Title :
Design of a W-band second-harmonic TE02 gyro-TWT amplifier
Author :
Wang, Q.S. ; Huey, H.E. ; McDermott, D.B. ; Hirata, Y. ; Luhmann, N.C., Jr.
Author_Institution :
Micramics Inc., Santa Clara, CA, USA
fDate :
12/1/2000 12:00:00 AM
Abstract :
A harmonic gyrotron traveling-wave tube (gyro-TWT) amplifier is described that can stably deliver high peak and average power in the low-loss TE02-mode at 91.4 GHz. The single-stage second-harmonic TE02 gyro-TWT is predicted to produce a peak power of 600 kW with an efficiency of 24%, a saturated gain of 30 dB, and a 3-dB bandwidth of 2.7%. The amplifier employs a 100-kV, 25-A electron beam emitted from a magnetron injection gun with v⊥ /v||=1.2 and Δv||/v|| =8%. The device is based on the proven concept that the electron beam current can be much higher in a stable harmonic gyro-TWT amplifier than at the fundamental due to the relatively weaker strength of the harmonic interaction. The TE02 overmoded interaction waveguide is sufficiently large to handle an average power of 60 kW and provides considerable clearance for the high current electron beam. An innovative mode-selective interaction circuit prevents the amplifier from oscillating in undesired modes
Keywords :
gyrotrons; microwave amplifiers; travelling wave amplifiers; travelling wave tubes; 100 kV; 24 percent; 25 A; 3 dB; 30 dB; 60 kW; 600 kW; 91.4 GHz; W-band second-harmonic TE02 gyro-TWT amplifier; amplifier modes; amplifier oscillation; average power; bandwidth; efficiency; electron beam current; electron beam emission; harmonic gyrotron traveling-wave tube amplifier; harmonic interaction; high peak power; low-loss TE02-mode; magnetron injection gun; mode-selective interaction circuit; saturated gain; single-stage second-harmonic TE02 gyro-TWT; undesired modes; Circuits; Cyclotrons; Dispersion; Electromagnetic scattering; Electron beams; Equations; High power amplifiers; Magnetic fields; Stability; Tellurium;
Journal_Title :
Plasma Science, IEEE Transactions on
