Description
The objective of the activity was the development of a very lightweight linear polarisation sensitive dual gridded antenna for future Ku‐band missions (KuDGR). The applied technology was based on HPS’s patented KaDGR‐Technology (patent N° 10711326.8‐1959/2406855) in which the reflective surface is realised by a high number of thin CFRP rods stabilized and connected with a small number of perpendicular non‐conductive rods. For the KuDGR‐activity the front and rear reflector had to be shaped, both grids had been designed out of CFRP rods. The selected reference mission scenario was a co‐polar coverage split into three areas over north Africa.
The most difficult task was the development of manufacturing processes for the single shaped rods. A breadboard was built in order to check the manufacturability in advance. Finally an engineering model has been manufactured and tested: thermal vacuum cycling, thermal distortion test and an extensive RF test. The results have been correlated with the models.
The KuDGR project demonstrated that the principal design for a
• shaped DGR with a completely new concept (see above)
• without any dielectrical shells
• with grids being manufactured as CFRP rods and
• with structural parts also made of pure CFRP
is working well w.r.t. structural/thermal design and also for the RF properties. This new design is thermally extremely stable and does not need any thermal protection in the assumed configuration as Earth-deck antenna. It also results in clearly reduced mass of just 4.2 kg “as built”. In relation of the available budget of the activity the results can be rated as very successful.
