US Patent 9541639 MIMO antenna with elevation detection

A multiple input multiple output (MIMO) antenna for a radar system includes a receive antenna, a first transmit-antenna-arrangement, and a second transmit-antenna-arrangement. The receive-antenna is configured to detect radar-signals reflected by a target toward the receive-antenna. The first transmit-antenna-arrangement includes a first vertical-array of radiator elements and a second vertical-array of radiator elements. The first transmit-antenna-arrangement is configured so the first vertical-array can be selectively coupled to a transmitter independent of the second vertical-array. The second transmit-antenna-arrangement includes a third vertical-array of radiator elements and a fourth vertical-array of radiator elements. The second transmit-antenna-arrangement is configured so the third vertical-array can be selectively coupled to a transmitter independent of the fourth vertical-array. The second transmit-antenna-arrangement is vertically offset from the first transmit-antenna-arrangement by a vertical offset distance selected so an elevation angle to the target can be determined by the receive-antenna.