The Tapered Wall Gyrotron Traveling-Wave Amplifier

Abstract

Gyrotron traveling-wave amplifiers using tapered waveguide circuits are being investigated as a method of obtaining very wide bandwidths at millimeter-wave frequencies. The axial magnetic field is profiled to maintain synchronism. A first experiment using a 70kV, 1 A annular electron beam operating in the TE01 circular-electric mode produced a 13% small signal bandwidth with 18 dB midband gain at 35GHz. A new experiment is being planned which will operated in the TE011 mode with a goal of achieving a two-to-three factor of bandwidth improvement over the first experiment.