On 8 April, 2015, the first ESA workshop on using W-band for satellite communications was held at ESTEC, ESA's technical facility located in Noordwijk, the Netherlands. Some sixty people from industry, academia, and ESA attended the workshop. Their backgrounds ranged from radiowave propagation scientists to system designers and component development experts.
The W-band has great potential for satellite communications. Adding the W-band to Q-/V-band feeder links will make it possible to reduce by approximately half the number of gateways required for high-throughput systems. Considering the high development and operational costs of such gateways, this could result in a very significant reduction of overall system cost. In addition, the frequency allocation system for W-band allows for continuous 5-GHz bandwidth for both transmitting and receiving, which simplifies system design in comparison with current Q-/V-band implementations.
Before W-band solutions can be widely deployed, however, various technical challenges must be addressed. Currently, the behaviour of the atmospheric channel in this frequency band is not well known. A few estimations based on extrapolations from lower frequency bands are available, but more accurate propagation measurements are required to characterise the channel in a way that allows for proper system design.
From a hardware point of view, W-band RF components are also needed. Although a few components have been flown in Earth Observation and Science missions at these frequencies, and terrestrial applications in E-band (the terrestrial equivalent to W-band) are starting to appear in systems such as anti-collision radars, space-qualified components with the right performance (e.g. power amplifiers with the required output) are not yet available.
To address these requirements, ESA will be issuing several Invitations to Tender (ITT) to develop W-band components and technologies for future high-throughput feeder links. For a start, an ARTES 5.1 ITT, Cubesat-based W-band channel measurements, is planned for mid-2015. It will support the acquisition of propagation data from a Cubesat-like platform to improve channel knowledge.
"This event has brought together the main European actors in the W-band field to discuss the latest developments", said Arturo Martín Polegre, ESA Flight Product Engineer and organiser of the workshop. "It gave us good indication how high throughput satellite systems could benefit from the use of W-band in the future."
