Journal ArticleDOI
Optimal Antenna Currents for Q, Superdirectivity, and Radiation Patterns Using Convex Optimization
Mats Gustafsson,Sven Nordebo +1 more
TLDR
Convex optimization is used to determine current distributions that provide upper bounds on the antenna performance and formulations for maximal gain Q-Factor quotient, minimal Q-factor for superdirectivity, and minimum Q for given far-fields are presented.Abstract:
The high Q-factor (low bandwidth) and low efficiency make the design of small antennas challenging. Here, convex optimization is used to determine current distributions that provide upper bounds on the antenna performance. Optimization formulations for maximal gain Q-factor quotient, minimal Q-factor for superdirectivity, and minimum Q for given far-fields are presented. The effects of antennas embedded in structures are also discussed. The results are illustrated for planar geometries.read more
Citations
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Journal ArticleDOI
Topology Optimization of Metallic Antennas
TL;DR: In this article, an approach to carry out layout optimization of metallic antenna parts is introduced, where local conductivity values in a given region are used as design variables and are iteratively updated by a gradient-based optimization algorithm given a set of time-domain signals from exterior sources.
Journal ArticleDOI
Antenna Bandwidth Optimization With Single Frequency Simulation
Marius Cismasu,Mats Gustafsson +1 more
TL;DR: Results suggest that the method can be used to yield antennas with Q factors within 20% of their corresponding physical bound, and the optimization time of some antenna parameters may be significantly reduced.
Journal ArticleDOI
Optimal Currents on Arbitrarily Shaped Surfaces
Lukas Jelinek,Miloslav Capek +1 more
TL;DR: In this paper, the Rao-Wilton-Glisson basis representation is used to simplify the underlying algebra while still allowing surface current regions of arbitrary shape to be treated, and it is shown that the optimal current can, in principle, be found as a combination of a few eigenmodes.
Journal ArticleDOI
Characteristic Mode Analysis of a Class of Empirical Design Techniques for Probe-Fed, U-Slot Microstrip Patch Antennas
Mahrukh Khan,Deb Chatterjee +1 more
TL;DR: In this paper, three empirical design techniques for the probe-fed, symmetrically located, U-slot microstrip patch antenna, on a single-layer grounded substrate, are presented with supporting experimental data.
Journal ArticleDOI
Antenna Q and Stored Energy Expressed in the Fields, Currents, and Input Impedance
Mats Gustafsson,B. L. G. Jonsson +1 more
TL;DR: In this paper, the stored energy of an antenna is defined from the difference between the energy density and the far field energy for many but not all cases, and the results indicate that stored energy in the fields, currents, and circuit models agree well for small antennas.
References
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Journal ArticleDOI
Physical Limitations of Omni-Directional Antennas
TL;DR: In this paper, the physical limitations of omni-directional antennas are considered and the potentiality of a broad band width of an antenna with the maximum dimension of 2a has been shown.
Book
Introduction to applied mathematics
Gilbert Strang,L. B. Freund +1 more
TL;DR: In this article, the authors introduce the concept of applied mathematics and apply it to applied mathematics problems in the context of applied applications. [2]... ].. [3]
Journal Article
Electromagnetic Optimization by Genetic Algorithms
TL;DR: This book describes numerous applications of genetic algorithms to the design and optimization of various low- and high-frequency electromagnetic components and provides a comprehensive list of the up-to-date references applicable to electromagneticdesign problems.