Physical Bounds and Optimal Currents on Antennas
Author
Summary, in English
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 considered stored electric energy can be negative for electrically large objects. This effect is mitigated by a Helmholtz decomposition of the current density. Moreover, it is 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.
Publishing year
2011
Language
English
Publication/Series
Technical Report LUTEDX/(TEAT-7210)/1-22/(2011)
Full text
Document type
Report
Publisher
[Publisher information missing]
Topic
- Electrical Engineering, Electronic Engineering, Information Engineering
Status
Published
Report number
TEAT-7210
Research group
- Electromagnetic theory