Active Beamforming Implementation for CubeSat Antenna Arrays: Exploring Trade-offs in IC Requirements, Power, and Performance

Beamsteering in CubeSat antenna systems increases coverage flexibility and optimizes signal strength for effective communication. This paper explains the relation between the number of elements in an antenna array and important parameters such as size, directivity, and effective isotropic radiated power (EIRP). To efficiently implement active beamforming, two different circuit architectures are introduced using commercial beamformer and frontend integrated circuits (ICs) for three antenna array configurations: $1 \times 4,2 \times 2$, and $4 \times 4$. In addition, a detailed analysis of trade-off between the required ICs, output power, size, and overall power consumption is performed. Considering the EIRP, available transmitter output power, and required radiated power, one beamformer along with four frontend ICs and four beamformer ICs are used for a 4 -element and $4 \times 4$ arrays, respectively. Furthermore, to evaluate the beamforming performance, the array factor and beam pattern are simulated. The results show that the $2 \times 2$ array achieves two-dimensional beamforming but with low directivity. The $1 \times 4$ array improves beam-steering capability with the same number of elements but in one dimension, and the $4 \times 4$ array emerges as the optimal solution by further enhancing the directivity and steering range. This configuration maximizes the performance while consuming comparable power and meeting the area constraints of a $\mathbf{1 U}$ CubeSat.