Iris Public Event ANTARES SPACE SEGMENT DESIGN. 04 & 05 February 2013 University Of Salzburg Unipark, Salzburg

Transcript

1 Iris Public Event ANTARES SPACE SEGMENT DESIGN 04 & 05 February 2013 University Of Salzburg Unipark, Salzburg 05 Giuseppe Grelli Thales Alenia Space - Italia R

2 Contents Design Drivers 2 Requirements, Performances & Characteristics Highlights Coverages / Services Operating Frequencies Traffic profiles EIRP and G/T Main Architectural Features Block diagram Main functionalities Technical Choices and Technological Challenges Antenna farm Digital processing High Power Section

3 Space Segment / Payload Design Drivers Drivers Solutions 3 Low cost user terminal Traffic Demand and Traffic Flexibility Availability Requirements High G/T on board Large antenna at L Band High EIRP demand per carrier HPA & Ouput section sizing Payload Architecture: Flexible Frequency Spectrum Management Flexible Power Management Space segment constellation & deployement strategy Combination of in orbit hot redundancy and on ground spare

4 ANTARES Space Segment Highlights Infrastructure/Constellation to cope with availability requirements 1 satellite active + 1 hot redundant in orbit On ground spare ready for lunch in 6 months Sat in orbit lifetime: 15 years Main Sat Hot Redundant Sat 4 Design Options to cope with SRD capacity requirement for operational system Minumum traffic profile Maximum Traffic Profile User link at L Band: Mobile Forward Link frequency band [1545 MHz 1555 MHz] Mobile Return Link frequency band [ MHz MHz] User Link at L band Feeder Link at Ku band Forward and return link carriers Carriers with bandwidth of 192 khz (8 khz guard band) EIRP and G/T at L band FWD single carrier/eirp: 48.3 dbw RTN G/T requirement: 2.5 db/k Feeder link at Ku Band (Ka/X/C Band also possible)

5 Coverages / Services shall ORP ADS-C shall ORP ATS+AOC+Voice+ADS-C shall TMA+ENR ATS+AOC+Voice 5

6 Payload Architecture and Main Features Digital IF section for flexible frequency spectrum management Ku band Tx/Rx antenna 6 Tx and Rx semi active large antennas at L band for spot beams coverage over ECAC L band User Link Global Coverage for ADS-C services Multiport Amplifier with parallesised TWTAs for Dynamic Power Management according to traffic demand and traffic distiribution over service area Ku band feeder link

7 EIRP & G/T Perfomance 7 Equivalent Isotropic Radiated Power (EIRP) Gain Over Temperature (G/T)

8 Technical Choices/Technological Challanges Large L Band reflector (3.7 m trimmed reflector) driven by: L band G/T requirement Inter-beam isolation for frequency re-use 8 IF Digital Transparent Processing Flexibility of Carrier Frequency allocation Channel filtering granularity Multiport Amplifier (very high power handling to cope with traffic demand) Butler Matrix High Power Amplifier: linearized TWTAs working at 3 db OBO

9 L-band Antenna Farm for User Link Coverage: 5 spot covering the ECAC service area Tx feed array apertures arranged in triangular mesh N Rx feed array apertures arranged in triangular mesh. 9 Antenna system architecture: 2 offset reflector antennas 1Tx + 1Rx fed by a Multi-matrix distributed amplification architecture of reduced complexity: 12/16 radiating chains connected to 3/4 4x4 Butler Matrices in Tx low power BFN s directly following LNA s front-end in Rx L-Band Tx Antenna Trimmed reflector E P/F S W L-Band Rx Antenna Trimmed reflector Antenna technology: lightweight composite reflector with truncated elliptical rim to reduce the size in stowed configuration hi-efficiency compact feed array

10 On Board Digital Processing OBDP Processor functions implemented in ASIC/FPGA: A/D conversion at I/F frequency carrier filtering carrier level control carrier frequency tuning carriers combination and D/A conversion Local oscillator for the frequency conversion provided by dedicated circuitry (PLL and fractional) 10 Key features I/F Digital Transparent carrier processing Carrier bandwidth filtering configurability Complete flexibility for Carrier frequency allocation in a large spectrum

11 Multi-matrix distributed amplification 11 Tx Antenna 4x4 BTLM architecture and beams association (16 feed option) Tx Antenna element beams footprint 5 zones ECAC coverage: 8 Matrix D 4x Flexible management of frequency specturm Frequency reuse for spectral efficiency Radiated Power dynamic management to cope with traffic variation and distribution (flexible power to beam allocation)

12 Summary Drivers Low cost user terminal Traffic profiles Traffic & frequency flexibility Availability 12 Space Segment / Payload Design Options vs System Architecture Options Design, architecture, analyses performances, budgets, for each of the options SPS Constellation/Infrastructure to meet avaibility rqmts Choices/Challanges High G/T: Large Antennas for User Link EIRP/carrier and traffic need: High power handling & DC demand Flexible payload architecture and IF digital processing

13 13 Thanks for Your attention!