Absorptive and Frequency-Selective Plasma Limiters


Project ID: TECH-2024-14



In the field of electronic circuits, ensuring signal integrity while protecting sensitive components from damage due to excessive signal levels is important. Limiter circuits may be used to handle issues by managing and controlling signal amplitude. Conventional limiter circuits often face challenges in accurately maintaining signal quality, especially when the input signal varies in amplitude and frequency. This can lead to problems such as signal distortion, clipping, and potential damage to electronic components if the signal exceeds safe operational levels. Furthermore, the limitation of signals based solely on amplitude without considering frequency may be inadequate in applications where different frequency bands carry varying significance or risk. This can result in undesirable alterations to the signal and reduced effectiveness in applications requiring precise control over both the amplitude and frequency of the signal. Thus, there is a need in the art for improved limiter circuits that can provide both amplitude and frequency-selective control.

Invention Description

Researchers at the University of Toledo have developed a novel frequency selective limiter (FSL) utilizing a plasma cell in conjunction with resonators allowing high input power in excess of 100 W and over 60 dB selective isolation.


 Protection of sensitive equipment from electromagnetic pulse (EMP) and high-power microwaves.


  • Extreme power handling (≥52 dBm) and isolation (≥60 dB)
  • Near instantaneous response and recovery (<10ns)
  • Able to easily reconfigure for specific power (36-17 dBm) and frequency thresholds.
  • No exotic manufacturing techniques necessary to scale.

IP Status: Patent Pending   


Patent Information:
For Information, Contact:
Seth Smith
Licensing Associate
The University of Toledo
Sandeep Narasapura Ramesh
Abbas Semnani