New types of severed circuits to increase the gain and bandwidth of magnetron amplifiers

Previous progress on injected-beam, non reentrant crossed-field forward-wave amplifiers has resulted in tubes capable of large bandwidth, high power, good efficiency but capable of only moderate gain. Until recently, most of the work on this type of device has been done on tubes of circular format. The circular format amplifier is limited to moderate gain because of the many possible modes of r.f. feedback from output to input. Recent work on the linear form of the injected-beam crossed-field amplifier has greatly reuucea the feedback problem and, coupled with severed circuit techniques, has put the crossed-field amplifier in the same high gain class as the conventional O-type traveling-wave tube and the multiple-cavity klystron.