Reflectarray Antenna Design for Satellite Communications

Reflectarray antennas combine the low profile of phased arrays with the simple geometry of reflectors to steer microwave beams for satellite links. They are composed of an array of scattering elements, or unit cells, that impart a tailored phase shift to an incident wave, synthesising a desired beam shape and direction. Recent advances in materials, element topology and synthesis algorithms have improved bandwidth, gain and scan capability. Designs now span from compact X-band modules for low-Earth-orbit terminals to large Ku- and Ka-band arrays for high-throughput satellites. Key challenges remain in maintaining phase fidelity over wide frequency ranges, minimising losses at element interconnects and reducing fabrication cost through additive-manufacturing methods. Practical applications include shaped-beam user terminals, earth-coverage payload sub-systems and rapid beam-steering modules for mega-constellation networks.

Research from Nature Portfolio

Recent studies have demonstrated shaped-beam reflectarrays tailored for large constellations of small satellites. One design employs stacked microstrip patches to achieve a wideband Ku-band isoflux pattern, ensuring constant power distribution on the ground surface. An advanced optimisation algorithm synthesises a 2 GHz bandwidth with full-wave electromagnetic analysis, yielding a low-profile array with more than 360° of phase control across each element. Another investigation has introduced quaternary Huygens-element gratings to create an anomalous reflection with beam-squint capability. By arranging four sub-elements per period and varying the grating period in orthogonal directions, the reflectarray achieves high aperture efficiency and a frequency-dependent beam steering from 12 GHz to 15 GHz, offering both narrow side-lobes and reconfigurable beam directions.

Research from all publishers

A magnetoelectric-dipole based reflectarray was demonstrated for both fixed-beam and reconfigurable satellite applications. Four prototypes achieved broad fractional bandwidths and high aperture efficiencies through the introduction of ME-dipole elements, with simulated and measured gains exceeding 25 dBi in the Ka-band. A single-layer metasurface reflectarray for X-band terminals uses H-shaped slotted patches on a low-loss substrate to realise a phase range beyond 480°, delivering a peak gain of 25.5 dBi with 20% 1-dB gain bandwidth and side-lobe levels below –21 dB. In the millimetre-wave regime, a 3D printed dielectric reflectarray has been developed to produce left- and right-hand circular polarisation from a linear feed. By independently varying cuboid geometries in three dimensions, the prototype achieves a 30% gain bandwidth around 34 GHz with aperture efficiencies up to 38%, showing the promise of additive manufacturing for lightweight, high-gain satellite antennas.

Reflectarray Antenna Design for Satellite Communications publication trend

The graph below shows the total number of articles in reflectarray antenna design for satellite communications across all publications each year (not limited to Nature Index journals).

Technical terms

Reflectarray: A flat antenna consisting of an array of scattering elements that reflect and phase-shift an incident wave to form a directed beam.

Metasurface: A two-dimensional arrangement of sub-wavelength elements engineered to control electromagnetic waves’ phase, amplitude or polarization.

Unit cell: The smallest repeating element of a reflectarray or metasurface, designed to impart a specific phase shift to the incident field.

Aperture efficiency: The ratio of the effective radiating aperture to the physical area of the antenna, indicating how effectively the antenna converts aperture into radiated power.

Beam squint: A frequency-dependent shift in the direction of the main beam produced by a phased or reflectarray antenna.

References

1. Transmitarray and Reflectarray Antennas Based on a Magnetoelectric Dipole Antenna. Electromagnetic Science (2023).
2. Single-Layer Metasurface-Based Reflectarray Antenna with H-Shaped Slotted Patch for X-Band Communication. Nanomaterials (2024).
3. A two-dimensional grating surface made of quaternary Huygens elements excited by a real source. Scientific Reports (2023).
4. Reflectarray antennas: a smart solution for new generation satellite mega-constellations in space communications. Scientific Reports (2020).
5. Dual Circularly Polarized 3-D Printed Broadband Dielectric Reflectarray With a Linearly Polarized Feed. IEEE Transactions on Antennas and Propagation (2022).