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.
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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