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In this paper the ability of SCT to simulate 1-D non-uniform finite patch arrays is demonstrated. It is shown that SCT has better convergence than the FEM based method which makes it a suitable tool for simulating large and complex structures. Moreover the modular nature of the SCT can be exploited toeconomize both memory and processing resources therefore making it an ideal design and optimization...
In recent years, the computational electromagnetics community has witnessed a rapid increase in the electrical size of scattering problems that can be solved. This increase can be mainly attributed to the use of boundary integral equations and the development of the multilevel fast multipole algorithm (MLFMA) and its parallelized analogues. However, many challenges remain, especially when it comes...
In this paper, the effects of geometrical perturbations on the geometry of a reference fractal antenna have been carefully analyzed to provide a set of analytic rules for describing the resonant behavior of the antenna. As regards to the antenna synthesis, the obtained results can be profitably used to initialize an optimization process for identifying an optimal solution thus allowing non-negligible...
In this work we have extended the applicability of the GMM to a wide range of arbitrary geometries. The basis functions show excellent approximation qualities for the current, its curl and its divergence. In addition, the use of the surface Helmholtz decomposition results in a well conditioned system of equations over a wide range of frequencies. Future work is directed at fully utilizing these two...
In this paper two distinct methods by which creeping wave radiation field can be obtained from its eigenfunction series has been shown. For the continuing investigations, the results for the creeping wave propagation constant results will be presented at the time of the conference for validation.
The new concept of having a dual mode operation using a single dielectric resonator has been designed and simulated for both radiation and direction-finding purposes. The main concept was based on the rat-race ring hybrid circuit design. Promising results were obtained for the simulated design geometry and future experimental work will be done for verification. The current development in the use of...
The idea of using element rotation to provide phase shift for circularly polarized (CP) reflectarray antennas is studied here. Investigations on these antenna sub-types often involve element design and the simulation as well as measurement of phase shifting properties using a waveguide simulator. Modern refiectarray antennas are typically fabricated using dielectric laminates. For passive elements,...
To assess the impact of pseudo-conformal geometry in the irradiative pattern of a K-band antenna array, a three-waveguide array was designed that allows the forward displacement of the outer waveguides in relation to the central element. The field pattern of the antenna array for different geometric configurations was simulated using the correct excitation reaching the individual waveguide through...
The analysis of XPol suppression techniques in linear arrays reveals that, even though some particular structures can cancel these fields efficiently, the geometrical composition of the entire array affects the side lobe levels. Previous reports have proposed geometries where the Chebyshev SLL control technique is not effective. This work presents a novel geometrical approach, whose radiation pattern...
The use of Graphical Processing Units (GPUs) to perform computational electromagnetic simulations has been proven over past several years to increase the calculation speed. By examining the various mathematical processes used in various techniques, appropriate algorithms for the GPU can be developed to speed up the simulations. Understanding how to map algorithms appropriately to the GPU is of vital...
Integral equations arising from the time-harmonic Maxwell equations contain the Green function of the Helmholtz equation as the integration kernel. The structure of this Green function has allowed the development of so-called fast multipole methods (FMMs), i.e. methods for accelerating the matrix-vector products that are required for the iterative solution of integral equations. Arguably the most...
A freestanding planar NIM comprised of two Au metallic screens sandwiched between three layers of polyimide was optimized to have low loss and an impedance match to free space. Constraints were incorporated into the optimization so that the result is compatible with our fabrication scheme. Measured material properties were included in the full- wave electromagnetic simulation to ensure that the predicted...
Two planar multilayer metallo-dielectric metamaterials with two and four metallic screens, respectively, were optimized by a genetic algorithm to have a zero refractive index and an impedance matched to free space in the mid-IR. The structure geometries were constrained to make fabrication easier and a freestanding device possible. The full- wave simulation predicts excellent performance at the design...
A family of dielectric resonator antennas, the supershaped DRAs, has been introduced in this communication. These DRAs exhibit wideband matching characteristics and broadside radiation. The cross section of the supershaped DRAs was described by means of a simple analytical expression depending on a set of six real parameters. By modifying these parameters it is possible to re-shape the antennas and...
A new structure that effectively behaves like ENZ material was proposed. This structure which is composed of parallel metallic wires allows super coupling and wave squeezing in waveguide junctions. The performance of the structure was numerically tested in a number of waveguide geometries with different junction shapes. The primary advantage of the structure proposed here is in its simple construction,...
The paper aims to develop a method to non-invasively characterize cardiac blood-flow dynamics, including stroke volume and cardiac output along with spatial resolution of flow profiles. The research develops techniques to gather additional information about blood flow that can supplement present non-invasive ultrasound techniques for the evaluation of heart failure. This additional blood flow information...
In this paper, a new hybrid FE/RCWA formulation is presented for the modeling of electromagnetic wave interactions with dielectric structures which are doubly periodic. Employment of Fourier series expansion and Floquet's theory in one of the periodic dimensions helps to reduce the dimensions of the mesh grids. Therefore, 2D grids are used rather than 3D meshes of the structures of interest. This...
A fast modeling of the wave propagation inside a rectangular room surrounded by walls of arbitrary thickness was presented. The solution was based on derivation and evaluation of the Green's function for the separable rectangular room, obtained by separation of variables method. The results for the test cases showed a good agreement when compared with the results obtained by the ray tracing technique.
A compact low-cost planar antenna is proposed to cover the WLAN frequency bands centered at 2.4, 5.2 and 5.8 GHz. It was observed that the resonant frequencies of the antenna can be easily adjusted. The return loss in the 5.2 to 5.8 GHz range is effectively controlled by using a strip to short out the surface current. The antenna shows a donut-shaped radiation pattern in the E-plane and an omnidirectional...
In this paper we have developed a framework to extend the GMM technique to any arbitrary tesselation, both linear and higher order. Further, we have demonstrated that integration rules can be easily derived from those for the triangulations. In a companion paper in this conference, we have presented a set of results obtained using these techniques on arbitrary triangulations of surfaces. Future work...
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