Programme Element: ARTES 5.1
Reference nr.: 13.1TT.63
Planned Tender Issue: quarter 2, 2013
Objective: to design, manufacture and test an Engineering Model (EM) of a wideband Ka-band lineariser having an in-orbit performance tuning capability.
Targeted Improvements: to increase the operational bandwidth to 3 GHz and to introduce an in-orbit tuning capability to maximise the performance over any operational sub-band.
Today' s Ka-band multi-beam systems typically feature 500 MHz of spectrum allocated to the forward link (downlinks to users) and up to 2 GHz for the return link (downlinks to gateways), within a total bandwidth of 2.5 GHz. Currently available Ka-band linearisers have a maximum bandwidth capability of 1.5 to 2 GHz, requiring separate linearisers for the forward and return downlinks. Future higher capacity systems will likely require operation over an extended frequency range (up to 3 GHz bandwidth). A single wideband lineariser would also support both the forward and return functions, which would simplify the hardware matrix and reduce the number of equipment design variations. An in-orbit AM/AM and AM/PM tuneability capability would allow the performance to be optimised for the operational sub-band, which will typically be less than 3 GHz, and would offset the performance deterioration that is to be expected when extending the bandwidth to 3 GHz.
Current qualified lineariser products exist nowadays with a bandwidth capability of 1.5 to 2 GHz and with fixed performance tuning.
The implementation of future higher capacity systems will be highly inefficient if current lineariser products are employed because of the need to partition the available bandwidth (~3 GHz) into separate sub-bands served by different lineariser types. This exacerbates an already difficult situation with regard to equipment accommodation, given that such high capacity systems would require a very large amount of payload equipment.
Task 1. Trade-off, computer simulation and definition of wideband, on-board-tuneable Ka-band linearisers.
Task 2. Design, manufacture and test of an EM of a wideband, on-board-tuneable Ka-band lineariser.
Task 3. Conclusions and recommendations for future developments.