Research On The Electromagnetic Properties Of Graphene And Its Passive Components

With the rapid development of microelectronic technology, the density of the transistors on chips is ever growing. Aiming at continuously improving the performance of the devices, it is of great necessity to enhance all the aspects of the devices, that is, people need to keep exploring and studying novel materials, structures, operation principles and so forth. Graphene has become one of the most promising candidates of potential materials for next generation electronic devices since it has extraordinary electric, thermal and mechanical properties.Based on the fundamental properties of graphene and the modeling methods of graphene in both microscopic and macroscopic scales, the dissertation mainly focuses on the following innovative aspects of characterization, modeling and applications of graphene:novel simple precise electromagnetic characterization of graphene samples, graphene-based heterogeneous interconnects, tunable antennas, absorbers and frequency selective surfaces (FSS), which are outlined as follows.A non-contact test method is proposed to characterize the graphene property at microwave frequency by combining Raman spectroscopy and Amphenol Precision Connector (APC-7). The chemical vapor deposition (CVD) grown graphene is characterized by Raman spectroscopy to estimate its doping density and the related Fermi energy. The graphene is then sandwiched between two APC-7 coaxial connectors. The S parameters under transverse electromagnetic (TEM) mode normal incident waves are measured by Vector Network Analyzer (VNA) to extract the surface conductivity. In this method, the de-embedding process can be avoided. By combing the Kubo formula with proposed equivalent circuit model, the scattering rate of graphene on Teflon substrate is obtained and analyzed.By utilizing the equivalent circuit model of multilayer graphene nanoribbons (MLGNRs) and the partial element equivalent circuit (PEEC) method, the performance of the novel heterogeneous Cu-graphene interconnects in driver-interconnect-load (DIL) systems is studied. The design of a flexible transparent butterfly antenna based on graphene-metal grid is presented, and the dependence of the antenna performance on the graphene properties and the deformation of the antenna is simulated. A novel graphene loaded dipole antenna is developed. It has an obvious tunable range by changing the loaded graphene surface impedance. Furthermore, a transparent microwave absorber, whose reflector layer, substrate and absorbing layer are Fluorine-doped tin oxide (FTO), glass and monolayer graphene, respectively, is proposed. The absorptions are measured by the rectangular waveguide. An improved equivalent circuit model is utilized to analyze the transparent absorber and shows good accuracy.Lastly, a novel type of vertical graphene strips based three dimensional frequency-selective surface and absorber are demonstrated to realize the dynamic tunability of the frequency response in both center frequency and bandwidth. The stopband and absorption peak are obtained at the plasmon resonant frequency of the graphene strips of the FSS and the absorber. An equivalent circuit model of the proposed FSS is derived. Additionally, according to the scaling law, the transmission zero frequency of the FSS and the absorption peak frequency of the absorber can be predicted rapidly and accurately. Based on the combination of the equivalent circuit model and scaling law, the transmission property of the FSS structure is analyzed. By using the trapezoid graphene strips, the absorbing bandwidth can be improved significantly. In addition, the absorber shows a good stability with various incident angles and polarizations.