Array antennas: Flexible satellite services of the future
An array antenna is a collection of basic radiators where excitation amplitudes and phases of the individual elements of the array constitute degrees of freedom that can be exploited for steering, scanning, and shaping the array antenna radiation pattern, in ways that are not possible with the individual radiating elements.
With the quest for flexible payloads, where satellite services can be moved and reconfigured based on demand from customers, array antennas, with digitally controlled and reprogrammable element excitations, are set to play a central role in future telecommunication satellite missions. Eutelsat’s Quantum satellite, launched in 2021, is with its direct radiating Ku-band active phased array antenna one of the first examples of such a reconfigurable payload.
Historically, so-called array-fed reflector antennas were used in the 1970s and 1980s for generating contoured beams on earth from geostationary satellites. Here, by proper adjustment of excitation coefficients, a shaped beam on ground is produced to provide signals at the desired coverage area. In the late 1980s, this technology was replaced by shaped reflector antennas, avoiding the use of heavy feed arrays, and TICRA’s POS software became the industry-standard for reflector shaping. In 2000, TICRA’s array optimisation software SCOPES was merged with single- and dual-reflector shaping into POS. Today, POS is part of the TICRA Tools framework and offers powerful array optimisation, both for array-fed and direct radiating array antennas.
In addition to powerful array optimisation, fast and efficient RF modelling of array antennas is also paramount for the future success of flexible payloads. Today, array antennas are typically modelled using direct full-wave methods, such as with MoM/MLFMM in TICRA’s ESTEAM software as done for the Vivaldi array antenna. TICRA is currently involved in two industrial PhD projects on improved full-wave analysis algorithms for large arrays as well as fast direct solvers for array antennas, while several projects with the European Space Agency – ESA are ongoing and upcoming.
With TICRA’s unchanged mission to provide the best modelling tools for space applications, it is natural to invest in array modelling capabilities so that we continue to be at the forefront and deliver state-of-the-art antenna design software for the space industry.
More details on industrial PhD project on array antennas: Link
More details on the Vivaldi array antenna: Link