Formation of arrays (FoA) distributed antennaFormation of arrays (FoA) distributed antennatechnology has recently been proposed to provide 5G-like mobilesatellites services in the context of the integration of non terrestrialwith terrestrial networks – the overall system goal being asufficiently high throughput in terms of bit rate per unit area onthe ground. This large distributed array configuration (resultingfrom the formation of many satellites each carrying its own smallantenna) must be carefully engineered to provide the desiredbenefits. In this paper, we tackle some fundamental issues related toFoA design, namely, frequency selectivity, power generation, and optimalformation configuration. Concerning frequency selectivity, weevaluate the intrinsic FoA frequency response assuming a widebandsignal, and suggest how to mitigate possible impairments from acommunication system perspective. Regarding power generation, weshow how to decouple the functions of antenna and solar arrays tocome to a power-efficient satellite configuration and design. Finally,in terms of formation optimization, we investigate a formationthinning approach with random placement of satellites on a grid,leading to a significant reduction of secondary beams in the emissionof the FoA as well as fully satisfying the constraints placed byoptimum power generation.