view article
Figure 1
Possible radiator configurations are, for example, round tubes (a), and curved (b) or flat (c) parallel plate waveguides (PPWG). Parallel plate waveguides offer a tuning possibility via the distance of the plates but suffer from a reduced mode confinement as compared with the geometrical simple round tubes. While the outer structure of the radiator is a highly conducting metal, the inner coating can be a thin dielectric layer or a metal with low conductivity (d), but also patches of a dielectric material (e), regular geometrical structures like corrugations in a metal (f) or simply a rough metal surface (g). The last three cases are examples of meta-materials, because the radiation characteristics are described by an effective permittivity.

Journal logoJOURNAL OF
SYNCHROTRON
RADIATION
ISSN: 1600-5775
Volume 28| Part 1| January 2021| Pages 18-27
https://doi.org/10.1107/S1600577520014058
Follow J. Synchrotron Rad.
Sign up for e-alerts
E-alerts
Follow J. Synchrotron Rad. on Twitter
Twitter
Follow us on facebook
Facebook
Sign up for RSS feeds
RSS