Genetic Algorithm-based Beamforming in Subarray Architectures for GEO Satellites

The incorporation of subarrays in Direct Radiating Array (DRA) for satellite missions is fundamental in reducing the number of Radio Frequency (RF) chains, which correspondingly diminishes cost, power consumption, space, and mass. Despite the advantages, previous beamforming schemes incur significant losses during beam scanning, particularly when hybrid beamforming is not employed. Consequently, this paper introduces an algorithm capable of compensating for these losses by increasing the power, for this, the algorithm will activate radiating elements required to address a specific Effective Isotropic Radiated Power (EIRP) for a beam pattern over Earth, projected from a Geostationary Orbit (GEO) satellite. In addition to the aforementioned compensation, other beam parameters have been addressed in the algorithm, such as beamwidth Side Lobe Level (SLL). To achieve these objectives, we propose employing the array thinning concept through the use of genetic algorithms, which enable beam shaping with the desired characteristics and power. The full array design considers an open-ended waveguide, configured to operate in circular polarization within the Ka-band frequency range of 17.7-20.2 GHz.