The STENTOR active antenna: design, performances and measurement results

This paper presents the performances of the Ku-band active antenna implemented on STENTOR, the French Technological Satellite Program. First, the performances analysis is presented. They are obtained from the statistical behaviour of the antenna´s constitutive equipments measured at flight model level, and a computation methodology is also suggested to get guaranteed values able to be measured during an assembly and integration tests sequence. In a second part, the antenna calibration logic is presented - how the antenna amplitude and phase commands are computed to realise a goal radiated pattern and a goal ElRP value. The calibration operations can be realised during AIT sequence or in orbit to measure the evolution of the antenna performances and takes these data into account for a new set of coefficients computation, if necessary. At last, the antenna performance measurements in conducted conditions (with 821 measurements from antenna input to SSPA outputs) and radiated conditions (in Alcatel Near Field test facility) are presented and discussed with regard to the objectives provided in the sub-system specifications.