European Space Agency

Radio Frequency Transmitter for Multimedia Ground Terminals


In this project, cost effective high performance Radio Frequency Transmitters (RFT) for Multimedia Ground Terminals will be developed.

Multimedia Ground Terminals have to support varying traffic loads over time. This requires high flexibility and a dynamic range of data rates to be supported by each terminal. The MF-TDMA access technology addresses this flexibility, but requires a higher transmit power to support the dynamic range resulting in more expensive RFTs. The RFT significantly contributes to the total costs of the Multimedia Terminal. Therefore ND SatCom believes, that for the overall success of Multimedia Ground Terminals this cost portion has to be reduced. The development of RFTs addresses C-Band (5W, 10 W, and 40 W units) and Ku-Band (4W, 8W, and 20 W units).


Key issues addressed in the project are cost reduction combined with high quality. 'High quality' has two major aspects:


  • The RFT shall allow its smooth and trouble-free deployment at almost any place on the world like deserts, polar regions, tropic areas, high mountains, shore and off-shore withstanding tough environmental conditions.
  • All relevant national and international standards as well as satellite operators' requirements shall be met.


The experience gained from this project will help to extend the technology base for Multimedia Ground Stations in Europe. ND SatCom will have immediate commercial use for the RFT by integrating it into the SkyWAN product portfolio. SkyWAN VSAT terminals are sold to service providers and end customers in quantities of more than 700 per year with an installed base of 2500 terminals world wide currently.

Based on a highly flexible priority and bandwidth allocation scheme, SkyWAN VSAT terminals offer multimedia services such as interconnection of Local Area Networks (LANs) including Internet access, video transmission for point-to-point and point-to-multipoint videoconferencing, telephony (with several compression rates) as well as support of legacy data services such as X.25 and Frame Relay.


A block diagram of a ground station is shown employing an RFT unit. The indoor equipment on the left comprises the processing and control unit, the modem, the frequency converters, the M&C interface (RS 485), the reference signal source, and the multiplexers (one of them is optional). The outdoor equipment on the right comprises the active components FPS, RFT, and RFR as well as the antenna and the waveguide components.


Ground Station including an RFT
(click for larger image).

This includes:

  • FDC Frequency Down Converter
  • FPS Front End Power Supply
  • FUC Frequency Up-Converter
  • RFR Radio Frequency Receiver
  • RFT Radio Frequency Transmitter


The complete development will be accomplished in two prototype phases. The first prototype will be used for proof of concept and first design iterations. This phase will be completed at the end of 2002. 2003 will start with a redesign leading to the 2nd prototype phase. Based on an integrated 2nd prototype system (available the middle of 2003) performance verification and integrity testing will commence. The goal of this will be to release it for production at the end of 3rd quarter of 2003.

Current status

The Project is Completed.

Status date

Saturday, December 10, 2011 - 13:20