Conceptual spaceborne Ka-band spotlight synthetic aperture radar with reconfigurable aperture

Two principal objectives of this investigation are a) to produce using a reconfigurable aperture circular beam footprints for grazing angles from 15degrees to 70degrees, and b) to maintain high efficiency of high-power 35 GHz solid-state devices in a feed array. An elliptical reflector 8.51 m high and 2.9 m wide is proposed with a near-zone programmable, transmit-receive phased array feed in a beam waveguide to deliver 25.5 w/m(2) at the radiating aperture. By redirecting the beam to track a particular area, called "spotlight-mode," fine azimuth resolution and multi-look images can be produced. A 700 kin altitude orbit is assumed and the resolution goal is 1.0 m.