Radar device with a directional antenna

Claim 1

A radar device including a directional antenna comprising a plurality of individual fed dipoles, a central feeding system, and a plurality of phase changers connected between said feeding system and said dipoles, said phase changers being controlled electrically over a range of from between 0* and 360* and the maximum sum of all the phase differences between adjacent feed lines exceeding 360* during beam scanning, means for omitting all multiples of 360* during phase changing, the improvement therein comprising means for transmitting several radar signals from the radar device simultaneously at frequencies which differ sufficiently from one another that the corresponding echo signals from a target can be separately processed, a plurality of different transmitters producing said different radar signals and a plurality of different receivers processing said different radar signals, a plurality of horn antennas, each transmitter-receiver combination being connected to a horn antenna, each of said horn antennas feeding said plurality of dipoles which are arranged at a distance from the horn antennas at one side of a block, said dipoles being connected to said phase changers, a plurality of further dipoles arranged at the other side of said block and respectively connected to said phase changers, and wherein the number of different frequency radar signals is selected to be as near as possible to a maximum value given by the ratio between the required distance resolution for the radar device as a system parameter and the maximum distance resolution obtainable with the given directional antenna due to the omitted multiple 360* arriving radar signals from the different individual dipoles phase shifted at the target.