Analysis of a double discontinuity in a coaxial line

摘要

This paper presents a field analysis of two closely spaced, abrupt discontinuities in a coaxial transmission line. The discontinuities occur in the radius of the inner conductor of the transmission line. The problem is formulated in terms of two simultaneous integral equations whose solution is obtained by a variational technique. The solution for the admittance is expressed in terms of an infinite series of field modes. The first 11 mode amplitudes have been obtained numerically for different dielectrics and different radii, and admittances calculated. A comparison is made with the results obtained from a transmission-line theory approximation.