Radar antenna array for a medium to long range radar sensor, comprising at least one first antenna group having a plurality of individual, mutually coupled antenna elements and at least one second antenna group having a plurality of individual, mutually coupled antenna elements, said individual antenna elements (33,34) of different antenna groups not being galvanically connected to one another, but being arranged in a common, preferably planar area at the front side of a printed circuit board and in a mutually interlaced manner at least along a spatial direction within this area in such way that along one such interleaving direction immediate consecutive antenna elements (33,34) of different antenna groups alternate each other, and wherein the interlaced antenna elements (33,34) are arranged in a regular aerial pattern with columns and lines, wherein adjacent antenna elements (33,34) in the same antenna group always have approximately similar distances with regard to each other, characterized in that a) said first and said second antenna groups are each assigned their own HF transmission and/or HF receiver module, to which the connectors of the respective said mutually coupled antenna elements (33,34) of the particular antenna group are permanently connected, making it possible for both antenna groups to be operated simultaneously; b) further wherein an intermediate layer being separated from the front side of the printed circuit board only by a thin electrically insulating layer, apart from that being immediately adjacent the front side of the printed circuit board, is designed as a nearly closed, electrically conducting ground layer; c) wherein a further layer with a first conducting path system is provided behind the electrically conducting ground layer, and is separated from this only by a further, electrically insulating layer, which conducting path system connects exclusively the antenna areas of a first antenna group to each other and/or to a common terminal conductor; d) while a second conducting path system connecting exclusively the antenna areas of the second antenna group to each other and/or to a common terminal conductor is arranged behind a second, nearly closed, electrically conducting ground layer, which is separated from the first and second conducting path system only by an electrically insulating layer; e) and wherein for each antenna group there exists at least one antenna element (33,34) which is flanked in at least one interleaving direction of the regarding antenna arrangement by at least two antenna elements (33,34) of the other antenna group at similar distances as well as by at least two antenna elements (33,34) of the same antenna group, wherein the area of all antenna elements (33,34) within each column is largest at the central antenna area (33,34) and decreases constantly towards the upper and lower ends of the column. a) said first and said second antenna groups are each assigned their own HF transmission and/or HF receiver module, to which the connectors of the respective said mutually coupled antenna elements (33,34) of the particular antenna group are permanently connected, making it possible for both antenna groups to be operated simultaneously; b) further wherein an intermediate layer being separated from the front side of the printed circuit board only by a thin electrically insulating layer, apart from that being immediately adjacent the front side of the printed circuit board, is designed as a nearly closed, electrically conducting ground layer; c) wherein a further layer with a first conducting path system is provided behind the electrically conducting ground layer, and is separated from this only by a further, electrically insulating layer, which conducting path system connects exclusively the antenna areas of a first antenna group to each other and/or to a common terminal conductor; d) while a second conducting path system connecting exclusively the antenna areas of the second antenna group to each other and/or to a common terminal conductor is arranged behind a second, nearly closed, electrically conducting ground layer, which is separated from the first and second conducting path system only by an electrically insulating layer; e) and wherein for each antenna group there exists at least one antenna element (33,34) which is flanked in at least one interleaving direction of the regarding antenna arrangement by at least two antenna elements (33,34) of the other antenna group at similar distances as well as by at least two antenna elements (33,34) of the same antenna group, wherein the area of all antenna elements (33,34) within each column is largest at the central antenna area (33,34) and decreases constantly towards the upper and lower ends of the column.