Wave energy amplification in a metamaterial-based traveling-wave structure

Abstract

We consider the interaction between a particle beam and a propagating electromagnetic wave in the presence of a metamaterial. We show that the introduction of a metamaterial gives rise to a novel dispersion curve which determines a unique wave particle relationship, via the frequency dependence of the metamaterial and the novel ability of metamaterials to exhibit simultaneous negative permittivity and permeability. Using a modified form of Madey's theorem we find that the novel dispersion of the metamaterial leads to a amplification of the EM wave power.PACS numbers:

Absolute Instability near the Band Edge of Traveling-Wave Amplifiers

“…An absolute instability will occur if the dispersion diagram is convex at that point if the beam current exceeds a certain threshold value, (or if the beam line intersects the backward wave side of the circuit dispersion curve). These general conclusions are applicable to novel TWT's of current interest, including meta-materials TWT [34,35,36], and the THz Smith-Purcell radiation sources [37,38,39]. Recent simulations indeed reveal an absolute instability at the upper band edge of a TWT that uses a disk-on-rod slow wave structure [40].…”

Theory and New Amplification Regime in Periodic Multimodal Slow Wave Structures With Degeneracy Interacting With an Electron Beam

“…Some other commonly used SWSs include comb structure [15], disk structures [16], interdigitated structures [17] and folded-waveguides for terahertz radiation [18], [19], among others. Metamaterial based slow-wave structures were proposed recently [20] by embedding subwavelength resonant elements inside waveguides, like ring-bars [21] or split-ring resonators [22], [23]. Typically at microwave frequencies, periodic structures are implemented as metallic obstacles or slots due to lower losses than in dielectrics and to the ability to sustain very large field gradients [24].…”

Towards photonic crystal and metamaterial high-power microwave applications

“…This novel behavior of MM has been used by many authors to consider a variety of technologies such as; In [34] the authors introduce a metamaterial into the FWTWT at the interaction region between beam and wave to trigger a novel gain-frequency phenomena. Controlling the FWTWT dispersion relationship via the metamaterial, to define a unique beam-wave interaction phenomenon.…”