A research of W-band folded waveguide traveling wave tube with elliptical sheet electron beam

Abstract

Folded waveguide (FWG) traveling wave tube (TWT), which shows advantages in high power capacity, moderate bandwidth, and low-cost fabrication, has become the focus of vacuum electronics recently. Sheet electron beam devices are better suited for producing radiation sources with large power in millimeter wave spectrum due to their characteristics of relatively low space charge fields and large transport current. A FWG TWT with elliptical sheet beam working in W-band is presented in this paper, with the analysis of its dispersion characteristics, coupling impedance, transmission properties, and interaction characteristics. A comparison is also made with the traditional FWG TWT. Simulation results lead to the conclusion that the FWG TWT with elliptical sheet beam investigated in this paper can make full use of relatively large electric fields and thus generate large output power with the same electric current density.

A novel H-plane loaded folded waveguide slow wave structure for traveling wave tube

“…However, as the operating frequency extends to the short millimeter or terahertz wave band, the traditional TWT with FWG slow wave circuit cannot be hold high power because of the limitation of the low beam-wave efficiency which is originally determined by the slow wave circuit. This problem may be solved by tapering the period of the slow wave circuit [1], loading ridges on the straight portions of SWS [2][3], operating at higher order mode but not fundamental mode [4], utilizing sheet beam with higher current transport capacity [5], and so on. In this paper, taper H-plane loaded FWG-SWS for traveling wave tube (TWT) has been proposed.…”

Study on two kinds of novel 220 GHz folded-waveguide traveling-wave tube

“…11,12) Recently, based on the earlier investigation of FWG TWTs, considerable effort has been devoted to searching for novel structures with a circle-beam tunnel or sheet-beam tunnel to improve the performance of tubes. [13][14][15][16] In this paper, two kinds of novel FWG structure with a circle-beam tunnel and sheet-beam tunnel are proposed for TWT application. The three models of the conventional FWG and novel FWGs are shown in Fig.…”

A Novel Gap-Groove Folded-Waveguide Slow-Wave Structure for G-Band Traveling-Wave Tube

“…Therefore, the improvement of the output power is limited [4]. In recent studies, sheetbeam FW with a rectangular electron beam tunnel has been presented in which most strong electric fields can be used in the interaction process [4]- [5]. However, the presence of the larger beam tunnel can considerably aggravate the perturbation and introduce a substantial stopband [6].…”

“…However, in traditional FWs, due to the height limitation of the straight section, the radius of the circular beam tunnel cannot be so large for utilizing the full strength of the electric fields in the interaction process. Therefore, the improvement of the output power is limited [4]. In recent studies, sheetbeam FW with a rectangular electron beam tunnel has been presented in which most strong electric fields can be used in the interaction process [4]- [5].…”