Coupling Structure for a High-Q Corrugated Cavity as a Microwave Undulator

Microwave undulators can achieve smaller wiggler periods compared with permanent magnet undulators. This article follows on the design of a microwave undulator composed of a corrugated waveguide operating at 36 GHz. Compatible end caps and coupling structures for the waveguide to form a complete cavity were studied and are presented in this article. Their design is scalable for different operating frequencies and periods of the corrugated waveguide. A set of empirical equations that allow the geometry to be determined analytically were found from the post-processing of the finite-difference time-domain (FDTD) simulation.