Modeling and simulation of a 250 GHz metal PBG waveguide for gyrotron amplifier

Abstract

The traditional cylindrical waveguide in a gyrotron traveling wave amplifiers has been replaced with a novel Photonic Band Gap (PBG) waveguide structure having two dimensional triangular arrays of metal posts to address the mode competition problem and also to increase the power handling capability of these devices at short wavelengths of operation. This structure has been modeled and simulated for TE 03 - like operating mode at 250 GHz. The cut off frequency of the guide was calculated as 242.68 GHz. The pass band and stop band characteristics of the waveguide have been shown by making the transient study on this structure and also the bandwidth of the amplifier was found to be ∼ 8 GHz. The coupling coefficient of the PBG waveguide has been computed numerically to choose the radius of the beam and the input coupler for the PBG waveguide also been discussed. © 2012 IEEE.