The present project is integrated in a more general payload architecture analysis aiming at offering flexible payload solutions to future operator request for proposal. The advantages of flexible payloads for operators are quite numerous. Let’s consider here, only few major points:
- For a given satellite: Optimization of the resource management; it means capability to adapt the satellite use to the real and moving traffic conditions in a given zone.
- To be in a position for the operator to catch the volatile or emergent markets
- More generally speaking, to be able to optimize the fleet management: having on backup satellite for several services optimizes redundancy for a given orbital position and coverage.
The role of a Digital Transparent Processor (DTP) in such a context is to offer the flexibility in terms of connectivity, channelization and frequency plan.
Following a FLIP study (CNES support) for the design of the product, the objective of the contract was to manufacture and test an Engineering Qualification Model (EQM) of a DTP responding to the customers demand. The goal is to have a product on the shelf, thus reducing the development delay for a flight model program.
In order to be able to respond to the maximum of requirements, the equipment is developed:
- To be scalable in term of mechanical aspect: the equipment can process up to a 20x20 matrix, but the mass and volume is adapted to the exact request of number of input and output accesses.
- To be used in different environment: the design is both compatible to the Thales Alenia Space (TAS) platform Spacebus 4000 or the Alphabus platform.
Compared to previous qualified TAS product, thanks to the present contract, mass, power consumption & dissipation have been drastically reduced, and the processing capacity has been doubled. In the same time, the RF performance remains as high.
The DTP allows to offer in orbit frequency plan flexibility in term of number of channels, size of channels and position of channels, with quite easy control interface.
The DTP modular architecture is based on the assembly in one single mechanical housing of different sub-assemblies:
· Receiver chains, at the analog input interface, implementing the A to D conversion of the analogue input signals.
· Transmitter chains, at the analogue input interface, implementing the D to A conversion and the analogue output signal transmission to the up-converters.
· Digital channel filtering, gain control and routing.
· A dedicated interface board, with serial bus interface for on board configuration.
· DC/DC converter boards whose voltages were customized for very low voltage high
· Clock generation boards for digital processing and converters sampling frequency.
Thus, further to the flexibility in terms of functionality, the DTP also offers a high flexibility in term of modularity. It is achieved through the adaptation of several sub-assemblies of each type, depending on the customers needs (platform, frequency, number of inputs or outputs to be processed). It allows to tailor mass and volume budgets to the exact need of each customer.
The DTP can connect up to 20 inputs and up to 20 outputs ports. The number of ports is scalable from 6 to 20, by step of one. The DTP is able to embed in the same mechanical assembly Forward (FWD) and return (RTN) processor for aeronautical application for example.
The number of inputs and outputs can be non symmetric if required.
The useful bandwidth per access is up to 250 MHz. In the useful input and output accesses, routed channels can be defined with complete flexibility in term of interconnectivity, frequency position, frequency bandwidth and gain control. Depending on the required frequency plan, the granularity of flexibility is around the hundred of kHz.
EQM activities were dedicated to qualification of the unit associated with a dedicated test bench developed:
All key reviews (PDR, CDR, TRR, FR) have been held successfully.
The EQM DTP 20x20 has been fully tested and qualified with expected performances and under multi-platform environmental conditions.
The project is completed.