SUPER-RELTRON analysis and experiments

The authors have developed a highly efficient, high-power microwave tube called SUPER-RELTRON. They have achieved operation at >400 MW with approximately 50% efficiency at 1 GHz and >300 MW with 50% efficiency at 3 GHz. The RF pulse durations are typically a few hundred nanoseconds. These lightweight, compact tubes do not require an external magnetic field. The RF output coupling is straightforward and power is delivered directly via the fundamental TE/sub 10/ wave in a rectangular waveguide without a mode converter. The key features of the tube include (1) generation of a well-modulated electron beam by periodic virtual cathode formation: (2) postacceleration of the modulated beam to reduce the relative electron energy spread; and (3) a multicavity output section that efficiently extracts power without RF breakdown. The authors discuss various aspects of the device and briefly summarize experimental results.<>