Title :
A Modified Wideband Dipole Antenna for an Airborne VHF Ice-Penetrating Radar
Author :
Byers, Kyle J. ; Harish, A.R. ; Seguin, Sarah A. ; Leuschen, Carlton J. ; Rodriguez-Morales, Fernando ; Paden, John ; Arnold, Emily J. ; Hale, Richard D.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Univ. of Kansas, Lawrence, KS, USA
fDate :
5/1/2012 12:00:00 AM
Abstract :
A 15-element wideband dipole antenna array was developed for operation with the Multichannel Coherent Radar Depth Sounder/Imager on board the National Aeronautics and Space Administration P-3B aircraft. The array, aligned in the cross-track direction, was designed for applying digital beam forming and direction of arrival estimation algorithms to improve clutter suppression and for 3-D imaging of ice sheets. The antenna array is embedded inside an aerodynamic fairing structure designed for airborne operation. While the fairing meets all the structural and aircraft requirements, initial measurements performed on the original prototype array revealed the adverse impact of the fairing structure on antenna performance. The materials used for the construction of the fairing produced electrical loading effects on the radiating structure, which adversely impacted the bandwidth and return loss characteristics of individual antenna elements. This paper describes a set of modifications to the original antenna design based on computer simulations and laboratory measurements, aimed at optimizing antenna return loss and bandwidth while reducing mutual coupling. The final antenna and fairing structure achieved a fractional bandwidth of 40% at a center frequency of 195 MHz with a demonstrated peak power handling capability of 150 W. We were able to reduce the mutual coupling between antenna elements by a factor of two through modification of the dipole ends.
Keywords :
VHF antennas; airborne radar; array signal processing; broadband antennas; dipole antenna arrays; direction-of-arrival estimation; interference suppression; radar antennas; radar clutter; radar imaging; 3D imaging; National Aeronautics and Space Administration P-3B aircraft; aerodynamic fairing structure; airborne VHF ice-penetrating radar; antenna elements; antenna return loss characteristics; clutter suppression; computer simulations; cross-track direction; digital beamforming; direction of arrival estimation algorithms; electrical loading effects; frequency 195 MHz; ice sheets; laboratory measurements; modified wideband dipole antenna array; multichannel coherent radar depth sounder-imager; mutual coupling; power 150 W; radiating structure; Antenna arrays; Antenna measurements; Arrays; Dipole antennas; Impedance matching; Radar antennas; Antennas; airborne radar; antenna arrays; antenna measurements; mutual coupling;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
DOI :
10.1109/TIM.2011.2181780