Measurements on Fast switches and combiners (FADIS-BC) for High-Power Millimeter-wave beams based on dielectric beam splitters

An upgraded version of a quasi-optical diplexer combiner, based on a resonating system coupling two transmission lines using three Dielectric Beam Splitters, has been realized and tested. This device is principally thought to combine power coming from different transmission lines into a single output or to switch the injected power between different outputs, but it could also be used as mode filter or in line viewing system for Electron Cyclotron Emission (ECE) or Collective Thomson Scattering (CTS) diagnostics. The design was implemented in order to link two transmission lines of the ECRH system on FTU, for power combination of two beams into a single line of the new ECRH launcher recently installed. This device is based on Dielectric Beam Splitters (DBS); it has been tested at low power in order to confirm the splitting ratio foreseen from simulation and its efficiency has been evaluated measuring the beam exiting the system. The design and the characterization of the diplexer combiner are reported in this paper.