Papantonis wins best paper at IWAT
Held from Feb. 29 to March 2 in Florida this year, IWAT focuses on the research and development of innovative antenna technologies. Among other topics addressed, he said, “advancing noise- and interference-reduction capabilities for wideband communications systems” received special attention.
Papantonis’ winning paper is titled, “Reconfigurable Tightly-Coupled Array With Tunable Band Rejection.” The co-authors include distinguished student Ersin Yetisir and researcher Nima Ghalichechian, as well as ESL director and professor John Volakis.
The Defense Advanced Research Projects Agency (DARPA) Arrays at Commercial Timescales (ACT) II project provides a solution to a significant engineering issue.
“(The) main objective is to achieve a reconfigurable, wideband system with agile bandwidth,” Papantonis said. “A wideband communication system’s resistance to noise and interference is imperative for its unhindered performance. Tightly-coupled arrays are a class of antenna arrays that offer ultra-wide bandwidth and are, therefore, essential for a wide range of bandwidth-demanding applications.”
He said these can include Synthetic-Aperture Radar (SAR) and Software-Defined Radio (SDR).
“Integration of multiple functions in a single aperture, high gain and wide-angle scanning capabilities are additional features that render tightly-coupled arrays highly attractive for many wideband communication systems. However, wideband systems are inherently prone to noise and interference,” he said.
Within this framework, Papantonis said, ESL teamed up with Northrop Grumman Aerospace Systems to develop a compact, low-cost reconfiguration scheme that allows a wideband antenna to dynamically reject certain frequencies to avoid reception of undesired intentional or unintentional interferers.
The noise interference mechanism proposed in his paper, he said, is realized on the antenna feeding/matching network (a folded Marchand Balun).
“(It) constitutes an integrated, tunable notched filter. Unlike conventional mechanisms that are carried out at baseband and in the digital domain, the present reconfiguration scheme is implemented in analog, at the RF frequency and prevents possible saturation of the receiver’s low noise amplifier that can completely block communication,” Papantonis said. “It is a very simple, straightforward scheme that minimizes passband loss and can achieve more than 20dB rejection within the operational bandwidth.”
