European Space Agency

Optical RF Distribution Flight Demonstrator (ORFD)


The main objective of the project is to assess the behaviour of analogue optical links for reference signals distribution under space environment.

In a follow-on phase, it is intended to perform the in orbit validation of the final developments of the optical links. Therefore, as part of this project the test bed that will accommodate the optical links will be also designed and EBB will be functionally tested.


The main key issues of the activity are the use of non qualified components and a new technology.


New concept of satellite payloads requires a high number of feeds or even phased array systems for multi-beam applications composed of a high quantity of converters. For these applications the frequency distribution unit networks could become a critical issue. A high number of feeds and converters make analogue optical links a promising signal distribution candidate compared to traditional RF systems in terms of properties such as:

  • Mass and size saving for medium/high reference signal distribution requirements
  • Cable management flexibility: For those applications where a high number of cables have to be routed from the satellite payload there will be a considerable cable bundle to be managed
  • Lower optical fiber transmission losses
  • Better phase stability over temperature and when bent in comparison with coaxial cable
  • Low electromagnetic emissions


The test bed for the IoV, called AOLTB, will accommodate two complete optical RF links. The AOLTB will provide information regarding power and phase deviation of the optical RF links, levels of power consumption and radiation performances during the mission.

The AOLTB will comprise the following units:

  • Optical block. This block is the core of the development.
  • Power Supply Unit (PSU). The PSU is in charge of the generation of all power supplies needed in the different subsystems of the equipment. The PSU extracts the voltages from the power supply main bus and generates secondary voltages.
  • Power Distribution Unit (PDU). The PDU receives the primary power from PSU and then distributes it to the experimental boards or subsystems, being controlled and monitored by the ICU.
  • Interface Control Unit (ICU). The ICU is the overall controller of the experiment, interfacing the internal system through the backplane and the SC via 1553. It also receives primary power from the PSU.
  • Optical Control Unit (OCU). The OCU interfaces with the optical units and performs the scientific measurements calculations of phase and amplitude.
  • Backplane for boards interconnection. The backplane is the internal gateway of the all system. All power and signal lines (except optical ones) should be routed through it.
  • Mechanical enclosure and other parts.


In the current Artes5.2 activity it is planned to cover the Phase B of the mission, comprising review and consolidation of the specifications, Preliminary Design of the optical links as well as for the test bed. After preliminary design, two tasks will be carried out in parallel, the evaluation campaign of optical components and modules, and the EBB development. Finally functional tests on the entire test bed will be performed.

It is the intention to continue the qualification of this development in a follow-on Artes 3-4 activity.

Current status

Evaluation campaign has been completed.

EBB development has been completed and integration tests have been done with successful results.

Status date

Wednesday, June 28, 2017 - 09:56