Patent ID: 6909235
Filing Date: 2005-06-21
Classification: H03F

Abstract:
1. In a spacecraft, a traveling wave tube amplifier system having a traveling wave tube for containing and producing an electron beam to amplify radio frequency signals, said traveling wave tube including a cathode structure for generating electrons, an anode structure, a collector structure for collecting said electrons, a helical coil disposed with a central axis along an electron beam path between anodes of said anode structure, a radio frequency source; a radio frequency output; and at least a first voltage source, said first voltage source coupled to said cathode structure, the improvement comprising: a beam-forming electrode structure for forming said electron beam along said electron beam path between said cathode structure and said anode structure and said collector structure; a modulation source coupled to said beam forming electrode structure to modulate electron emissions of said beam forming electrode structure; a second voltage source d.c. coupled to said beam forming electrode structure for supplying a bias voltage relative to the first voltage source to the beam forming electrode structure; and a bias control circuit coupled to said modulation source to control said second voltage source for selectively adjusting said bias voltage so as to turn on or shut off the electron beam and thereby selectively suppressing output energy from the traveling wave tube amplifier during selected periods, so that, during said selected periods, low-level RF input signals are not amplified, no significant RE power is output from a satellite, and power is conserved.