Analysis of fin-line tapers and transitions

A design method for tapered transitions between arbitrary types of fin line (unilateral, bilateral, antipodal fin lines and, as special case, rectangular waveguide) is presented which optimises the profile of the slot width itself. The procedure, which can easily be implemented on a desk-top computer, is based only on the knowledge of the propagation constant of the fundamental mode. Results are presented for tapers between various fin lines.