One of the most promising approaches to achieve high-speed wireless communication in the terahertz regime is by designing and fabricating devices based on the unique electrical properties of graphene. Certain bands in the THz range (300 GHz – 3 THz) encounter minimal water absorption over short distances and high-speed information transfer is possible. Nonetheless, conventional bulk devices cannot operate at that speed. In the more basic wireless communications system, there are three basic components: a source, a modulator and an antenna. With the use of the Rochester Institute of Technology Semiconductor manufacturing and Fabrication laboratory a graphene-based modulator was designed and fabricated. Electrical testing was performed using the TeraNova THz testbed at the Ultra-Broadband Nano Communication and Networking Lab at the State University of New York at Buffalo.
As proof of concept, a passive modulator was preliminary fabricated following a simple capacitor design. The top plate is an aluminum diffraction grating and couples a THz signal to the underlying graphene monolayer, which acts as the bottom plate. This passive graphene-based device showed a 50\% higher absorbance of a 1 THz signal when compared to a device without graphene.
The active modulator was then fabricated and tested. Varying the applied DC bias between the aluminum grating and the buried p+ silicon well, modifies the electric field on the graphene layer and its conductivity. It was found to modulate a THz signal by up to 18 dBm when a +24 Volt bias was applied. These are very promising results for future wireless THz communications and provides practical devices for the THz gap.
Library of Congress Subject Headings
Terahertz technology; Modulators (Electronics)--Materials; Graphene--Industrial applications
Microelectronic Engineering (MS)
Department, Program, or Center
Microelectronic Engineering (KGCOE)
Sanchez, Ky-el, "Design, Fabrication and Test of a Graphene-Based THz Modulator" (2019). Thesis. Rochester Institute of Technology. Accessed from
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