Ka-band dual sheet beam traveling wave tube using supported planar ring-bar slow wave structure

Abstract

A dual-beam planar slow wave structure (SWS), named dielectric supported ring-bar SWS is proposed in this paper. The planar SWS is supported by two dielectric rods at the side edges, making it fit for dual sheet beam operation. The high frequency and transmission characteristics of the proposed SWS are investigated. The backward-wave oscillation and higher harmonic waves are effectively suppressed by setting two cathodes in the same plane parallel to the SWS and negative phase-velocity jumping. The hot performance of the proposed SWS is carried out by using particle-in-cell (PIC) simulation, in which two sheet electron beams (9.7 kV, 0.2 A) are employed to provide direct current power. With an input power of 1W, the output power is 180 W at 38 GHz and the corresponding gain is 22.6 dB. Besides, after adding dielectric rods to the output part, the entire structure dissipates heat well by thermal analysis.

Multiple Dielectric-Supported Ridge-Loaded Rhombus-Shaped Wideband Meander-Line Slow-Wave Structure for a V-Band TWT

“…Table 5 lists the key operation parameters of meander-line SWSs in the literature, as well as those of the proposed SWS; as it can be seen, compared with the specific parameters of the meander-line SWSs supported by dielectric rods [21,22,26], the gain of the proposed structure can exceed 30 dB while keeping a miniaturized structure. Compared with the structure in [18], the proposed structure has a lower operating voltage while maintaining a wide relative bandwidth.…”

“…In order to solve these problems, a new type of meander-line supported by dielectric rods was proposed in [20][21][22][23], in which the dielectric substrate was replaced by side…”

“…In order to solve these problems, a new type of meander-line supported by dielectric rods was proposed in [20][21][22][23], in which the dielectric substrate was replaced by side rods. The so-called dielectric-rod-supported metallic meander-line SWS is suitable for a dualsheet electron beam, thus having large power capability.…”

“…The so-called dielectric-rod-supported metallic meander-line SWS is suitable for a dualsheet electron beam, thus having large power capability. For example, the Ka-band meander-line SWS supported by dielectric rods mentioned in [21] can achieve a gain of 23.4 dB at a voltage of 10.6 kV and a bandwidth of 6 GHz; the Ka-band ring-bar SWS supported by dielectric rods proposed in [22] can achieve a gain of 22.6 dB at 9.7 kV and a bandwidth of 2 GHz.…”

Study of an Attenuator Supporting Meander-Line Slow Wave Structure for Ka-Band TWT

“…Therefore, a meander-line (ML) SWS supported by side dielectric rods instead of a bottom substrate slab was proposed [17] and furtherly developed with different patterns [18,19]. The ML which was cut off from a metal sheet by laser is much thicker (~200 µm) than those fabricated by magnetron sputtering.…”