High-Power Millimetre-Wave Components Combining Quasi-Optics With Oversized Rectangular Corrugated Waveguide

The oversized rectangular corrugated waveguide has been considered so far mainly for the Remote Steering concept of the Upper ECRH launcher foreseen for neoclassical tearing modes stabilization in ITER[1]. A new application of this type of waveguide is based on a resonating quasi-optical configuration for gaussian beams, apt to be used as a narrow-band diplexer for switching the power between two launchers synchronously with the island rotation [see Ref.2 and 3]. Advantages of this particular solution are the compact size and the tunability on the gyrotron frequency. Moreover it can be used with two inputs and two outputs independently, to split and combine the power of two gyrotrons, as far as the frequency of them can be changed with sufficient control. This allows combining the power of different gyrotrons into the same transmission line.