Flexibility/complexity trade-offs in payload design

Before launching constellations of LEO satellites, a careful benchmark the flexibility/complexity of payloads and antenna subsystems shall be done. Orbiting satellites experience a diversity of user distributions. At the same time, low-cost systems are needed to limit the overall cost of launching a megaconstellation. A method has been applied to several multiple-beam antenna architectures in a megaconstellation use case. To benchmark the presented solutions, a method to compare the flexibility of antenna and payload solutions in servicing non-uniform user demand distributions was developed. The method was applied to three payload architectures. These payloads all involved an innovative quasi-optical beamformer as a primary radiator. The three architectures enable beam hopping, beam steering, as well as static resource allocation. A resource allocation algorithm was used to estimate the performances of the BH and beam steering payloads in each scenario. A measure of the non-uniformity of the user distribution is introduced to observe how non-uniformity affects the throughput of each payload solution. The choice for the most appropriate payload depends on the non-uniformity parameter and encountered demands during the satellite orbits and the complexity of each payload architecture. Complexities have in turn been estimated in regards of the mass and power required by each payload. In the considered user distribution scenario, the beam hopping and the beam steering architectures prove to be efficient solutions compared to the architecture with static resource allocation. However, with 1.9 times less mass and 40% less consumed power, the beam hopping architecture appears to be the most adapted payload design.