Infinite elements and base functions for rotationally symmetric electromagnetic waves

The finite-element method is applicable to infinite domains if the outermost `finite´ elements are infinite and their base functions satisfy the boundary conditions at infinity. Appropriate infinite elements fitted to triangular or quadratic finite-element net and corresponding base functions satisfying Sommerfield´s radiation condition of electromagnetic waves are introduced. The application of the defined infinite elements is illustrated for the problem of the radiation of a coaxial cable to a half-space. The results are in very good agreement with those found in the literature