Abstract :
Miniaturization of low-noise traveling-wave amplifiers including integral power supplies has taken great strides in the last few years. This paper describes a recent development resulting in the operation of multiple low-noise tubes and power supplies within a single shielded enclosure. Utilization of one magnet structure with multiple focusing holes for all the tubes, and integration of solid-state supplies within the magnet shield environment significantly reduces overall volume and weight. The major key to short-length packaging is the use of hollow-electron-beam TWT´s focused in uniform-field permanent magnets. This approach maintains very low noise figures with high values of gain per circuit wavelength. An additional feature is the small, sintered-heater cathode operating at 10% of the normal 2-watt dissipation. This, in turn, has allowed miniaturization of the electron gun and vacuum envelope. Similarly, the reduced wattage requirement results in lower power supply volume and line drain.
