Frequency-Agile, Efficient, Circularly Polarized, Near-Field Resonant Antenna: Designs and Measurements

Tang, MC; Ziolkowski, RW

Frequency-Agile, Efficient, Circularly Polarized, Near-Field Resonant Antenna: Designs and Measurements

Tang, MC Ziolkowski, RW

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Publication Type:: Journal Article
Citation:: IEEE Transactions on Antennas and Propagation, 2015, 63 (11), pp. 5203 - 5209
Issue Date:: 2015-11-01

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Field	Value	Language
dc.contributor.author	Tang, MC	en_US
dc.contributor.author	Ziolkowski, RW https://orcid.org/0000-0003-4256-6902	en_US
dc.date.issued	2015-11-01	en_US
dc.identifier.citation	IEEE Transactions on Antennas and Propagation, 2015, 63 (11), pp. 5203 - 5209	en_US
dc.identifier.issn	0018-926X	en_US
dc.identifier.uri	http://hdl.handle.net/10453/119100
dc.description.abstract	© 2015 IEEE. A frequency-agile, efficient, circularly polarized (CP), nearfield resonant parasitic (NFRP) antenna is presented. It consists of two orthogonal capacitively loaded loops (CLLs) with similar configurations placed vertically with respect to a finite ground disc and serve as the NFRP elements. They are placed in the near field of two monopoles fed from a single coax feedline. A pair of varactor diodes is incorporated into the NFRP elements to achieve its frequency-agile behavior. The NFRP elements produce nearly complete matching at frequencies much lower than the fundamental modes of the monopoles without any matching circuit. Frequency tunability is demonstrated over a wide effective impedance bandwidth and the antenna is characterized as having good axial ratio (AR) and high radiation efficiency. A proof-of-concept experiment produced reasonable agreement with the simulation studies. The measured results demonstrate that the frequency-agile prototype produced a 3.92% fractional 3-dB AR bandwidth, which is more than four times larger than the 0.84% value of the original fixed-capacitor passive system. Moreover, good impedance matching (\|S11\|AR,min ≤13 dB); relatively high radiation efficiency (RE 85%); symmetrical, stable, and uniform radiation patterns; CP performance; and peak gain values between 5.81 and 5.93 dB were measured over this frequency-agile range.	en_US
dc.relation.ispartof	IEEE Transactions on Antennas and Propagation	en_US
dc.relation.isbasedon	10.1109/TAP.2015.2477563	en_US
dc.rights	info:eu-repo/semantics/closedAccess
dc.subject.classification	Networking & Telecommunications	en_US
dc.title	Frequency-Agile, Efficient, Circularly Polarized, Near-Field Resonant Antenna: Designs and Measurements	en_US
dc.type	Journal Article
utslib.citation.volume	11	en_US
utslib.citation.volume	63	en_US
utslib.for	0906 Electrical and Electronic Engineering	en_US
utslib.for	1005 Communications Technologies	en_US
pubs.embargo.period	Not known	en_US
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Engineering and Information Technology
pubs.organisational-group	/University of Technology Sydney/Faculty of Engineering and Information Technology/School of Electrical and Data Engineering
pubs.organisational-group	/University of Technology Sydney/Strength - GBDTC - Global Big Data Technologies
utslib.copyright.status	closed_access	*
pubs.issue	11	en_US
pubs.publication-status	Published	en_US
pubs.volume	63	en_US

Abstract:

© 2015 IEEE. A frequency-agile, efficient, circularly polarized (CP), nearfield resonant parasitic (NFRP) antenna is presented. It consists of two orthogonal capacitively loaded loops (CLLs) with similar configurations placed vertically with respect to a finite ground disc and serve as the NFRP elements. They are placed in the near field of two monopoles fed from a single coax feedline. A pair of varactor diodes is incorporated into the NFRP elements to achieve its frequency-agile behavior. The NFRP elements produce nearly complete matching at frequencies much lower than the fundamental modes of the monopoles without any matching circuit. Frequency tunability is demonstrated over a wide effective impedance bandwidth and the antenna is characterized as having good axial ratio (AR) and high radiation efficiency. A proof-of-concept experiment produced reasonable agreement with the simulation studies. The measured results demonstrate that the frequency-agile prototype produced a 3.92% fractional 3-dB AR bandwidth, which is more than four times larger than the 0.84% value of the original fixed-capacitor passive system. Moreover, good impedance matching (|S11|AR,min ≤13 dB); relatively high radiation efficiency (RE 85%); symmetrical, stable, and uniform radiation patterns; CP performance; and peak gain values between 5.81 and 5.93 dB were measured over this frequency-agile range.

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http://hdl.handle.net/10453/119100