Design technique for mm-wave IC realization of the load network of switched-mode class-EF power amplifier

Analysis and synthesis of the new Class-EF power amplifier (PA) are presented in this paper. The proposed circuit offers means to alleviate some of the major issues faced by existing Class-EF and Class-EF PAs, such as (1) substantial power losses due to parasitic resistance of the large inductor in the Class-EF load network, (2) unpredictable behaviour of practical lumped inductors and capacitors at harmonic frequencies, and (3) deviation from ideal Class-EF operation mode due to detrimental effects of device output inductance at high frequencies. The transmission-line load network of the Class-EF PA topology elaborated in this paper simultaneously satisfies the Class-EF optimum impedance requirements at fundamental frequency, second, and third harmonics as well as simultaneously providing matching to the circuit optimum load resistance for any prescribed system load resistance. Furthermore, an elegant solution using an open and short-circuit stub arrangement is suggested to overcome the problem encountered in the mm-wave IC realizations of the Class-EF PA load network due to lossy quarter-wave line. © 2010 IEICE Institute of Electronics Informati.

The Role of Arg228 in the phosphorylation of galactokinase: The mechanism of GHMP kinases by QM/MM studies

GHMP kinases are a group of structurally-related small molecule kinases. They have been found in all kingdoms of life and are mostly responsible for catalysing the ATP-dependent phosphorylation of intermediary metabolites. Although the GHMP kinases are of clinical, pharmaceutical and biotechnological importance, the mechanism of GHMP-kinases is controversial. A catalytic base mechanism was suggested for mevalonate kinase that has a structural feature of the ?-phosphate of ATP close to an aspartate residue; however, for one GHMP member, homoserine kinase, where the residue acting as general base is absent, a direct phosphorylation mechanism was suggested. Furthermore, it has been proposed by some authors that all the GHMP kinases function via the direct phosphorylation mechanism. This controversy in mechanism has limited our ability to exploit these enzymes as drug targets and in biotechnology. Here the phosphorylation reaction mechanism of the human galactokinase, a member of GHMP kinase was investigated using molecular dynamics simulations and density functional theory-based QM/MM calculations (B3LYP-D/AMBER99). The reaction coordinates were localized by potential energy scan using adiabatic mapping method. Our results indicate that a highly conserved Glu174 captures Arg105 to the proximity of the a-phosphate of ATP forming a H-bond network, therefore the mobility of ATP in the large oxyanion hole is restricted. Arg228 functions to stabilize the negative charge developed at the ß,?-bridging oxygen of the ATP during bond cleavage. The reaction occurs via direct phosphorylation mechanism and the Asp186 in proximity of ATP does not directly participate in the reaction pathway. Since Arg228 is not conserved among GHMP kinases, reagents which form interactions with Arg228, and therefore can interrupt its function in phosphorylation may be developed into potential selective inhibitors for galactokinase.

Are there species smaller than 1 mm?

The rapid advance in genetic sequencing technologies has provided an unprecedented amount of data on the biodiversity of meiofauna. It was hoped that these data would allow the identification and counting of species, distinguished as tight clusters of similar genomes. Surprisingly, this appears not to be the case. Here, we begin a theoretical discussion of this phenomenon, drawing on an individual-based ecological model to inform our arguments. The determining factor in the emergence (or not) of distinguishable genetic clusters in the model is the product of population size with mutation rate—a measure of the adaptability of the population as a whole. This result suggests that indeed one should not expect to observe clearly distinguishable species groupings in data gathered from ultrasequencing of meiofauna.

Electronically Reconfigurable Liquid Crystal Based Mm-Wave Polarization Converter

An electronically tunable reflection polarizer which exploits the dielectric anisotropy of nematic liquid crystals (LC) has been designed, fabricated and measured in a frequency band centered at 130 GHz. The phase agile polarizing mirror converts an incident slant 45° signal upon reflection to right hand circular (RHCP), orthogonal linear (-45 °) or left hand circular (LHCP) polarization depending on the value of the voltage biasing the LC mixture. In the experimental set-up this is achieved by applying a low frequency bias voltage of 0 V, 40 V and 89 V respectively, across the cavity containing the LC material.

Impact of antenna choices on the reliability of mobile broadband transmission at mm-wave frequencies

This paper deals with the impact of several antenna choices on the radio transmission performance within a cellular Mobile Broaband System (MBS) currently under research in Europe. Several antenna types are considered, namely switchble-beam antennas and adaptive antennas employing a phased array approach.

Red de arrastre pelágica 124/1800 y resultados del filtrado de los paneles de malla 150 y 75 mm en la prspección de la vinciguerria Crucero BIC Jose Olaya Balandra 9910, del Callao a Chancay

Se presentaron los resultados de la modificación y adaptaciones de la red pelágica 124/1800 para la captura del recurso Vinciguerria.

Recueil périodique de législation, de doctrine et de jurisprudence en matière de procédure civile, commerciale, criminelle et administrative / publié par MM. Rodolphe Rousseau,... Laisney,...

1900 (A21).

Recueil périodique de législation, de doctrine et de jurisprudence en matière de procédure civile, commerciale, criminelle et administrative / publié par MM. Rodolphe Rousseau,... Laisney,...

1916 (A37).

Recueil périodique de législation, de doctrine et de jurisprudence en matière de procédure civile, commerciale, criminelle et administrative / publié par MM. Rodolphe Rousseau,... Laisney,...

1892 (A13).

Recueil périodique de législation, de doctrine et de jurisprudence en matière de procédure civile, commerciale, criminelle et administrative / publié par MM. Rodolphe Rousseau,... Laisney,...

1913 (A34).

Recueil périodique de législation, de doctrine et de jurisprudence en matière de procédure civile, commerciale, criminelle et administrative / publié par MM. Rodolphe Rousseau,... Laisney,...

1899 (A20).

Recueil périodique de législation, de doctrine et de jurisprudence en matière de procédure civile, commerciale, criminelle et administrative / publié par MM. Rodolphe Rousseau,... Laisney,...

1880 (A1).

Recueil périodique de législation, de doctrine et de jurisprudence en matière de procédure civile, commerciale, criminelle et administrative / publié par MM. Rodolphe Rousseau,... Laisney,...

1896 (A17).

Recueil périodique de législation, de doctrine et de jurisprudence en matière de procédure civile, commerciale, criminelle et administrative / publié par MM. Rodolphe Rousseau,... Laisney,...

1893 (A14).