Photonic Crystal-Coupler for Sheet Beam THz Vacuum Electron Tubes

Photonic crystal (PhC) technology was recently proposed as a compact and effective solution to improve the performance and ease the fabrication of terahertz vacuum electron devices. In particular, the introduction of defects in a bi-dimensional, all metallic PhC provides very effective transmission of the useful signal in a compact input/output coupler where a novel tunnel for sheet-beam injection/collection is realized. Simulation results are experimentally validated here via measurements on a Ku-band scaled model of the PhC-coupler, which confirm the validity of the concept.