A high efficiency, miniaturized Ka band traveling wave tube based on a novel finned ladder RF circuit design

Summary form only given. Space communications architectures are being planned to meet the high rate data of future NASA Enterprise missions. These will require the use of traveling wave tube amplifiers (TWTAs) to provide the high frequency, RF power and efficiency needed for many of the communications links. A program addressing these requirements is underway for the development of a high efficiency, 20 watt, 32 GHz TWT of reduced size and weight that is based on a novel high gain slow-wave circuit design, termed the "finned ladder". The finned ladder slow-wave circuit, has an exceptionally high gain per unit length. The very high RF/electron beam interaction impedance (>100 ohms) enables more than 40 dB of gain over a 5 cm length and an RF efficiency greater than 20%, which offers a significant reduction in RF circuit length and the potential for TWT miniaturization. Fabrication by micromachining techniques is being investigated.