[1] Coaker, B.; Challis, T. “Travelling Wave Tubes: Modern Devices and Contemporary Applications”; Microwave Journal 2008, 32-45.##
[2] Pchelnikov, Y. N.; Abe, D. K. “A Novel Millimeter-Wave Structure for Longitudinal Interaction with a Sheet Electron Beam”; IEEE Trans. Electron Devices 2018, 65, 2135-2141.##
[3] Wang, J.; Shu, G.; Liu, G.; Yang, L. Y.; Luo, Y. “Ultrawideband Coalesced-mode Operation for a Sheet-beam Traveling-wave Tube”; IEEE Trans. Electron Devices 2016, 63, 504–511.##
[4] Kowalski, E. J.; Shapiro, M. A.; Temkin, R. J. “An Overmoded W-band Coupled-cavity TWT”; IEEE Trans. Electron Devices 2015, 62, 1609–1616.##
[5] Kompfner, R. “The Traveling-wave Tube as Amplifier of Microwaves”; Proc. IRE 1947, 35, 124–127.##
[6] Swaminathan, K.; Zhao, C.; Chua, C.; Aditya, S. “Vane-loaded Planar Helix Slow-wave Structure For Application in Broadband Traveling-wave Tubes”; IEEE Trans. Electron Devices 2015, 62, 1017–1023.##
[7] Lucken, J. A. “Some Aspects of Circuit Power Dissipation in High Power CW Helix Traveling-wave Tubes, part I: General Theory”; IEEE Trans. Electron Devices 1969, 16, 813–820.##
[8] Gilmour, A. S. “Principles of Klystrons, Traveling Wave Tubes, Magnetrons, Crossed-field Amplifiers, and Gyrotrons”; Artech House, MA, USA, 2011.##
[9] https://www2.l3t.com/edd/old/products/products_helix.htm##
[10] Gholamrezaei, M.; Razavi, M.; Hamidi, E.; Kashani, F. H. “Multihelix Structure (MHS) for Traveling Wave Tube Power Enhancement”; Proc. 24th Int. Iranian Conf. Electrical Eng. (ICEE), Shiraz, Iran, 2016.##
[11] Pozar, D. M. “Microwave and RF Design of Wireless Systems”; New York, NY, USA: Wiley, 2012.##
[12] Gholamrezaei, M.; Hamidi, E.; Kashani, F. H. “∞-Shaped (Lemniscatical) Helix Slow-Wave Structure (LH-SWS) for High-Power Traveling-Wave Tubes”; IEEE Trans. Electron Devices 2018, 65, 2607-2613.##
[13] Shatrov, A. D.; Sivov, A. N. ; Chuprin, A. D. “Investigation of Multifilar Helical Antennas with Small Radius and Large Pitch Angle on Basis of Eigenmodes of Infinite Sheath Helix”; Electronics Letters 1994, 30, 1558-1560.##
[14] Kumar, A.; Aditya, S. “Simplified Tape-Helix Analysis of the Planar Helix Slow Wave Structure with Straight-Edge Connections”; IEEE Trans. Electron Devices 2018, 65, 2280-2286.##
[15] Wei, W.; Wei, Y.; Wang, W.; Zhang, M.; Gong, H. “Dispersion Equations of a Rectangular Tape Helix Slow-Wave Structure”; IEEE Trans. Microwave Theory and Techniques 2015, 63, 1445-1456.##
[16] Pchelnikov, Y. N.; Abe, D. K. “A Novel Millimeter-Wave Structure for Longitudinal Interaction with a Sheet Electron Beam”; IEEE Trans. Electron Devices 2018, 65, 2135-214.##
[17] Safi, D.; Birtel, P.; Meyne, S.; Jacob, A. F. “A Traveling-Wave Tube Simulation Approach with CST Particle Studio”; IEEE Trans. Electron Devices 2018, 65, 2257-2263.##
[18] Fu, C.; Wei, Y.; Gong, Y.; Wang, W. “Simulation of Rectangular Helix Slow-Wave Structure for 140 GHz Traveling-Wave Tube”; IEEE Trans. Plasma Sci. 2016, 44, 1069-1074.##
[19] Abu-elfadl, T. A.; Nusinovich, G. S.; Shkvarunets, A. G.; Carmel, Y.; Antonsen Jr, T. M.; Granatstein, V. L. “Efficiency of Helix Pasotron Backward-wave Oscillator”; IEEE Trans. Plasma Sci. 2002, 30, 1126-1133.##
[20] Gewartowski, J. W.; Watson, H. A. “Principles of Electron Tubes”; D. Van Nostrand, NJ, USA, 1965.##
[21] Chong, C. K.; Davis, J. A.;
Le Borgne, R. H.; Ramay, M. L.;
Stolz, R. J.;
Tamashiro, R. N.;
Vaszari, J. P. “Development of High Power Ka-band and Q-band Helix-TWTs”; IEEE Trans. Electron Devices 2005, 52, 653-659.##
[22] Chong, C. K.; Layman, D.; Le Borgne, R. H.; Olivieri, M.; Ramay, M. L.;
Stolz, R. J. “Development of High Power Ka/Q Dual-band and Communications/radar Dual-function Helix-TWT”; IEEE Trans. Electron Devices 2009, 55, 913-918.##
[23] Dayton, J. A.; Dayton, J. A.; Kory, C. A.;
Mearini, G. T.; Malta, D.;
Lueck, M.;
Bower, C. A. “A 650 GHz helical BWO”; Proc. IEEE Int. Vac. Electron. Conf., Monterey, CA, 2008.##
[24] L3 Electron Devices “L2086 Helix Traveling Wave Tube”; http://www.L3.com, 2017.##
[25] Chong, C. K. “500 W Ka-band Helix-TWT: Transition from Development to Production”; Proc. IEEE Int. Vac. Electron. Conf., 2009.##
[26] L3 Electron Devices “MMW-band Traveling Wave Tube”; http://www.L3.com, 2017.##
[27] Pierce, J. R. “Traveling-wave Tubes”; D. Van Nostrand, 1950.##
[28] Basu, B. N. “Electromagnetic Theory and Applications in Beam-wave Electronics”; Singapore, World Scientific, 1995.##
[29] Zhang, K.; Li, D. “Electromagnetic Theory for Microwaves and Optoelectronics”; Springer-Verlag, NY, USA, 1998.##
[30] Macphie, R. H.; Wu, K. L. “A Full-wave Modal Analysis of Inhomogeneous Waveguide Discontinuities with Both Planar and Circular Cylindrical Boundaries”; IEEE Trans. Microwave Theory and Techniques 2001, 49, 1132-1136.##
[31] Yeo, T. “Cutoff Frequencies of an Asymmetrically Loaded Cylindrical Waveguide”; IEEE Trans. Microwave Theory and Techniques 1998, 46, 1331-1334.##
[32] Roumeliotis, J. A.; Savaidis, S. P. “Cutoff Frequencies of Eccentric Circular-elliptic Metallic Waveguides”; IEEE Trans. Microwave Theory and Techniques 1994, 42, 2128-2138.##
[33] Sebak, A. “Electromagnetic Scattering by Two Parallel dielectric elliptic cylinders”; IEEE Trans. Antennas and Propag. 1994, 42, 1521-1527.##
[34] Balanis, C. A. “Advanced Engineering Electromagnetics”; John Wiley & Sons, Inc. 2012.##
)
