Reflectarray antennas: a smart solution for new generation satellite mega-constellations in space communications

Abstract

One of the most ambitious projects in communications in recent years is the development of the so-called satellite mega-constellations. Comprised of hundreds or thousands of small and low-cost satellites, they aim to provide internet services in places without existing broadband access. For the antenna subsystem, reflectarrays have been proposed as a cheap solution due to their low profile and manufacturing costs, while still providing good performance. This paper presents a full design of a reflectarray antenna for mega-constellation satellites with a shaped-beam isoflux pattern for constant power flux in the surface of the Earth. A unit cell consisting of two stacked rectangular microstrip patches backed by a ground plane is employed, providing more than 360° of phase-shift. The generalized intersection approach optimization algorithm is employed to synthesize the required isoflux pattern in a 2 GHz bandwidth in Ku-band. To that purpose, a full-wave electromagnetic analysis is employed for the wideband design. The optimized reflectarray layout complies with the specifications of the isoflux pattern in the frequency band 16 GHz–18 GHz, demonstrating the capabilities of this type of antenna to provide a low-cost, low-profile solution for the user beam segment, including different types of shaped beams.

Intelligent Reflecting Surface-Aided LEO Satellite Communication: Cooperative Passive Beamforming and Distributed Channel Estimation

“…×1 can be regarded as the joint active and passive array response vectors at the GN and SAT sides, respectively. It can be shown in (11) that the effective SAT-GN channel matrix H is decomposed into the outer product of two low-dimensional channel vectors f 1 (θ 1 ) and f 2 (θ 2 ) at the GN and SAT sides, respectively. Accordingly, by substituting (11), i.e., H = f 1 (θ 1 )f T 2 (θ 2 ) into ( 6), the effective SAT-GN channel gain in ( 6) can be rewritten as…”

“…Remark 1: According to the decomposition structure shown in (11) and ( 12), the distributed local CSI at the GN and SAT sides is sufficient for designing the active and passive beamforming {θ 1 , w 1 } and {θ 2 , w 2 }, respectively, without loss of optimality. Specifically, at the GN side, since the IRS 1→GN channel H I 1 −G as well as its rank-one decomposition in (18) can be determined offline based on the fixed geometric relationship, we only need to acquire the local real-time CSI in terms of AoA pairs {(ϑ G , ϕ G ), (ϑ I 1 , ϕ I 1 )} and the phase-shift difference ∆ ρ1 ∠ (ρ G ) − ∠ (ρ I 1 ) for the joint active and passive beamforming design {θ ⋆ 1 , w ⋆ 1 } based on ( 13), (20), and (22).…”

Systematic Study of the Influence of the Angle of Incidence Discretization in Reflectarray Analysis to Improve Support Vector Regression Surrogate Models

“…Some of these unit cells have been employed in other works for the design of reflectarray antennas. For instance, (b) is taken from [24], (c) from [25] and (d) from [26]. The results for a design using unit cell (a) are unpublished.…”

Analysis and Design of an X-Band Reflectarray Antenna for Remote Sensing Satellite System

“…Reflectarray antennas are based on focusing the incident fields from an antenna feeding element to obtain the required radiation pattern by compensating for the phase differences between the reflectarray elements. There are different types of reflectarrays, such as planar microstrip reflectarrays [ 2 , 3 , 4 , 5 , 6 ] and dielectric resonator reflectarrays [ 7 , 8 , 9 ]. The main feature of the reflectarray is that its radiation characteristics can be manipulated by tuning the geometrical dimensions of its unit cells [ 10 , 11 , 12 ].…”