Conception et Réalisation de filtres RF passe-bas à structures périodiques et filtres Ultra Large Bande, semi-localisés en technologie planaire

摘要

In recent years, extensive research and development efforts have been put into exploiting planar filters for their potential qualities of low cost, tiny weight and high degree of integration. The aim of the research work presented in this manuscript is the design and the realization of selective and miniaturized planar filters. A new topology of compact low-pass filter with periodic structures, constituted by a transmission line loaded by SMT capacitors, is proposed. A rigorous design method for the low-pass filter is also implemented. The measurements of the low-pass filters, realized near to 1 GHz in a CPW technology, in good agreement with simulations demonstrated interesting electrical proprieties of rejection, matching and spurious suppression. The validity of this topology is also investigated for higher frequencies with the realization of a low-pass filter in the X-band. Several capacitor's characterization approaches were also investigated. The implementation of capacitors in a low pass filter with periodic structure carried out constitutes the most precise way to characterize capacitors. A new topology of Ultra Wide Band band-pass filters, based on the combination of a high pass filter with short circuited stubs and a low pass filter with capacitively loaded lines, is proposed. The measurements of the prototype filters realized in a microstrip technology, in good agreement with simulations, show interesting proprieties of selectivity, miniaturization and spurious suppression.