| Customer: ESA/ESTEC (2006 – 2009) | |
 | The objective of this activity is the development of new DGR technologies in order to make available a combined Tx/Rx DGR ensuring successful future Ka-band missions. |
In the frame of this activity the DGR should be designed for an Earth deck application and for this reason the diameter has been limited to 1.2m. The activity considered the complete DGR, i.e. front and rear reflectors and the peripheral ring. Apart from the general requirements for reflector antennas operating on satellites in GEO there have been particularly stringent requirements for operation at – up to - Ka-band regarding surface manufacturing accuracy, in-flight thermoelastic/hygroelastic surface stability, RF losses and a mass lower than 3.5 kg.
Different new concepts have been treated in a classical trade-off. The finally selected innovative concept, exclusively for linear polarisations, is a grid out of almost 700 highly stable CFRP rods attached to a highly stable CFRP sandwich ring with a CFRP honeycomb core.
Several tests with a demonstrator have been performed: highly accurate surface measurement of the grid, an RF test campaign for front and rear reflector with different frequencies, thermal cycling under vacuum and, currently under performance, a thermo-elastic test campaign. Further activities under a separate national R&D contract are planned in order to investigate larger sizes, a shaped surface and an application at the side panels of the satellite.
The DGR shall operate in both the transmit and receive frequency bands. These are:
Transmit: 17.5GHz - 20.5GHz
Receive: 27.5GHz - 30.0GHz
The activity is intended to bring the development of a Ka-band DGR antenna to the level of a PDR in Phase 1 and includes in Phase 2 the development of an EM. A final RFtest shall verify the concept.
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