Physical Bounds and Optimal Currents on Antennas

Author

Gustafsson, Mats ; Cismasu, Marius ; Jonsson, B.L.G.

Author_Institution

Dept. of Electr. & Inf. Technol., Lund Univ., Lund, Sweden

Volume

60

Issue

6

fYear

2012

fDate

6/1/2012 12:00:00 AM

Firstpage

2672

Lastpage

2681

Abstract

Physical bounds on the directivity Q-factor quotient and optimal current distributions are determined for antennas of arbitrary shape and size using an optimization formulation. A variational approach offers closed form solutions for small antennas expressed in the polarizability of the antenna structure. Finite sized antennas are solved using Lagrangian parameters in a method of moments formulation. It is also shown that the optimal charge density for a small antenna can be generated by several current densities. Numerical examples for small and large antennas are used to illustrate the results.

Keywords

Q-factor; antenna radiation patterns; antenna theory; method of moments; optimisation; Lagrangian parameters; antenna structure; arbitrary shape; arbitrary size; directivity Q-factor quotient; finite sized antennas; method of moments formulation; optimal current distributions; optimal currents; optimization formulation; physical bounds; small antennas; Current density; Dipole antennas; Integral equations; Minimization; Optimization; Q factor; Antenna Q; antenna theory; physical limitations; polarizability;

fLanguage

English

Journal_Title

Antennas and Propagation, IEEE Transactions on

Publisher

ieee

ISSN

0018-926X

Type

jour

DOI

10.1109/TAP.2012.2194658

Filename

6183472