Análise de dispositivos baseados em guias de onda integrados ao substrato

Abstract

In this work, the analysis of devices based on surface-integrated waveguides (SIW). Two transitions to SIW have been analyzed. In this work, the microstrip-SIW and coaxial-SIW transitions are studied. For the microstrip-SIW transition, two diameters for the metallic vias have been considered. This was because the diameter copper wire existing in the laboratory was modified during the study. For the diameter for 1.0 mm, reflection coefficient level of −42.00 dB was obtained, whereas vias with diameter of 0.6 mm yielded −29.61 dB. For the coaxial-SIW transition, only vaias with diameter of 0.6 mm were used. On one side of the guide, a coaxial-SIW transition was used, whereas a microstrip-SIW was used to terminate the waveguide. In this case, the reflection coefficient was −14.22 dB, which has been obtained with simulations carried out with ANSYS HFSS. Phase shifters implemented with air holes were studied. The main idea was to change the effective dielectric constant of the substrate and, consequently, to yield an variation on the phase constant of the strucutre. The air holes have been inserted in the center of the waveguide, since this is the region where the highest concentration of electric field lines occurs. Phase variations were analyzed only for vias with diameter equal to 0.6 mm. By using microstrip-SIW transitions, the phase shift could be set up to a maximum of 60.03◦. For the coaxial-SIW transition, the maximum simulated phase shift was 45.25◦.