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If a scattering problem is solved by finite element, finite volume or finite difference methods, it is necessary to predict the far field pattern (or radar cross‐section) by using a near field to far field transformation. Usually this is done using the Stratton‐Chu integral relations, which give the far field pattern in terms of a near field surface integral. When volume‐based methods are used this is unnatural, and it may be necessary to employ interpolation procedures to provide the necessary surface data. In this paper an alternative method based on volume integrals is proposed. The main advantage of the new procedure is that it allows the use of discrete quantities that are naturally available from the numerical scheme. However, it is now necessary to perform volume integrals. The error in the new procedure is examined, and a simple numerical example provided.

The purpose of this paper is to analyze far and near field emitted field patterns through more exact calculation of the modes formed in finite periodic dielectric gratings.

For the mode calculation, equations are newly defined by applying vertical boundary condition on the assumption that transverse electric modes are generated in the structure. After finding modes, near field patterns are calculated using the wave number and coefficient of the mode.

Additionally, the results from these calculations are compared with that of the rigorous-coupled method. Finally, far field patterns are derived by applying fast Fourier transform to near field patterns and also compared with the results of rigorous-coupled method.

For convenience of coordinate, we use rectangular coordinate, though the shape of radome is a hemisphere.

In this paper, the authors derive more exact near field patterns without the assumption of infiniteness so that these results can be used practically for a making real frequency-selective structure.

Conventional periodic finite dielectric gratings analysis has been done using Floquet–Bloch wave theory, coupled-mode, rigorous-coupled method which is based on the assumption of infiniteness of the structure.

The purpose of this paper is to calculate near field and far field scattering of SH waves by multiple multilayered anisotropic circular inclusions using parallel volume integral equation method (PVIEM) quantitatively.

The PVIEM is applied for the analysis of elastic wave scattering problems in an unbounded solid containing multiple multilayered anisotropic circular inclusions. It should be noted that this numerical method does not require the use of the Green’s function for the inclusion – only the Green’s function for the unbounded isotropic matrix is needed. This method can also be applied to solve general elastodynamic problems involving inhomogeneous and/or anisotropic inclusions whose shape and number are arbitrary.

A detailed analysis of the SH wave scattering problem is presented for multiple multilayered orthotropic circular inclusions. Numerical results are presented for the displacement fields at the interfaces and the far field scattering patterns for square and hexagonal packing arrays of multilayered circular inclusions in a broad frequency range of practical interest.

To the best of the authors’ knowledge, the solution for scattering of SH waves by multiple multilayered anisotropic circular inclusions in an unbounded isotropic matrix is not currently available in the literature. However, in this paper, calculation of displacements on interfaces and far field scattering patterns of multiple multilayered anisotropic circular inclusions using PVIEM as a pioneer of numerical modeling enables us to investigate the effects of single/multiple scattering, fiber packing type, fiber volume fraction, single/multiple layer(s), the multilayer’s geometry, isotropy/anisotropy and softness/hardness.

The article aims to present an efficient numerical method for computing the far-fields of phased antenna arrays over broad frequency bands as well as wide ranges of steering and look angles.

The suggested approach combines finite-element analysis, projection-based model-order reduction, and empirical interpolation.

The reduced-order models are highly accurate but significantly smaller than the underlying finite-element models. Thus, they enable a highly efficient numerical far-field computation of phased antenna arrays. The frequency-slicing greedy method proposed in this paper greatly reduces the computational costs for constructing the reduced-order models, compared to state-of-the-art methods.

The frequency-slicing greedy method is intended for use with matrix factorization methods. It is not applicable when the underlying finite-element system is solved by iterative methods.

In contrast to conventional finite-element models of phased antenna arrays, reduced-order models are very cheap to evaluate. Hence, they provide an enabling technology for computing radiation patterns over broad frequency bands and wide ranges of steering angles.

The paper presents a two-step model-order reduction method for efficiently computing the far-field patterns of phased antenna arrays. The suggested frequency-slicing greedy method constructs the reduced-order models in a systematic fashion and improves computing times, compared to existing methods.

A boundary element method in terms of the field variables is applied to three‐dimensional electromagnetic scattering problems. Especially, the influence of a dipole excited field on low conducting materials situated very close to the antenna will be discussed. We use higher order edge elements of quadilateral shape for the field approximation on curved surfaces. The tangential components of the unknown field variables are interpolated by vector element functions. The Galerkin method is implemented to obtain a set of linear equations. The applicability of the proposed edge element is investigated by the comparison of different BEM‐formulations and FEM‐results.

The purpose of this paper is to present an optimization process for the design of a 2×2 patch antenna phased array with application for an UHF RFID system.

The optimization process is based on a method of moment (MoM)-solver, which was individually made to create such patch antenna phased arrays and simulate the radiated field pattern. In combination with this MoM-solver, a GUI, which gives the opportunity to change every physical antenna factor and create the antenna structure within a few minutes is presented. Furthermore the golden section search method is used to produce an even better solution in a more efficient way compared to the first attempt. After the simulation, different types of presentation of results can be chosen for a fast and easy optimization.

The design process is discussed while the authors try to optimize the distance between the elements and the difference of input phase for each patch element. The final goal is to create an antenna with maximum directivity and coverage of field pattern.

A physical implementation of an optimized patch antenna phased array and the results of measurement are presented in the end.

An optimization process for the design of a 2×2 patch antenna phased array with application for an UHF RFID system is presented. Furthermore the golden section search method is combined with the design process to increase the accuracy of the solution and decrease the time effort.

This paper aims to introduce design challenges of modern telecommunication satellite antennas. The antenna farms accommodated on a satellite are systems of high complexity. From the radio frequency (RF) point of view, the most important design issues, e.g. high power applications in space (vacuum) or typical antenna scenarios (single/multi beam antennas), and their solution are considered.

The paper presents the application of electro-magnetic (EM) field simulation in the design and optimisation process. The design of a telecommunications satellite antenna splits into several areas, for which different types of EM field solvers are used.

The use of EM field solvers enables an accurate and efficient design approach of modern geostationary telecommunications satellite antennas. Due to the use of EM field solvers, an excellent agreement between predictions and measurement results on feed as well as antenna system level is achieved.

This paper gives an overview of state-of-the-art telecommunications satellite antenna architectures and their efficient RF design due to the use of EM field solvers. Typical high power effects and other design issues are explained. RF engineers are encouraged to work on this exciting topic to further improve the design process and to develop new satellite antenna and feed products.

The purpose of this paper is to investigate of the ultra‐wide band (UWB) characteristics of a conical antenna covered by an electromagnetic band‐gap (EBG) structure composed of alternating high‐ and low‐permittivity dielectric spherical shells.

A finite difference time domain in spherical coordinates is implemented in order to characterize the antenna's performance and waveform fidelity in case an UWB pulse is used. The method of projected effective permittivity is used in order to treat accurately the dielectric interfaces between the dissimilar spherical shells.

The design achieves a very wide impedance bandwidth above 5.5 GHz and presents UWB radiation characteristics and high average gain over the whole bandwidth. The radiation patterns are monopole‐like and their frequency dependence is small in the whole UWB frequency band. A time domain study has shown that the antenna distorts the excitation pulse in a moderate way.

In this paper, a quasi‐planar wideband conical antenna coated on a dielectric EBG structure is proposed for what is believed to be the first time. It is mechanically stable and, relatively easy to build and integrate with the planar circuits.

The purpose of this paper is to revisit the recursive computation of closed-form expressions for the topological derivative of shape functionals in the context of time-harmonic acoustic waves scattering by sound-soft (Dirichlet condition), sound-hard (Neumann condition) and isotropic inclusions (transmission conditions).

The elliptic boundary value problems in the singularly perturbed domains are equivalently reduced to couples of boundary integral equations with unknown densities given by boundary traces. In the case of circular or spherical holes, the spectral Fourier and Mie series expansions of the potential operators are used to derive the first-order term in the asymptotic expansion of the boundary traces for the solution to the two- and three-dimensional perturbed problems.

As the shape gradients of shape functionals are expressed in terms of boundary integrals involving the boundary traces of the state and the associated adjoint field, then the topological gradient formulae follow readily.

The authors exhibit singular perturbation asymptotics that can be reused in the derivation of the topological gradient function in the iterated numerical solution of any shape optimization or imaging problem relying on time-harmonic acoustic waves propagation. When coupled with converging Gauss−Newton iterations for the search of optimal boundary parametrizations, it generates fully automatic algorithms.

In this work, a microstrip antenna array for wireless power transfer (WPT) application is reported. The proposed 4 × 4 antenna array operating at 16 GHz is designed using a flexible Kapton polyimide substrate for a far-field charging unit (FFCU).

The proposed antenna is designed using the transmission line model on a flexible Kapton polyimide substrate. The finite element method (FEM) is used to perform the full-wave electromagnetic analysis of the proposed design.

The antenna offers −10 dB bandwidth of 240 MHz with beam width and broadside gain found to be 29.4° and 16.38 dB, respectively. Also, a very low cross-polarization level of −34.23 dB is achieved with a radiation efficiency of 36.67%. The array is capable of scanning −15° to +15° in both the elevation and azimuth planes.

The radiation characteristics achieved suggest that the flexible substrate antenna is suitable for wireless charging purposes.