Design of helix slow wave structure for X band helix TWT using multi-dispersion

In this paper, a compact, multi dispersive helix slow-wave structure (SWS) with coaxial input coupler for a high efficiency X-band helix TWT has been proposed. Design of SWS has been carried out using in-house developed analytical code GANGA, SUNRAY-1D and commercial software ANSYS Electronics Desktop. The helix SWS has been modelled in three sections each having different dispersion characteristics – realized by different loading scheme to each section to achieve desired output characteristics. Due to different dispersion characteristics, coupling system has also been suitable modelled to exchange RF power from SWS.