Journal ArticleDOI
Optimization of radar cross section by a gradient method
TLDR
In this article, the derivatives of radar cross sections (RCS) with respect to scatterer shape in two and three dimensions are derived from a single solution of the scattering problem, and gradient-based optimizations converge with a small number of iterations to shapes with strongly reduced RCS in specified angular intervals.Abstract:
Analytical expressions are derived for the derivatives of radar cross sections (RCS) with respect to scatterer shape in two and three dimensions. Using the adjoint formulation, the derivatives of the RCS, with respect to an arbitrary number of design parameters, are found from a single solution of the scattering problem. In two dimensions, gradient-based optimizations converge with a small number of iterations to shapes with strongly reduced RCS in specified angular intervals. The optimal shapes have sharp corners in directions where the RCS is minimized and exhibit corrugations, which can be suppressed by use of penalty functions. The method is also applied to RCS optimization using dielectric and magnetic absorbing materials.read more
Citations
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Journal ArticleDOI
Spread-Spectrum Selective Camouflaging Based on Time-Modulated Metasurface
Xiaoyi Wang,Christophe Caloz +1 more
TL;DR: The object covered by the metasurface is hence perfectly camouflaged to a foe radar and can be detected by a friend radar possessing the spread-spectrum demodulation key corresponding to the metAsurface modulation, and this detection is robust to interfering signals.
Journal ArticleDOI
Optimum Spatial Arrangement of Array Elements for Suppression of Grating-Lobes of Radar Cross Section
TL;DR: In this article, a new method to optimize the radar cross section (RCS) for array antennas is presented, which can reduce the strong scattering from an equally spaced array by optimizing the array RCS factor.
Journal ArticleDOI
Gradient optimization of microwave devices using continuum design sensitivities from the adjoint problem
Yongtao Yang,Tomas Halleröd,David Ericsson,Alexander Hellervik,Anders Bondeson,Thomas Rylander +5 more
TL;DR: In this article, the shape and material parameters optimization of radar cross section (RCS) and T-junction's reflection coefficient were applied to microwave problems derived in continuum form.
Hybrid Intelligent Optimization Methods for Engineering Problems
TL;DR: It was concluded that the variants of the present multi-frequency vibrational GA and PSO were efficient algorithms, since they successfully avoided all local optima within relatively short optimization cycles.
Journal ArticleDOI
Compressed Sensing for the Detection and Positioning of Dielectric Objects Inside Metal Enclosures by Means of Microwave Measurements
TL;DR: In this paper, a convex quadratic optimization problem with 1-norm regularization is proposed for the detection and positioning of dielectric objects inside a metal enclosure, where the number of objects is unknown but assumed to be limited.
References
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Book
Optimal Shape Design for Elliptic Systems
TL;DR: The techniques of the calculus of variation and of optimization proved to be successful for several optimal shape design problems however these remain expensive both in the qualification of the engineers required to understand the method and in computing time.
Journal ArticleDOI
Numerical analysis of the exterior boundary value problem for the time-harmonic Maxwell equations by a boundary finite element method. I. The continuous problem
TL;DR: In this article, a general finite element method is applied to compute the skin currents flowing on a perfectly conducting surface when it is illuminated by a time-harmonic incident electromagnetic wave.
Journal ArticleDOI
Design sensitivities for scattering-matrix calculation with tetrahedral edge elements
H. Akel,Jon P. Webb +1 more
TL;DR: In this paper, the authors present a finite element formulation for the problem of computing the rates of change of the scattering matrix of a microwave device with respect to geometric or material parameters.
Journal ArticleDOI
Optimization of microwave devices using 3-D finite elements and the design sensitivity of the frequency response
D. Nair,Jon P. Webb +1 more
TL;DR: In this article, a method for finding sensitivities of the scattering matrix efficiently over a range of frequencies, from a finite-element analysis, is applied to the optimization problem of microwave devices with 1-4 design parameters: a rightangle miter bend, an E-plane U-bend, and a waveguide impedance transformer.
Journal ArticleDOI
A systematic optimum design of waveguide-to-microstrip transition
Hong-Bae Lee,Tatsuo Itoh +1 more
TL;DR: In this paper, a waveguide-to-microstrip probe-type transition is designed by using the proposed method, which consists of the finite element method (FEM), design sensitivity analysis (DSA), and the steepest descent algorithm.