Low-voltage operation of the retarding-field oscillator at X-band and the millimeter wavelength region

The retarding-field oscillator is similar to the reflex klystron except that the repeller (the reflector of the reflex klystron) is an integral part of the resonant cavity and the rf power is coupled to the load in a different manner. The basic difference between the operation of the tubes lies in the fact that the regions for bunching, drifting, and working of the electron beam are not distinct in the retarding-field oscillator as they are in the reflex klystron. This paper concerns the partial development of two low-voltage designs of the Retarding-Field Oscillator. These two designs differ fundamentally in the method of coupling the rf power to the load. The X-Band model has coaxial-line coupling to a waveguide while the millimeter wavelength model has double cavity coupling to a waveguide.