Abstract: The present disclosure provides a two-dimensional antenna system. The two-dimensional antenna system includes a transmitting antenna array and a receiving antenna array. The transmitting antenna array includes one or more circularly polarized transmitting antennas having a first direction of rotation. The receiving antenna array includes two or more first circularly polarized receiving antennas having a second direction of rotation arranged in a first direction, and two or more second circularly polarized receiving antennas having the second direction of rotation arranged in a second direction. The first direction is perpendicular to the second direction, and the first direction of rotation is opposite to the second direction of rotation.

Abstract: An unmanned movable platform (UMP) includes at least one sensor configured to detect a movement associated with the UMP, at least one radar configured to transmit a radar signal, and at least one processor configured to receive a sensor signal associated with the movement from the at least one sensor and direct the at least one radar to adjust a direction of a beam of the radar signal based at least in part on the sensor signal.

Abstract: A method for radar-based object avoidance for a movable platform includes performing a plurality of “ping-pong” measurements to receive electromagnetic signals corresponding to an object and background clutters by a radar of the movable platform, and distinguishing the object from the background clutters. Each of the “ping-pong” measurements includes a first measurement and a second measurement. A first direction of the first measurement is different from a second direction of the second measurement.

Abstract: The present disclosure provides a two-dimensional antenna system. The two- dimensional antenna system includes a transmitting antenna array and a receiving antenna array. The transmitting antenna array includes one or more circularly polarized transmitting antennas having a first direction of rotation. The receiving antenna array includes two or more first circularly polarized receiving antennas having a second direction of rotation arranged in a first direction, and two or more second circularly polarized receiving antennas having the second direction of rotation arranged in a second direction. The first direction is perpendicular to the second direction, and the first direction of rotation is opposite to the second direction of rotation.