Investigatiom of stop and pass bands in the spectrum of a periodically corrugated waveguide

Jury: Prof Dr. Victor POGREBNYAKProf. Dr. Süleyman GÜNGÖRAss. Prof. Dr. Turgut K ZBragg reflection phenomenon that is revealed by electromagnetic wavestraveling in periodic structures is used in many microwave devices and antennas.Bragg reflection occurs because of the constructive interference of the longitudinalmodes of the electromagnetic wave propagating in the waveguide. The Braggreflection gives rise to band gap (stop band) in the frequency spectrum of theperiodically corrugated waveguide. Bragg reflection phenomena have described welltheoretically by the coupled-waves equation method and studied experimentally.Wave phenomenon arising in the frequency range located far from the Braggreflections, non-Bragg phenomena, have studied theoretically in a planar periodicallycorrugated waveguide. Non-Bragg reflections occur because of the interactionbetween transverse modes of the different space harmonics of the electromagneticwave propagating in the waveguide.In this thesis, stop and pass bands in the spectrum of a planar periodicallycorrugated waveguide are investigated in detailed theoretically and experimentally.Experimentally such wave phenomenons have been investigated respectively;observation of stop and pass bands and transmitted power on changing of phase shiftbetween parallel plates, dependency of transmitted power and stop and pass band?swidth and location in the frequency spectrum on distance between antennas andaverage distance between parallel plates, distribution of scattered power along thecorrugation. In addition of these, evolution of stop and pass band?s width andlocation in the frequency spectrum and distribution of scattered power along thecorrugation have been investigated upon gradual transformation from periodicwaveguide to smooth waveguide.Keywords: periodic waveguide, pass band, stop band, frequency spectrumI