فهرست مطالب رضا صفیان

Application of a substrate integrated waveguide with wiggly ridge shape is presented for excitation longitudinal shunt slot antenna. Two main design equations for design substrate integrated waveguide structure and get parameters of structures، for longitudinal shunt slot excitation by shape wiggly ridge in substrate integrated waveguide are modified. Proposed method is used by applied the crinkle shape to ridge for ridge substrate integrated waveguide structure. This shape wiggly ridge just under longitudinal slot. The slot is place at centreline of substrate integrated waveguide (siw) in center of waveguide and on dielectric copper surface، top of substrate integrated waveguide. Amount of crinkle depth of waveguide centreline is proportional with needful radiation of slot and normalized conductance could be much to increase crinkle depth. In this paper the shunt element distribution assumption for prposed structure is spoted. Results of simulation show، proposed method is suitable candidate for replacing with usual longitudinal shunt slot. Structure’s useful is، low fabrication price، small profile and adaptation with microstrip circuit. Also slot place along waveguide centerline and wiggle depth substitute slot offset، therefore this procedure can suppress second order bim in array containing suggestion structure.

Substrate Integrated Waveguide (SIW) is a new type of guided wave structure which could be implemented in both microwave and millimeter wave integrated circuits. In this paper a novel waveguide type directional coupler based on substrate integrated waveguide consisting a double layer dielectric substrate is proposed. The design process is carried out using coupling theory and Chebyshev method. The proposed structure is fully based on SIW structure except at the input-output ports which are microstrip lines. The SIW bends are optimized for the lowest insertion loss using HFSS software. The center frequency of designed 20dB coupler is at 10GHz with 6GHz bandwidth. Based on the simulations the coupling remains almost constant over the coupler bandwidth with less than 2 dB variations. Larger bandwidth can be achieved by increasing the number of apertures. Also if we used a second set of apertures opposite side wall، the coupling would be increased by 6 dB.