Current status of crossed-field devices

It is noted that the response to advanced system requirements has lead to technological advances in crossed-field development, exemplified by low-noise versions of crossed-field amplifiers and phase-locked magnetrons. Upgraded systems requirements are motivating a new generation of crossed-field devices characterized by clear improvements in noise reduction, signal coherence, bandwidth, mode purity, reliability and format factors. The following developments are considered: circuited cathode crossed-field amplifiers (CFAs) for low-noise operation; cathode-driven CFAs as linear accelerator drivers, a millimeter-wave axial-gain CFA; spaceborne power transmission systems; MBWO (M-type backward wave oscillator) advances; and secondary electron emitter materials.<>