Metamaterial-Enhanced Resistive Wall Amplifiers: Theory and Particle-in-Cell Simulations

The resistive wall amplifier (RWA), a vacuum electron device, has been theoretically predicted to provide extremely high gain. However, the properties of practical, naturally available bulk materials for the resistive wall support structure significantly reduce achievable gain. This paper investigates the capabilities of a metamaterial-enhanced RWA (ME-RWA). We predict that using epsilon-negative metamaterials can yield high gains that closely approach the idealized performance limit. ME-RWAs may exhibit bandwidths and gains much higher than many commercially available vacuum electron devices.