Static quarks with improved statistical precision

We present a numerical study for different discretisations of the static action, concerning cut-off effects and the growth of statistical errors with Euclidean time. An error reduction by an order of magnitude can be obtained with respect to the Eichten-Hill action, for time separations beyond 1.3 fm, keeping discretization errors small. The best actions lead to a big improvement on the precision of the quark mass Mb and F_Bs in the static approximation.Comment: 3 pages, 4 figures, Lattice2003(heavy

Towards a precision computation of f_Bs in quenched QCD

We present a computation of the decay constant f_Bs in quenched QCD. Our strategy is to combine new precise data from the static approximation with an interpolation of the decay constant around the charm quark mass region. This computation is the first step in demonstrating the feasability of a strategy for f_B in full QCD. The continuum limits in the static theory and at finite mass are taken separately and will be further improved.Comment: Lattice2003(heavy), 3 pages, 2 figure

Smart Antenna Terminal - SANTANA

The demand for broadband data communication will increase rapidly in the next years. Satellite systems offer unique possibilities to connect professional mobile users to broadband data networks and services. The targeted markets are users on aircraft, ships and cars. High bandwidths must be utilized to realize the projected high data rates. Therefore, the attention of system providers will eventually move to systems operating in the Ka-band. The terminal antennas must meet complex requirements like high antenna gain, fast target acquisition and tracking, interferer cancellation and handling of several satellites at the same time. Here, smart antenna terminals employing digital beamforming are most promising. These antennas are very flexible and can be reconfigured easily to new mission profiles. The goal of the project Smart Antenna Terminal was the development, realization and test of demonstrators of broadband terminal antennas using digital beamforming in the Ka-band. These demonstrators can be used as building blocks for larger terminal antennas

Miniaturised DBF Communication Modules for Broadband Mobile Satellite Access at Ka-Band

This paper describes the implementation of and measurements on highly integrated transmitter and receiver modules featuring digital beamforming (DBF) at Ka-band frequencies. These modules can be used as building blocks for large receiver or transmitter terminal antennas. After a review of the essential parts of the receiver and transmitter modules like antenna elements, Ka-band frontends, miniaturised interfaces and IF / baseband circuitry, measurement results of one receiver and one transmitter module are presented and discussed