High resolution 4-d millimeter-wave imaging radar

Abstract

All existing state-of-the-art high resolution millimeter wave imaging systems experience a trade off between image acquisition time and transceiver array complexity. The proposed dual reflector antenna breaks this trade-off by drastically reducing the array formation time while maintaining the relative simplicity that comes with using a single transceiver element. It consists of a dual mode horn feed, a rotating ellipsoidal sub-reflector and a conic main reflector. The rotating sub-reflector creates a virtual phase center that rotates about an axis to produce a synthetic circular array with a diameter of 120λ. The main reflector redirects the beams from each of these virtual phase centers to overlap and illuminate the scene over a wide field of view. The proposed system can reduce the image acquisition time to the order of milliseconds/seconds which makes real-time SAR imaging a practical alternative to MIMO and phased arrays at millimeter-wave and sub-millimeter-wave frequencies.