TRANSFORMATION OF SURFACE WAVES OF COUPLED DIELECTRIC WAVEGUIDES INTO VOLUME WAVES USING DIFFRACTION GRATINGS

Abstract

Development and improvement of operational characteristics of communication lines, radiolocation and navigation, surface overview, remote control and warning systems at the airports and at the railway stations is provided due to development of shorter-wave electromagnetic ranges. Designing new millimeter and submillimeter wave band radio complexes requires not only upgrading of existing antennas but also creation of new antenna classes – diffraction radiation antennas, for example. One of the basic problems in antenna engineering is the formation of required amplitude-phase distribution (APD) of the electromagnetic field on antenna aperture that provides for the given operational characteristics. The known techniques of APD forming at the aperture of diffraction radiation antennas are acceptable for the apertures, which are not less than 50 wavelengths. The possibility of forming the amplitude distribution with symmetrically falling edges at the 10...50 wavelength aperture by supplementing an additional segment of dielectric waveguide is investigated in this paper. The additional segment of dielectric waveguide changes the serial system of radiating elements feeding into a serial-parallel one. The efficiency of energy and APD transformation in the antenna aperture for different values of dielectric waveguide – dielectric waveguide and dielectric waveguide – grating coupling factor is evaluated. The results can be applied in the design of millimeter range antenna systems and functional units based on open transmission lines.