Advanced Bragg Resonator Integration for Enhanced Bandwidth and Stability in G-Band TWT With Staggered Double Vane Structure

This article presents the design and analysis of a wideband staggered double vane (SDV) sheet-beam-based traveling-wave tube (TWT) for stable amplification in the G-band. Unlike conventional SDV structures, which often suffer from oscillations within the interaction region due to upper and lower cutoff regions, our design employs several key innovations to overcome these limitations. First, the newly designed filter configuration effectively eliminates oscillations within the interaction region. Second, the shape of the Bragg resonator is modified to a diamond configuration, which significantly enhanced impedance matching around 200 GHz, ensuring broader bandwidth and improved transmission characteristics. Finally, we discuss the advantages of E-plane fabrication compared to H-plane fabrication and presents a study on the design of an E-plane filter structure that is feasible for manufacturing. Particle-in-cell (PIC) simulations and experimental validations confirm that our proposed design achieves a 40 GHz 3 dB bandwidth and stable operation without oscillations, demonstrating its potential for high-performance millimeter-wave (mmWave) applications.