Nonlinear theory of the backward wave oscillator with relativistic electron beam

Summary form only given, as follows. A theory has been developed to study the nonlinear behavior of a BWO (backward wave oscillator) with a relativistic electron beam. This theory is an extension of a simpler model in which only small variations in longitudinal electron velocity are allowed. The formulation is adequate to describe high-efficiency interaction in a BWO with arbitrary electron beam velocity. The effect of the reflection of the forward wave at the output boundary is also considered. The effect of this reflection on the starting current and the BWO efficiency at the saturation was investigated