Ph.D. student John Logan of the Electrical and Computer Engineering (ECE) Department won the “Best Student Paper” Award at the 39th Allerton Symposium on Antenna Applications, held from September 22 to 24 in Monticello, Illinois. Logan’s faculty advisor is ECE Professor Marinos Vouvakis, and the title of his winning paper was “Low Cross-Polarization Single-Polarized Vivaldi Arrays.”
According to the abstract of the article, Logan and Vouvakis are presenting a class of single-polarized Vivaldi antenna arrays with greater than a decade bandwidth and low cross-polarization.
“The proposed element topology elegantly solves the long-standing problem of poor polarization in Vivaldi arrays when scanned in the non-principal planes,” say the two researchers. “The enabling technical innovation hinges upon the re-configuration of the high-profile continuous metal Vivaldi fin into a series of disconnected and vertically stacked metal strips that follow the envelope of the original Vivaldi fin.”
This sliced fin topology, termed Sliced Notch Antenna (SNA), can effectively control current contributions responsible for high cross-polarized radiation, without significantly affecting the input impedance of the array.
Technically speaking, as the abstract explains, “An exemplary PCB-based sliced notch antenna array is designed to operate over a 10:1 (1.2-12 GHz) bandwidth; simulations suggest VSWR <2 broadside-scan, VSWR < 2.05 out to θ=45° in the E-/H-planes, and polarization purity better than 8 dB within the θ ≤ 45° scan cone across the band – an improvement of more than 12 dB over its typical Vivaldi array counterpart. Preliminary measured results of a proof-of-concept designed SNA element and its Vivaldi array counterpart in linear (1×19) array configurations are also presented to further validate the SNA array concept.”
The Antenna Applications Symposium and its predecessor, the Air Force Antenna Symposium, have for more than fifty years provided a unique forum for exchange of ideas and information about the practical aspects of antenna design, development, and use in systems. The Antenna Applications Symposium emphasizes antenna design and application to systems. Papers typically span antenna design based on empirical and/or numerical methods, feed networks, system architecture, integration with other systems and subsystems, materials, compatibility with modern platforms and composite materials, and measurements. (October 2015)