Wideband Power Combining of Four Microfabricated W-Band Traveling-Wave Tubes
Date of Issue2017
School of Electrical and Electronic Engineering
Wideband power combining of four W-band microfabricated traveling-wave tubes (TWTs) is presented. The proposed TWTs are based on a planar helix slow-wave structure (SWS) with straight-edge connections (PH-SEC) that can be microfabricated with stripline input-output feed. A novel 1:4 WR-10 waveguide-to-stripline power divider- combiner is designed that covers the frequency range of 92-104 GHz. The simulation results show that S11 is less than -20 dB and the magnitude and phase differences among the four output signals are less than 0.01 dB and 0.41°, respectively, indicating a power combining efficiency as high as 99.9%. The power divider, four PH-SEC SWSs, and the power combiner are assembled and the performance of the overall assembly is checked by simulation. The overall S11 is better than -15 dB in the frequency range of 91.7-100.7 GHz and S21 is better than -12.3 dB. Effects of power and phase variation of individual TWTs have also been considered. With four 5-kV and 10-mA sheet electron beams, particle-in-cell simulations show that the combined TWTs can give 25-W saturation peak power at 94 GHz with a gain of 18 dB.
IEEE Transactions on Electron Devices
© 2017 Institute of Electrical and Electronics Engineers (IEEE). This is the author created version of a work that has been peer reviewed and accepted for publication by IEEE Transactions on Electron Devices, Institute of Electrical and Electronics Engineers (IEEE). It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1109/TED.2017.2720191].