Description
The objective of the activity is to reduce the size of a multi-feed-per-beam feed system implemented in waveguide technology by using advanced and more integrated components designs.
Targeted improvements: To reduce by a factor of at least two the length and mass of a multi-feed-per-beam feed system with respect to the state-of-the-art designs.
Description:
Multi-feed-per-beam feed systems are of great interest for broadband satellite missions as they enable the production of full multibeam coverage using only two reflector antennas (one for transmit and the other one for receive) instead of the usual four, as demonstrated in a recent ARTES 3-4 activity.
Moreover, this technology could enable future multibeam broadband missions to be implemented on either small platforms or as secondary payloads. or the technology could enable missions to host larger reflectors, thus generating smaller antenna beams.
At Ka-band, waveguide technology using standard milling manufacturing is the preferred solution as it provides low insertion losses and excellent performance, offering the possibility of having a corrective machining after a preliminary RF measurement to reduce amplitude and phase dispersion effects. Recent developments, including studies funded by ESA, have fully demonstrated the potential of these waveguide multi-feed-per-beam feed systems. However current designs are based on E-plane directional couplers and couplers also relying on septum polarizers and H-plane bends.
Due to increasing bandwidth requirements and the number of splitting layers required, the design of the feed system is still quite bulky. In particular, the length of the feed system needs to be reduced to enable more compact feed system designs.
Three techniques may offer opportunities to reduce the feed size. Firstly by taking advantage of the recent improvements on electromagnetic modelling software to further integrate the design of the feed system, by combining for example E-plane and H-plane couplers and by implementing 1:n power dividers (with n being larger than 3). This may also enable new feed overlapping schemes and additional size reduction of the overall feed system. Secondly the same modelling improvements may offer ways to improve and integrate septum polarizers and layer transitions. Thirdly Spline profiles could be considered as they have demonstrated significant benefit in other component designs such as horn antennas.
While there is a clear need for this technology for Ka-Band applications, the technology is applicable across the high frequency bands including C and Ku-Band.
The activity shall start with a review of existing waveguide component designs and a discussion on novel BFN topologies implementing more advanced components concepts. A design procedure in line with an efficient BFN topology optimisation process shall be defined. A detailed antenna design shall be performed and a representative feed system EM shall be defined, manufactured and tested.
Tender Specifics