A radar sensor includes a housing, cover, and a plurality of transmit and receive antennas. The housing includes a cavity retaining a processing board. The cover defines a radome having a recess into the cavity with two separate and connected areas. The transmit and receive antennas are positioned on the processing board, adjacent to, and separated by a gap from, the recess. The transmit antennas are configured to transmit RF signals through the first area of the recess. The receive antennas are configured to receive RF signals returning through the second area of the recess.