Abstract :
This paper describes characteristics of a new type of broadband backward-wave oscillator utilizing permanent-magnet electron beam focusing, but permitting attainment of remarkably light weight, complete magnetic shielding, and efficiency values at least as high as those obtainable with more conventional O-type oscillators. The new tubes completely eliminate the most important disadvantages of previous BWO´s, such as, variously, the size, weight, complexity, low reliability, low efficiency, or sensitivity to external magnetic fields of solenoid-, PM-, or electrostatically-focused tubes.
