Abstract: According to an example embodiment, an antenna assembly for a radar apparatus is provided, the antenna assembly comprising: a feed antenna arranged to radiate outbound radio waves that represent a transmitted RF signal supplied thereto and capture a received RF signal that represents inbound radio waves received thereat; and a focusing element arranged to collimate the outbound radio waves into a transmitter beam for transmission towards a monitoring direction and focus inbound radio waves of a receiver beam received at the focusing element from the monitoring direction for reception at the feed antenna, wherein the arrangement of the feed antenna and the focusing element is configured to transmit the transmitter beam as a sequence of substantially concave radio waves and receive the receiver beam as a sequence of substantially convex radio waves.

Abstract: An antenna assembly includes first and second feed antennas and a lens element. The first feed antenna is arranged to transmit outbound radio waves of a transmitter beam. The second feed antenna is arranged to capture a received RF signal. The lens element is arranged to collimate the transmitter beam and to focus the receiver beam. The first and second feed antennas are disposed on a conductive ground plane that is offset from a back end of the lens element by a predefined distance in direction of a center axis of the lens element. A volume between the back end of the lens element and the ground plane comprises material that has a refractive index that is smaller than that of the lens element for converging the outbound and inbound RF beams between the back end of the lens element and the first and second feed antennas.