The Office of Naval Research recently awarded a researcher at The University of Toledo two grants totaling $770,000 to develop ways to defend electronic systems against high-power threats and improve the performance of small antennas.
Dr. Abbas Semnani, assistant professor of electrical engineering and computer science, is investigating ways to develop low-cost radio-frequency (RF) techniques based on cold plasma technology to help achieve these goals. Semnani’s primary research focuses on utilizing electromagnetic-plasma interactions for high-power microwave applications. These applications are most frequently associated with communication, radar, sensing and electronic warfare systems.
Semnani’s first grant aims to develop wideband and efficient plasma-based small antennas, especially for high-frequency (HF) systems.
To achieve a longer range, communication systems must operate over lower frequency ranges, such as HF and VHF (very high frequency). Employing resonant antennas, however, is exceedingly difficult in most scenarios because of space limitation. As the default option, small antennas present fundamental limitations in terms of their bandwidth and efficiency.
Semnani’s research will investigate plasma-based techniques to cope with the limitations of small antennas and to improve the performance of HF antennas.
“Having more efficient radiators with smaller dimensions than normal antennas is an important step toward miniaturization of wireless systems,” Semnani said, “specifically for long-range communications.”
The second grant explores cold plasma-based devices to offer high-frequency and high-power protection solutions. Specifically, the proposed effort will investigate frequency-selective plasma protections so that an electronic system can operate over safe frequency bands while shutting off a frequency window, including a high-power threat.
This is significantly important for the protection of electronics systems against new threats of electromagnetic weapons. Semnani will work in collaboration with researcher Dr. Allen Garner at Purdue University on this project.
“Protection of susceptible electronic systems against modern threats of high-energy waves is a critical but challenging task,” Semnani said. “In this project, we will pursue a new approach to realize plasma protection schemes with faster response and less spectrum pollution.”
Semnani also recently received a $349,000 grant from Lockheed Martin to research plasma impedance matching networks.
Plasma devices can be used as a variable resistor, a tunable capacitor or both. Plasma tuning occurs very fast, typically on the order of nanoseconds, and plasma can quite easily tolerate very high powers as well as wide temperatures and also can safely operate in harsh environments.
Semnani will investigate plasma-based matching networks as viable solutions for improving the performance of high-power transmitters, for example, in long-range communication and radar systems, where other technologies are limited.
“This research will pave the road toward realization of high-power matching networks necessary for efficient energy transfer in a transmitter system,” he said.