skip to main content

SciTech ConnectSciTech Connect

Title: Low-voltage harmonic multiplying gyrotron traveling-wave amplifier in G band

Harmonic multiplying operation in a gyrotron traveling-wave amplifier (gyro-TWA) permits for magnetic field reduction and frequency multiplication. Lowering a beam voltage is an important step toward miniaturization of a harmonic multiplying gyro-TWA. However, the additional degree of freedom that is provided by the multitude cyclotron harmonics in a low-voltage harmonic multiplying gyro-TWA still easily generates various competing modes. An improved mode-selective circuit, using circular waveguides with various radii, can provide the rejection points within the frequency range to suppress competing modes. Simulated results reveal that the mode-selective circuit can provide an attenuation of more than 14 dB to suppress the competing modes. Furthermore, the performance of the gyro-TWA is analyzed for studying the sensitivity of the saturated output power and full width at half maximum bandwidth of the gyro-TWA to the beam voltage and the magnetic field. A stable low-voltage harmonic multiplying gyro-TWA with the mode-selective circuit is predicted to yield a peak output power of 24 kW at 200.4 GHz, corresponding to a saturated gain of 56 dB at an interaction efficiency of 20%. The full width at half maximum bandwidth is 3.0 GHz.
Authors:
; ; ; ;  [1] ;  [2] ;  [3]
  1. Department of Electro-Optical Engineering, Southern Taiwan University of Science and Technology, Tainan, Taiwan (China)
  2. Department of Communication Engineering, National Penghu University of Science and Technology, Penghu, Taiwan (China)
  3. Department of Physics, National Tsing Hua University, Hsinchu, Taiwan (China)
Publication Date:
OSTI Identifier:
22489958
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 12; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AMPLIFIERS; ATTENUATION; BEAMS; COMPUTERIZED SIMULATION; CYCLOTRON HARMONICS; DEGREES OF FREEDOM; ELECTRIC POTENTIAL; GHZ RANGE; INTERACTIONS; MAGNETIC FIELDS; MINIATURIZATION; MODE SELECTION; POWER GENERATION; SENSITIVITY; TRAVELLING WAVES; WAVEGUIDES