Contribution à l’élaboration d’un modèle de couplage électromagnétique ligne microstrip - guide d’onde intégré au substrat.

Abstract

The substrate integrated waveguide (SIW) technology is an emerging design and very promising for the development of circuits and components operating in the region of millimeter waves and microwave. Among major advantages of SIW technology is the ability to manufacture a complete circuit in planar form, using a standard printed circuit board or other plan processing techniques. Transitions between the microstrip line and GIS structures represent another important element related to the SIW components. More importantly, it is required to use low-reflection transitions to microstrip in order to integrate SIW circuits with active components, and therefore it is necessary to create low-reflection transitions so that the component design is independent of the influences of the transitions. In this context for improving the transition between the microstrip line and the substrate integrated waveguide, we proposed a novel transition based on the idea of good confinement of electromagnetic fields on both sides of the microstrip line. This transition constructed by placing one row of not metallized air-vias on both sides of the microstrip line. Thereafter, we will present the studies of the cavities and filters based on substrate integrated waveguide technologies by the mode matching Method and extraction of the S parameters . Finally, microwave filters are essential components in all types of telecommunication systems. The development of future applications of wireless technologies, filters should be compact, lightweight and exhibiting high selectivity with low insertion loss. To achieve these desired properties simultaneously, we will present a new planar cavity, which we used to design the filter. The idea of this cavity are based on a periodic artificial modification of the main line material with a permittivity of εr1 by drilling air vias in the substrate to reach a specific permittivity εr2. The resonator cavity shows an unloaded Q factor of 815. The new filter shows improved performance in terms of loss and bandwidth.