Abstract :
The crossed-field amplifier (CFA) is an outgrowth of the magnetron. Several varieties exist including the forward-wave/ backward-wave types, and the injected-beam continuous-cathode (emitting-sole) types. Of these, the continuous-cathode type has found the most usage and has been established in many systems. Emphasis is placed upon this type. The CFA interaction process has similarities to a synchronous generator. From this, many of the characteristic features can be deduced or understood. The size, efficiency, range of performance, phase stability, and operating parameters are a feature of the crossed-field interaction process which distinguishes the CFA from other microwave tubes. Its greatest usage is in light-weight transportable radar systens, although not restricted to these. Its future lies in the extension of its gain capability and in the incorporation of technological advances such as new materials.