Henri Baudrand

A Design and Modelling of Microwave Active Screen Using a Combination of the Rectangular and Periodic Waveguides Modes

A rigorous full wave technique based on the transverse wave concept iterative procedure (WCIP) is used to design and model a microwave active Screen. This approach takes the advantage of the combination of the rectangular and periodic waveguide modes. We demonstrate that 18 × 18 active elements in the closed packages are sufficient to have the same amplification as in the infinite Screen configuration.

Efficient Analysis of Via Hole Grounds by Using the Iterative Method

The via hole ground has many applications in the synthesis of microstrip microwave circuits. Indeed, it can be used for the realization of stub, the parallel insertion of lumped element and the photonic gap structures. This paper presents an extension of the iterative method based on the concept of waves combined with the two-dimensional Fast Fourier Transformation algorithm (F.M.T: Fast Modal Transformation) to analyze microstrip microwave distributed circuits including via hole grounds. The results provided by this method are in good agreement with the data determined by MDSs approach.

Wave concept iterative procedure for inhomogeneous multi-layered circuits

An improvement of the wave concept iterative procedure is presented to qualify multi-layered circuits with inhomogeneity. The approximation made is interesting as far as small substrate are considered, but leads to inaccuracy for large substrate. the substrate height limit is qualified in this paper.

Tunable FSS simulation using WCIP method for multiband and dual polarized applications

A novel multiband-operating and dual polarization frequency selective surface (FSS) for radomes applications for radar stealth is proposed. The design is based on an open metallic ring with coupled end strips. The proposed FSS rejects electromagnetic waves at frequencies 9.1, 10.8 and 11.5 GHz simultaneously with bandwidths of 900, 100 and 200 MHz, respectively, when the structure is excited by the x-polarized plane wave, and it rejects at one frequency 7.3 GHz with bandwidth of 1000 MHz, when the structure is excited by the y-polarized plane wave. Frequency tenability is provided by varying the length of the FSS coupled strips and the left edge of vertical U-shaped metallic strip composing the FSS structure. An enhancement of the x-polarized FSS bandwidth from 900 to 1500 MHz and from 200 and 100 to 500 MHz has been achieved. Simulation results obtained by the WCIP method were compared with the simulation results obtained by the COMSOL multiphysics software 4.3b and with the measurements. A good agreement of the results was observed.

Characterization of dual band and double polarized notched metallic ring FSS and their equivalent parallel metallic strip structures

ABSTRACT In this work three rejecting band filters for multi band and dual polarization applications are proposed. The first proposed structure is an open quasi square FSS with a centered notch. The variation of the notch position to the left leads to the tenability of frequencies in both directions of polarization. The addition of a second notch has resulted in a third frequency in the y direction maintaining two resonant frequencies in the x direction. The structures are simulated by the Wave concept Iterative Method and the Comsol Multiphysics software 4.3b. In the second part of this paper a new approach is proposed to obtain an equivalent FSS structures based on non-coupled parallel metallic strips. The new equivalent FSS structures allow the frequency adjustment by the variation of the corresponding strip lengths. The results obtained by the WCIP method and measurements are compared and a good agreement is obtained.

Analysis of double layered frequency selective surface based on WCIP-SM technique

In this paper a technique combining the wave concept iterative method WCIP and the scattering matrix SM method is used to analyze a double screen rectangular conducting patches FSS structure, the WCIP method is used to obtain the scattering characteristics of the two FSS then the scattering matrix technique is applied to obtain the total scattering characteristics of the two level FSS structure. The WCIP-SM results are successfully compared with numerical and experimental results presented in literature.

WCIP method applied to modeling a modified rectangular metallic ring FSS for multiband applications

A modified rectangular metallic ring Frequency Selective Surface (FSS) with single layer for multiband applications is proposed in this article. By using the wave concept iterative process method WCIP, the resonant characteristics of the proposed FSS are derived. This structure is sensitive to polarization of the incident wave. The proposed FSSs elements are composed by development of a basic rectangular metallic ring FSS. The tuning of the ring dimensions allows the adjustment of the FSS resonant frequencies. The results found by the WCIP method and compared with those simulated by COMSOL Multiphysics software and a good agreement is recorded.

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.