This ESA-funded feasibility study explored advanced beam steering antenna technologies to significantly improve the communication capabilities of CubeSats operating in Low Earth Orbit (LEO). CubeSats, due to their compact form factor, are subject to severe size, weight, and power (SWaP) constraints, which pose unique challenges to achieving high-performance, reliable communication links. Addressing these limitations, the project investigated both passive and active beamforming strategies with a focus on system-level integration, power efficiency, and scalability. 

The study introduced an innovative metasurface-based leaky wave MIMO antenna designed specifically for CubeSats. With a footprint of only 40 × 30 mm², the antenna achieves high gain (12.5 dBi), excellent radiation efficiency (85%), and circular polarization—key attributes for robust, orientation-independent communication. The unique flower-like metasurface design allows frequency- and phase-dependent beam steering without mechanical component, ensuring minimal complexity and low power consumption. This passive solution is particularly well-suited to data-intensive missions such as Earth observation and inter-satellite networking.

Building on this foundation, the project also presented a scalable active beamforming architecture optimized for X-band CubeSat communications. Through extensive evaluation of antenna array configurations, a 4×4 planar array was identified as the optimal choice, offering superior directivity and beam-steering performance while maintaining low power consumption. By leveraging commercial beamformer ICs and implementing a modular sub-array design, the proposed system meets CubeSat-specific constraints while enabling high-speed, directional data links. 

A comprehensive system-level analysis was conducted to assess the trade-offs between array size, power budget, and communication performance. Simulation results demonstrated that the proposed beam steering systems can significantly increase link duration, data throughput, and reliability— extending typical ground contact windows. 

In addition to the technical contributions, the project has delivered multiple academic outputs, including a published review article, a submitted journal manuscript on the novel antenna design, and a peer-reviewed conference paper on active beamforming implementation. 

This study not only validates the feasibility of advanced beam-steering antenna systems for CubeSats but also charts a clear path toward their integration in future missions. The results align with ESA’s goals of fostering scalable, cost-effective space technologies and position Europe at the forefront of next-generation small satellite communications.