Design of novel hybrid traveling-wave amplifiers in X- and Ka-band

Summary form only given. We present the design of two broadband microwave circuits which contain elements of both linear and gyrotron microwave tubes. These tubes utilize a helix slow-wave structure to bunch a linearly-streaming annular electron beam. Linear momentum is converted to rotational momentum via a non-adiabatic magnetic transition which is placed at the location where the beam bunching is maximized. The beam then travels through a tapered right-circular waveguide, where microwave energy is extracted via the gyrotron interaction. The X-band design considers a first-harmonic interaction between a 45 kV, 8A beam and a microwave signal near 10 Hz. The output is generated in the TE/sub 01/ mode and the drive and output frequencies are identical. The Ka-band design involves a second-harmonic interaction between a 65 kV, 6A beam and a microwave signal near 35 GHz. The output is generated in the TE/sub 02/ mode. Drive signals at the output frequency and at half the output frequency are considered.