The results of an experimental study the dispersion characteristics and field distribution of main and higher order modes of multirow interdigital slow wave structures with their resized are presented. The ways of increasing the frequency separation of main and higher order modes and the working excitation band of the main mode are offered. Investigation the forced oscillations of the multirow interdigital slow wave structure with exponential H-waveguide power ports has shown the possibility of a single-mode excitation in a wide bandwidth.
