2023 Volume 1 Article ID: 72
Currently, a demonstration experiment using a small satellite is planned to realize future solar power satellites (SPS). There are two purposes for the experiment. One is to demonstrate satellite-mounted equipment in space, such as the highprecision beam-forming antennas used in SPS. The other is to conduct small-scale space-ground power transfer demonstrations, if possible. As the transmitting (Tx) antenna for the SPS, an active phased array antenna is used because the satellite is capable of forming a Tx beam in an arbitrary direction. For the onboard test, it is necessary to accurately evaluate the beam shape transmitted from the satellite on the ground. For this purpose, as an experiment on ground reception, we propose a method for installing receiving stations in multiple straight lines and arranging them in a direction orthogonal to the moving direction of the satellite. We calculated the theoretical pattern from the satellite's phased array antenna, which was 1.9 mφ, and tried to reproduce the Tx antenna pattern from the measured value of the reception level of each receiving station on the ground. The pattern was approximated by a quadratic function and sinc function, and reproduction up to the main beam and the first side lobe was confirmed, respectively. We calculated the boresight position error with respect to the number and spacing of the receiving stations and showed that it can be estimated with an error of 1 m or less by approximating the quadratic function. In addition, two different orbit inclination angles were calculated as candidate satellite orbits, two receiving station sites were selected, and their superiority and inferiority were compared. As a result, appropriate guidelines were obtained regarding the arrangement and spacing of the receiving stations in the ground evaluation of the SPS demonstration test satellite. Furthermore, the requirements for candidate sites for the receiving station and the satellite orbit are summarized. This makes it possible to reproduce the shape of the transmission antenna beam and the antenna pointing direction.
