tube (TWT) was studied by proposing a novel metamaterial (MTM) slow wave structure (SWS). The dispersion results show that n = −1 space harmonic of the fundamental mode exhibits the “forward” wave properties, which is the foundation of the MTM-inspired TWT. Meanwhile, the interaction impedance for mode 2 of the novel MTM SWS can be sharply decreased by introducing four blend edges to weaken the corresponding longitudinal electric field. Also, two coaxial couplers are presented to input/output the signals. The transmission results show that the reflection is as low as −15 dB from 2.90 GHz to 3 GHz, which ensures the amplified signal can be effectively outputted. The MTM-inspired TWT exhibits miniaturized superiority for its compact high frequency structure including the MTM SWS and the coaxial couplers. Especially, for the high-frequency structure, the transverse and longitudinal sizes are ~λ/5 and ~3λ, respectively (λ is the free-space wavelength at the operating frequencies). The simulation of the beam wave interaction shows that the proposed MTM-inspired TWT yields output powers of kW levels from 2.90 GHz to 3 GHz, with a gain of 23.5–25.8 dB and electronic efficiency of 14–22% when the beam current is 0.5 A and the beam voltage is 13 kV. The results indicate that the gain per wavelength is as high as 8.5 dB in the operating bands. The simulation results confirm that it is possible to weaken the backward wave oscillation from the higher mode in the miniaturized MTM-inspired TWT.

show abstract