Thesis

Sweep-frequency microwave pulse compression using a helically corrugated waveguide

Creator
Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2004
Thesis identifier
  • T11133
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • A new type of pulse compressor based on sweep frequency pulse compression has been developed using a helically corrugated waveguide as a dispersive medium. This structure provides selective coupling between a TE₁₁ travelling wave and a near cut-off TE₂₁ wave, creating an eigenwave where the dispersion characteristics of one mode gradually converts into that of other. As the compressor works far from cut-off the reflections associated with operation close to cut-off are reduced and allows the compressor to be used at the output of a powerful amplifier. An experimental and theoretical study of swept-frequency based pulse compression as well as a theoretical and experimental investigation of the dispersive properties of a circular waveguide with a helical corrugation on its inner surface was carried out. Measurements of the helically corrugated compressor obtained a maximum optimum power compression ratio of 10.9 for a helically corrugated waveguide of length 208.08cm. A 1 kilowatt input pulse with a frequency sweep from 9.60GHz to 9.35GHz over 70ns was compressed by the helically corrugated waveguide. The compressed pulse had a duration of 3ns and gave a compression efficiency of 44%. The helical compressor experiments conducted were the first of their kind to be carried out and were found to be in good agreement with theory. A numerical study of the potential of the helically corrugated waveguide to produce multi-GW output pulses using frequency modulation at the falling edge of a microwave pulse produced from a high-power BWO was investigated.
Resource Type
DOI
EThOS ID
  • uk.bl.ethos.410207
Date Created
  • 2004
Former identifier
  • 698898

Relations

Items