P2-16: Improved method of determining the dielectric properties of basic rods used in traveling wave tubes

The method of determination a dielectric permittivity ε and tangent of a dielectric loss angle tgδ of basic rods of any cross sizes between cross sizes of two initial samples is offered. It consists in decomposition of functions containing ε and tgδ, in a series on degrees of (ε -1) and reservation of two terms of a series for a rod that does not obey to a requirement ≪insignificance of perturbations≫, and one term of a series - for a rod satisfying this requirement. The analytical formulas that contain biases of resonant frequencies for two initial samples and for the tested rod are obtained.