Spatially-Distributed Electron Beam Technology for Millimeter-Wave Amplifiers

BWRI proposes the full scale development (fabricate, assemble, and test) of a three-beam electron gun for used in future advanced millimeter-wave amplifiers in the proposed Phase-II program. Under the Phase-I base program, a baseline design study establishing the gun feasibility was completed. Results indicate the proposed gun can generate 3 x 0.55 A electron beams at 20 kV for a total of 33 kW of beam power. Beam transport was also studied as an integral part of the Phase-I program to ensure that the individual beamlets can be transported through the small beam tunnels required for efficient beam-wave interactions in Ka-band for a variety of magnetic field configurations. In addition, the beam optics from the electron gun and transport system were used to investigate beam-wave interactions with our novel three-beam cascaded serpentine traveling-wave tube. Simulations results indicated that this electron gun will enable a new generation of amplifiers capable of 4.2 kW of peak power over a 3-dB bandwidth of 9.5 GHz, spanning the important 32.5 42 GHz frequency range