Multibeam antennas for global satellite coverage: theory and design

Abstract

Today there is an increasing request for high‐throughput communication payloads in satellite communications. Capacity in the order of 100 Gbit/s is becoming available and further significant improvement is expected in the coming years. A key element in order to guarantee this high performance is constituted by the multibeam antennas, able to generate multiple narrowly focused spot beams with frequency and polarisation reuse. Direct radiating arrays are able to generate multibeam coverage with a single aperture with the possibility of reconfiguring the coverage and the power distribution among the beams. Sparse arrays permit to reduce the number of radiators and to increase the DC to RF power efficiency by exploiting a ‘space tapering’ instead of an ‘amplitude tapering’, typically adopted in periodic arrays to control the sidelobe level. In this study, a deterministic procedure for the design of large planar sparse arrays is extended to the case, where the antenna, from a geostationary satellite, has to generate a multibeam coverage on the full Earth. The synthesis procedure is presented and validated with several numerical examples illustrating the scanning losses, array pattern deformation during the scanning and grating lobe effects.

On the Near-Field Spherical Wave Formation in Resonant Leaky-Wave Antennas: Application to Small Lens Design

“…At mm-and sub-mm wave frequencies, when scanning to limited angles is required, there is an interest of developing sparse arrays to reduce the integration complexity [15]- [18]. Leaky-wave antennas with overlapped feeds have been proposed for improving the performances of sparse arrays [8], [19]- [21] where sparse arrays with periodicities in the order of a free-space wavelength (λ 0 ), bandwidths smaller than 10%, and scanning angles of at most 10 • have been demonstrated.…”

A Model of Addressing Abnormal Users in IP/LEO Satellite Communication System Based on Geographical Information Subnet

“…Combined with the above analysis, with the high-speed motion of the satellite, there will be frequent user and beam switching, as well as user and satellite switching. In this paper, based on the studies of literature [14] and [18], the coverage area of satellite to earth is modeled as a circle, and the switching between different satellites of ground users is focused on. For the addressing anomaly problem, Xiao proposed a timeratio model for addressing abnormal users [14] [15].…”

“…It has been shown in research [18] that in a satellite-ground communication scenario, the satellite's actual accessible range on the Earth's surface can be modeled as a circle with the sub-satellite point as the center. The communication capability of the satellite determines the radius R of this circle.…”

Multibeam Reflectarrays in Ka-Band for Efficient Antenna Farms Onboard Broadband Communication Satellites

“…Different multibeam antenna solutions have been proposed lately to reduce the number of antennas onboard the satellite [5]. The use of lenses [6] or array antennas [7] reduces the radiation efficiency and increases the complexity of the antenna architecture, while the highly oversized reflector proposed in [8] comprises a prohibitive stowage volume. In this paper, four different multibeam antenna solutions are proposed based on reflectarray antennas [9], following the study introduced in [10].…”