Overmoded subterahertz surface wave oscillator with pure TM{sub 01} mode output

Journal Article · Mon Feb 15 04:00:00 EST 2016 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4941098· OSTI ID:22493889

Wang, Guangqiang; Zeng, Peng; Wang, Dongyang ^[1]; Wang, Jianguo ^[1]; Li, Shuang ^[1]

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1. Northwest Institute of Nuclear Technology, P. O. Box 69-1, Xi'an 710024 (China)

Overmoded O-type Cerenkov generators using annular electron beams are facing the problem of multi-modes output due to the inevitable structural discontinuities. A simple but effective method to achieve the pure TM{sub 01} mode output is applied on the 0.14 THz overmoded surface wave oscillator (SWO) in this paper. In spite of still using an overmoded slow wave structure to ensure the easy fabrication, the followed smooth circular waveguide is shrinkingly tapered to the output waveguide with appropriate radius that it cuts off other higher modes except TM{sub 01} mode. Moreover, the modified device here has the same power capacity as the previous one according to the numerical analysis. By optimized lengths of the transition waveguide and tapered waveguide, particle-in-cell simulation results indicate that the subterahertz wave with output power increased 14.2% at the same frequency is obtained from the proposed SWO under the previous input conditions, and importantly, the output power is all carried by TM{sub 01} mode as expected. Further simulation results in the pulse regime confirm the feasibility of the optimized structure in the actual experiments. This simple and viable design is also applicable to overmoded devices in the lower frequency band of subterahertz wave.

• OSTI ID: 22493889
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 2 Vol. 23; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COMPUTERIZED SIMULATION
ELECTRON BEAMS
NUMERICAL ANALYSIS
OSCILLATORS
PULSES
WAVE PROPAGATION
WAVEGUIDES