We provide expert advice to government regulators and to industry on all matters related to the use of the entire radio spectrum, from HF to optical, in terrestrial and Earth-space applications. In particular we study the commercial use of higher frequency bands and provide propagation models appropriate for planning innovative new services. This modelling work is closely coupled to studies and measurements of the troposphere and the ionosphere.

Recent emphasis has been in research for ESA in the use of higher frequency bands for earth-space communications, and the impact of weather conditions on the design of earth-space links.

Alphasat experiment

Inmarsat-4A F4, also known as Alphasat, is a large geostationary communications satellite operated by Inmarsat in partnership with the European Space Agency. Launched in 2013, it is used to provide mobile communications to Africa and parts of Europe and Asia. Alphasat carries several experimental communications packages in addition to its commercial payload. One of these experimental packages includes two beacon transmitters, one operating at 19.701GHz and the other at 39.402GHz. These beacons are monitored 24/7 by several ground stations across Europe to study the effects of the atmosphere, including cloud and precipitation, on the received signal level. RAL Space operates two separate ground stations, each station monitoring the beacon signals. The long term measurement data is used to develop propagation models that are needed in order to develop future satellite communications systems at these frequencies.

Radio Research into Higher frequencies

The ever increasing demand for higher data rates has triggered development of higher frequency data links where higher bandwidths are available. Alphasat represents an active propagation experiment at two frequencies that are higher than typically used for current satellite systems. In 2017 ESA funded an initial study into using even higher frequencies with the long term aim to implement a propagation measurement experiment at 76GHz. RAL Space led the consortium that performed the study. The outputs from this included high level designs for the satellite transmitter and ground station receiver as well as prototypes for the Transmitter power amplifier and the receiver low noise amplifier.

For more information please contact: RAL Space Enquiries