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A general approach for the synthesis of the optimal sequential network for use in sequentially rotated antenna (SRA) arrays with an arbitrary number of elements is presented. The performance of this class of antennas are strictly bound to the capacity of the feeding network to produce the nominal power distribution and phase progression. Despite the very high interest in the scientific community on SRA architectures, very few papers have addressed the problem of synthesizing a generic network, with an arbitrary number of outputs. In this paper we propose a novel approach based on closed formulas which solves the synthesis problem exactly, for a given frequency. The proposed approach is then validated with a set of simulations and with the fabrication and measurement of a prototype. Both the simulations and the experimental validation confirms the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

This article applies a new method to analyze modes in empty waveguides having perfectly conducting walls and a rather generic cross‐section. The method is based on a coordinate transformation that maps the generic profile of the waveguide cross‐section to a circular waveguide (CW) filled with an anisotropic material. Modes in this latter waveguide can be represented as a series over the corresponding free‐space CW modes. This representation is particularly useful if used as a modal expansion over the port of a 2.5D or 3D device treated with a transformation optics approach. The method is particularly efficient when the waveguide is "similar" to a CW. Applications are shown to the analysis of some waveguides of arbitrary cross‐section with a view on practical applications. [ABSTRACT FROM AUTHOR]

This paper presents a novel approach to the localization of moving targets in a complex environment based on the measurement of the perturbations induced by the target presence on an independently‐generated time‐varying electromagnetic field. Field perturbations are measured via a set of sensors deployed over the domain of interest and used to detect and track a possible target by resorting to a particle Bernoulli filter (PBF). To comply with real‐time operation, the PBF works along with an artificial neural network (ANN) model of the environment trained offline via finite elements (FEs). The performance of the proposed algorithm is assessed via simulation experiments. [ABSTRACT FROM AUTHOR]

ABSTRACT This article presents a modular reciprocal multiplexer in which the number of channels can be reduced or expanded. The proposed configuration is based on reactive loads designed to substitute channel filters. This is at the same time easy to manufacture and easy to reconfigure as reactive loads are conceived, so as not to modify the characteristics of the active channels if a channel is added or removed. Additional filter tuning after a reconfiguration is not required. The proposed reciprocal design allows for both low costs and low losses since it does not require circulators or additional components, such as hybrid junctions, usually present in reconfigurable multiplexers, although maintaining a good degree of flexibility. A prototype of the proposed design has been fabricated and measured. © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:538-546, 2016. [ABSTRACT FROM AUTHOR]

Taguchi's method is a quality design technique whose applications in numerical single-objective optimization have been recently exploited. In this article, a novel multi-objective (MO) algorithm based on Taguchi's technique is illustrated and its performances assessed. Validation is performed through a comparison between the presented algorithm and a MO genetic algorithm (GA) based optimization, first on different sets of test functions and then on a practical antenna array synthesis problem. Results indicate a generally better behavior of the proposed algorithm in terms of convergence and spreading over the Pareto front with respect to the GA benchmark. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE , 2013. [ABSTRACT FROM AUTHOR]

In this article, an algorithm able to deal at the same time with wire frame and surface patch models for the method of moments in time domain is presented. After a unified theory combining both models, attention is focused on stability dependence issues on the time basis function chosen and on other algorithm parameters. An accurate analysis of time interpolation functions and of their time filtering properties is provided. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011. [ABSTRACT FROM AUTHOR]

High efficiency, compactness, light weight and low return loss are of high importance in antennas, especially in space applications. In this contribution a modified nondominated sorting genetic algorithm (NSGA-II) is applied to the design of Horn antennas for discrete lens applications to achieve a Pareto-optimal solution. Horn design is aimed not only towards higher possible efficiency but also towards large band and compactness. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011. [ABSTRACT FROM AUTHOR]

A domain decomposition approach is here applied to the finite element solution of a multiport waveguide passive device. The approach allows separating the problem in multiple, coupled subproblems which can be solved individually. By appropriately defining one of these subdomains as containing all the possible variations to be studied it is hence possible to restrict the tolerance analysis to this latter, smaller domain. Numerical results showing the gain in computing time are presented. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009. [ABSTRACT FROM AUTHOR]

Cylindrical post-based waveguide filters are a relevant component of antenna feeding networks. Their synthesis performed via automatic optimization based on full-wave analyses can be very time consuming. In this article a novel fast-design approach based on Levy's and Moore's algorithms and an artificial neural network (ANN) architecture is presented. © 2006 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006. [ABSTRACT FROM AUTHOR]

This paper deals with many different neural network architectures that have been introduced to simulate the electromagnetic behavior of complex microwave devices and antennas. Many issues linked to the peculiarities of such devices are addressed. Furthermore, the inverse problem of designing a microwave device, once the required characteristics are given, is also developed by using a neural network approach. © 2002 John Wiley & Sons, Inc. Int J RF and Microwave CAE 12: 90–97, 2002. [ABSTRACT FROM AUTHOR]

In many filtering applications, direct-coupled cavity filters are often used for their symmetry and handling easiness. In this paper, a method is described for the design of these filtering devices by using an artificial neural network (ANN). Starting from design requirements, the procedure discussed herein directly determines the geometric dimensions of the filtering device with good accuracy and very short processing time. ©1999 John Wiley & Sons, Inc. Int J RF and Microwave CAE 9: 287–296, 1999. [ABSTRACT FROM AUTHOR]