Calculation of Cutoff Wavenumbers for TE and TM Modes in Tubular Lines with Offset Center Conductor (Short Paper)

The cutoff wavenumbers of TE and TM modes (higher order modes) in a tubular line having an offset center conductor have heen calculated. Whereas most previous methods used to study this structure were of an approximate nature, the analytical method developed by Singh and Kothari leads to a rigorous analytical formulation. The boundary conditions on both conductor boundaries, assumed to be perfectly conducting, are satisfied exactly. The cutoff values calculated show that some results previously reported are inaccurate.