[IEEE The Fifth International Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter, and Submillimeter Waves (IEEE Cat. No.04EX828) - Kharkov, Ukraine (June 21-26, 2004)] The Fifth International Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter, and Submillimeter Waves (IEEE Cat. No.04EX828) - Theoretical investigations of waveguide propagation electromagnetic waves in periodical conducting structure