Multi-beam antenna for space-based ADS-B

ADS-B (Automatic Dependent Surveillance Broadcast) provides the means of transmitting a signal containing aircraft onboard flight related information by aircrafts at fixed intervals at low L-band frequencies. The terrestrial based ADS-B is already in use as an extension of the standard radar systems, and will expand air traffic management services in areas were ground based infrastructures can be installed. For other areas where this is not possible, a space-based ADS-B system can be a solution. At the moment, a system is being developed by TAS-D that is based on the acquisition by satellites of the mode S 1090MHz extended squitter signal. This approach has no impact on ADS-B aircraft equipment and requires no costly standardization. The RF frontend of latter system requires a space based multi-beam receiving antenna that has to be designed for low earth orbit satellites. A first engineering model of this ADS-B multi-beam antenna has been realized and measured. The measurements show great prospects for a future spaced based ADS- B system.