Advanced

State-space models and stored electromagnetic energy for antennas in dispersive and heterogeneous media

Gustafsson, Mats LU and Ehrenborg, Casimir LU (2017) In Technical Report LUTEDX/(TEAT-7245)/1-21/(2017)
Abstract
Accurate and efficient evaluation of the stored energy is essential for Q-factors, physical bounds, and antenna current optimization. Here, it is shown that the stored energy can be estimated from quadratic forms based on a state-space representation derived from the electric and magnetic field integral equations. The derived expressions are valid for small antennas embedded in temporally dispersive and inhomogeneous media. The quadratic forms also provide simple single frequency formulas for the corresponding Q-factors. Numerical examples comparing the different Q-factors are presented for dipole and meander line antennas in conductive, Debye, and Lorentz media for homogeneous and inhomogeneous media. The computed Q-factors are also... (More)
Accurate and efficient evaluation of the stored energy is essential for Q-factors, physical bounds, and antenna current optimization. Here, it is shown that the stored energy can be estimated from quadratic forms based on a state-space representation derived from the electric and magnetic field integral equations. The derived expressions are valid for small antennas embedded in temporally dispersive and inhomogeneous media. The quadratic forms also provide simple single frequency formulas for the corresponding Q-factors. Numerical examples comparing the different Q-factors are presented for dipole and meander line antennas in conductive, Debye, and Lorentz media for homogeneous and inhomogeneous media. The computed Q-factors are also verified with the Q-factor obtained from the stored energy in Brune synthesized circuit models. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Book/Report
publication status
published
subject
in
Technical Report LUTEDX/(TEAT-7245)/1-21/(2017)
issue
7245
pages
21 pages
publisher
Elektro- och informationsteknik
language
English
LU publication?
yes
id
ba1ac2a2-373f-45d5-a633-7b36aeace6da
date added to LUP
2017-02-10 16:23:05
date last changed
2018-05-12 04:00:26
@techreport{ba1ac2a2-373f-45d5-a633-7b36aeace6da,
  abstract     = {Accurate and efficient evaluation of the stored energy is essential for Q-factors, physical bounds, and antenna current optimization. Here, it is shown that the stored energy can be estimated from quadratic forms based on a state-space representation derived from the electric and magnetic field integral equations. The derived expressions are valid for small antennas embedded in temporally dispersive and inhomogeneous media. The quadratic forms also provide simple single frequency formulas for the corresponding Q-factors. Numerical examples comparing the different Q-factors are presented for dipole and meander line antennas in conductive, Debye, and Lorentz media for homogeneous and inhomogeneous media. The computed Q-factors are also verified with the Q-factor obtained from the stored energy in Brune synthesized circuit models. },
  author       = {Gustafsson, Mats and Ehrenborg, Casimir},
  institution  = {Elektro- och informationsteknik},
  language     = {eng},
  month        = {02},
  number       = {7245},
  pages        = {21},
  series       = {Technical Report LUTEDX/(TEAT-7245)/1-21/(2017)},
  title        = {State-space models and stored electromagnetic energy for antennas in dispersive and heterogeneous media},
  year         = {2017},
}