Similarity of the Properties of Conventional Periodic Structures with Metamaterial Slow Wave Structures

A study of the evolution of wave dispersion in systems of all‐metallic periodic structures with increasing corrugation depth shows a similarity of the properties of waves in metamaterial slow wave structures (MSWSs) and traditional metallic slow wave structures (SWSs) used in high‐power microwave (HPM) sources. This chapter aims to identify MSWSs with novel dispersion characteristics for use in HPM source concepts. It explores the effects of increasing corrugation depth on conventional periodic SWSs using HFSS. It is shown that using direct asymptotic analysis makes it possible to recover an effective surface impedance model directly from Maxwell's equations. Furthermore, without assuming infinitely thin corrugations, it is shown that effective impedance is a subwavelength phenomenon. The characteristic feature of MTMs is the coupling of macroscopic fields through structurally generated subwavelength resonance.