PAGE CONTENTS
Objectives
FSS and BSS services in Ku-band are expected to remain the strongest branch in the satellite telecommunications market.
Objective of the project was the development of successors for the existing Ku band OMTs, which were used successfully over a decade. The requests for additional band width, higher power handling and the avoidance of resonances caused of higher order modes necessitated a family of new products, since all requirements cannot be covered with a single feed chain.
Airbus decided to meet the demands of the market with three feed chains tailored for:
- FSS Tx/Rx, 10.7 – 14.8 GHz, dual linear polarisation
- Extended FSS/BSS Tx/Rx 10.7 – 14.8 & 17.2 – 18.4 GHz, dual linear polarisation
- Extended BSS Tx/Rx 10.7 – 12.75 & 17.2 – 18.4 GHz, dual circular polarisation
The corresponding polariser devices were designed, manufactured and assembled. Typical axial corrugated horns were used to demonstrate the performance of the feed chains. Figure 1 shows the EQM feed chains with assembled horn and also the stand alone polarising devices (PDs).
All feed chains passed the environmental testing comprising thermal cycling and vibration test successfully. The RF testing showed good accordance to the predictions and revealed excellent performance of all three products.
Challenges
The major challenges for the devices to be developed were:
- High power handling considering
- Multipaction threshold
- Losses and dissipation power
- PIM performance
- Thermal concept
- Avoidance of resonances caused of higher order modes
Plan
The entire project was divided in two phases.
In the first phase, a comprehensive study was performed to collect current and future market requirements for Ku band feed chains on telecommunication satellites. Simultaneously, a literature study was carried out to find suitable possible solutions. At the end of the study phase requirements for three devices covering the different requests were defined and the most promising design solutions identified.
In the second phase, the RF designs were finalized and fitted to the mechanical and thermal design of the polariser devices. The PDs where manufactured and qualified to flight standard.
Current Status
Project is finished successfully.
The first units out of the developed products are already manufactured for flight application.
