Wideband Glide-Symmetric Double-Corrugated Gap-Waveguide Traveling-Wave Tube for Millimeter Waves

TL;DR

This paper introduces a wideband glide-symmetric double corrugated gap waveguide for traveling-wave tubes, demonstrating broad bandwidth and high gain with reduced backward wave oscillations through innovative electromagnetic bandgap technology.

Contribution

It presents a novel glide-symmetric double corrugated waveguide structure with EBG features, enabling wideband operation and improved stability for millimeter-wave TWTs.

Findings

12 GHz bandwidth from 54.5 to 66.3 GHz

Maximum gain of 23 dB

Reduced backward wave oscillations

Abstract

We explore the use of glide symmetry (GS) and electromagnetic bandgap (EBG) technology in a glide-symmetric double corrugated gap waveguide (GSDC-GW) slow wave structure (SWS) for traveling wave tube (TWT) applications. Notably, this GS structure provides the advantage of wide-band operation and the EBG eliminates the need for a conductive connection between the top and bottom waveguide plates. The TWT performance is evaluated via particle-in-cell simulations that reveal a 3-dB bandwidth of approximately 12 GHz spanning from 54.5 GHz to 66.3 GHz, accompanied by a maximum gain of 23 dB. Because of GS, the backward wave in the first spatial harmonic is not longitudinally polarized, leading to a low risk of backward wave oscillations in the TWT. This work places the GSDC-EBG structure within the arena of potential SWS topologies for TWTs operating under similar conditions.