Publication Date


Document Type


Committee Members

Elliott Brown (Committee Member), Joseph Slater (Advisor), Henry Young (Committee Member)

Degree Name

Master of Science in Engineering (MSEgr)


This research focuses on improving the spatial resolution of terahertz (THz) imaging. Using a sub-wavelength aperture in a metal ground plane is the most common way to improve the spatial resolution, but a sub-wavelength aperture has low radiation transmission. To increase the radiation transmission of a sub-wavelength aperture, periodic circular grooves were put in the metal around the aperture. The sub-wavelength circular aperture and the periodic circular grooves around it are known as the bull's-eye structure. The bull's-eye structure shows high radiation transmission at its design frequency, and it also has sub-wavelength spatial resolution. This research designed the bull's-eye structure to perform at ~3 mm wavelength in W band (75-110 GHz). Simulations were conducted on the 3D model of the bull's-eye structure to study its performance in the desired frequency range. Then a bull's-eye structure was fabricated and tested by the knife-edge technique to measure its spatial resolution. The knife-edge test results show the obtained sub-wavelength spatial resolution of the fabricated bull's-eye structure. This research also includes the designs of a 500 GHz bull's-eye structure and 100 GHz reflective probe.

Page Count


Department or Program

Department of Mechanical and Materials Engineering