Year: 2026
Type: article
Abstract: In this paper, a 1.1 THz staggered double-grating slow-wave structure (SWS) for traveling wave tubes (TWTs) is fabricated using UV-LIGA processes based on RD-2150 photoresist. The designed SWS has a wide side of 170 μm and a narrow side of 50 μm, and when half of the SWS is fabricated, the height of the structure is 85 μm, which is half of the wide side. The fabrication process includes lithography, electroforming, grinding, polishing, and resist removal. The top surface, bottom surface, and sidewall roughness of the as-fabricated structure were measured to be 21 nm, 20 nm, and 17 nm. The mean measured sidewall verticality of the structure was 90.1°, with a standard deviation of 0.5° obtained from four independent sampling positions. For the structure's nominal dimensions of 85 μm in height and 50 μm in width, the achieved dimensional accuracies were ±2 μm and ±1 μm, with corresponding standard deviations of 1.05 μm and 0.59 μm, respectively, confirming excellent structural uniformity. We subsequently evaluated the impact of these dimensional deviations on the electromagnetic performance of the structure. The results indicate that the deviations had a negligible effect on the dispersion characteristics. Specifically, the linewidth deviation led to a 21% reduction in coupling impedance, while the height deviation caused a 600 V increase in the synchronous operating voltage.
Source: Micromachines
DOI: 10.3390/mi17040427
Authors: Qi Jiang, Xinghui Li, Yuanfei Hui, Pan Pan, Jinjun Feng
Institution: Beijing Vaccum Electronic Research Institute
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,534
OpenAlex ID: W7144003460