Graphene Quadrature amplitude backscatter modulator on paper (GRAMOP)

• Applicant: Dr.-Ing. Muhammad Yasir, Ph.D.
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering ; Communication Technology and Networks, High-Frequency Technology and Photonic Systems, Signal Processing and Machine Learning for Information Technology ; Measurement Systems
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 500122702

The onset of the internet of things and ubiquitous computing will drastically increase the number of communication devices. Most of the devices are based on conventional materials which if not recycled properly may pose a risk to the environment. Besides, the functionality of most of these devices will require power conservation for reliable communication. Hence ecological consideration and power conservation are vital for future communication devices. Besides being biodegradable and ecological, paper is a serious contender for radiofrequency (RF) substrates due to microwave characteristics close to conventional RF substrates. Backscattered communication devices are considered power efficient since they are powered by incident waves. Therefore, backscattered communication devices designed on paper substrate can provide a good solution for being ecological and power efficient. They consist of a switching element usually based on lumped elements or RF switches, all based on conventional materials. Research on graphene has shown that it has a variable fermi energy level and its resistance is tunable by an applied voltage bias. Besides, this tunable resistance is valid in the cm- and mm frequencies. The variable fermi energy level of graphene makes it a good contender for replacing conventional switching elements in backscattered communication devices.This project aims to design, fabricate and characterize a graphene-based quadrature backscattered modulator on paper substrate. Equivalent circuit analysis will be performed for proposed topologies followed by Finite element models (FEM) based simulations. Graphene will be characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), scanning microwave microscopy (SMM) and modelled appropriately as a lumped element. Preliminary versions of paper-based quadrature amplitude modulators (QAM) will be tested with lumped impedances substituting graphene on prototypes. After optimization of lumped elements based QAM, prototypes with graphene will be fabricated and measured. The fabrication of the prototypes will be aided by microrobotics in order to optimize the fabrication process for reliability. Measurements of the prototypes will involve scattering parameter measurements and demodulation measurements. The prototypes will be rigorously tested in different ambient conditions and accordingly optimized for better performance.

• DFG Programme: Research Grants