Mohamed Karim Azizi

ALMOST PERIODIC LUMPED ELEMENTS STRUCTURE MODELING USING ITERATIVE METHOD: APPLICATION TO PHOTONIC JETS AND PLANAR LENSES

In this work, we show that it is possible to produce a planar electromagnetic jet using a flat structure consisting of elementary cells based on lumped elements and fed with a source line. A combination of elementary cells may represent a gradient index, locating the electromagnetic energy in a small area, consisting of a few cells and having a size of about 0.75λ. The theoretical framework of the study is based on the Wave Concept Iterative Process method (WCIP) formulated in both spectral and spatial domains. An analogy with an optical model based on optical paths equality enables predicting the location of formation of this spot. The use of such a system can provide solutions for the development of new kinds of applications such as engraving sub-wavelength, data storage, improved scalpel optics for ultra-precise laser surgery, and detection of cancer.

METAMATERIAL-BASED FLAT LENS: WAVE CONCEPT ITERATIVE PROCESS APPROACH

Metamaterials left-hand negative refractive index has remarkable optical properties; this paper presents the results obtained from the study of a flat metamaterial lens. Particular interest is given to the interaction of electromagnetic waves with metamaterials in the structure of the lens Pendry. Using the new approach of the Wave Concept Iterative Process (WCIP) based on the auxiliary sources helps to visualize the behavior of the electric field in the metamaterial band and outside of its interfaces. The simulation results show an amplification of evanescent waves in the metamaterials with an index of n = −1, which corresponds to a resonance phenomenon to which the attenuation solution is canceled, leaving only the actual growth of these waves. This amplification permits the reconstruction of the image of the source with a higher resolution.

Analysis of planar microwave structures using transmission line-periodic lumped circuit by an iterative method WCIP

The theory of a novel approach of the WCIP method to analyze periodic lumped circuits has been presented. Transmission lines in their planar form (microstrip technology) can be modelled by an equivalent periodic lumped circuit that permits a fast analysis instead of the use of many electromagnetic full wave simulators which require a great running time and great memory size. The validation of the proposed approach was made by comparing the results of simulation with ADS simulator of a bandpass filter designed in its planar form and equivalent periodic lumped circuit.

Analyzing of one dimensional quasi periodic circuit by using auxiliary sources in a WCIP method

A new approach of the iterative method WCIP (Wave Concept Iterative Process) using the technique of the auxiliary sources considers a pixel or a unit cell in a periodic structure as an electrical circuit instead of a sub-domain representing metal or dielectric in the classical iterative method. The intersection of this new approach with the old is on the application of the iterative process in waves between the space and spectral domains in order to calculate the electric field and the density of current. The novel approach is introduced by the study of two types of defects on an uniform transmission line. The first one is a defect of a resistance, the other is a defect of a reactance. The results of simulation of the variation of current along the transmission line are agree with the theory which validates our proposed approach.