X-band microwave transmission through waveguide with variable lateral periodic profile

ABSTRACTMSc. THESISX-BAND MICROWAVE TRANSMISSION THROUGH WAVEGUIDEWITH VARIABLE LATERAL PERIODIC PROFILEAli Neşet KÜÇÜKALTUNDEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERINGINSTITUTE OF NATURAL AND APPLIED SCIENCESUNIVERSITY OF ÇUKUROVASupervisor: Prof. Dr. Victor POGREBNYAKYear: 2006, Page: 65Jury: Prof Dr. Victor POGREBNYAKProf. Dr. Hamide KAVAKAsst. Prof. Dr. Sami ARICAAnalysis of electromagnetic wave propagation in periodic structures is ofconsiderable interest due to their extensive use in many fields of electrical andoptical engineering such as microwaves, antennas and radars, communications,optoelectronics, photonic crystals, fiber grating sensors.The propagation of microwaves through different types of hollow metallicwaveguides has been investigated. The aim of the thesis is to find a shape of wallsthat can stop transmission of electromagnetic radiation through the hollow metallicwaveguide without closing its cross-section. For this purpose planar and rectangularwaveguides with variable lateral periodic profile manufactured and setup fortransmission measurements had assembled.It was shown that microwave transmission depends on the relative position oftwo periodically corrugated plates. The transmission varies from zero to a maximumvalue upon shifting one periodic plate with respect to another on the half period ofthe corrugation. The results confirm the theoretical prediction of the geometry-drivenspectrum transformation from the band structure spectrum to a gapless one uponsuch a shift of one of the plates.Keywords: Planar waveguide, electromagnetic wave, periodicity, Bragg reflection.I