Active lens: a mass, volume, and energy efficient antenna for space-based radar

Very large, lightweight phased array antenna apertures are highly desirable for space-based ground surveillance and tracking radars since power is limited by the mass efficiency of solar power collection and distribution systems which compete for the limited payload capability of the launch vehicle. This leads to relatively low power density apertures whose power budget can be dominated by the overhead (non-radiated) power used during the receive portion of the radar timeline. We have developed a novel lens antenna concept to meet the extreme demands of next-generation, large-aperture space-based radar with significantly improved electrical and mechanical efficiency. The agile beam design offers better aperture efficiency over the entire field of regard compared with reflector designs and better electrical and mass efficiency than active array designs. The lens contains embedded MMIC modules that have been optimized for low power consumption on receive, a significant departure from T/R modules used in airborne radar applications.