Study Of High-frequency Characteristics Of The Elliptical Helix Slow Wave Structure

This paper gives a brief introduction of research progress about high power microwave electronic device during the last decade. Based on it, a new kind of helix slow-wave structure named elliptical helix slow-wave structure used in helix traveling wave tubes has been detailedly investigated. By studying the RF characteristics of this slow-wave structure, it's found that higher operation frequency and interaction impedance will be obtained by increasing the eccentricity of helix or decreasing it of the shield. Meanwhile, great potential of improving system bandwidth has also been found if the eccentricity of helix or shield or the two are properly choosed.Mathieu function is the base of field theory analysis in elliptical cylinder coordinate system. So, firstly, detail investigation has been given about the problem of numerical analysis of Matheiu functions, based on the predecessor's contribution, an improved faster algorithm of numerical analysis and confirmation algorithm of Matheiu functions has been presented. The numerical experiments proved that the improved algorithm has the characteristics of easily to program and precision higher .Based on it, detailed computational procedure package and curve storehouse of arbitrary kinds of Mathieu function has also been obtained.Detailedly investigation about wave properties of a free elliptical helix slow wave structure with arbitrary eccentricity and RF characteristics of elliptical helix slow-wave structure supported by well-proportioned dielectric with elliptical confocal shield has been given in chapter 3 and chapter 4. By studying the RF characteristics of this slow-wave structure, it's found that higher operation frequency and interaction impedance will be obtained by increasing the eccentricity of helix or decreasing it of the shield. Meanwhile, great potential of improving system bandwidth has also been found if the eccentricity of helix or shield or the two are properly choosed.Finally, a brief summary of the conclusion and deficiency about this paper has been given, the further worked emphasis and necessity has also been pointed coinstantaneously in the last chapter.