DocumentCode :
622971
Title :
An efficient, electrically small antenna with large impedance bandwidth simultaneously with high directivity and large front-to-back ratio
Author :
Ziolkowski, Richard W. ; Ming-Chun Tang ; Ning Zhu
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Arizona, Tucson, AZ, USA
fYear :
2013
fDate :
20-24 May 2013
Firstpage :
885
Lastpage :
887
Abstract :
Non-Foster element-augmented, electrically small electric and magnetic antennas have been designed, characterized numerically, fabricated and tested. Specifically tailored broad bandwidth inductive and capacitive devices were introduced into the near-field resonant parasitic (NFRP) components of their narrow bandwidth counter-parts. This internal non-Foster element approach led to nearly complete matching of the entire system to a 50 Ω source without any matching network and high radiation efficiencies over a 10dB fractional bandwidth that surpasses the fundamental passive bound. By including additional resonant parasitic elements, one can also enhance the directivity. Further augmentation of those parasitic elements with a non-Foster device leads to a large directivity bandwidth. A 300 MHz design with ka = 0.94 is reported which simultaneously achieves high radiation efficiencies (>81.63%), high directivity (> 6.25 dB) and large front-to-back-ratios (> 26.71 dB) over a 10.0% fractional bandwidth.
Keywords :
VHF antennas; antenna radiation patterns; directive antennas; electric impedance; NFRP component; broad bandwidth inductive device; capacitive device; directivity bandwidth; fractional bandwidth; frequency 300 MHz; high directivity; high radiation efficiency; internal nonFoster element approach; large front-to-back ratio; large impedance bandwidth; magnetic antenna; near-field resonant parasitic component; resonant parasitic element; small electric antenna; Antenna theory; Bandwidth; Dipole antennas; Impedance; Resonant frequency;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Electromagnetic Theory (EMTS), Proceedings of 2013 URSI International Symposium on
Conference_Location :
Hiroshima
Print_ISBN :
978-1-4673-4939-0
Type :
conf
Filename :
6565884
Link To Document :
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