Capacitance of nonuniform coaxial transmission lines

The physical realisation of a nonuniform transmission line. possessing some desirable characteristic impedance profile, is usually achieved using calculations which do not take into account the expanding or contracting nature of the line and the associated distortions of the electromagnetic fields. A method has been devised which gives an improved realisation of such lines in a coaxial configuration. Corrections for the conductor slopes and effective lengths are made and a design example is used to illustrate these effects.