Particle swarm optimization (PSO) is an evolutionary algorithm based on the bird fly. Differential evolution (DE) a vector population stochastic method. The fact that both algorithms can handle efficiently arbitrary problems has made them popular for solving in electromagnetics. In this paper, we apply design technique self-adaptive DE (SADE) to real-valued antenna and microwave problems. These include linear-array synthesis, patch-antenna microstrip filter design. number of unknowns varies...

In this paper we present a multi-objective optimization approach to subarrayed linear antenna arrays design. We define problem as bi-objective one. consider two objective functions for directivity maximization and sidelobe level minimization. Memetic algorithms (MAs) are hybrid that combine the benefits of global search Evolutionary Algorithm (EA) with local method. paper, introduce new memetic evolutionary algorithm namely generalized differential evolution (MGDE3). This is extension...

This letter addresses the problem of designing sparse linear arrays with multiple constraints. The constraints could include minimum and maximum distance between two adjacent elements, total array length, sidelobe level suppression in specified angular intervals, main-lobe beamwidth, predefined number elements. Our design method is based on differential evolution (DE) strategy adaptation. We apply a DE algorithm (SaDE) that uses previous experience both trial vector generation strategies...

Antenna design problems often require the optimization of several conflicting objectives such as gain maximization, sidelobe level (SLL) reduction and input impedance matching.Multiobjective Evolutionary Algorithms (MOEAs) are suitable techniques for solving problems.An efficient algorithm is Generalized Differential Evolution (GDE3), which a multi-objective extension (DE).The GDE3 can be applied to global any engineering problem with an arbitrary number objective constraint...

A method is presented to design bandpass or bandstop filters in the microwave region. The procedure based on analysis of discontinuity problem a circular cylindrical dielectric rod centered rectangular waveguide. For some special relations between frequency, constant, and radius rod, reflection transmission coefficient becomes equal zero. This relation gives narrow-band filter. Experimental results for filter with help plastic porcelain rods are given.

This work aims at the establishment of a methodology providing characteristic modes mobile devices realistic models including their metallic parts as well material-dielectric loading. A modified integral equation Moment method is employed to yield impedance matrix such metal-dielectric structures. In turn mode approach formulate and solve related eigenproblem.

A switch beam base-station antenna is presented. The an improvement on the Butler matrix. input ports of are excited with equal or unequal amplitudes. feed network analyzed and presented in a simple manner. comprises main part base station, useful for broadband communications. architecture station described, services that can be provided given. Finally, comments made about tradeoffs benefits comparison to classical Butler-matrix switched-beam adaptive arrays.

An optimization procedure for the layout assessment of electrically large but finite planar arrays is presented. The synthesis takes into account desired directivity pattern that prescribed employing bound constraints. Moreover, size radiators taken account, which results in a hard nonoverlapping, between elements, constraint. latter should not be violated if we want attained solution only to obey far-field mask, also physically realizable. As stated, problem twofold. antenna design...

A dual-band base station wire-antenna design is presented. The MoM and the simulated-annealing technique, for optimizing antenna geometry, are used. procedure starts from of a primary radiator, consisting dielectric covered driven dipole parasitic element. Chebyshev array checked in both 900 1800 MHz frequency bands, with without appropriate feed network. All electrical characteristics, as well patterns antenna,

In this work, the design, fabrication, and testing of low sidelobe level (SLL) Butler matrix-based beamformers is presented. The paper divided in two parts. first part deals with conventional technique simultaneous excitation input ports. second introduces some novel modified SLL matrices, as an alternative advantageous design choice. Circuit architecture makes use asymmetric branch line couplers able to provide high values output power division ratios. Radiation patterns SLLs far lower than...

This paper addresses the problem of designing nonuniform linear arrays with reduced number elements. The synthesis such has several practical applications in cases where cost and weight reduction is important. proposed design method based on Biogeography-based Optimization (BBO). We apply BBO algorithm order to find optimum element positions amplitudes that produce a desired pattern Additional constraints include minimum maximum distance between two adjacent Design found literature are...

A study of the maximally sparse large planar arrays with electrically elements is presented. The conditional probabilities element placements and their resulting auxiliary radiation integrals are derived. Through them average directivity pattern formulas also Employing these formulas, we present a convex method that provides solution to problem when main lobe constraints imposed on pattern. In particular, by taking possible types into account, manage obtain lower bound an array should...

The emission level from multiple sources inside shielded enclosures is presented. Fields are expressed through the dyadic Green's function. Integrated circuits modeled as electric and magnetic dipoles. Induced current magnitudes on walls of analytically calculated. Probabilistic models based measurement data for various source configurations derived Monte Carlo simulations produced. results used prediction possible margins. Applications in PCB design discussed suggestions made.

The field singularities near the tip of an elliptic cone are presented. We prove that electric singularity depends on first even Dirichlet eigenvalue while Neumann is related to magnetic singularity. Some data eigenvalues given.

An eigenanalysis of an array periodically located wires covered with axially magnetized ferrites is presented. The interest in this structure stems from our previous analytical study which revealed that such a wire may support backward surface and possibly leaky waves. It thus expected periodic these ferrite loaded behave as wave media offering equivalent negative index refraction well electromagnetic band gaps. These possibilities are examined herein by extending two - dimensional...

In this paper, new planar spiral antennas with meander lines and loads for passive Radiofrequency identification tag application at ultra-high-frequency band are designed optimized using the global best (gbest)-guided Artificial Bee Colony (GABC) algorithm. The GABC is an improved algorithm, which includes gbest solution information into search equation to improve exploitation. optimization goals antenna size minimization, gain maximization, conjugate matching. dimensions were evaluated in...

An optimal design for the RLSA (radial line slot array) antenna useful DBS reception is presented. Classical geometries and structures given in literature are first used. It found that some cases these not suitable. So, optimization techniques by using right objective functions have been applied. Two different methods were developed three antennas designed. Numerical results comparisons with other similar give advantages of our design.

The exact solution for the electromagnetic field diffracted by a perfectly conducting slotted elliptic cone is determined. presented in form of dyadic Green's function, which most general possible solution. Some numerical results are and compared with others given past simpler geometries.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A technique that compensates the excitation of an array with mutual coupling between elements is presented. The expressed in a matrix form. rows are defined help orthogonal method. has been applied to linear arrays parallel and identical seems be suitable for beam-forming antenna even small interelement distances. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1578–1583, 2006; Published online InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21723

The electromagnetic field scattered by a perfectly conducting elliptic cone is discussed. problem three-dimensional and presented the dyadic Green function, expressed help of Lame periodic nonperiodic functions. Numerical results for current distribution are some special cases.