5 Watt GaN HEMT Power Amplifier for LTE

This work presents the design and implementation of a stand-alone linear power amplifier at 2.4 GHz with high output power. A GaN HEMT transistor is selected for the design and implementation of the power amplifier. The device exhibits a gain of 11.7 dB and a drain efficiency of 39% for an output power of 36.7 dBm at 2.4 GHz for an input power of 25dBm. The carrier to intermodulation ratio is better than 25 dB for a two tone input signal of 25 dBm of total power and a spacing of 5 MHz. The fabricated device is also tested with LTE input signals of different bandwidths (5MHz to 20MHz)

Crítica de traduccions

Paul FRIEDLÄNDER, Platón : verdad del ser y realidad de la vida

Filtenna Integration Achieving Ideal Chebyshev Return Losses

This paper demonstrates that it is possible to find an ideal filter response (Chebyshew, Butterworth,..) considering the antenna as the last resonator of a filter under certain circumstances related with the antenna performance and the bandwidth of the filtenna device. If these circumstances are not accomplished, we can achieve excellent performance as well, by means of an iterative process the goal of which is defined by either a filter mask or a classical filter function itself. The methodology is based on the conventional coupling matrix technique for filter design and has been validated by fabricating a microstrip prototype using hairpin resonators and a rectangular patch antenna

Nonlinear Performance of BAW Filters Including BST Capacitors

This paper evaluates the nonlinear effects occurring in a bulk acoustic wave (BAW) filter which includes barium strontium titanate (BST) capacitors to cancel the electrostatic capacitance of the BAW resonators. To do that we consider the nonlinear effects on the BAW resonators by use of a nonlinear Mason model. This model accounts for the distributed nonlinearities inherent in the materials forming the resonator. The whole filter is then implemented by properly connecting the resonators in a balanced configuration. Additional BST capacitors are included in the filter topology. The nonlinear behavior of the BST capacitors is also accounted in the overall nonlinear assessment. The whole circuit is then used to evaluate its nonlinear behavior. It is found that the nonlinear contribution arising from the ferroelectric nature of the BST capacitors makes it impractical to fulfill the linearity requirements of commercial filters

Experiencia, empatía y conversión: una teología de la música como epifanía del Misterio.

En nuestro entorno cultural, la pregunta religiosa actual se formula en términos de «¿cómo decir Dios?». Esta búsqueda se concreta privilegiadamente en el ámbito de la experiencia estética. En este horizonte, el autor ensaya elaborar una teología de la música como epifanía del Misterio partiendo de la experiencia, la empatia y la conversión. Se subraya la presencia de compositores que interpretan hermenéuticamente la Palabra llevándola a una comprensión empática y que va más allá de cualquier explicación. A la hora de decir una palabra sobre el Inefable y sobre el misterio de su comunicabilidad, los teólogos pueden ser sensibles a los lenguajes meta-lingüísticos, como la música y la percepción estética. En ellos pueden encontrar un camino de comunicación de la percepción estética del Misterio del Dios que se revela

Simultaneous Surface Plasmon Resonance and X-ray Absorption Spectroscopy

We present here an experimental set-up to perform simultaneously measurements of surface plasmon resonance (SPR) and X-ray absorption spectroscopy (XAS) in a synchrotron beamline. The system allows measuring in situ and in real time the effect of X-ray irradiation on the SPR curves to explore the interaction of X-rays with matter. It is also possible to record XAS spectra while exciting SPR in order to detect the changes in the electronic configuration of thin films induced by the excitation of surface plasmons. Combined experiments recording simultaneously SPR and XAS curves while scanning different parameters can be carried out. The relative variations in the SPR and XAS spectra that can be detected with this set-up ranges from 10-3 to 10-5, depending on the particular experiment

Caracterización y cartografía fitoclimáticas del bosque nativo subantártico en la Isla Grande de Tierra del Fuego (Patagonia, Argentina)

Isla Grande de Tierra del Fuego is especially peculiar in phytoclimatic terms, situated as it is at an extreme southerly latitude, surrounded by large water masses and close to the great mass of Antarctic ice. Its main peculiarities in this sense are the coolness of its summers and a very narrow temperature range. As a result, the woodland landscapes in the parts with forest cover are dominated by microphyllous broadleaf physiognomies, both evergreen and deciduous, of the Nothofagus genus. This paper reports a more in-depth investigation of the hitherto little-known phytoclimatic conditions in that territory which included calibration and validation of a model of phytoclimatic suitability that addresses the principal plant physiognomic units and phytoclimatic mapping. It discusses the causes behind the presence of broadleaf formations in thermal conditions which in the northern hemisphere would allow only coniferous formations or no tree formations at all, and also the edaphic peculiarities that may explain the presence of a evergreen species like Nothofagus betuloides in subantarctic mixed forests.La Isla Grande de Tierra del Fuego presenta una muy marcada originalidad fitoclimática por su posición en latitudes muy australes, estar rodeada por grandes masas de agua y por su cercanía a la gran masa de hielo polar antártica. Esta originalidad se traduce en un escaso calor estival y una oscilación térmica muy reducida como principales peculiaridades, dando lugar en sus porciones arboladas a paisajes boscosos dominados por fisionomías planifolias de carácter micrófilo, tanto perennifolias como caducifolias del género Nothofagus. Este trabajo profundiza en las hasta hoy escasamente conocidas condiciones fitoclimáticas de este territorio, mediante la calibración y validación de un modelo de idoneidad fitoclimática respecto de las principales unidades fisionómicas de vegetación y el establecimiento de una cartografía fitoclimática. Se discuten las causas que provocan la existencia de formaciones planifolias en condiciones térmicas que darían lugar a formaciones aciculifolias o desarboladas en el hemisferio Norte, así como las particularidades edáficas que condicionan la presencia de la estrategia perennifolia representada por Nothofagus betuloides en los bosques mixtos subantárticos

Nonlinear software sensor for monitoring genetic regulation processes with noise and modeling errors

Nonlinear control techniques by means of a software sensor that are commonly used in chemical engineering could be also applied to genetic regulation processes. We provide here a realistic formulation of this procedure by introducing an additive white Gaussian noise, which is usually found in experimental data. Besides, we include model errors, meaning that we assume we do not know the nonlinear regulation function of the process. In order to illustrate this procedure, we employ the Goodwin dynamics of the concentrations [B.C. Goodwin, Temporal Oscillations in Cells, (Academic Press, New York, 1963)] in the simple form recently applied to single gene systems and some operon cases [H. De Jong, J. Comp. Biol. 9, 67 (2002)], which involves the dynamics of the mRNA, given protein, and metabolite concentrations. Further, we present results for a three gene case in co-regulated sets of transcription units as they occur in prokaryotes. However, instead of considering their full dynamics, we use only the data of the metabolites and a designed software sensor. We also show, more generally, that it is possible to rebuild the complete set of nonmeasured concentrations despite the uncertainties in the regulation function or, even more, in the case of not knowing the mRNA dynamics. In addition, the rebuilding of concentrations is not affected by the perturbation due to the additive white Gaussian noise and also we managed to filter the noisy output of the biological systemComment: 21 pages, 7 figures; also selected in vjbio of August 2005; this version corrects a misorder in the last three references of the published versio

Numerical modelling of oocytes partially covered by magnetic nanoparticles in external magnetic fields

Nanorep® is a novel device based on the magnetic tweezer concept that has been developed for precise, fast, and non-aggressive oocytes and embryos manipulation. To operate the reproductive cells, they are first immersed in a standard host medium with ferrite containing nanoparticles. The magnetic particles are attached to the external matrix of the oocytes/embryos thanks to a linked protein making possible to control them by using external magnetic fields. Electron microscope photographs show magnetic particle aggregates around the oocyte. The total mass and distribution of the attached magnetic particles per oocyte show a wide range of variability, which strongly affects their magnetic response. Despite the uncertainties on the attachment of magnetic nanoparticles, the set formed by the oocyte and the nanoparticles can be caught and transported by using standard neodymium magnets. Here we present an initial study of the interaction between the set oocyte/nanoparticles and the external magnetic field in aqueous environment. We are going to discuss several relevant topics of the model such us the characterization of magnetic field produced by cylindrical neodymium magnets, the model of the ferrite magnetization as an effective spherical dipole or a magnetized spherical shell, the measurement processes to obtain the temporal evolution of the particle position and the different observed dynamic behaviours