This paper presents an analysis of the dispersion and |S_21 | frequency characteristics of three periodic structures constructed in rectangular waveguides. Unit cells with dielectric-loaded step discontinuities based on double steps, symmetric double steps, and glide-symmetric double steps were investigated using full-wave electromagnetic simulation software. All dispersion diagram results obtained from the three different models are compared to each other by fixing the period of the unit cell (p = 13.68mm) for each periodic structure. |S_21 | frequency characteristics of the first propagating mode are examined for finite implementations of all considered structures. The transmission characteristics of different numbers of periodic arrangements of each periodic unit cell were investigated. Then, the effect of geometric variations, including glide symmetry, on the transmission characteristics is investigated by keeping the number of unit cells constant (N=10). Furthermore, the filter performance characteristics of the proposed structure are compared with those of the reported studies in the open literature.