Sensitivity analysis of a double corrugated waveguide slow wave structure for a 151 – 161.5 GHz TWT*

Jeevan M Rao, Rupa Basu, Rosa Letizia, and Claudio Paoloni
School of Engineering, Lancaster University, Lancaster, LA1 4YW, United Kingdom
Dedicated to Prof B N Basu

TWTs at D-band (141 – 174.5 GHz) are the most promising solution to provide high transmission power for enabling long range wireless links with high capacity at sub-THz frequency. A D-band TWT was designed in the 151-161.5 GHz frequency band with about 10 W output power. The double corrugated waveguide is adopted as slow wave structure (SWS) for the relatively easy fabrication and alignment in comparison to other SWSs typically used at sub-THz frequency. Due to the short wavelength at D-band, the fabrication requires high precision computerised numerically controlled (CNC) milling machining and tight tolerance control. The sensitivity analysis of performance as a function of the dimensions of a device is an important method to predict in advance how the performance of the device is affected by geometry variations, and also to ascertain the required level of fabrication accuracy to meet the specifications. The sensitivity analysis is also useful to define the best initial dimensions for further optimization. This paper discusses the sensitivity analysis applied to the double corrugated waveguide (DCW) to be used in a 151-161.5 GHz TWT. A broad range of parameters are considered demonstrating the importance of fabrication accuracy and the eventual correction options for a correct functioning. The impact of fillets in the DCW pillars is also evaluated to eventually ease the fabrication requirement. © Anita Publications. All rights reserved.
Keywords: Sub-THz, D-band, Traveling wave tube, Double corrugated waveguide, Sensitivity analysis.

Peer Review Information
Method: Single- anonymous; Screened for Plagiarism? Yes
Buy this Article in Print © Anita Publications. All rights reserve

References

1. Dhillon S S, Vitiello M S, Linfield E H, Davies A G, Hoffmann M C, Booske J, Paoloni C, Gensch M, Weightman P,  Williams G P, Castro-Camus E, Cumming D R S, Simoens F, Escorcia-Carranza I, Grant J, Lucyszyn S, Kuwata-Gonokami M, Konishi K, Koch M, Schmuttenmaer C A, Cocker T L, Huber R, Markelz A G, Taylor Z D, Wallace V P, Zeitler J A, Sibik J, Korter T M, Ellison B, Rea S, Goldsmith P, Cooper K B, Appleby R, Pardo D, Huggard P G, Krozer V, Shams H, Fice M, Renaud C, Seeds A, Stöhr A, Naftaly M, Ridler N, Clarke R, Cunningham J E, Johnston M B, The 2017 terahertz science and technology roadmap, J Phys D: Appl Phys, 50(2017)043001; doi. 10.1088/1361-6463/50/4/043001.
2. Paoloni C, Sub-THz wireless transport layer for ubiquitous high data rate, IEEE Commun Mag, 59(2021)102–107.
3. Maiwald T, Li T, Hotopan G.-R, Kolb K, Disch K, Potschka J, Haag A, Dietz M, Debaillie B, Zwick T, Aufinger K, Ferling D, Weigel R, Visweswaran A, A review of integrated systems and components for 6g wireless communication in the d-band, Procd IEEE, 111(2023)220–256.
4. Paoloni C, Gamzina D, Letizia R, Zheng Y, Luhmann N C (Jr), Millimeter wave traveling wave tubes for the 21st century, J Electromagn Waves Appl, 35(2021)567–603.
5. Gamzina D, Himes L G, Barchfeld R, Zheng Y, Popovic B K, Paoloni C, Choi E, Luhmann N C, Nano-cnc machining of sub-THz vacuum electron devices, IEEE Trans Electron Devices, 63(2016)4067–4073.
6. Basu R, Rao J M, Le T, Letizia R, Paoloni C, Development of a D-band traveling wave tube for high data-rate wireless links, IEEE Trans Electron Devices, 68 (2021)4675–4680.
7. Andre F, Racamier J, Zimmermann R, Le Q T, Krozer V, Ulisse G, Minenna D F G, Letizia R, Paoloni C, Technology, assembly, and test of a W-band traveling wave tube for new 5g high- capacity networks, IEEE Trans Electron Devices, 67(2020)2919–2924.
8. Wenqiang L, Yi J, Quanfeng Z, Peng H, Linlin H, Lei Y, Hongbin C, Development of D-band continuous-wave folded waveguide traveling-wave tube, in 2015 IEEE International Vacuum Electronics Conference (IVEC), pp 1–3, 2015.
9. Wang Z, Zhou Q, Gong H, Liao J, Wei Y, Duan Z, Liu H, Gong Y, Development of a 140-GHz folded-waveguide traveling-wave tube in a relatively larger circular electron beam tunnel, J Electromagn Waves Appl, 31(2017)1914–1923.
10. Field M, Kimura T, Atkinson J, Gamzina D, Luhmann N C, Stockwell B, Grant T J, Griffith Z, Borwick R, Hillman C, Brar B, Reed T, Rodwell M, Shin Y.-M, Barnett L R, Baig A, Popovic B, Domier C, Barchfield R, Zhao J, Higgins J A, Goren Y, Development of a 100-W 200-GHz high bandwidth mm-wave amplifier, IEEE Trans Electron Devices, 65(2018)2122–2128.
11. Paoloni C, Basu R, Billa L, Rao M, J, Letizia R, Ni Q, Wasige E, Al-Khalidi A, Wang J, Morariu R, Long-range millimetre wave wireless links enabled by travelling wave tubes and resonant tunnelling diodes, IET Microw Antennas Propag, 14(2020)2110–2114.
12. Mineo M, Paoloni C, Double-corrugated rectangular waveguide slow-wave structure for terahertz vacuum devices, IEEE Trans Electron Devices, 57(2010)3169–3175.
13. Mineo M, Paoloni C, Improved corrugation cross-sectional shape in terahertz double corrugated waveguide, IEEE Trans Electron Devices, 59(2012)3116–3119.