FREQUENCY-MODULATION IN A SUBMILLIMETER-WAVE GYROTRON

A first demonstration has been made of frequency modulation of a gyrot ron output signal. The experiment was performed on a submillimeter-wav e gyrotron operating near 300 GHz. The modulation amplitude of several tens of MHz has been achieved by a 120 V modulation of the accelerati ng voltage; this results in variation of the relativistic electron mas s and corresponding variation in the electron cyclotron frequency f(c) . The observed modulation of the output frequency is 2.3 times smaller than the variation in f(c). There is reasonable agreement between the experimental results and a simulation employing the energy transfer f ormula in a cavity.