Optimizing Antenna Activation for Even Power Distribution in Multi-Beam Satellite Systems Using Genetic Algorithm

Recent advancements in onboard satellite communication have significantly enhanced the ability to dynamically modify the radiation pattern of a Direct Radiating Array (DRA), which is essential for both conventional communication satellites like Geostationary Orbit (GEO) and those in lower orbits such as Low Earth Orbit (LEO). This is particularly relevant for communication at 28 GHz, a key frequency in the mmWave spectrum, used for high-bandwidth satellite links and 5G communications. Critical design factors include the number of beams, beamwidth, and Side Lobe Level (SLL) for each beam. However, in multibeam scenarios, balancing these design factors can result in uneven power distribution, leading to over-saturation in centrally located antenna elements due to frequent activations. This paper introduces a Genetic Algorithm (GA)-based approach to optimize beamforming coefficients by modulating the amplitude component of the weight matrix, while imposing a constraint on activation instances per element to avoid over-saturation in the Radio Frequency (RF) chain. The proposed method, tested on an 16×16 DRA patch antenna array at 28 GHz for a CubeSat orbiting at 500 km, demonstrates how the algorithm efficiently meets beam pattern requirements and ensures uniform activation distribution. These findings are particularly relevant for emerging satellite systems and 5G networks operating in the mmWave spectrum.