Tradeoff Between Antenna Efficiency and QFactor
(2019) In IEEE Transactions on Antennas and Propagation Abstract
The tradeoff between radiation efficiency and antenna bandwidth, expressed in terms of Qfactor, for small antennas is formulated as a multiobjective optimization problem in current distributions of predefined support. Variants on the problem are constructed to demonstrate the consequences of requiring a selfresonant current as opposed to one tuned by an external reactance. The tradeoffs are evaluated for sample problems and the resulting Paretooptimal sets reveal the relative cost of valuing low radiation Qfactor over high efficiency, the cost in efficiency to require a selfresonant current, the effects of lossy parasitic loading, and other insights. Observations are drawn from the sample problems selected, though the tradeoff... (More)
The tradeoff between radiation efficiency and antenna bandwidth, expressed in terms of Qfactor, for small antennas is formulated as a multiobjective optimization problem in current distributions of predefined support. Variants on the problem are constructed to demonstrate the consequences of requiring a selfresonant current as opposed to one tuned by an external reactance. The tradeoffs are evaluated for sample problems and the resulting Paretooptimal sets reveal the relative cost of valuing low radiation Qfactor over high efficiency, the cost in efficiency to require a selfresonant current, the effects of lossy parasitic loading, and other insights. Observations are drawn from the sample problems selected, though the tradeoff evaluation method is valid for studying arbitrary antenna geometries. In the examples considered here, we observe that small increases in Qfactor away from its lower bound allow for dramatic increases in efficiency toward its upper bound.
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 author
 Gustafsson, Mats ^{LU} ; Capek, Miloslav ^{LU} and Schab, Kurt ^{LU}
 organization
 publishing date
 20190108
 type
 Contribution to journal
 publication status
 epub
 subject
 keywords
 Antenna theory, Antennas, Bandwidth, Conductivity, Current distribution, current distribution, eigenvalues and eigenfunctions, Method of moments, Optimization, optimization methods, Qfactor, radiation efficiency
 in
 IEEE Transactions on Antennas and Propagation
 publisher
 IEEEInstitute of Electrical and Electronics Engineers Inc.
 external identifiers

 scopus:85059804840
 ISSN
 0018926X
 DOI
 10.1109/TAP.2019.2891448
 language
 English
 LU publication?
 yes
 id
 e0be02a6b0454541af5ae8ee90b96a71
 date added to LUP
 20190124 10:50:18
 date last changed
 20190220 11:44:28
@article{e0be02a6b0454541af5ae8ee90b96a71, abstract = {<p>The tradeoff between radiation efficiency and antenna bandwidth, expressed in terms of Qfactor, for small antennas is formulated as a multiobjective optimization problem in current distributions of predefined support. Variants on the problem are constructed to demonstrate the consequences of requiring a selfresonant current as opposed to one tuned by an external reactance. The tradeoffs are evaluated for sample problems and the resulting Paretooptimal sets reveal the relative cost of valuing low radiation Qfactor over high efficiency, the cost in efficiency to require a selfresonant current, the effects of lossy parasitic loading, and other insights. Observations are drawn from the sample problems selected, though the tradeoff evaluation method is valid for studying arbitrary antenna geometries. In the examples considered here, we observe that small increases in Qfactor away from its lower bound allow for dramatic increases in efficiency toward its upper bound.</p>}, author = {Gustafsson, Mats and Capek, Miloslav and Schab, Kurt}, issn = {0018926X}, keyword = {Antenna theory,Antennas,Bandwidth,Conductivity,Current distribution,current distribution,eigenvalues and eigenfunctions,Method of moments,Optimization,optimization methods,Qfactor,radiation efficiency}, language = {eng}, month = {01}, publisher = {IEEEInstitute of Electrical and Electronics Engineers Inc.}, series = {IEEE Transactions on Antennas and Propagation}, title = {Tradeoff Between Antenna Efficiency and QFactor}, url = {http://dx.doi.org/10.1109/TAP.2019.2891448}, year = {2019}, }