Tunable tranmission spectrum of a periodically corrugatedwaveguide

ABSTRACTMSc THESISTUNABLE TRANMISSION SPECTRUM OF A PERIODICALLYCORRUGATED WAVEGUIDEEser AKRAYDEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERINGINSTITUTE OF NATURAL AND APPLIED SCIENCESUNIVERSITY OF CUKUROVASupervisor: Prof. Dr. Victor POGREBNYAKYear: 2006, Pages: 172Jury : Prof. Dr. Victor POGREBNYAKProf. Dr. Süleyman GÜNGÖRDoç. Dr. Turgut İKİZAnalysis of electromagnetic wave propagation in periodic structures is ofconsiderable interest due to their extensive use in many fields of electrical andelectronics engineering and technology such as quantum- and optoelectronics,photonic crystals, fiber grating sensors and microwaves.Although the applications of periodic structures are well developed, there arestill some basic experimental problems, such experimental problem as tunabilitymechanism of the transmission spectrum in a planar periodically corrugatedwaveguide, which need more detailed investigation.Aside from considerable interest to the propagation of waves in periodicstructures great interest to the propagation of waves in disordered structures byscientists has never been remained behind that of periodic structures as well.In this thesis, the tunability of the transmission spectrum of a planarperiodically corrugated waveguide was investigated theoretically and experimentallyat the microwave range of frequency. Measurement of the transmission propertiesshowed that the location of the gap in the frequency spectrum as well as its widthdepends on the relative position of two corrugated plates. The transmission variesfrom zero to a maximum value upon shifting one periodic plate with respect toanother on the half period of the corrugation. The results confirm the theoritecalprediction of the transformation of tunabilty of the transmission spectrum from aband structure form to a gapless one upon such a shift of one of the plates.Then the effect of randomizing period of a corrugated waveguide wasinvestigated. The corrugated waveguide having randomized periods was designed,manufactured, and its transmission spectrum was investigated experimentally. Theexperimental results are in a good agreement with the known theoretical predictionsand results.Keywords: Electromagnetic wave, planar waveguide, Bragg reflection, periodicity,tunable frequency spectrum