Mode dynamics in a free electron maser with broadband frequency-dispersive feedback

For a free-electron oscillator, problems of mode dynamics are studied for a case when the feedback has a wide, but finite band (the feedback coefficient depends on the frequency). It is shown that even a broadband frequency-dispersive feedback can significantly affect both the electron-current threshold of stability of the single-mode operation and the process of frequency tuning. (C) 2001 American Institute of Physics.