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1993 documents found for International Journal
DC and radio-frequency transmission characteristics of double-walled carbon nanotubes-based ink
Sébastien Pacchini, Emmanuel Flahaut, Norbert Fabre, Véronique Conédéra, Fabien Mesnilgrente, Fabio Coccetti, Mircea Dragoman, Robert Plana
Published online : 01-10-2010
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In this paper, double-walled carbon nanotubes (DWNTs) network layers were patterned using inkjet transfer printing. The remarkable conductive characteristics of carbon nanotubes (CNTs) are considered as promising candidates for transmission line as well as microelectronic interconnects of an arbitrary pattern. In this work, the DWNTs were prepared by the catalytic chemical vapor deposition process
Impact of the CNT growth process on gold metallization dedicated to RF interconnect applications
Chin Chong Yap, Dunlin Tan, Christophe Brun, Hong Li, Edwin Hang Tong Teo, Dominique Baillargeat, Beng Kang Tay
Published online : 01-10-2010
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Carbon nanotubes (CNTs) are a unique group of materials with high aspect ratio, mechanical and electrical properties, which are of great interests in the field of interconnects, and radio frequency applications. In order to incorporate CNTs into any of these applications successfully, one important issue that has to be resolved is the critical parameters (temperature and reactant gases) associated
60 GHz current gain cut-off frequency graphene nanoribbon FET
Nan Meng, Francsico-Javier Ferrer, Dominique Vignaud, Gilles Dambrine, Henri Happy
Published online : 01-10-2010
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We report investigations on the fabrication and characterization of graphene nanoribbon (GNR) field-effect transistors. Graphene layers are obtained from the thermal decomposition of a Si-face 4H-SiC substrate. To achieve high dynamic performance, a structure with an array of GNR connected in parallel was fabricated by e-beam lithography. The best intrinsic current gain cut-off frequency of 60 GHz
A carbon-nanotube-based frequency-selective absorber
Ugo F. D'Elia, Giuseppe Pelosi, Stefano Selleri, Ruggero Taddei
Published online : 01-10-2010
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A recently developed material based on carbon nanotubes is used here for the realization of single- and double-layered frequency-selective surfaces (FSSs) with relevant absorbing properties. The peculiar characteristics of carbon nanotubes are exploited to devise high-loss resonant ring structures periodically arranged to build the FSS. By introducing two layers of rings, an absorber with stable c
Simulation of microwave optical links and proof of noise figure lower than electrical losses
Anne-Laure Billabert, Mourad Chtioui, Christian Rumelhard, Catherine Algani, Mehdi Alouini, Quentin Lévesque, Christophe Feuillet, Alexandre Marceaux, Thomas Merlet
Published online : 01-12-2010
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The operation of a microwave photonic link is thoroughly investigated both theoretically and experimentally. To this aim, we have developed a simulation tool based on an accurate physical model embedded in a radio frequency (RF) chain simulator. The theoretical predictions are tested on an intensity modulation-direct detection (IMDD) link we have specifically developed to this purpose. Our simulat
MRF volume 2 issue 5 Cover and Back matter
Published online : 01-10-2010
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MRF volume 2 issue 5 Cover and Front matter
Published online : 01-10-2010
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Methodology for designing microwave acoustic filters with Butterworth/Chebyshev response
Óscar Menéndez, Pedro de Paco, Joan Gemio, Jordi Verdú, Edén Corrales
Published online : 01-02-2009
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This work presents a methodology for designing microwave acoustic filters, based on two-port bulk acoustic wave resonators (also known as stacked crystal filters), with either Butterworth or Chebyshev response. The presented methodology makes it possible to design this type of filter without any optimization work, and, moreover, for its closed-form expressions design can be obtained. As a validati
Piezoelectric materials parameters for piezoelectric thin films in GHz applications
P. Muralt, J. Conde, A. Artieda, F. Martin, M. Cantoni
Published online : 01-02-2009
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Piezoelectric thin films have existing and promising new applications in microwave filter technologies. The final performance depends on many parameters, and very specifically on the materials properties of each involved material. In this article, materials and properties for thin-film bulk acoustic wave resonators are discussed on some selected issues: the piezoelectric coefficients and acoustic
Vertical displacement detection of an aluminum nitride piezoelectric thin film using capacitance measurements
Mahmoud Al Ahmad, Robert Plana
Published online : 01-02-2009
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Piezoelectric materials have a strong interaction between their mechanical and electrical properties that translates into innovative components and circuits architectures. This work describes an original method using the electromechanical properties of the aluminum nitride (AlN) piezoelectric material to characterize its vertical extension when an electric field is applied. The novel techniques ba
High-frequency monolithic thin-film piezoelectric-on-substrate filters
Reza Abdolvand, Farrokh Ayazi
Published online : 01-02-2009
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A class of micromachined acoustic filters is presented in which the number of individual resonant structures is reduced to 1 (monolithic filter). This resonant structure is comprised of a stack of thin-film piezoelectric-on-silicon. Symmetric and anti-symmetric resonance modes (dual modes) of the silicon structure are piezoelectrically excited and coupled to realize a 2-pole narrowband filter. Hig
Lithographical bending control method for a piezoelectric actuator
Tamio Ikehashi, Etsuji Ogawa, Hiroaki Yamazaki, Tatsuya Ohguro
Published online : 01-02-2009
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This paper presents the theoretical formulation of a lithographical bending control (LBC) method that uses lithographical degrees of freedom to control the bending of a multilayered beam. LBC is applied to a piezoelectric actuator that uses PZT as the piezoelectric material. The theoretical model is compared with measurements using a weakly fixed bridge structure suited for curvature measurement.
Experimental system level analysis of a concurrent dual-band power amplifier for WiMAX and WCDMA applications
Alessandro Cidronali, Iacopo Magrini, Niccolò Giovannelli, Massimiliano Mercanti, Gianfranco Manes
Published online : 01-04-2009
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This paper presents a feasibility study for the implementation of a concurrent dual-band power amplifier (PA) design suitable for 1.98 GHz WCDMA and 3.42 GHz WiMAX digital systems. The proposed PA design was compared with a test bed based on a pair of dedicated single-frequency band PAs. The dual-band PA exhibited simultaneous peak output power levels of 24 and 17 dBm in the lower and in the highe
Concurrent dual-band SiGe HBT power amplifier for Wireless applications
Vittorio Camarchia, Rocco Giofrè, Iacopo Magrini, Luca Piazzon, Alessandro Cidronali, Paolo Colantonio, Simona Donati Guerrieri, Giovanni Ghione, Franco Giannini, Marco Pirola, Gianfranco Manes
Published online : 01-04-2009
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This paper presents an investigation of a concurrent low-cost dual-band power amplifier (PA) fabricated in SiGe technology, able to simultaneously operate at two frequencies of 2.45 and 3.5-GHz, including an evaluation of its system level performance potentiality. Taking into account the technology novelty and the lack of device characterization and modeling, a hybrid (MIC) approach has been adopt
Behavioral modeling and linearization of a millimeter-wave power amplifier
Ilan Melczarsky, Pere L. Gilabert, Valeria Di Giacomo, Eduard Bertran, Fabio Filicori
Published online : 01-04-2009
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The use of digital predistortion for linearizing a millimeter-wave power amplifier (PA) is investigated. A PA operating at 38 GHz is designed using an accurate non-quasi-static transistor model, taking into account both short- and long-term memory effects. A realistic test signal is then used for the identification of a nonlinear auto-regressive moving average (NARMA) behavioral model of the PA. T
Nonlinear modeling of InP devices for W-band applications
Davide Resca, Valeria Di Giacomo, Antonio Raffo, Rafael Cignani, Alberto Santarelli, Giorgio Vannini, Fabio Filicori, Dominique Schreurs, Farid Medjdoub, Nicolas Thouvenin, Christophe Gaquière
Published online : 01-04-2009
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A recently proposed technique for the distributed modeling of extrinsic parasitic effects in electron devices is used for the very first time in conjunction with a lumped equivalent circuit model for the intrinsic device.
Nonideality sources and implementation considerations in polar transmitters
José A. García, José C. Pedro, Pedro Miguel Cabral, Christian Fager, Hossein Mashad Nemati, Anding Zhu, Paolo Colantonio
Published online : 01-04-2009
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In this paper, the main nonidealities appearing in polar transmitters will be addressed, together with several implementation considerations. Special attention will be paid to the role of AM modulation nonlinearity and parasitic AM-to-PM conversion, once architecture mechanisms such as time-delay mismatch between branches or limited bandwidth in the amplitude path are controlled. The device limiti
A semi-lumped microstrip UWB bandpass filter
Darine Kaddour, Jean-Daniel Arnould, Philippe Ferrari
Published online : 01-02-2009
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In this paper, a miniaturized bandpass filter for ultra-wide-band applications is proposed. It is based on the embedding of high-pass structures in a low-pass filter. A semi-lumped technology combining surface-mounted capacitors and transmission lines has been used. The filter design rules have been carried out. Furthermore, two filters having a 3-dB fractional bandwidth of 142 and 150%, centered
Mitigation of wideband interference on UWB-IR transmission using multi-carrier templates
Madan Kumar Lakshmanan, Homayoun Nikookar
Published online : 01-02-2009
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Ultra wideband (UWB) wireless systems are highly susceptible to interference from other services. To reduce the effect of interference from co-existing sources such as the WLAN standard IEEE 802.11a on UWB Communication, the construction of a modified template waveform using multi-carrier sinusoids is proposed in Ohno and Ikegami (2003), Ohno et al. (2004), Ohno and Ikegami (2006), and Lakshmanan
Criteria for the evaluation of linear two-port stability using two geometrically derived parameters
Chinchun Meng, Hung-Ju Wei, Po-Hsing Sun
Published online : 01-02-2009
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Two geometrically derived stability parameters, µ? (or µ) and ??(or ?), are used to analyze the stability of a two-port network. The magnitudes of both µ? (or µ) and ?? (or ?) parameters determine geometrical relations between the stability circle and the unit Smith chart in the (or ) plane. |µ?| (or |µ|) is defined as the minimum distance from the stability circle to the origin of the unit Smith
A correlation of capacitive RF-MEMS reliability to AlN dielectric film spontaneous polarization
Eleni Papandreou, George Papaioannou, Tomas Lisec
Published online : 01-02-2009
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This paper investigates the effect of spontaneous polarization of magnetron-sputtered aluminum nitride on the electrical properties and reliability of Radio Frequency ? Micro-Electro-Mechanical Systems capacitive switches. The assessment is performed with the aid of application of thermally stimulated polarization currents in metal-insulator-metal capacitors and temperature dependence of device ca
Improved IP2 calibration method using a perturbance-based algorithm
Karim Aoulad Ali, Philippe Barré, Guillaume Andrieux, Jean-François Diouris
Published online : 01-02-2009
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To achieve a high IIP2 level on a mixer, static calibration techniques have been developed. Most of them are based on an intentional introduction of a calibrated mismatch in the structure of the mixer. They are performed at production stage. It is also possible to automate them but their activation is strongly limited in portable devices because of system restrictions. Furthermore, IIP2 is sensiti
GaN devices for power amplifier design
Teresa M. Martín-Guerrero, Damien Ducatteau, Carlos Camacho-Peñalosa, Christophe Gaquière
Published online : 01-04-2009
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This paper describes some aspects of the fabrication and modeling of a GaN device to be employed in a power amplifier covering one WiMAX frequency band. The work has been carried out in the frame of the TARGET's NoE work package WiSELPAS. Details concerning the AlGaN/GaN device technology and the performed linear and nonlinear measurements are provided. Since these new devices require specific non
Piezo-controlled microwave devices
Yuriy M. Poplavko, Vitally I. Molchanov, Yuriy I. Yakimenko
Published online : 01-02-2009
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At present, millimeter wave fast tunable components are required for telecommunication systems, car collision prevention radar, etc. The only mechanical way of control inserts practically no loss in the frequency agile system. That is why micro-electromechanical systems devices are being studied intensively. In an overview, an alternative way ? piezo-electromechanical tuning of microwave component
Coherent sources separation based on sparsity: an application to SSR signals
Nicolas Petrochilos, Gaspare Galati, Emilio Piracci
Published online : 01-06-2009
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Systems based on secondary surveillance radar (SSR) downlink signals, both with directional and with omni-directional antennae (such as in multilateration), are operational today and more and more installations are being planned. In this frame, high-density traffic leads to the reception of a mixture of several overlapping SSR replies. By nature, SSR sources are sparse, with amplitude equal to ze
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