EIGENMODES ANALYSIS OF SECTORAL COAXIAL RIDGED WAVEGUIDES BY TRANSVERSE FIELD-MATCHING TECHNIQUE. PART 1. THEORY

Introduction. The utilization of ridged structures in modern waveguide devises is discussed. The goals of the research presented in the paper are defined. TE modes. The geometrical configurations of sectoral coaxial ridged waveguides are shown. The formulas obtained in the section allow to compute cutoff wave numbers and electric and magnetic fields distributions of TE modes in the presence of the ridge either on the inner or the outer wall of the waveguide. TM modes. The formulas obtained in the section allow to compute cutoff wave numbers and electric and magnetic fields distributions of TM modes in the presence of the ridge either on the inner or the outer wall of the waveguide. Solutions convergence for cutoff wave numbers. The cutoff wave numbers convergence analysis depending on the amount of partial modes has been carried out. Residual errors plots for cutoff wave numbers computing of first four modes as dependences on the amount of partial modes are presented. It has been shown that it is enough to use 24 partial modes for the calculation of sectoral coaxial ridged waveguides cutoff wave numbers for both configurations by transverse field-matching technique with residual error less than 0.1%. Conclusions. General conclusions of the paper are given.