The international scientific communities founded a world consortium to develop a new generation radiotelescope. It is called SKA (Square Kilometer Array) and it will have a 1 km² of collective area (like to 200 football fields). It will be the greatest radiotelescope in the world, a technological giant that the humans has ever built. Ska will be able to receiver radio wave coming from high distance cosmic radio-sources with low power emission. It will receiver signals 100 time more weaks than the signals received now trough the best radiotelescope. Ska will allow the observation of distant universe regions ever explored. It will define the application of modern Gravity theories and the Einstein's Theory of General Relativity. For the first time, Ska will look out to search traces of intelligent life in the universe.

This radiotelescope works in a radio band from 100 MHz to 30 GHz and it will not built by a single big antenna, but trough some small antennas connected all together. These antennas are distributed in a spiral array over a region of 3000 Km of diameter. 

 Antennas SKA dislocation

The spiral core will be formed by two typologies of antennas: parabolic dishes (6 m of diameter) to “capture” high frequency radio-signal and planar array to receiver low frequency radio-signal. Parabolic dishes can be moved mechanically in all the sky direction, while the planar array are fixed, but they can be pointed electronically. The sub-station dislocated long the spiral arms are only equipped by 6 metric parabolic dishes. 

Core picture composed by aperture array (in the centre) and parabolic dishes (external crown)

In order to define the Ska design, research institutes of the whole world are developing new technologies and algorithms that will be experimented on "test benches" (antennas with reduced dimensions). Italy is part of the Europe project called SKADS (SKA Design Study), financed thanks the sixth EU framework programme. Italian engineers are using some part of the Northern Cross antenna to test new electronics and new software developed in the Medicina station. The Northern Cross will be the biggest Ska demonstrator of the world. It will also allows to do science at high level thanks the high antenna sensitivity. Italian universities and industries are involved and are collaborating with the Medicina engineers.

The Italian Ska demonstrator is called BEST (Basic Element for Ska Training) and by it, Italian engineers will develop experience regarding the following objects:

   - Low cost and low noise amplifiers.

   - Digital and analogical optical link.

   - Phase Shifter and Vector Modulator.

   - Digital receivers.

   - Digital Back End and data processing.

   - Decimation techniques.

   - Polyphase Filter Bank.

   - FX e XF correlator based on FPGA.

   - Calibration.

   - Multi-beaming.

                                                                          Webmaster