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Examination of acoustic waves' scattering by flat impedance strip (FIS) is presented. The problem of wave's scattering by the FIS is treated in the classically rigorous formulation on the base of the integral equation technique. Several mathematical models are used for the process of acoustic wave's interaction with the FIS. Asymptotic model of wave's scattering by narrow impedance strip, which have...
The paper presents CAD models for computing dispersive and conductor thickness based line parameters of semi-elliptical/circular cylindrical coplanar striplines (CPS) on single-layered dielectric substrates. Analysis of the non-planar CPS has been performed using conformal mapping technique (CMT). The developed models are verified and validated for wide range of line geometries from 1 GHz–60 GHz....
A spatially modulated impedance strip is examined. Field symmetries are used to decouple the two integral equations. This allows us to solve for the electric and magnetic currents independently. The method of moment is used to solve the integral equations. For the special case of sinusoidal modulation, the MoM solution is validated by comparing with an analytic solution presented by Oliner and Hessel...
Solved the problem of synthesizing an inhomogeneous anisotropic impedance plane reflecting a homogeneous plane wave in various preset directions on a coherent and cross polarization is solved. Formulated the restrictions on the class of scattering diagrams realized with the help of a dense array of orthogonal reactant strips of variable.
The design and optimization of low insertion loss finline filters is described in this paper. Finline filter with a large pass band has been designed using equivalent circuit approach. Mode matching method has been used for the analysis of discontinuities in the filter. The performance of the filter obtained through this method is further optimized to achieve improved pass band and stop-band performance...
This work presents an analysis of a reconfigurable self-resonant structure using an equivalent circuit model. Reconfiguring the electrical length of the structure results in uniquely identifiable changes to its forward and reflected frequency response. Equivalent circuit models are known to reduce computational time drastically and to provide an insight into the physics of the electromagnetic problem...
The scattering of high-frequency waves by two-part impedance strips is an important topic in diffraction theory because it can provide usefull information concerning the radiation of electromagnetic waves in the presence of discontinuity in the material properties of a surface of finite width, as well as of composite structures on aircrafts, satellites etc. According to the Geometrical Theory of Diffraction...
In this paper, the total far-field pattern around a finite width strip in presence of an electric line source using perfect electric conductor (PEC) and impedance strip equations are presented. We used two dimensional uniform geometrical theory of diffraction (UTD) in both analysis for soft (TM) polarization. For finite PEC strip, we used PEC strip equations and for finite impedance strip we used...
The asymptotic behavior of the characteristic impedance (Z0) of a slotted microstripline is used to develop a very simple and accurate approximate formula for Z0. A method of moments (MoM) analysis of the structure is used to verify the formula's accuracy. The use of a 2-D quasi-static complex images Green's function in MoM allows fast and accurate computation of the characteristic impedance Z0. It...
An annular ring based metamaterial absorber for S- and C-microwave bands is presented in this paper. The proposed structure is resonating at two frequencies of 3.06 GHz and 7.65 GHz with 99.40 % and 98.83 % absorptivities, respectively. The unit cell of the proposed absorber fits in a small volume of 12 mm × 12 mm × 1.6 mm. The proposed structure is polarization insensitive and performs well up to...
The problem of synthesis of an inhomogeneous anisotropic impedance plane, reflecting a uniform plane wave in a given direction with the conversion to the desired polarization is solved. The impedance distribution law is obtained in an explicit form. The restrictions on the class of implemented scattering diagrams using reactive impedance are formulated. Numerical results are obtained. The particular...
We investigate the ability of surface impedance mantle cloaks for cloaking of elliptical cylinders excited by an electric line source. The exact analytical solution of the problem utilizing Mathieu functions is obtained and is used to derive optimal surface impedances to cloak a number of configurations. Specifically, theoretical designs are presented which can minimize the scattering from line source...
The previous numerical matching method can't apply in the whole angle space (0° ≪ β0 ≪ 90°) whether only based on the normal incidence case nor based on grazing to the edge incidence case when solving the diffraction problem of the anisotropic impedance wedge at oblique incidence by plane wave. A revised numerical matching method (NMM) based on the framework of the uniform geometrical theory of diffraction(UTD)...
The global surface impedance boundary condition (GSIBC), which is an exact relation between tangential electric and magnetic fields on the boundary, is used in the approximate formulation of mixed potential integral equation (MPIE) for analyzing some plasmonic structures. A criterion is defined based on the eigenvalues of GSIBC matrix and it is shown that for the conventional plasmonic circuits this...
We describe a thin, conformai device for focusing microwave radiation across a curved interface between air and tissue. To design the lens, the matched filter for a multiport system consisting of annuiar metai strips and a point source placed at the focal spot is solved and then implemented by reactively loading the strips. We numerically show that the focal spot produced deep in tissue is much smaller...
A novel beamwidth reconfigurable antenna is presented. The design methodology uses tunable strip gratings placed on the sides of a magneto-electric (ME) dipole along its H-plane. A fully functional prototype with an as wide as 40% impedance bandwidth (for SWR ≤ 1.5) is developed and tested, demonstrating the H-plane beamwidth with a tuning range from 81° to 153°. With the wide beamwidth variation...
Negative group delay is one of the anomalous characteristics of the metamaterial, and can be used to compensate the group delay of systems and is applicable to signal processing devices. In this paper, to achieve negative group delay with not only wide-band characteristics but also low-insertion loss, we newly propose the embedded transmission line with half-wavelength type folded-stepped impedance...
This paper presents a dual band and multiple band frequency selective surface (FSS) on energy saving glass (ESG). In this paper, there are two designs that have been presented, namely Design A which is a combination of double strip in vertical and horizontal position and Design B is a combination of double strip in vertical and horizontal position using complementary techniques. Design A and Design...
A planar triple-band antenna with size 40 × 18×0.8 mm3 for LTE/GSM/UMTS and WLAN/ WIMAX is developed in this paper. The antenna is constructed in four steps. The first step is named Antl. In one side of the substrate, a non-folded strip is connected with a ground plane and a rectangle patch at both end of the non-folded strip, respectively. Antl is fed by a T-strip, which is in the other side of the...
The tolerance of dielectric constant between raw material before the substrate production and real sample after the process variation is the kernel of this project. In the past, the electrical data sheet of dielectric material always comes from the suppliers. However, material suppliers do not consider the effect of substrate manufacture but only implement the measurement through raw materials. Therefore,...
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