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This work presents a new application of the finite-difference time-domain (FDTD) method to the generalized analysis of phased array antennas. The generality of the FDTD method brings important advantages to the phased array antenna analysis problem, allowing the modeling of complex conductor and dielectric geometries with relative ease. Additionally, a new broad-band FDTD periodic boundary condition is developed which allows the array problem to be simplified to a periodic unit cell computational domain. This hybrid frequency/time-domain periodic boundary condition enables solution of the periodic phased array problem for arbitrary scan conditions in a broadband fashion. The new method is applied to waveguide and stacked microstrip antenna arrays and the numerical results are compared to experimental or analytic solutions, demonstrating the validity and utility of this method. Index Terms - FDTD, microstrip antennas, phased arrays, stacked arrays.

Background: The human face significantly affects the individuals' quality of life, attitude, and mental state. The study of anatomy would always be on the spotlight, as the beauty of the face is desired by humans worldwide. However, age, stress, and negative emotions could lead to stimulation of the corrugator supercilii and procerus muscles in the glabellar region and, subsequently, to alterations in face's characteristics, which could be associated with isolation and avoidance of engaging in social contacts. Aims: Here, we aimed to examine the degree to which treatment with botulinum toxin type A (BoNT A) can affect patients' quality of life and mental state. Patients/Methods: The data collection was performed using 11 questionnaires, which were filled by 83 individuals who underwent BoNT A treatment (sex, 95% female and 5% male; mean age, 48 years). Results: The results showed that the treatment with BoNT A improved the patients' social and psychological behavior, and their opinion regarding their appearance. This effect developed within 1 month following completion of the treatment. Moreover, the effect was higher in patients' social behavior and was better in patients aged 40–49 years compared to those aged <40 and ≥49 years. Conclusions: Thus, BoNT A treatment could be considered as an important way to improve the social behavior and socialization of individuals by raising their psychology and self‐esteem. [ABSTRACT FROM AUTHOR]

Microstrip ring antennas deserve special attention because they can yield a larger bandwidth compared to other conventional patches and outstanding gain-bandwidth characteristics that renders them useful for applications that require reduced size and good radiation efficiency, like the area of mobile communications. In this paper, the stacked microstrip ring antennas for dual-frequency behavior and improved bandwidth are studied and analyzed. The cavity model for single microstrip antennas is extended with some modifications for the stacked geometry to account for coupling between the upper and lower cavities, fringe fields, dispersion effects, and effective loss tangent of the dielectric material. Green's functions are used to allow for modal analysis and closed-form solutions. Results for radiation patterns and input impedance predicted through this simple model are compared with experimental data. Index Terms - Microstrip antennas.

The problem of direction of arrival (DOA) estimation of mobile users using linear antenna arrays is addressed. To reduce the computational complexity of superresolution algorithms, e.g. multiple signal classification (MUSIC), the DOA problem is approached as a mapping which can be modeled using a suitable artificial neural network trained with input output pairs. This paper discusses the application of a three-layer radial-basis function neural network (RBFNN), which can learn multiple source-direction findings of a six-element array. The network weights are modified using the normalized cumulative delta rule. The performance of this network is compared to that of the MUSIC algorithm for both uncorrelated and correlated signals. It is also shown that the RBFNN substantially reduced the CPU time for the DOA estimation computations. Index Terms - Antenna arrys, direction of arrival estimation.

Individual antenna-coupled IR bolometers have recently been demonstrated at wavelengths near 10 [[micro]meter]. If focal-plane arrays (FPA's) of antenna-coupled detectors can be fabricated, enhancement of IR-imager performance is possible. A first step in the design process is to analyze the image-quality potential of antenna-coupled, FPA-based imagers in terms of the modulation transfer function (MTF). The key step in our analysis is development of a cross-talk MTF that accounts for the electromagnetic coupling between adjacent antennas in the FPA. We find that electromagnetic cross talk will not be a significant image-quality factor in antenna-coupled IR FPA's. Key words: Infrared detector, bolometer, antenna, focal-plane array, image quality, modulation transfer function.

A formulation is developed to treat radiation from structures consisting of conducting and/or dielectric bodies of revolution (BOR) in the presence of multiple arbitrary shaped three-dimensional objects. A set of integral equations is developed on the surfaces of the combined structure and the resulting integro-differential equations are solved using the method of moments. On the BOR, harmonic entire domain expansion functions are used for the circumferential dependence, while overlapping sub-domain functions are used to model axial curvature. The arbitrary shaped portions of the structure are modeled using triangular surface patch basis functions. The resulting matrix has a partial block diagonal nature which provides a more economical solution for structures which have some rotational symmetry. The accuracy of the BOR and arbitrary surface formulation is verified using the self-consistency method and measured data.

A formulation is developed to treat radiation from structures consisting of a body of revolution (BOR) in the presence of multiple arbitrarily shaped three-dimensional objects. An electric field integral equation is set up on the surface of the combined structure. The resulting integro-differential equation is solved using the method of moments (MM). On the BOR, harmonic entire domain expansion functions are used for the circumferential dependence, while overlapping subdomain functions are used to model the axial curvature. The arbitrarily shaped portions of the structure are modeled using triangular surface patches. The resulting system matrix has a partial block diagonal nature, which provides a more economical solution for structures that have some rotational symmetry. Numerical results are presented and compared to measurements of a unique cavity-backed patch fed antenna.