Continuous-wave Y-band planar BWO with wide tunable bandwidth

Hongzhu Xi,Rong Li,Gang Zhu,Jianguo Wang,Luwei Liu,Hao Wang,Zhaochang He,Zaigao Chen,Yue Wang

doi:10.1038/s41598-017-18740-w

Abstract

A high performance continuous-wave (CW) backward wave oscillator (BWO) with planar slow wave structure (SWS) and sheet electron beam in Y-band is presented in this paper. The mode selection is discussed by studying the dispersion curve of SWSs, distributions of the electric field, and particle-in-cell simulation results, showing that the designed BWO operates in the fundamental mode TM11. The planar SWSs are fabricated by using the UV-LIGA technology with the processing error less than 0.003 mm. The electron gun can provide the 2.5 mm × 0.14 mm sheet electron beam with maximum current density of 57 A/cm2 at the CW mode. Experimental results show that the developed BWO can operate in the fundamental mode TM11 and generate the state-of-art output power of 182 mW at the frequency of 0.3426 THz with a large frequency tuning range from 0.318 THz to 0.359 THz.

Highlights

Radiation of the terahertz (THz) wave has drawn lots of attention in many areas of science and technology, including the plasma diagnostic in nuclear fusion, high data rate communications, remote high-resolution imaging, chemical spectroscopy, materials research, deep space research and communications, basic biological spectroscopy and biomedical diagnostics[1,2,3,4,5,6,7,8]
We developed a backward wave oscillator (BWO)-like CW clinotron with sheet electron beam of 5 kV at 0.26 THz15
A kind of BWO is developed in this paper

Summary

BWO with wide tunable bandwidth

Hongzhu Xi1, Jianguo Wang[2,3], Zhaochang He1, Gang Zhu[1], Yue Wang[2], Hao Wang[1], Zaigao Chen[2], Rong Li1 & Luwei Liu[1]. A high performance continuous-wave (CW) backward wave oscillator (BWO) with planar slow wave structure (SWS) and sheet electron beam in Y-band is presented in this paper. Experimental results show that the developed BWO can operate in the fundamental mode TM11 and generate the state-of-art output power of 182 mW at the frequency of 0.3426 THz with a large frequency tuning range from 0.318 THz to 0.359 THz. Radiation of the terahertz (THz) wave has drawn lots of attention in many areas of science and technology, including the plasma diagnostic in nuclear fusion, high data rate communications, remote high-resolution imaging, chemical spectroscopy, materials research, deep space research and communications, basic biological spectroscopy and biomedical diagnostics[1,2,3,4,5,6,7,8]. To perform the experiments of collective Thomson scattering, a THz radiation source with enough power will be needed, the vacuum electronic devices (VEDs) with high output power may be one of the suitable choices of the terahertz sources[9]. To obtain the terahertz wave with the output power of watt-level or hundreds of mW at the frequency above 0.3 THz, many research works are being conducted, but most of them are still at the stages of theoretical design and numerical simulations[7]

Physical Design of the Planar BWO

Fabrication of the BWO

Experimental Studies on the BWO

Conclusions

Author Contributions

Additional Information