Antenna device for a radar detector having at least two radiation directions, and motor vehicle having at least one radar detector

1. An antenna device for a radar detector, comprising:

a circuit board having an electrically insulating substrate having a first side and a second side opposite the first side, wherein a respective electrically conductive layer is positioned on each of the first and second sides of the electrically insulating substrate, and wherein the electrically conductive layer positioned on the first side of the electrically insulating substrate forms at least one main antenna and at least one feeder cable electrically coupled to the at least one main antenna, the at least one main antenna being a patch antenna; and

at least one antenna structure integrated with the electrically insulating substrate, wherein the at least one antenna structure integrated with the electrically insulating substrate comprises a plurality of cutouts which are formed in the electrically insulating substrate and arranged in a waveguide, wherein an electrically conductive material is arranged at least partially in each cutout, and wherein the feeder cable formed by the electrically conductive layer positioned on the first side of the electrically insulating substrate is further electrically coupled to the electrically conductive material of at least one cutout of the plurality of cutouts, and is configured for simultaneously feeding an electromagnetic wave into the at least one main antenna and the at least one antenna structure integrated with the electrically insulating substrate.

2. The antenna device according to claim 1 , wherein each feeder cable is connected with a supply line formed by the electrically conductive layer of the first side of the electrically insulating substrate of the at least one main antenna.

3. The antenna device according to claim 1 , wherein the electrically conductive material arranged at least partially in at least one cutout is configured as a wave fence or wave cage for electromagnetic waves fed into the waveguide by means of the feeder cable.

4. The antenna device according to claim 1 , wherein each cutout of the plurality of cutouts extends in a longitudinal direction, such that the cutouts are arranged parallel to each other or vertical to an extension plane of the circuit board.

5. The antenna device according to claim 1 , wherein the electrically conductive material arranged at least partially in each cutout is electrically short-circuited by means of the electrically conductive layer of at least one of the first side or the second side.

6. The antenna device according to claim 1 , wherein an electrically conductive layer of a second side of the electrically insulating substrate is formed as a reflector for the at least one main antenna.

7. The antenna device according to claim 1 , wherein a respective main radiation direction of the at least one main antenna and a respective main radiation direction of the at least one antenna structure are oriented vertically to each other or in an angle range of 70° to 110° with respect to each other.

8. The antenna device according to claim 1 , wherein the at least one main antenna is formed in a rectangular shape.

9. A motor vehicle with at least one radar detector for detecting objects in at least one of an environment of the motor vehicle or an interior of the motor vehicle, wherein the at least one radar detector comprises an antenna device, the antenna device comprising:

a circuit board having an electrically insulating substrate having a first side and a second side opposite the first side, wherein a respective electrically conductive layer is positioned on each of the first and second sides of the electrically insulating substrate, and wherein the electrically conductive layer positioned on the first side of the electrically insulating substrate forms at least one main antenna and at least one feeder cable electrically coupled to the at least one main antenna, the at least one main antenna being a patch antenna; and

at least one antenna structure integrated with the electrically insulating substrate, wherein the at least one antenna structure integrated with the electrically insulating substrate comprises a plurality of cutouts which are formed in the electrically insulating substrate and arranged in a waveguide, wherein an electrically conductive material is arranged at least partially in each cutout, and wherein the feeder cable formed by the electrically conductive layer positioned on the first side of the electrically insulating substrate is further electrically coupled to the electrically conductive material of at least one cutout of the plurality of cutouts, and is configured for simultaneously feeding an electromagnetic wave into the at least one main antenna and the at least one antenna structure integrated with the electrically insulating substrate.

10. The antenna device according to claim 1 , wherein at least a subset of the cutouts are provided as VIA through-holes extending from the first side of the electrically insulating substrate to the second side of the electrically insulating substrate.

11. The motor vehicle according to claim 9 , wherein at least a subset of the cutouts are provided as VIA through-holes extending from the first side of the electrically insulating substrate to the second side of the electrically insulating substrate.