This chapter presents case studies of various ways to perform dispersion engineering using various slow-wave structures (SWSs). Metamaterials (MTMs) with negative effective permittivity and permeability have been realized using a periodic arrangement of metallic rods and split ring resonator. Studies on the effective medium property of MTMs have led to various applications in high-power microwave (HPM) sources. The chapter presents a MTM-based SWS design for high-power microwave generation. This design features broadside split rings that are loaded in a cylindrical waveguide and grounded using metallic support. A design goal would be to design a SWS that exhibits degenerate band edge characteristics for efficient HPM generation applications. The chapter shows how a volumetric axially symmetric mode operating near cutoff can be coupled to an evanescent surface mode on a two-dimensional periodic surface lattice. Traveling wave tube amplifiers are HPM sources that find application in radar and satellite communication systems, among others.
