Left-Handed Structures for Accelerator Applications

Abstract

Metamaterials are artificial periodic structures made of small elements and designed to obtain specific electromagnetic properties. As long as the periodicity and the size of the elements are much smaller than the wavelength of interest, an artificial structure can be described by a permittivity and permeability, just like natural materials. When the permittivity and permeability are simultaneously negative in some frequency range, the metamaterial is called double negative or left‐handed and has some unusual properties. Left‐handed metamaterials (LHM) have potential applications in active and passive devices at millimeter waves and at much higher frequencies. Waveguides loaded with metamaterials are of interest because the metamaterials can change the dispersion relation of the waveguide significantly. Slow backward waves can be produced in a LHM‐loaded waveguide without corrugations. The dispersion relation of a LHM‐loaded waveguide has several interesting frequency bands which are described. Left‐hande...