Analysis of the coaxial helical-groove slow-wave structure

A coaxial helical-groove structure is presented and analyzed in this paper. The dispersion equation and coupling impedance of the structure are given. Numerical calculations of the dispersion relation and coupling impedance with different structure dimensions are carried out. Calculated results indicate that the cold bandwidth of this structure can reach 60%, while the coupling impedance is more than 16 /spl Omega/. It is shown that the coaxial helical groove is a wide-band slow-wave structure with high-power capacity.