Alexander B. Yakovlev, Ph.D. - US grants

This proposal addresses two areas of critical emerging technology in the microwave and millimeter wave regions. The first area is the fundamental characteristics of dielectric resonator antennas and finite antenna arrays operating in a cylindrical waveguide environment. The study and analysis of single dielectric resonator antenna element show the advantages of this new antenna type at millimeter wave frequencies in comparison with traditionally used microstrip and patch printed antennas. This new radiator is expected to be an excellent element in antenna arrays used in many critical applications. This part of the project focuses on the development of new analytical and numerical tools for full-wave analysis of antenna radiation characteristics and on the investigation of performance of dielectric radiators as elements in waveguide-based antenna arrays. Based on the understanding of dielectric resonator antenna performance in cylindrical waveguides, the second part of the project addresses the issue of modeling a fully integrated cylindrical waveguide-based spatial power combining amplifier array. A cylindrical spatial power combining architecture, which utilizes an array of dielectric resonators, is proposed. In this system, dielectric resonator antennas play a critical role, which is justified by their radiation characteristics and high power handling capabilities. Our goal here is to develop an integrated modeling scheme for the full-wave analysis of a complete waveguide-based spatial power combining system, including the interaction of passive (dielectric resonator and hard-horn antennas) elements and active (amplifier) circuits. The newly proposed system will allow to operate in dual and circular polarization regimes.

A high level educational component is considered here by training two graduate students during the course of this project that merge the basic research with high level practical applications. In order to broaden the scope of benefits, a new course will be developed to involve and expose more graduate students to this area. The course will be developed based on the study of dielectric resonator antennas in an array environment and the use of hard surfaces as an artificial magnetic surface.

This project is Phase II of the Broadband Wireless Access Center (BWAC), a multi-university multi-industry organization composed of five universities (the University of Arizona, Virginia Tech, University of Notre Dame, University of Mississippi (UM), and the Catholic University of America) and 20+ affiliates from industry and government. In the past decade, wireless communications has made major technological leaps. Wireless connectivity is pervasive in society, leading to a shortage in wireless spectrum, network congestion, cyber-attacks and personal security issues. The mission of BWAC is to address these challenges and offer creative solutions.

This project will bring to bear UM research capabilities and real-world industry interest in several BWAC thrust areas. Center as a whole addresses research areas, including wireless spectrum sharing, security, and future milli-meter wave technology. UM research problems address spectrum sharing for heterogeneous wireless systems, network optimization to mitigate mutual interference in BLE (low energy Bluetooth) and WiFi systems, and 3 D printing of antennas and the design and fabrication of closely spaced antennas and antenna arrays using elliptical metasurface cloaking. Collaboration with industries in the Southeastern U.S. will provide for our students additional co-op and internship opportunities.

The results of this collaborative industry-university center will have a direct effect on public well-fare, enabling several applications such as remote health and broadband access in rural areas. The partnering universities will broaden their activities to include REU site programs, RET program, participation of under-represented minority students and faculty in research projects, and involvement of multidisciplinary projects. New curriculum at UM will have courses on Internet of Things (IoT) systems and cognitive radios. With its research, established partnerships, and long history of collaboration between its members, BWAC will likely create intellectual property and spin-off companies, leading to job growth.

The lead site, University of Arizona manages the central BWAC project website at www.bwac.arizona.edu. This website contains various information about the center including the overview of the center, mission, industry membership, projects, meeting announcements and technical data. Center proprietary documents are managed through a secure internal pages requiring access credentials. The data repository will be managed at the main website with links to the other university sites. The repository will contain technical papers, project descriptions, relevant software, testbed details, etc. The repository will be maintained during the project and for an additional five years beyond its termination.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.