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The Square Kilometre Array (SKA) ushers in the new generation of large radio telescopes that will work at wavelengths between meters and centimeters. In order to competitively design interferometric antenna arrays such as SKA, it is crucial to focus on the optimization of system performance. In this paper, we contribute to the solution by introducing a new optimization algorithm called Division Algorithm (DA). This algorithm finds the optimal positions of antennas to simultaneously maximize u-v coverage and decrease sidelobe level (SLL). The DA is able to optimize the configuration of the interferometric array in both snapshot and Earth rotation synthesis observations. To demonstrate its efficiency, the DA is applied to configure an optimum 30-element array for the Giant Metrewave Radio Telescope. The proposed algorithm is able to improve the overlapped samples parameter by about 4% and the unsampled cells parameter by about 12%, at snapshot observation, compared to the Genetic Algorithm (GA). DA is able to improve these two parameters for a 6-hr tracking observation as well. Finally, the proposed algorithm is compared with the GA for different source declination. Results show that the DA is able to decrease the SLL better than the GA.

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In this paper, the advantages of UWB (Ultra-Wide Band) transmission for satellite communications are investigated together with the ones coming from the use of EHF (Extremely High Frequency) where there is the possibility of exploiting a huge spectrum availability. In particular, a comparison among UWB approaches is shown in terms of BER performance, considering hardware impairments

Nowadays W band (75-110 GHz) is an experimental frontier since no satellite telecommunication mission has been developed and the technology at these frequencies is still poor and relatively not ready.In this framework, a preliminary useful step toward the W band exploitation in satellite telecommunications is represented by the analysis and the validation of a terrestrial link operating at these frequencies with the capability to carry out transmission/reception experiments. Such experiment could give important feedback from the technology point of view and also for the channel characterization.In this frame, the University of Rome Tor Vergata in collaboration with the company Rheinmetall Italy is carrying out an experiment to investigate a W band terrestrial point-to-point link over a distance of around 15 km. Many technological issues must be faced.In this paper, we present an overview of preliminary design of an experimental W band terrestrial air link identifying main critical elements.Index Terms-terrestrial telecommunication link, W band, millimeter wave propagation, channel evaluation.978-1-4244-3062-8/08/$25.00 ©2008 IEEE