PAGE CONTENTS
Objectives
The purpose of the present development was to adapt to the EADS ASTRIUM needs (Eurostar 3000 P/F) the equipment already developed by THALES ALENIA SPACE for their own platform in the frame of previous ESA contracts (in particular contract ref 20141/NL/NH).
The developed RF equipment is dedicated to be used on EUROSTAR 3000 Platform (EADS ASTRIUM) and has to operate with one or several Ka band beacons.
When connected all together, the developed equipment is the constituent for the RF Sensing Subsystem which uses the RF signal transmitted from one or several ground beacons to measure the angular pointing errors of the antennas.
Four types of equipment were developed and qualified in the frame of the present contract:
- Ka Band Signal Combiners
- Ka Band Antenna Switch Matrix
- Ka to C Down Converters
- C Band Autotrack Receivers
The designs of this equipment were derived from those developed in the frame of ESA ARTES 4 contract 20141/NL/NH (in Ku + Band) and from the developments of Ka Equipment which were performed previously in the frame of ESA DOMINO program (contract nr. 14278 and 14279).
The Signal Combiner and the Antenna Switch Matrix equipment were developed in Ka frequency band (27 – 31 GHz), the Down Converter was developed with an input frequency range in Ka Band (27-31 GHz) and an output frequency range in C Band (5.9 to 6.4 GHz). The Autotrack Receiver has RF interfaces in C band (5.9-6.4 GHz).
The equipment was developed to be compatible with the EADS ASTRIUM EUROSTAR 3000 platform.
Those 4 EQMS were to be delivered (after qualification) to EADS ASTRIUM for inclusion (together with an EM signal combiner) in their test bench for subsystem and system level tests.
Also, a ground equipment named “ Digital Simulator”, which was simulating the Autotrack Receiver digital operation, was manufactured and delivered to EADS ASTRIUM for advanced testing.
Challenges
Apart from the technical issues linked to the development of each particular unit, the main challenges of the development were the following:
The development contract was conducted in parallel to the Ka SAT satellite contract where flight models had to be delivered to EADS ASTRIUM very close to the dates of qualification of the EQMs.
The equipment was derived from THALES ALENIA SPACE system design. Therefore, EADS ASTRIUM was discovering their particularities and building their own system in parallel of the equipment design activities.
Plan
(Features Continued)
Main specifications
| Performance | Requirement |
| Input Frequency Band | 27 to 31 GHz |
| Output Frequency Band | 5856 MHz +- 6MHz |
| Operating Bandwidth | 12 MHz |
| Input Power Range | -110 to -60 dBm |
| Power consumption | <6.5W |
| Gain | >20 dB |
| Input interface | WR 34 |
| Output | SMA -F |
| Power supply &TM TC | 15P connector |
| Mass | 820 g |
| Size | 183*46*153 mm |
C-band Autotrack Receiver:
General description:
The Autotrack Receiver RF input reflects the 2 components (ρ, θ) of the pointing error of the on-board antennas. The Receiver is able to process subsequently from 1 up to 8 antennas. Its main function is to demodulate the pointing error data into accurate ρ, θ values. It also processes the ground beacon identification coding acknowledgement.
After processing, and under request, it directs these RF sensor relative phase and amplitude values to EUROSTAR 3000 Satellite through its specific MIL-STD 1553 serial interface. It drives the Switch Matrix, by sequencing the antennas being received via the individual LNA power supply switching.
It provides the modulation signal to the Signal Combiners, via the Switch Matrix.
Main specifications:
| Performance | Requirement |
| Frequency Band | 5856 MHz |
| Operating Bandwidth | 12 MHz |
| Types of Uplink Waveforms | PM/BPSK modulated CW or pure carrier wave |
| Input Power Range of Σ Signal | from –90dBm to –60dBm |
| Power consumption | <23W |
| Input | SMA female connector |
| TM&TC interface | 1* 25P LF connector |
| Bus interface | 1*15P LF connector |
| Mass | 1720 g |
| Size | 229*78*195 mm |
Digital Simulator:
General description:
The Digital Simulator functionalities are as follows:
- Generate or receive the command signals of antenna de-pointing parameters,
- Generating through a modulator a signal similar to the one generated by the signal combiners,
- Demodulating that signal,
- Calculating the antenna de-pointing parameters,
- Estimating the performance with regards to the input data.
Project Plan
The equipment development plans were as follows:
Signal Combiner
Simulations and breadboarding of the RF part;
EQM manufacturing, qualification and delivery to EADS ASTRIUM.
Antenna Switch Matrix
Breadboarding of LNA RF slice, DC/DC converter, TMTC interface; Modification of distribution and protection board schemes;
EQM manufacturing and qualification and delivery to EADS ASTRIUM.
Down Converter
Partial breadboarding and testing of DC/DC converter and RF modules; EQM manufacturing and qualification and delivery to EADS ASTRIUM.
Autotrack Receiver
Design and breadboarding of 1553 interface board, DC/DC converter; Modification of mechanical housing; EQM manufacturing and qualification and delivery to EADS ASTRIUM.
Digital Simulator
Use of EUROSTAR 3000 Autotrack Receiver low frequency and of Spacebus 4000 Digital Simulator;
Manufacturing;
Delivery to EADS ASTRIUM.
Current Status
The four RF equipment have been qualified successfully.
They were delivered to EADS ASTRIUM at their full satisfaction, as well as the Digital Simulator.
The KaSAT satellite equipment was also delivered to EADS ASTRIUM.
The Satellite is to be launched end of year 2010.
EADS ASTRIUM and THALES ALENIA SPACE already initiated meetings with the purpose of defining which modifications / improvements could be performed on the equipment for next generation.