Continuous spectrum of a flange-backed slotted waveguide with application

The continuum of an open waveguide describes radiation as simply, in principle, as the discrete spectrum of a classical guide describes any physical field in it. This part of the spectrum, however, has received little attention for guides of nonseparable two-dimensional cross-sections. To illustrate its derivation, the authors establish the continuum of a flange-backed rectangular waveguide slotted on its narrow wall. As a demonstration for its use, they determine the transmission and radiation properties of the junction between an ordinary and a slotted guide