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In this paper, a reconfigurable graphene transmission array is proposed for the generation of vortex radio waves at THz. By perforating the substrate with holes of various diameters, different values of effective permittivity are obtained. The transmission coefficient can be adjusted by changing the chemical potential of graphene. With the excitation of planar wave, the phase-compensation of corresponding...
Penta-graphene (PG) has a large ratio of surface to volume and an intrinsic quasi-direct band gap that may benefit for the application of semiconductor sensors. In order to investigate the adsorption behavior of nitric oxide (NO) molecule on the surface of PG, in this study, the adsorption energy, charge transfer and adsorption distance of NO at different locations of pristine and Al-doped PG are...
Terahertz grapheme surface plasmon polaritons (GSPPs) radiation source excited by electron beam has been presented. Here we show the theoretical analysis and initial experimental results on this kind of terahertz source. The theoretical calculations of greatly enhancement due to GSPPs and wide tunability indicate that this mechanism has huge potential. THz TDS is utilized to obtain conductance of...
A novel physical mechanism is reported which can generate coherent and tunable terahertz (THz) radiation. Due to the natural periodicity of 2π of circular cylindrical graphene structure, the surface plasmon polaritions (SPPs), excited by a cyclotron electron beam (CEB), can be transformed into radiation. The radiation density is strongly enhanced over two orders, up to 105 W/cm2. The radiation frequency...
Terahertz grapheme surface plasmon polaritons (GSPPs) radiation source excited by electron beam has been proposed. We demonstrate the initial experimental measurement of conductivity of single layer graphene sheet. Conductivity mapping of sheet graphene has been carried out which is helpful for both of theoretical analysis and experimental design. The changes of conductance and mobility of graphene...
Graphene has been proved to be a promising candidate nanomaterial for tunable electronics. In this paper, a novel tunable terahertz resonator is proposed based on an electrically biased intercalation doped-multilayer graphene ribbon (ID-MGR). The induced self-heating effect is taken into account. Then, the equivalent circuit parameters are predicted. The resonant frequencies and Q-factors of the resonator...
A graphene absorber is proposed using frequency selective surface (FSS) and resistive graphene strips on a grounded dielectric slab. The FSS unit is based on two concentric Minkowski loops. The simple circuit model indicates that the combination of loops with different substrate thicknesses can be utilized to realize two adjacent absorption bands. Then, the inner loop is located within the middle...
A graphene patch reflectarray is proposed for the first time to generate THz wave with orbital angular momentum (OAM). It is shown that by properly assigning the graphene patches with specific reflection coefficients, an OAM-carrying beam can be generated. The graphene reflectarray, which consists of 8 regions and each region contains about 170 patches with uniform chemical potential and size, has...
This paper describes guide-wave characteristics of graphene based waveguides. The model of graphene conductivity is derived at first. The guided wave and the characteristics of PEC-graphene and graphene-graphene waveguides are studies in details with boundary condition defined. The dispersion equation is then derived by solving the Maxwell's equations. The propagation constant is shown with the transverse...
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