Modelling of passive and active circuits and antennas. Application to metamaterials.

H.Baudrand*, N.Raveu*, M.Titaouine**, G.Fontgalland***

*Laplace laboratory, ENSEIHT-GRE. Toulouse

** Faculté des Sciences, Batna, Algérie

***Faculté des Sciences UFCG , Brésil

The objectives of this  conference is to present firstly the Wave Concept Iterative Procedure (WCIP)   showing it’s possibilities as a an efficient method suitable for modelling the stratified circuits antennas and quasi-optical devices. The two advantages of this method lies in the facts that the iterative process is always convergent (except at resonance frequency as for  other methods), and by a description of any surfaces by pixels it is no necessary to use a meshing describing a part of the surface corresponding to metal layer (or to the dual dielectric layer).  Two examples are given: a frequency selective surface (FSS), and a highly compact quasi-optical amplifier.

In a second part, a generalization of WCIP is presented. The principles of  WCIP are respected, i.e. by the presence of two linked equations, one of them expressed in the spatial domain, and the other in the spectral domain. The solution being obtained by a balance between these two domains. The description of the device is not given by rectangular homogeneous pixels but by almost periodic  cells. These last are defined as periodic cells fed by no periodic sources. This facts permits the study of Substrates Integrated Circuits (SIC), which has been widely developed with success since few years, as  the results show it in the given examples.

The last part of the conference gives an aperture towards other interesting applications in non homogenous metamaterials. Up to now, the metamaterials are considered as homogeneous, permitting the determination of their equivalent medium. The link between a metamaterial and a device (patch antenna for instance),or another material presents difficulties and is not approached except in some global analysis. Finally, another generalization of the WCIP are presented. It’s consists in almost periodic circuits described by lumped elements. There are many applications for this kind of structures, as filters, or power amplifiers.