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This paper presents the modeling and design of one-dimensional metamaterial phase shifters (MPSs) in monolithic-microwave integrated-circuit technology based on the composite right/left-handed transmission-line approach. From a theoretical point-of-view, we show that existing design expressions are restricted to phase shifters behaving as effective media,(More)
The gate-controllable complex conductivity of graphene offers unprecedented opportunities for reconfigurable plasmonics at terahertz and mid-infrared frequencies. However, the requirement of a gating electrode close to graphene and the single 'control knob' that this approach offers limits the practical implementation and performance of these devices. Here(More)
This paper presents the modeling and design methods of true-time distributed microelectromechanical systems transmission lines (DMTLs) making use of periodic structure theory. New contributions to the analysis and reduction of the microelectromechanical systems (MEMS) shunt capacitors parasitics are also introduced. A prototype of a digital DMTL has been(More)
Crucial developments to the recently introduced signal-space approach for multiplexing multiple data symbols using a single-radio switched antenna are presented. First, we introduce a general framework for expressing the spatial multiplexing relation of the transmit signals only from the antenna scattering parameters and the modulating reactive loading.(More)
(c) 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users.  Abstract—Recently, a technique called beam-space MIMO has been demonstrated as an effective approach for transmitting multiple signals while using a single RF-chain. In this work, we present novel design considerations and a compact(More)
This article considers the exploitation of parasitic antenna arrays in multiuser (MU) wireless communication systems by using their adaptive beamforming capabilities in order to improve the average system throughput. The use of parasitic arrays and especially the electrically steerable passive array radiator (ESPAR) antennas enables the design of terminals(More)
The plane wave scattering and absorption by finite and infinite gratings of free-space standing graphene strips are studied in the THz range. Both finite and infinite gratings are studied. The formulation involves modified boundary conditions imposed on the strips. We build an accurate numerical solution to this problem based on the hyper-singular integral(More)
1  Abstract—The performance and design of the novel single-RF-chain beam-space MIMO antenna concept is evaluated for the first time in the presence of the user. First, the variations of different performance parameters are evaluated when placing a beam-space MIMO antenna in close proximity to the user body in several typical operating scenarios. In(More)
The concept, analysis, and design of series switches for graphene-strip plasmonic waveguides at near infrared frequencies are presented. Switching is achieved by using graphene's field effect to selectively enable or forbid propagation on a section of the graphene strip waveguide, thereby allowing good transmission or high isolation, respectively. The(More)
The propagation of surface waves along spatially dispersive graphene-based 2-D waveguides is investigated in detail. Graphene is characterized using a full-k<sub>&#x03C1;</sub> conductivity model under the relaxation-time approximation, which allows to obtain analytical and closed-formed expressions for the wavenumber of plasmons supported by sheets and(More)